The Dusty Disc of NGC 247

NASA Astrophysics Data System (ADS)

2011-03-01

This image of NGC 247, taken by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile, reveals the fine details of this highly inclined spiral galaxy and its rich backdrop. Astronomers say this highly tilted orientation, when viewed from Earth, explains why the distance to this prominent galaxy was previously overestimated. The spiral galaxy NGC 247 is one of the closest spiral galaxies of the southern sky. In this new view from the Wide Field Imager on the MPG/ESO 2.2-metre telescope in Chile large numbers of the galaxy's component stars are clearly resolved and many glowing pink clouds of hydrogen, marking regions of active star formation, can be made out in the loose and ragged spiral arms. NGC 247 is part of the Sculptor Group, a collection of galaxies associated with the Sculptor Galaxy (NGC 253, also shown in eso0902 and eso1025). This is the nearest group of galaxies to our Local Group, which includes the Milky Way, but putting a precise value on such celestial distances is inherently difficult. To measure the distance from the Earth to a nearby galaxy, astronomers have to rely on a type of variable star called a Cepheid to act as a distance marker. Cepheids are very luminous stars, whose brightness varies at regular intervals. The time taken for the star to brighten and fade can be plugged into a simple mathematical relation that gives its intrinsic brightness. When compared with the measured brightness this gives the distance. However, this method isn't foolproof, as astronomers think this period-luminosity relationship depends on the composition of the Cepheid. Another problem arises from the fact that some of the light from a Cepheid may be absorbed by dust en route to Earth, making it appear fainter, and therefore further away than it really is. This is a particular problem for NGC 247 with its highly inclined orientation, as the line of sight to the Cepheids passes through the galaxy's dusty disc. However, a team of astronomers is currently looking into the factors that influence these celestial distance markers in a study called the Araucaria Project [1]. The team has already reported that NGC 247 is more than a million light-years closer to the Milky Way than was previously thought, bringing its distance down to just over 11 million light-years. Apart from the main galaxy itself, this view also reveals numerous galaxies shining far beyond NGC 247. In the upper right of the picture three prominent spirals form a line and still further out, far behind them, many more galaxies can be seen, some shining right through the disc of NGC 247. This colour image was created from a large number of monochrome exposures taken through blue, yellow/green and red filters taken over many years. In addition exposures through a filter that isolates the glow from hydrogen gas have also been included and coloured red. The total exposure times per filter were 20 hours, 19 hours, 25 minutes and 35 minutes, respectively. Notes [1] The Araucaria Project is a collaboration between astronomers from institutions in Chile, the United States and Europe. ESO's Very Large Telescope provided data for the project. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

"Catch a Star !"

NASA Astrophysics Data System (ADS)

2002-05-01

ESO and EAAE Launch Web-based Educational Programme for Europe's Schools Catch a star!... and discover all its secrets! This is the full title of an innovative educational project, launched today by the European Southern Observatory (ESO) and the European Association for Astronomy Education (EAAE). It welcomes all students in Europe's schools to an exciting web-based programme with a competition. It takes place within the context of the EC-sponsored European Week of Science and Technology (EWST) - 2002 . This unique project revolves around a web-based competition and is centred on astronomy. It is specifically conceived to stimulate the interest of young people in various aspects of this well-known field of science, but will also be of interest to the broad public. What is "Catch a Star!" about? [Go to Catch a Star Website] The programme features useful components from the world of research, but it is specifically tailored to (high-)school students. Younger participants are also welcome. Groups of up to four persons (e.g., three students and one teacher) have to select an astronomical object - a bright star, a distant galaxy, a beautiful comet, a planet or a moon in the solar system, or some other celestial body. Like detectives, they must then endeavour to find as much information as possible about "their" object. This information may be about the position and visibility in the sky, the physical and chemical characteristics, particular historical aspects, related mythology and sky lore, etc. They can use any source available, the web, books, newspaper and magazine articles, CDs etc. for this work. The group members must prepare a (short) summarising report about this investigation and "their" object, with their own ideas and conclusions, and send it to ESO (email address: eduinfo@eso.org). A jury, consisting of specialists from ESO and the EAAE, will carefully evaluate these reports. All projects that are found to fulfill the stipulated requirements, including a reasonable degree of scientific correctness, are entered as "registered projects" and will receive a lottery number. The first 1000 participants from the corresponding groups will also get a "Catch a star" T-Shirt by mail. All accepted entries will be listed at the corresponding website and all accepted reports will be displayed soon after the expiry of the deadline for submission on November 1st, 2002 . Winners to be Announced on November 8, 2002 On November 8th, 2002, at the end of the European Week of Science and Technology, the winners will be found by drawing numbers in a lottery. This event will take place at the ESO Headquarters in Garching (Germany) and will be webcast. The First Prize is a free trip for the members of the group to the ESO Paranal Observatory in Chile , the site of the ESO Very Large Telescope (VLT) . The Paranal trip will be realised in any case, but because of age restrictions, it can only be offered to a group in which all participants are 15 years of age or older at the time of the drawing. Younger participants may win an interesting trip within Europe. There will also be other prizes, to be announced later. Starting now The programme starts now and is open for groups of up to three students and one teacher, who must all belong to a school in Europe on November 1, 2002 . This means that only students who did not yet terminate their school studies on this date can participate. No student may participate in more than one group. The programme is administered by the ESO Educational Office , in close collaboration with members of the EAAE, mostly physics teachers. Details about how to register and how to prepare the report about "your" object are available on the web at: http://www.eso.org/public/outreach/eduoff/cas/ About the ESO Educational Office The ESO Educational Office was established in July 2001. It is part of the EPR Department at ESO Headquarters in Garching near Munich. The aim is to provide support of astronomy and astrophysics education, especially at the high-school level. This includes teaching materials, courses for teachers and specific educational projects, for instance in the context of the yearly European Week of Science and Technology. More information is available in ESO PR 29/01 and at the ESA/ESO Astronomy Excercise Series website. Note also the Frontline Astrophysics for School Teachers (FAST 2002) , an ESO teacher training course just announced. The application deadline for participation is June 1, 2002 . Contact for the "Catch a Star!" Programme: ESO Education Office eduinfo@eso.org

Dutch Minister of Science Visits ESO Facilities in Chile

NASA Astrophysics Data System (ADS)

2005-05-01

Mrs. Maria van der Hoeven, the Dutch Minister of Education, Culture and Science, who travelled to the Republic of Chile, arrived at the ESO Paranal Observatory on Friday afternoon, May 13, 2005. The Minister was accompanied, among others, by the Dutch Ambassador to Chile, Mr. Hinkinus Nijenhuis, and Mr. Cornelis van Bochove, the Dutch Director of Science. The distinguished visitors were able to acquaint themselves with one of the foremost European research facilities, the ESO Very Large Telescope (VLT), during an overnight stay at this remote site, and later, with the next major world facility in sub-millimetre and millimetre astronomy, the Atacama Large Millimeter Array (ALMA). At Paranal, the guests were welcomed by the ESO Director General, Dr. Catherine Cesarsky; the ESO Council President, Prof. Piet van der Kruit; the ESO Representative in Chile, Prof. Felix Mirabel; the Director of the La Silla Paranal Observatory, Dr. Jason Spyromilio; by one of the Dutch members of the ESO Council, Prof. Tim de Zeeuw; by the renowned astrophysicist from Leiden, Prof. Ewine van Dishoek, as well as by ESO staff members. The visitors were shown the various high-tech installations at the observatory, including many of the large, front-line VLT astronomical instruments that have been built in collaboration between ESO and European research institutes. Explanations were given by ESO astronomers and engineers and the Minister gained a good impression of the wide range of exciting research programmes that are carried out with the VLT. Having enjoyed the spectacular sunset over the Pacific Ocean from the Paranal deck, the Minister visited the VLT Control Room from where the four 8.2-m Unit Telescopes and the VLT Interferometer (VLTI) are operated. Here, the Minister was invited to follow an observing sequence at the console of the Kueyen (UT2) and Melipal (UT3) telescopes. "I was very impressed, not just by the technology and the science, but most of all by all the people involved," expressed Mrs. Maria van der Hoeven during her visit. "An almost unique level of international cooperation is achieved at ESO, and everything is done by those who can do it best, irrespective of their country or institution. This spirit of excellence is an example for all Europe, notably for the new European Research Council." Catherine Cesarsky, ESO Director General, remarked that Dutch astronomers have been part of ESO from the beginning: "The Dutch astronomy community and industry play a major role in various aspects of the Very Large Telescope, and more particularly in its interferometric mode. With their long-based expertise in radio astronomy, Dutch astronomers greatly contribute in this field, and are now also playing a major role in the construction of ALMA. It is thus a particularly great pleasure to receive Her Excellency, Mrs. Maria van der Hoeven." ESO PR Photo 16d/05 ESO PR Photo 16d/05 Dutch Minister Maria van der Hoeven at Chajnantor - I [Preview - JPEG: 400 x 480 pix - 207k] [Normal - JPEG: 800 x 959 pix - 617k] ESO PR Photo 16e/05 ESO PR Photo 16e/05 Dutch Minister Maria van der Hoeven at Chajnantor - II [Preview - JPEG: 400 x 605 pix - 179k] [Normal - JPEG: 800 x 1210 pix - 522k] Caption: ESO PR Photo 16d/05: In front of the APEX antenna at Chajnantor. From left to right: Prof. Piet van der Kruit, Mrs. Maria van der Hoeven, Prof. Tim de Zeeuw, and Prof. Ewine van Dishoeck. ESO PR Photo 16e/05 shows the Delegation on the 5000m high Llano de Chajnantor plateau. From left to right: Dr. Leo Le Duc, Prof. Felix Mirabel, Prof. Tim de Zeeuw, Prof. Ewine van Dishoeck, Dr. Cornelius van Bochove, Mrs. Maria van der Hoeven, Mr. Hans van der Vlies, Dr. Joerg Eschwey, Mr. Hinkinus Nijenhuis, Prof. Piet van der Kruit, Mr. Hans van den Broek, and Mr. Eduardo Donoso. The delegation spent the night at the Observatory before heading further North in the Chilean Andes to San Pedro de Atacama and from there to the Operation Support Facility of the future ALMA Observatory. On Sunday, May 15, the delegation went to the 5000m Llano de Chajnantor, the future site of the large array of 12m antennas that is being build there and should be completed by 2013. The Minister in particular could visit the 12m APEX (Atacama Pathfinder Experiment) telescope and see the technical infrastructure. "I am fully confident that the worldwide cooperation in ALMA will be equally successful as the VLT, and I am convinced that the discoveries to be made here are meaningful for the Earth we live in", said Mrs. van der Hoeven. "History and future are coming together in the north of Chile, in a very special way," she added. "In the region of the ancient Atacamenos, scientists from all over the world are discovering more and more about the universe and the birth and death of stars. They even find new planets. They do that on Paranal with the VLT and soon will be doing that on the ALMA site." The Minister and her delegation left for Santiago in the afternoon.

ESO Delegation to Visit Chile: the Chile-Eso Treaty and Paranal

NASA Astrophysics Data System (ADS)

1994-05-01

The ESO Council, in its extraordinary session on 28 April 1994, among other matters discussed the relations with the Republic of Chile and the situation around Paranal mountain [1], the designated site for the ESO Very Large Telescope (VLT). Council decided to send a high ranking delegation to Santiago de Chile to discuss with Chilean authorities the pending problems, including the finalisation of the new Treaty between the Republic of Chile and ESO and the legal aspects of the Paranal location. The ESO delegation will consist of Dr. Peter Creola (President of ESO Council), Dr. Catherine Cesarsky (Vice-President of ESO Council), Dr. Henrik Grage (Former Vice-President of ESO Council) and Professor Riccardo Giacconi (ESO Director General), the latter accompanied by his advisers. The delegation will arrive in Chile during the second half of May 1994. The ESO delegation will meet with the Chilean Minister of Foreign Affairs, Mr. Carlos Figueroa, and the Secretary of State in the Ministry of Foreign Affairs, Mr. Jose Miguel Insulza. Other meetings at high level are being planned. The delegation will report about these discussions to the ESO Council during its ordinary session on 7 - 8 June 1994. FOUR PARANAL PHOTOS AVAILABLE A series of four photos which show the current status of the work at Paranal has been prepared. Photographic colour prints for use by the media can be requested from the ESO Information and Photographic Service (please remember to indicate the identification numbers). [1] See ESO Press Release 07/94 of 21 April 1994. PHOTO CAPTIONS ESO PR PHOTO 08/94-1: CERRO PARANAL This aerial photo of the Paranal mountain, the designated site for the ESO Very Large Telescope (VLT), was obtained on 22 March 1994. Paranal is situated in the driest part of the Chilean Atacama desert, approx. 130 km south of the city of Antofagasta, and about 12 km from the Pacific Ocean. In this view towards the West, the ocean is seen in the background. The altitude is 2650 metres. The top of the mountain has been levelled to make place for the extensive VLT installations. ESO has constructed a road from the main road in the area (the ``Old Panamericana'') to the summit. It passes by the ESO base camp (in the foreground, left of the road). The constructors' camp is located on the other side of the road. This photo (ESO PR Photo 08/94-1) accompanies ESO Press Release 08/94 of 6 May 1994 and may be reproduced, if credit is given to the European Southern Observatory. ESO PR PHOTO 08/94-2: CERRO PARANAL This aerial photo of the Paranal mountain, the designated site for the ESO Very Large Telescope (VLT), was obtained on 22 March 1994. Paranal is located in the driest part of the Chilean Atacama desert, approx. 130 km south of the city of Antofagasta, and about 12 km from the Pacific Ocean. The altitude is 2650 metres. In this view towards the East, the high mountains of the Andean Cordillera are in the background. The top of the mountain has been levelled to make place for the extensive VLT installations. The four excavations for the buildings that will house the four 8.2 metre VLT unit telescopes are clearly seen. There are some dust clouds from the construction activity at the site. There are several other peaks in this area which may possibly be used for astronomical installations. The one to the left on which some site testing equipment can be seen, is known as the ``NTT Peak''. This photo (ESO PR Photo 08/94-2) accompanies ESO Press Release 08/94 of 6 May 1994 and may be reproduced, if credit is given to the European Southern Observatory. ESO PR PHOTO 08/94-3: CERRO PARANAL This aerial photo of the Paranal mountain, the designated site for the ESO Very Large Telescope (VLT), was obtained on 22 March 1994. Paranal is located in the driest part of the Chilean Atacama desert, approx. 130 km south of the city of Antofagasta, and about 12 km from the Pacific Ocean. The altitude is 2650 metres. The top of the mountain has been levelled to make place for the extensive VLT installations. The four excavations for the buildings that will house the four 8.2 metre VLT unit telescopes are clearly seen. The positions of some of the future structures have been marked. The control building will be located on the platform at the rightmost edge of the mountain. This photo (ESO PR Photo 08/94-3) accompanies ESO Press Release 08/94 of 6 May 1994 and may be reproduced, if credit is given to the European Southern Observatory. ESO PR PHOTO 08/94-4: CERRO PARANAL This photo of the ESO Base Camp at the foot of the Paranal mountain, the designated site for the ESO Very Large Telescope (VLT), was obtained in late March 1994. Paranal is located in the driest part of the Chilean Atacama desert, approx. 130 km south of the city of Antofagasta, and about 12 km from the Pacific Ocean. The altitude is 2650 metres. The top of the mountain has been levelled to make place for the extensive VLT installations. This photo (ESO PR Photo 08/94-4) accompanies ESO Press Release 08/94 of 6 May 1994 and may be reproduced, if credit is given to the European Southern Observatory.

Thirty-Seven Years of Service with ESO!

NASA Astrophysics Data System (ADS)

Breysacher, J.

2002-12-01

On December 1st, 2002, after thirty- seven years of service, first in Chile and then in Garching, Ms. Christa Euler will leave ESO to enjoy a welldeserved retirement. Among the current staff, she is probably the only person who started her career at ESO just four years after the Organization was founded.

ESO Helps Antofagasta Region after the Earthquake

NASA Astrophysics Data System (ADS)

2007-11-01

On November 14 at 12:41 local time, a major earthquake with magnitude 7.7 on the Richter scale affected the north of Chile. The epicentre was located 35 km from the city of Tocopilla and 170 km of Antofagasta. Two persons died and tens were injured, while buildings were damaged in several cities. In the Maria Elena-Tocopilla area, several thousand homes were destroyed or damaged. In an act of solidarity with the local community and its authorities, ESO immediately announced a donation of 30 millions Chilean pesos (around 40,000 euros) to Antofagasta's Regional Government to support reconstruction in the Region II. ESO and its staff have been shocked by the earthquake and its impact on local communities, especially on the people of Tocopilla. The ESO Representation in Chile formally contacted the regional authorities to explore with them possible ways to collaborate in this difficult moment. In addition, many of ESO staff are personally cooperating with the victims, under the coordination of Cruz Roja, the organisation currently in charge of implementing individual efforts.

EVALSO: A New High-speed Data Link to Chilean Observatories

NASA Astrophysics Data System (ADS)

2010-11-01

Stretching 100 kilometres through Chile's harsh Atacama Desert, a newly inaugurated data cable is creating new opportunities at ESO's Paranal Observatory and the Observatorio Cerro Armazones. Connecting these facilities to the main Latin American scientific data backbone completes the last gap in the high-speed link between the observatories and Europe. This new cable is part of the EVALSO (Enabling Virtual Access to Latin American Southern Observatories) project [1], a European Commission FP7 [2] co-funded programme co-ordinated by the University of Trieste that includes ESO, Observatorio Cerro Armazones (OCA, part of Ruhr-Universität Bochum), the Chilean academic network REUNA and other organisations. As well as the cable itself, the EVALSO project involves buying capacity on existing infrastructure to complete a high-bandwidth connection from the Paranal area to ESO's headquarters near Munich, Germany. Project co-ordinator Fernando Liello said: "This project has been an excellent collaboration between the consortium members. As well as giving a fast connection to the two observatories, it brings wider benefits to the academic communities both in Europe and Latin America." The sites of Paranal and Armazones are ideal for astronomical observation due to their high altitude, clear skies and remoteness from light pollution. But their location means they are far from any pre-existing communications infrastructure, which until now has left them dependent on a microwave link to send scientific data back to a base station near Antofagasta. Telescopes at ESO's Paranal observatory produce well over 100 gigabytes of data per night, equivalent to more than 20 DVDs, even after compressing the files. While the existing link is sufficient to carry the data from the current generation of instruments at the Very Large Telescope (VLT), it does not have the bandwidth to handle data from the VISTA telescope (Visible and Infrared Survey Telescope for Astronomy, see eso0949), or for the new generation of VLT instruments coming online in the next few years. This means that for much of the data coming from Paranal, the only practical way to send it to ESO Headquarters has been to save it onto hard drives and send these by airmail. This can mean a wait of days or even weeks before observations from VISTA are ready for analysis. Even with this careful rationing of the connection and sophisticated data management to use the connection as efficiently as possible, the link can get saturated at peak times. While this causes no major problems at present, it indicates that the link is reaching capacity. ESO Director General Tim de Zeeuw said: "ESO's observatory at Paranal is growing, with new telescopes and instruments coming online. Our world-class scientific observatories need state-of-the-art infrastructure." In the place of the existing connection, which has a limit of 16 megabit/s (similar to home ADSL broadband), EVALSO will provide a much faster 10 gigabit/s link - a speed fast enough to transfer an entire DVD movie in a matter of seconds [3]. Mario Campolargo, Director, Emerging Technologies and Infrastructures at the European Commission, said: "It is strategically important that the community of astronomers of Europe gets the best access possible to the ESO observatories: this is one of the reasons why the European Union supports the deployment of regional e-infrastructures for science in Latin America and interlinks them with GÉANT [4] and other EU e-infrastructures." The dramatic increase in bandwidth will allow increased use of Paranal's data from a distance, in real-time. It will allow easier monitoring of the VISTA telescope's performance, and quicker access to VLT data, increasing the responsiveness of quality control. And with the expanded bandwidth, new opportunities will open up, such as astronomers and technicians taking part in meetings via high-definition videoconferencing without having to travel to Chile. Moreover, looking forward, the new link will provide enough bandwidth to keep up with the ever-growing volumes of information from Paranal and Armazones in future years, as new and bandwidth-intensive instruments come into use. Immediate remote access to data at a distant location is not just about saving money and making the observatory's work more efficient. For unexpected and unpredictable events, such as gamma-ray bursts, there is often not enough time for astronomers to travel to observatories, and EVALSO will give experts a chance to work remotely on these events almost as if they were at the observatory. Notes [1] EVALSO is funded under the European Commission FP7 and is a partnership among Universita degli Studi di Trieste (Italy), ESO, Ruhr-Universität Bochum (Germany), Consortium GARR (Gestione Ampliamento Rete Ricerca) (Italy), Universiteit Leiden (Netherlands), Istituto Nazionale di Astrofisica (Italy), Queen Mary, University of London (UK), Cooperacion LatinoAmericana de Redes Avanzasas (CLARA) (Uruguay), and Red Universitaria Nacional (REUNA) (Chile). [2] FP7 (the European Commission Seventh Framework Programme for Research and Technical Development) is the European Union's main instrument for funding research. Its aim is to make, or keep, the EU as a world leader in its priority areas in science and technology. [3] The newly laid cable has a bandwidth of 10 gigabit/s. The entire network infrastructure between Paranal to ESO HQ in Germany is theoretically capable of transferring data at a maximum of 1 gigabit/s. [4] GÉANT is a pan-European data network dedicated to the research and education community. It connects 40 million users across 40 countries. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Celestial Fireworks from Dying Stars

NASA Astrophysics Data System (ADS)

2011-04-01

This image of the nebula NGC 3582, which was captured by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile, shows giant loops of gas bearing a striking resemblance to solar prominences. These loops are thought to have been ejected by dying stars, but new stars are also being born within this stellar nursery. These energetic youngsters emit intense ultraviolet radiation that makes the gas in the nebula glow, producing the fiery display shown here. NGC 3582 is part of a large star-forming region in the Milky Way, called RCW 57. It lies close to the central plane of the Milky Way in the southern constellation of Carina (The Keel of Jason's ship, the Argo). John Herschel first saw this complex region of glowing gas and dark dust clouds in 1834, during his stay in South Africa. Some of the stars forming in regions like NGC 3582 are much heavier than the Sun. These monster stars emit energy at prodigious rates and have very short lives that end in explosions as supernovae. The material ejected from these dramatic events creates bubbles in the surrounding gas and dust. This is the probable cause of the loops visible in this picture. This image was taken through multiple filters. From the Wide Field Imager, data taken through a red filter are shown in green and red, and data taken through a filter that isolates the red glow characteristic of hydrogen are also shown in red. Additional infrared data from the Digitized Sky Survey are shown in blue. The image was processed by ESO using the observational data identified by Joe DePasquale, from the United States [1], who participated in ESO's Hidden Treasures 2010 astrophotography competition [2]. The competition was organised by ESO in October-November 2010, for everyone who enjoys making beautiful images of the night sky using astronomical data obtained using professional telescopes. Notes [1] Joe searched through ESO's archive and identified datasets that he used to compose his image of NGC 3582, which was the tenth highest ranked entry in the competition, out of almost 100 entries. His original work can be seen here. [2] ESO's Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO's vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. To find out more about Hidden Treasures, visit http://www.eso.org/public/outreach/hiddentreasures/. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

The Orion Nebula: Still Full of Surprises

NASA Astrophysics Data System (ADS)

2011-01-01

This ethereal-looking image of the Orion Nebula was captured using the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory, Chile. This nebula is much more than just a pretty face, offering astronomers a close-up view of a massive star-forming region to help advance our understanding of stellar birth and evolution. The data used for this image were selected by Igor Chekalin (Russia), who participated in ESO's Hidden Treasures 2010 astrophotography competition. Igor's composition of the Orion Nebula was the seventh highest ranked entry in the competition, although another of Igor's images was the eventual overall winner. The Orion Nebula, also known as Messier 42, is one of the most easily recognisable and best-studied celestial objects. It is a huge complex of gas and dust where massive stars are forming and is the closest such region to the Earth. The glowing gas is so bright that it can be seen with the unaided eye and is a fascinating sight through a telescope. Despite its familiarity and closeness there is still much to learn about this stellar nursery. It was only in 2007, for instance, that the nebula was shown to be closer to us than previously thought: 1350 light-years, rather than about 1500 light-years. Astronomers have used the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile to observe the stars within Messier 42. They found that the faint red dwarfs in the star cluster associated with the glowing gas radiate much more light than had previously been thought, giving us further insights into this famous object and the stars that it hosts. The data collected for this science project, with no original intention to make a colour image, have now been reused to create the richly detailed picture of Messier 42 shown here. The image is a composite of several exposures taken through a total of five different filters. Light that passed through a red filter as well as light from a filter that shows the glowing hydrogen gas, were coloured red. Light in the yellow-green part of the spectrum is coloured green, blue light is coloured blue and light that passed through an ultraviolet filter has been coloured purple. The exposure times were about 52 minutes through each filter. This image was processed by ESO using the observational data found by Igor Chekalin (Russia) [1], who participated in ESO's Hidden Treasures 2010 astrophotography competition [2], organised by ESO in October-November 2010, for everyone who enjoys making beautiful images of the night sky using real astronomical data. Notes [1] Igor searched through ESO's archive and identified datasets that he used to compose his image of Messier 42, which was the seventh highest ranked entry in the competition, out of almost 100 entries. His original work can be seen here. Igor Chekalin was awarded the first prize of the competition for his composition of Messier 78, and he also submitted an image of NGC3169, NGC3166 and SN 2003cg, which was ranked second highest. [2] ESO's Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO's vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. Participants submitted nearly 100 entries and ten skilled people were awarded some extremely attractive prizes, including an all expenses paid trip for the overall winner to ESO's Very Large Telescope (VLT) on Cerro Paranal, in Chile, the world's most advanced optical telescope. The ten winners submitted a total of 20 images that were ranked as the highest entries in the competition out of the near 100 images. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

A Picture-perfect Pure-disc Galaxy

NASA Astrophysics Data System (ADS)

2011-02-01

The bright galaxy NGC 3621, captured here using the Wide Field Imager on the 2.2-metre telescope at ESO's La Silla Observatory in Chile, appears to be a fine example of a classical spiral. But it is in fact rather unusual: it does not have a central bulge and is therefore described as a pure-disc galaxy. NGC 3621 is a spiral galaxy about 22 million light-years away in the constellation of Hydra (The Sea Snake). It is comparatively bright and can be seen well in moderate-sized telescopes. This picture was taken using the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. The data were selected from the ESO archive by Joe DePasquale as part of the Hidden Treasures competition [1]. Joe's picture of NGC 3621 was ranked fifth in the competition. This galaxy has a flat pancake shape, indicating that it hasn't yet come face to face with another galaxy as such a galactic collision would have disturbed the thin disc of stars, creating a small bulge in its centre. Most astronomers think that galaxies grow by merging with other galaxies, in a process called hierarchical galaxy formation. Over time, this should create large bulges in the centres of spirals. Recent research, however, has suggested that bulgeless, or pure-disc, spiral galaxies like NGC 3621 are actually fairly common. This galaxy is of further interest to astronomers because its relative proximity allows them to study a wide range of astronomical objects within it, including stellar nurseries, dust clouds, and pulsating stars called Cepheid variables, which astronomers use as distance markers in the Universe [2]. In the late 1990s, NGC 3621 was one of 18 galaxies selected for a Key Project of the Hubble Space Telescope: to observe Cepheid variables and measure the rate of expansion of the Universe to a higher accuracy than had been possible before. In the successful project, 69 Cepheid variables were observed in this galaxy alone. Multiple monochrome images taken through four different colour filters were combined to make this picture. Images taken through a blue filter have been coloured blue in the final picture, images through a yellow-green filter are shown as green and images through a red filter as dark orange. In addition images taken through a filter that isolates the glow of hydrogen gas have been coloured red. The total exposure times per filter were 30, 40, 40 and 40 minutes respectively. Notes [1] ESO's Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO's vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. Participants submitted nearly 100 entries and ten skilled people were awarded some extremely attractive prizes, including an all expenses paid trip for the overall winner to ESO's Very Large Telescope (VLT) on Cerro Paranal, in Chile, the world's most advanced optical telescope. The ten winners submitted a total of 20 images that were ranked as the highest entries in the competition out of the near 100 images. [2] Cepheid variables are very luminous stars - up to 30 000 times brighter than our Sun - whose brightness varies at regular intervals over several days, weeks or months. The period of this variation in luminosity is related to the star's true brightness, known as its absolute magnitude. By knowing the absolute magnitude of the star, and measuring how bright it appears, astronomers can easily calculate its distance from Earth. Cepheid variables are therefore vital for establishing the scale of the Universe. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

ESO Council Decides to Continue VLT Project at Paranal

NASA Astrophysics Data System (ADS)

1994-08-01

The Council [1] of the European Southern Observatory has met in extraordinary session at the ESO Headquarters in Garching near Munich on August 8 and 9, 1994. The main agenda items were concerned with the recent developments around ESO's relations with the host state, the Republic of Chile, as well as the status of the organisation's main project, the 16-metre equivalent Very Large Telescope (VLT) which will become the world's largest optical telescope. Council had decided to hold this special meeting [2] because of various uncertainties that have arisen in connection with the implementation of the VLT Project at Cerro Paranal, approx. 130 kilometres south of Antofagasta, capital of the II Region in Chile. Following continued consultations at different levels within the ESO member states and after careful consideration of all aspects of the current situation - including various supportive actions by the Chilean Government as well as the incessive attacks against this international organisation from certain sides reported in the media in that country - Council took the important decision to continue the construction of the VLT Observatory at Paranal, while at the same time requesting the ESO Management to pursue the ongoing studies of alternative solutions. THE COUNCIL DECISIONS In particular, the ESO Council took note of recent positive developments which have occurred since the May 1994 round of discussions with the Chilean authorities in Santiago. The confirmation of ESO's immunities as an International Organization in Chile, contained in a number of important statements and documents, is considered a significant step by the Chilean Government to insure to ESO the unhindered erection and later operation of the VLT on Paranal. Under these circumstances and in order to maintain progress on the VLT project, the ESO Council authorized the ESO Management to continue the on-site work at Paranal. Council also took note of the desire expressed by the Chilean Government to complete negotiation of a Supplementary and Amending Agreement and it was decided that a Council Delegation shall conclude as soon as possible the negotiation of this Agreement. Council noted that the Chilean Delegation has accepted ESO's invitation to hold the final round of negotiations in Europe and proposed that this final round shall be held in the period Sept. 15 - Oct. 15, 1994. Nonetheless, Council also expressed its preoccupation with regard to remaining ambiguities contained in some official statements according to which the formal recognition of ESO's status on Paranal would depend on the conclusion of the above mentioned Agreement. At the May 1994 meetings in Santiago [2], understanding had been reached that this Agreement will merely confirm the already existing legal situation. The main objective is to expand the cooperation between Chile and ESO by granting ensured access for Chilean astronomers to ESO's facilities and incorporate elements of Chilean labour legislation into the ESO internal staff regulations. In view of these circumstances, and pending the successful conclusion of these negotiations, Council therefore instructed the ESO Management to continue exploring alternative sites for the VLT. In a final statement, the ESO Council again expressed its hope that the scientific co-operation between Europe and Chile in the field of astronomy which began in 1963 will continue to develop and expand well into the next century to the mutual benefit of science in both communities. CONTINUATION OF THE VLT PROJECT In practical terms, the above decision by Council implies that ESO will now initiate the steps necessary to move from Europe to Paranal the main mechanical parts of the rotating dome (total weight around 500 tonnes) for the first VLT 8.2-metre unit telescope. It is expected that the sea transport will take place in September-October of this year and that assembly at Paranal will begin soon thereafter, once the concrete base, now under construction, is ready. This will enable the 500 million DEM VLT Project to stay within the planned timeline for completion just after the year 2000. 1. The Council of ESO consists of two representatives from each of the eight member states. It is the highest authority of the organisation and normally meets twice a year. 2. See ESO Press Release 12/94 of June 10, 1994.

A search for J-band variability from late-L and T brown dwarfs

NASA Astrophysics Data System (ADS)

Clarke, F. J.; Hodgkin, S. T.; Oppenheimer, B. R.; Robertson, J.; Haubois, X.

2008-06-01

We present J-band photometric observations of eight late-L and T type brown dwarfs designed to search for variability. We detect small amplitude periodic variability from three of the objects on time-scales of several hours, probably indicating the rotation period of the objects. The other targets do not show any variability down to the level of 0.5-5 per cent This work is based on observations obtained at the European Southern Observatory, La Silla, Chile (ESO Programme 72.C-0006). E-mail: fclarke@astro.ox.ac.uk (FJC); sth@ast.cam.ac.uk (STH); bro@amnh.org (BRO); xavier.haubois@obspm.fr (XH)

Sea & Space: a New European Educational Programme

NASA Astrophysics Data System (ADS)

1998-01-01

This spring, teachers across Europe will enjoy support for exciting, novel educational projects on astronomy, navigation and environmental observations. The largely web-based and highly interactive SEA & SPACE programme makes it possible for pupils to perform field experiments and astronomical observations and to obtain and process satellite images. A contest will take the best pupils for one week to Lisbon (Portugal), to Europe's space port in Kourou (French Guyana) where the European launcher lifts off or to ESO's Very Large Telescope at the Cerro Paranal Observatory in Chile, the largest optical telescope in the world. The SEA & SPACE project is a joint initiative of the European Space Agency (ESA) , the European Southern Observatory (ESO) , and the European Association for Astronomy Education (EAAE). It builds on these organisations' several years' successful participation in the European Week for Scientific and Technological Culture organised by the European Commission that they intend to continue in 1998. The 1998 World Exhibition EXPO98 in Lisbon will focus on the oceans. This is why the umbrella theme of SEA & SPACE is concerned with the many relations between the oceans and the space that surrounds us, from ancient times to present days. Under the new programme, teaching resources are offered for three major areas, Remote Sensing of Europe's Coastal Environment, Navigation and Oceans of Water. Remote Sensing of Europe's Coastal Environment : observations of the Earth from Space are made accessible to pupils who will appreciate their usefulness through interactive image processing and field observations; Navigation : the capabilities and functioning of different navigation techniques are explored through experiments using navigation by the stars, with GPS, and via satellite images/maps; Oceans of Water : What is the role of water in Nature? How can one detect water from satellites or with telescopes? How much water is there in rivers and floods, in an ocean, on Mars, in comets, in stars, in the Universe? SEA & SPACE will use the Internet and the WWW to transport teaching resources so that teachers and pupils can communicate with the organisers and among themselves. To this end, the National Committees of the European Association for Astronomy Education will operate sites onto which the information and resources provided by ESA and ESO are loaded. The Contest, in which pupils will write and design a poster or a newspaper on a subject related to SEA & SPACE, will be organised simultaneously in most European countries and will not require Internet access. SEA & SPACE will start as from 1 March 1998. Further information is provided on the Home Pages of ESA, ESO and EAAE. In early February, a dedicated joint SEA & SPACE Home Page will be operational where schools can register for the project and for regular mailing of new information: * http://www.esa.int/seaspace * http://www.eso.org/seaspace * http://www.algonet.se/~sirius/eaae/seaspace Note: [1] This press release is published jointly by ESA, ESO and EAAE. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

My Visit to La Silla

NASA Astrophysics Data System (ADS)

Muller, A.

1988-09-01

The Director General of ESO, Harry van der Laan, invited me to La Silla as consultant during the realuminization and the optical trimming of the ESO Schmidt telescope. I was very happy with this invitation because it gave me an opportunity not only to spend some time at the Schmidt, but also to meet with many friends in Chile. At La Silla I had the good luck to meet Richard West who suggested to me to write a short contribution for the Messenger about my stay in Chile which I have done with pleasure.

ESO takes the public on an astronomical journey "Around the World in 80 Telescopes"

NASA Astrophysics Data System (ADS)

2009-03-01

A live 24-hour free public video webcast, "Around the World in 80 Telescopes", will take place from 3 April 09:00 UT/GMT to 4 April 09:00 UT/GMT, chasing day and night around the globe to let viewers "visit" some of the most advanced astronomical telescopes on and off the planet. The webcast, organised by ESO for the International Year of Astronomy 2009 (IYA2009), is the first time that so many large observatories have been linked together for a public event. ESO PR Photo 13a/09 Map of Participating Observatories ESO PR Photo 13b/09 100 Hours of Astronomy logo Viewers will see new images of the cosmos, find out what observatories in their home countries or on the other side of the planet are discovering, send in questions and messages, and discover what astronomers are doing right now. Participating telescopes include those at observatories in Chile such as ESO's Very Large Telescope and La Silla, the Hawaii-based telescopes Gemini North and Keck, the Anglo-Australian Telescope, telescopes in the Canary Islands, the Southern African Large Telescope, space-based telescopes such as the NASA/ESA Hubble Space Telescope, ESA XMM-Newton and Integral, and many more. "Around the World in 80 Telescopes" will take viewers to every continent, including Antarctica! The webcast production will be hosted at ESO's headquarters near Munich, Germany, with live internet streaming by Ustream.tv. Anyone with a web browser supporting Adobe Flash will be able to follow the show, free of charge, from the website www.100hoursofastronomy.org and be a part of the project by sending messages and questions. The video player can be freely embedded on other websites. TV stations, web portals and science centres can also use the high quality feed. Representatives of the media who wish to report from the "front-line" and interview the team should get in touch. "Around the World in 80 Telescopes" is a major component of the 100 Hours of Astronomy (100HA), a Cornerstone project of the International Year of Astronomy 2009. 100HA is on track to be the largest single science public outreach event ever, with more than 1500 events registered in over 130 countries. 100HA will take place over four days and nights, from 2-5 April 2009. It is a worldwide celebration composed of a broad range of activities aimed at involving the public. During this period, people from around the globe will share the experience and wonder of observing the sky. For many, it will be their first glimpse of the marvels of the heavens through a telescope. For others, it is the perfect opportunity to impart their knowledge and excitement, helping unveil the cosmos to fresh and eager eyes. Astronomers at ESO are also organising local public events near their headquarters in Garching, near Munich. In the Munich city centre, ESO astronomers, together with colleagues from the Excellence Cluster Universe, will share their views of the cosmos with members of the public. ESO in Chile is also participating in a series of events to celebrate the 100 Hours of Astronomy. In Antofagasta, an exhibition by international and local astrophotographers will be unveiled at the main mall in the city. Star parties will be organised for the public in the desert outside Antofagasta, in coordination with the local university UCN. In Santiago, ESO is offering, along with other international observatories and the Chilean astronomical community, a complete set of programmes, including public talks, night observations and interactive exhibitions. In San Pedro de Atacama, the ALMA project will install an inflatable planetarium for the local community, and astronomy workshops and star parties will be offered to the public. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO plays also a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in the Atacama Desert region of Chile: La Silla, Paranal and Chajnantor. The vision of the IYA2009 is to help the citizens of the world rediscover their place in the Universe through the day and night-time skies the impact of astronomy and basic sciences on our daily lives, and understand better how scientific knowledge can contribute to a more equitable and peaceful society. Ustream.TV is the live interactive video broadcast platform that enables anyone with a camera and an internet connection to quickly and easily broadcast to a global audience of unlimited size. In less than two minutes, anyone can become a broadcaster by creating their own channel on Ustream or by broadcasting through their own site, empowering them to engage with their audience and further build their brand.

ESO's Hidden Treasures Brought to Light

NASA Astrophysics Data System (ADS)

2011-01-01

ESO's Hidden Treasures 2010 astrophotography competition attracted nearly 100 entries, and ESO is delighted to announce the winners. Hidden Treasures gave amateur astronomers the opportunity to search ESO's vast archives of astronomical data for a well-hidden cosmic gem. Astronomy enthusiast Igor Chekalin from Russia won the first prize in this difficult but rewarding challenge - the trip of a lifetime to ESO's Very Large Telescope at Paranal, Chile. The pictures of the Universe that can be seen in ESO's releases are impressive. However, many hours of skilful work are required to assemble the raw greyscale data captured by the telescopes into these colourful images, correcting them for distortions and unwanted signatures of the instrument, and enhancing them so as to bring out the details contained in the astronomical data. ESO has a team of professional image processors, but for the ESO's Hidden Treasures 2010 competition, the experts decided to give astronomy and photography enthusiasts the opportunity to show the world what they could do with the mammoth amount of data contained in ESO's archives. The enthusiasts who responded to the call submitted nearly 100 entries in total - far exceeding initial expectations, given the difficult nature of the challenge. "We were completely taken aback both by the quantity and the quality of the images that were submitted. This was not a challenge for the faint-hearted, requiring both an advanced knowledge of data processing and an artistic eye. We are thrilled to have discovered so many talented people," said Lars Lindberg Christensen, Head of ESO's education and Public Outreach Department. Digging through many terabytes of professional astronomical data, the entrants had to identify a series of greyscale images of a celestial object that would reveal the hidden beauty of our Universe. The chance of a great reward for the lucky winner was enough to spur on the competitors; the first prize being a trip to ESO's Very Large Telescope in Paranal, Chile, with guided tours and the opportunity to participate in a night's observations. Runner-up prizes included an iPod, books and DVDs. Furthermore, the highest ranked images will be released for the world to see on www.eso.org as Photo Releases or Pictures of the Week, co-crediting the winners. The jury evaluated the entries based on the quality of the data processing, the originality of the image and the overall aesthetic feel. As several of the highest ranked images were submitted by the same people, the jury decided to make awards to the ten most talented participants, so as to give more people the opportunity to win a prize and reward their hard work and talent. The ten winners of the competition are: * First prize, a trip to Paranal + goodies: Igor Chekalin (Russia). * Second prize, an iPod Touch + goodies: Sergey Stepanenko (Ukraine). * Third Prize, VLT laser cube model + goodies: Andy Strappazzon (Belgium). * Fourth to tenth prizes, Eyes on the Skies Book + DVD + goodies: Joseph (Joe) DePasquale (USA), Manuel (Manu) Mejias (Argentina), Alberto Milani (Italy), Joshua (Josh) Barrington (USA), Oleg Maliy (Ukraine), Adam Kiil (United Kingdom), Javier Fuentes (Chile). The ten winners submitted the twenty highest ranked images: 1. M78 by Igor Chekalin. 2. NGC3169 & NGC3166 and SN 2003cg by Igor Chekalin. 3. NGC6729 by Sergey Stepanenko. 4. The Moon by Andy Strappazzon. 5. NGC 3621 by Joseph (Joe) DePasquale. 6. NGC 371 by Manuel (Manu) Mejias. 7. Dust of Orion Nebula (ESO 2.2m telescope) by Igor Chekalin. 8. NGC1850 EMMI by Sergey Stepanenko. 9. Abell 1060 by Manuel (Manu) Mejias. 10. Celestial Prominences NGC3582 by Joseph DePasquale. 11. Globular Cluster NGC288 by Alberto Milani. 12. Antennae Galaxies by Alberto Milani. 13. Sakurai's Object by Joshua (Josh) Barrington. 14. NGC 1929, N44 Superbubble by Manuel (Manu) Mejias. 15. NGC 3521 by Oleg Maliy. 16. NGC 6744 by Andy Strappazzon. 17. NGC 2217 by Oleg Maliy. 18. VIMOS.2008-01-31T07_16_47j by Adam Kiil. 19. NGC 2467 - number 2 by Josh Barrington. 20. Haffner 18 and 19 by Javier Fuentes. Igor Chekalin, winner of the trip to Paranal, says: "It was a great experience and pleasure to work with such amazing data. As an amateur astrophotographer, this was the most difficult processing and post-processing job I have ever done. My participation in the Hidden Treasures competition gave me a range of challenges, from installing new software to studying techniques and even operating systems that I did not know before." The success of the ESO's Hidden Treasures 2010 competition and the enthusiasm of the skilled participants made it easy to decide to run a follow-up to the competition. Stay tuned and check www.eso.org for news about ESO's Hidden Treasures 2011. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

32 New Exoplanets Found

NASA Astrophysics Data System (ADS)

2009-10-01

oday, at an international ESO/CAUP exoplanet conference in Porto, the team who built the High Accuracy Radial Velocity Planet Searcher, better known as HARPS, the spectrograph for ESO's 3.6-metre telescope, reports on the incredible discovery of some 32 new exoplanets, cementing HARPS's position as the world's foremost exoplanet hunter. This result also increases the number of known low-mass planets by an impressive 30%. Over the past five years HARPS has spotted more than 75 of the roughly 400 or so exoplanets now known. "HARPS is a unique, extremely high precision instrument that is ideal for discovering alien worlds," says Stéphane Udry, who made the announcement. "We have now completed our initial five-year programme, which has succeeded well beyond our expectations." The latest batch of exoplanets announced today comprises no less than 32 new discoveries. Including these new results, data from HARPS have led to the discovery of more than 75 exoplanets in 30 different planetary systems. In particular, thanks to its amazing precision, the search for small planets, those with a mass of a few times that of the Earth - known as super-Earths and Neptune-like planets - has been given a dramatic boost. HARPS has facilitated the discovery of 24 of the 28 planets known with masses below 20 Earth masses. As with the previously detected super-Earths, most of the new low-mass candidates reside in multi-planet systems, with up to five planets per system. In 1999, ESO launched a call for opportunities to build a high resolution, extremely precise spectrograph for the ESO 3.6-metre telescope at La Silla, Chile. Michel Mayor, from the Geneva Observatory, led a consortium to build HARPS, which was installed in 2003 and was soon able to measure the back-and-forward motions of stars by detecting small changes in a star's radial velocity - as small as 3.5 km/hour, a steady walking pace. Such a precision is crucial for the discovery of exoplanets and the radial velocity method, which detects small changes in the radial velocity of a star as it wobbles slightly under the gentle gravitational pull from an (unseen) exoplanet, has been most prolific method in the search for exoplanets. In return for building the instrument, the HARPS consortium was granted 100 observing nights per year during a five-year period to carry out one of the most ambitious systematic searches for exoplanets so far implemented worldwide by repeatedly measuring the radial velocities of hundreds of stars that may harbour planetary systems. The programme soon proved very successful. Using HARPS, Mayor's team discovered - among others - in 2004, the first super-Earth (around µ Ara; in 2006, the trio of Neptunes around HD 69830; in 2007, Gliese 581d, the first super Earth in the habitable zone of a small star (eso0722); and in 2009, the lightest exoplanet so far detected around a normal star, Gliese 581e (eso0915). More recently, they found a potentially lava-covered world, with density similar to that of the Earth's (eso0933). "These observations have given astronomers a great insight into the diversity of planetary systems and help us understand how they can form," says team member Nuno Santos. The HARPS consortium was very careful in their selection of targets, with several sub-programmes aimed at looking for planets around solar-like stars, low-mass dwarf stars, or stars with a lower metal content than the Sun. The number of exoplanets known around low-mass stars - so-called M dwarfs - has also dramatically increased, including a handful of super Earths and a few giant planets challenging planetary formation theory. "By targeting M dwarfs and harnessing the precision of HARPS we have been able to search for exoplanets in the mass and temperature regime of super-Earths, some even close to or inside the habitable zone around the star," says co-author Xavier Bonfils. The team found three candidate exoplanets around stars that are metal-deficient. Such stars are thought to be less favourable for the formation of planets, which form in the metal-rich disc around the young star. However, planets up to several Jupiter masses have been found orbiting metal-deficient stars, setting an important constraint for planet formation models. Although the first phase of the observing programme is now officially concluded, the team will pursue their effort with two ESO Large Programmes looking for super-Earths around solar-type stars and M dwarfs and some new announcements are already foreseen in the coming months, based on the last five years of measurements. There is no doubt that HARPS will continue to lead the field of exoplanet discoveries, especially pushing towards the detection of Earth-type planets. More information This discovery was announced today at the ESO/CAUP conference "Towards Other Earths: perspectives and limitations in the ELT era", taking place in Porto, Portugal, on 19-23 October 2009. This conference discusses the new generation of instruments and telescopes that is now being conceived and built by different teams around the world to allow the discovery of other Earths, especially for the European Extremely Large Telescope (E-ELT). The new planets are simultaneously presented by Michel Mayor at the international symposium "Heirs of Galileo: Frontiers of Astronomy" in Madrid, Spain. This research was presented in a series of eight papers submitted - or soon to be submitted - to the Astronomy and Astrophysics journal. The team is composed of * Geneva Observatory: M. Mayor, S. Udry, D. Queloz, F. Pepe, C. Lovis, D. Ségransan, X. Bonfils * LAOG Grenoble: X. Delfosse, T. Forveille, X. Bonfils, C. Perrier * CAUP Porto: N.C. Santos * ESO: G. Lo Curto, D. Naef * University of Bern: W. Benz, C. Mordasini * IAP Paris: F. Bouchy, G. Hébrard * LAM Marseille: C. Moutou * Service d'aéronomie, Paris: J.-L. Bertaux ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky". * The web page of the conference "Towards Other Earths: perspectives and limitations in the ELT era" is at http://www.astro.up.pt/investigacao/conferencias/toe2009/

Brazil to Join the European Southern Observatory

NASA Astrophysics Data System (ADS)

2010-12-01

The Federative Republic of Brazil has yesterday signed the formal accession agreement paving the way for it to become a Member State of the European Southern Observatory (ESO). Following government ratification Brazil will become the fifteenth Member State and the first from outside Europe. On 29 December 2010, at a ceremony in Brasilia, the Brazilian Minister of Science and Technology, Sergio Machado Rezende and the ESO Director General, Tim de Zeeuw signed the formal accession agreement aiming to make Brazil a Member State of the European Southern Observatory. Brazil will become the fifteen Member State and the first from outside Europe. Since the agreement means accession to an international convention, the agreement must now be submitted to the Brazilian Parliament for ratification [1]. The signing of the agreement followed the unanimous approval by the ESO Council during an extraordinary meeting on 21 December 2010. "Joining ESO will give new impetus to the development of science, technology and innovation in Brazil as part of the considerable efforts our government is making to keep the country advancing in these strategic areas," says Rezende. The European Southern Observatory has a long history of successful involvement with South America, ever since Chile was selected as the best site for its observatories in 1963. Until now, however, no non-European country has joined ESO as a Member State. "The membership of Brazil will give the vibrant Brazilian astronomical community full access to the most productive observatory in the world and open up opportunities for Brazilian high-tech industry to contribute to the European Extremely Large Telescope project. It will also bring new resources and skills to the organisation at the right time for them to make a major contribution to this exciting project," adds ESO Director General, Tim de Zeeuw. The European Extremely Large Telescope (E-ELT) telescope design phase was recently completed and a major review was conducted where every aspect of this large project was scrutinised by an international panel of independent experts. The panel found that the E-ELT project is technically ready to enter the construction phase. The go-ahead for E-ELT construction is planned for 2011 and when operations start early in the next decade, European, Brazilian and Chilean astronomers will have access to this giant telescope. The president of ESO's governing body, the Council, Laurent Vigroux, concludes: "Astronomers in Brazil will benefit from collaborating with European colleagues, and naturally from having observing time at ESO's world-class observatories at La Silla and Paranal, as well as on ALMA, which ESO is constructing with its international partners." Notes [1] After ratification of Brazil's membership, the ESO Member States will be Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Manfred Ziebell Retires

NASA Astrophysics Data System (ADS)

Hofstadt, D.

2002-12-01

On December 1st, 2002, after thirty- seven years of service, first in Chile and then in Garching, Ms. Christa Euler will leave ESO to enjoy a welldeserved retirement. Among the current staff, she is probably the only person who started her career at ESO just four years after the Organization was founded.

The Trilogy is Complete - GigaGalaxy Zoom Phase 3

NASA Astrophysics Data System (ADS)

2009-09-01

The third image of ESO's GigaGalaxy Zoom project has just been released online, completing this eye-opening dive into our galactic home in outstanding fashion. The latest image follows on from views, released over the last two weeks, of the sky as seen with the unaided eye and through an amateur telescope. This third instalment provides another breathtaking vista of an astronomical object, this time a 370-million-pixel view of the Lagoon Nebula of the quality and depth needed by professional astronomers in their quest to understand our Universe. The newly released image extends across a field of view of more than one and a half square degree - an area eight times larger than that of the full Moon - and was obtained with the Wide Field Imager attached to the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. This 67-million-pixel camera has already created several of ESO's iconic pictures. The intriguing object depicted here - the Lagoon Nebula - is located four to five thousand light-years away towards the constellation of Sagittarius (the Archer). The nebula is a giant interstellar cloud, 100 light-years across, where stars are forming. The scattered dark patches seen all over the nebula are huge clouds of gas and dust that are collapsing under their own weight and which will soon give birth to clusters of young, glowing stars. Some of the smallest clouds are known as "globules" and the most prominent ones have been catalogued by the astronomer Edward Emerson Barnard. The Lagoon Nebula hosts the young open stellar cluster known as NGC 6530. This is home for 50 to 100 stars and twinkles in the lower left portion of the nebula. Observations suggest that the cluster is slightly in front of the nebula itself, though still enshrouded by dust, as revealed by reddening of the starlight, an effect that occurs when small dust particles scatter light. The name of the Lagoon Nebula derives from the wide lagoon-shaped dark lane located in the middle of the nebula that divides it into two glowing sections. This gorgeous starscape is the last in the series of three huge images featured in the GigaGalaxy Zoom project, launched by ESO as part of the International Year of Astronomy 2009 (IYA2009). Through three giant images, the GigaGalaxy Zoom project reveals the full sky as it appears with the unaided eye from one of the darkest deserts on Earth, then zooms in on a rich region of the Milky Way using an amateur telescope, and finally uses the power of a professional telescope to reveal the details of a famous nebula. In this way, the project links the sky we can all see with the deep, "hidden" cosmos that astronomers study on a daily basis. The wonderful quality of the images is a testament to the splendour of the night sky at ESO's sites in Chile, which are the most productive astronomical observatories in the world. "The GigaGalaxy Zoom project's dedicated website has proved very successful, drawing hundreds of thousands of visitors from all around the world," says project coordinator Henri Boffin. "With the trilogy now complete, viewers will be able to explore a magnificently detailed cosmic environment on many different scales and take a breathtaking dive into our Milky Way." More information As part of the IYA2009, ESO is participating in several remarkable outreach activities, in line with its world-leading rank in the field of astronomy. ESO is hosting the IYA2009 Secretariat for the International Astronomical Union, which coordinates the Year globally. ESO is one of the Organisational Associates of IYA2009, and was also closely involved in the resolution submitted to the United Nations (UN) by Italy, which led to the UN's 62nd General Assembly proclaiming 2009 the International Year of Astronomy. In addition to a wide array of activities planned both at the local and international level, ESO is leading four of the thirteen global Cornerstone Projects. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky". The third image of the GigaGalaxy Zoom project was taken with the Wide Field Imager (WFI) attached to the MPG/ESO 2.2-metre telescope at the ESO La Silla Observatory. In order to optimise telescope time, the images were obtained by ESO staff astronomers, who select the most favourable observations to be made at any given time, taking into account the visibility of the objects and the sky conditions. The La Silla Observatory, 600 km north of Santiago de Chile and at an altitude of 2400 metres, has been an ESO stronghold since the 1960s. Here, ESO operates several of the most productive 2-4-metre-class telescopes in the world.

Clear New View of a Classic Spiral

NASA Astrophysics Data System (ADS)

2010-05-01

ESO is releasing a beautiful image of the nearby galaxy Messier 83 taken by the HAWK-I instrument on ESO's Very Large Telescope (VLT) at the Paranal Observatory in Chile. The picture shows the galaxy in infrared light and demonstrates the impressive power of the camera to create one of the sharpest and most detailed pictures of Messier 83 ever taken from the ground. The galaxy Messier 83 (eso0825) is located about 15 million light-years away in the constellation of Hydra (the Sea Serpent). It spans over 40 000 light-years, only 40 percent the size of the Milky Way, but in many ways is quite similar to our home galaxy, both in its spiral shape and the presence of a bar of stars across its centre. Messier 83 is famous among astronomers for its many supernovae: vast explosions that end the lives of some stars. Over the last century, six supernovae have been observed in Messier 83 - a record number that is matched by only one other galaxy. Even without supernovae, Messier 83 is one of the brightest nearby galaxies, visible using just binoculars. Messier 83 has been observed in the infrared part of the spectrum using HAWK-I [1], a powerful camera on ESO's Very Large Telescope (VLT). When viewed in infrared light most of the obscuring dust that hides much of Messier 83 becomes transparent. The brightly lit gas around hot young stars in the spiral arms is also less prominent in infrared pictures. As a result much more of the structure of the galaxy and the vast hordes of its constituent stars can be seen. This clear view is important for astronomers looking for clusters of young stars, especially those hidden in dusty regions of the galaxy. Studying such star clusters was one of the main scientific goals of these observations [2]. When compared to earlier images, the acute vision of HAWK-I reveals far more stars within the galaxy. The combination of the huge mirror of the VLT, the large field of view and great sensitivity of the camera, and the superb observing conditions at ESO's Paranal Observatory makes HAWK-I one of the most powerful near-infrared imagers in the world. Astronomers are eagerly queuing up for the chance to use the camera, which began operation in 2007 (eso0736), and to get some of the best ground-based infrared images ever of the night sky. Notes [1] HAWK-I stands for High-Acuity Wide-field K-band Imager. More technical details about the camera can be found in an earlier press release (eso0736). [2] The data used to prepare this image were acquired by a team led by Mark Gieles (University of Cambridge) and Yuri Beletsky (ESO). Mischa Schirmer (University of Bonn) performed the challenging data processing. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Professor Tim de Zeeuw Takes Up Duty as New ESO Director General

NASA Astrophysics Data System (ADS)

2007-09-01

On 1 September, Tim de Zeeuw became the new ESO Director General, succeeding Catherine Cesarsky. In his first day in office, he kindly agreed to answer a few questions. ESO PR Photo 38/07 ESO PR Video 38/07 Watch the Video! How would you describe the current period for astronomy? Tim de Zeeuw: We are in an extremely exciting time for astronomy and I think this is understood worldwide and not just by astronomers. The technology is now available to look not only at the farthest objects in the Universe, where the light left a long time ago, allowing us to see how the Universe evolved and developed, but we can even detect signatures of planets around other stars, and that answers an age-old question which is a fundamental question in all of science, and really excites the general public. How do you see the role of ESO in this context? Tim de Zeeuw: ESO has a very important role in the context of European and worldwide astronomy because it is one of the leading organisations for ground-based astronomy. You may even say it is the pre-eminent organisation. Therefore, we have both an opportunity and a responsibility to lead the further developments in astronomy. Where do you see ESO developing in the coming years? Tim de Zeeuw: I see three main goals for ESO in the coming years. The first one is to get the best possible science out of the Very Large Telescope, the interferometer and the survey telescopes, all of them on Paranal. The second is to build ALMA, the new observatory at 5 000 metres in the high Andes. Together with our North American and East Asian partners, we need to deliver this on budget and on time, and prepare the European astronomers for leading the science. The third main goal is to design a world-leading Extremely Large Telescope (ELT), which may have a main mirror with a diameter larger than 40 metres and will enable wonderful science. And of course, we don't only want to design it, we also want to construct it. And what about La Silla? Tim de Zeeuw: La Silla is the cornerstone of the existence of ESO in Chile, and it is home to some wonderful telescopes, including the one that is discovering so many exoplanets. I see no reason why this could not continue for many years into the future. And on top of that, La Silla is one of the potential sites for the future ELT. What made you take up this position? Tim de Zeeuw: I took up this position because ESO is the most exciting astronomy organisation in the world, with highly qualified staff and long-term and stable support by the member countries. It will be a pleasure and a privilege to come and work here. What will you do in your first days in office? Tim de Zeeuw: First, I will further familiarise myself with the organisation but then I will very quickly travel to Chile. After all, the crown jewels of ESO are in Chile and it is very important that I meet not only the ESO staff in Chile, but also the Chilean astronomers and authorities.

Fast ray-tracing algorithm for circumstellar structures (FRACS). II. Disc parameters of the B[e] supergiant CPD-57°,2874 from VLTI/MIDI data

NASA Astrophysics Data System (ADS)

Domiciano de Souza, A.; Bendjoya, P.; Niccolini, G.; Chesneau, O.; Borges Fernandes, M.; Carciofi, A. C.; Spang, A.; Stee, P.; Driebe, T.

2011-01-01

Context. B[e] supergiants are luminous, massive post-main sequence stars exhibiting non-spherical winds, forbidden lines, and hot dust in a disc-like structure. The physical properties of their rich and complex circumstellar environment (CSE) are not well understood, partly because these CSE cannot be easily resolved at the large distances found for B[e] supergiants (typically ⪆1 kpc). Aims: From mid-IR spectro-interferometric observations obtained with VLTI/MIDI we seek to resolve and study the CSE of the Galactic B[e] supergiant CPD-57° 2874. Methods: For a physical interpretation of the observables (visibilities and spectrum) we use our ray-tracing radiative transfer code (FRACS), which is optimised for thermal spectro-interferometric observations. Results: Thanks to the short computing time required by FRACS (<10 s per monochromatic model), best-fit parameters and uncertainties for several physical quantities of CPD-57° 2874 were obtained, such as inner dust radius, relative flux contribution of the central source and of the dusty CSE, dust temperature profile, and disc inclination. Conclusions: The analysis of VLTI/MIDI data with FRACS allowed one of the first direct determinations of physical parameters of the dusty CSE of a B[e] supergiant based on interferometric data and using a full model-fitting approach. In a larger context, the study of B[e] supergiants is important for a deeper understanding of the complex structure and evolution of hot, massive stars. Based on VLTI/MIDI observations collected at the European Southern Observatory (ESO), Paranal, Chile under ESO Programmes 074.D-0101 and 078.D-0213. Also based on observations at the ESO 2.2-m telescope, La Silla, Chile, under agreement with the Observatório Nacional-MCT (Brazil).Figure 5 is only available in electronic form at http://www.aanda.org

Shaping ESO2020+ Together: Feedback from the Community Poll

NASA Astrophysics Data System (ADS)

Primas, F.; Ivison, R.; Berger, J.-P.; Caselli, P.; De Gregorio-Monsalvo, I.; Alonso Herrero, A.; Knudsen, K. K.; Leibundgut, B.; Moitinho, A.; Saviane, I.; Spyromilio, J.; Testi, L.; Vennes, S.

2015-09-01

A thorough evaluation and prioritisation of the ESO science programme into the 2020+ timeframe took place under the auspices of a working group, comprising astronomers drawn from ESO’s advisory structure and from within ESO. This group reported to ESO’s Scientific Technical Committee, and to ESO Council, concluding the exercise with the publication of a report, “Science Priorities at ESO”. A community poll and a dedicated workshop, held in January 2015, formed part of the information gathering process. The community poll was designed to probe the demographics of the user community, its scientific interests, use of observing facilities and plans for use of future telescopes and instruments, its views on types of observing programmes and on the provision of data processing and archiving. A total of 1775 full responses to the poll were received and an analysis of the results is presented here. Foremost is the importance of regular observing programmes on all ESO observing facilities, in addition to Large Programmes and Public Surveys. There was also a strong community requirement for ESO to process and archive data obtained at ESO facilities. Other aspects, especially those related to future facilities, are more challenging to interpret because of biases related to the distribution of science expertise and favoured wavelength regime amongst the targeted audience. The results of the poll formed a fundamental component of the report and pro-vide useful data to guide the evolution of ESO’s science programme.

Zooming to the centre of the Milky Way - GigaGalaxy Zoom phase 2

NASA Astrophysics Data System (ADS)

2009-09-01

The second of three images of ESO's GigaGalaxy Zoom project has just been released online. It is a new and wonderful 340-million-pixel vista of the central parts of our home galaxy as seen from ESO's Paranal Observatory with an amateur telescope. This 34 by 20-degree wide image provides us with a view as experienced by amateur astronomers around the world. However, its incredible beauty and appeal owe much to the quality of the observing site and the skills of Stéphane Guisard, the world-renowned astrophotographer, who is also an ESO engineer. This second image directly benefits from the quality of Paranal's sky, one of the best on the planet, where ESO's Very Large Telescope is located. In addition, Guisard has drawn on his professional expertise as an optical engineer specialising in telescopes, a rare combination in the world of astrophotographers. Guisard, as head of the optical engineering team at Paranal, is responsible for ensuring that the Very Large Telescope has the best optical performance possible. To create this stunning, true-colour mosaic of the Galactic Centre region, Guisard assembled about 1200 individual images, totalling more than 200 hours of exposure time, collected over 29 nights, during Guisard's free time, while working during the day at Paranal [1]. The image shows the region spanning the sky from the constellation of Sagittarius (the Archer) to Scorpius (the Scorpion). The very colourful Rho Ophiuchi and Antares region is a prominent feature to the right, although much darker areas, such as the Pipe and Snake nebulae also stand out. The dusty lane of our Milky Way runs obliquely through the image, dotted with remarkable bright, reddish nebulae, such as the Lagoon and the Trifid Nebulae, as well as NGC 6357 and NGC 6334. This dark lane also hosts the very centre of our Galaxy, where a supermassive black hole is lurking. "The area I have depicted in this image is an incredibly rich region of the sky, and the one I find most beautiful," says Guisard. This gorgeous starscape is the second of three extremely high resolution images featured in the GigaGalaxy Zoom project, launched by ESO as part of the International Year of Astronomy 2009 (IYA2009). The project allows stargazers to explore and experience the Universe as it is seen with the unaided eye from the darkest and best viewing locations in the world. GigaGalaxy Zoom features a web tool that allows users to take a breathtaking dive into our Milky Way. With this tool users can learn more about many different and exciting objects in the image, such as multicoloured nebulae and exploding stars, just by clicking on them. In this way, the project seeks to link the sky we can all see with the deep, "hidden" cosmos that astronomers study on a daily basis. The wonderful quality of the images is a testament to the splendour of the night sky at ESO's sites in Chile, which are the most productive astronomical observatories in the world. The third GigaGalaxy Zoom image will be revealed next week, on 28 September 2009. Notes [1] The image was obtained from Cerro Paranal, home of ESO's Very Large Telescope, by observing with a 10-cm Takahashi FSQ106Ed f/3.6 telescope and a SBIG STL CCD camera, using a NJP160 mount. The images were collected through three different filters (B, V and R) and then stitched together. This mosaic was assembled from 52 different sky fields made from about 1200 individual images totalling 200 hours exposure time, with the final image having a size of 24 403 x 13 973 pixels. More information As part of the IYA2009, ESO is participating in several remarkable outreach activities, in line with its world-leading rank in the field of astronomy. ESO is hosting the IYA2009 Secretariat for the International Astronomical Union, which coordinates the Year globally. ESO is one of the Organisational Associates of IYA2009, and was also closely involved in the resolution submitted to the United Nations (UN) by Italy, which led to the UN's 62nd General Assembly proclaiming 2009 the International Year of Astronomy. In addition to a wide array of activities planned both at the local and international level, ESO is leading three of the twelve global Cornerstone Projects. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky". A native of France, Guisard has worked for ESO in Chile since 1994, and is now the head Optics Engineer for ESO's Very Large Telescope (VLT). He is in charge of the optical alignment of the Paranal telescopes, as well as maintaining and improving the image quality of these telescopes and their active optics. Stéphane spends most of his free time photographing the night sky, enjoying the same crystal clear skies as the VLT. His fantastic astronomical images and time-lapse movies have been used in many books and TV programmes. Stéphane Guisard is also a photographer for The World At Night (TWAN).

Life in the Universe - Is there anybody out there?

NASA Astrophysics Data System (ADS)

2001-07-01

The Universe is indescribably huge. Can it be possible that Humanity is the only form of intelligent life which exists in all this immensity? Are we really alone ? Throughout history there have been sightings of creatures from elsewhere. Science fiction novels and films with flying saucers and bizarre looking aliens are part of our general culture. Perhaps the Earth is really only an experiment designed by mice and soon we will all be destroyed to make way for a new interstellar highway ! The possibility that there is life in the Universe has always excited the general public and scientists are equally enthusiastic. Physicists, biologists, chemists, cosmologists, astronomers are researching all over Europe to try to answer this age-old question : Is there life in the Universe ? Our current understanding What is our understanding at the beginning of the 21st century? Is there any scientific evidence for other forms of life? How can you define life? What signs are they looking for? What would the reaction be if other forms of life were discovered? The European Organisation for Nuclear Research (CERN) , the European Space Agency (ESA) and the European Southern Observatory (ESO) , in cooperation with the European Association for Astronomy Education (EAAE) have organised a competition to find out what the young people in Europe think. The European Molecular Biology Laboratory (EMBL) and the European Synchrotron Radiation Facility (ESRF) are also associated with the programme. The "Life in the Universe" programme ESO PR Video Clip 05/01 [192x144 pix MPEG-version] ESO PR Video Clip 05/01 (13300 frames/8:52 min) [MPEG Video+Audio; 192x144 pix; 12.1Mb] [RealMedia; streaming; 56kps] ESO Video Clip 05/01 is a trailer for the Europe-wide "Life in the Universe" programme. It touches upon some of the main issues and includes statements by members of the Experts' Panel. The "Life in the Universe" programme is being mounted in collaboration with the research directorate of the European Commission for the "European Week of Science and Technology" in November 2001. Competitions are already underway in 23 European countries [2] to find the best projects from school students between 14 and 18. The projects can be scientific or a piece of art, a theatrical performance, poetry or even a musical performance. The only restriction is that the final work must be based on scientific evidence. Two winning teams from each country will be invited to a final event at CERN's headquarters, in Geneva on 8-11 November, 2001 to present their projects to a panel of International Experts at a special three day event devoted to understanding the possibility of other life forms existing in our Universe. This final event will be broadcast all over the world via the Internet. The website The home base of the 'Life in the Universe" project is a vibrant web space http://www.lifeinuniverse.org where details of the programme can be found. It is still under development but already has a wealth of information and links to the national websites, where all entries are posted. Is there other life in the Universe? We do not know - but the search is on! To find out what is happening for "Life in the Universe" in each country, contact the National Steering Committees ! Notes [1] This is a joint Press Release by the European Organization for Nuclear Research (CERN) , the European Space Agency (ESA) and the European Southern Observatory (ESO). These European intergovernmental research organisations organised the highly successful Physics On Stage programme during the European Week of Science and Technology in 2000. [2] The 23 countries are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, the Slovak Republic, Spain, Sweden, Switzerland, United Kingdom. CERN , the European Organization for Nuclear Research , has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, the Slovak Republic, Spain, Sweden, Switzerland and the United Kingdom. Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have observer status. The European Space Agency (ESA) is an international/intergovernmental organisation made of 15 member states: Austria, Belgium, Denmark, Finland, France, Germany, Ireland, Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. ESA provides and promotes, for peaceful purposes only, cooperation among its member states in space research, technology and their applications. With ESA, Europe shapes and shares space for people, companies and the scientific community. The European Southern Observatory (ESO) is an intergovernmental organisation supported by Belgium, Denmark, France, Germany, Italy, the Netherlands, Portugal, Sweden and Switzerland. ESO is a major driving force in European astronomy, performing tasks that are beyond the capabilities of the individual member countries. The ESO La Silla Observatory (Chile) is one of the largest and best-equipped in the world. Of ESO's Very Large Telescope Array (VLT) at Cerro Paranal (Chile), the four 8.2-m telescopes, ANTU, KUEYEN, MELIPAL and YEPUN are already in operation; the VLT Interferometer (VLTI) follows next.

40+ Years of Instrumentation for the La Silla Paranal Observatory

NASA Astrophysics Data System (ADS)

D'Odorico, S.

2018-03-01

As ESO Period 100 comes to a close, I look back at the development of ESO's instrumentation programme over more than 40 years. Instrumentation and detector activities were initially started by a small group of designers, engineers, technicians and astronomers while ESO was still at CERN in Geneva in the late 1970s. They have since led to the development of a successful suite of optical and infrared instruments for the La Silla Paranal Observatory, as testified by the continuous growth in the number of proposals for observing time and in the publications based on data from ESO telescopes. The instrumentation programme evolved significantly with the VLT and most instruments were developed by national institutes in close cooperation with ESO. This policy was a cornerstone of the VLT programme from the beginning and a key to its success.

A Swarm of Ancient Stars

NASA Astrophysics Data System (ADS)

2010-12-01

We know of about 150 of the rich collections of old stars called globular clusters that orbit our galaxy, the Milky Way. This sharp new image of Messier 107, captured by the Wide Field Imager on the 2.2-metre telescope at ESO's La Silla Observatory in Chile, displays the structure of one such globular cluster in exquisite detail. Studying these stellar swarms has revealed much about the history of our galaxy and how stars evolve. The globular cluster Messier 107, also known as NGC 6171, is a compact and ancient family of stars that lies about 21 000 light-years away. Messier 107 is a bustling metropolis: thousands of stars in globular clusters like this one are concentrated into a space that is only about twenty times the distance between our Sun and its nearest stellar neighbour, Alpha Centauri, across. A significant number of these stars have already evolved into red giants, one of the last stages of a star's life, and have a yellowish colour in this image. Globular clusters are among the oldest objects in the Universe. And since the stars within a globular cluster formed from the same cloud of interstellar matter at roughly the same time - typically over 10 billion years ago - they are all low-mass stars, as lightweights burn their hydrogen fuel supply much more slowly than stellar behemoths. Globular clusters formed during the earliest stages in the formation of their host galaxies and therefore studying these objects can give significant insights into how galaxies, and their component stars, evolve. Messier 107 has undergone intensive observations, being one of the 160 stellar fields that was selected for the Pre-FLAMES Survey - a preliminary survey conducted between 1999 and 2002 using the 2.2-metre telescope at ESO's La Silla Observatory in Chile, to find suitable stars for follow-up observations with the VLT's spectroscopic instrument FLAMES [1]. Using FLAMES, it is possible to observe up to 130 targets at the same time, making it particularly well suited to the spectroscopic study of densely populated stellar fields, such as globular clusters. M107 is not visible to the naked eye, but, with an apparent magnitude of about eight, it can easily be observed from a dark site with binoculars or a small telescope. The globular cluster is about 13 arcminutes across, which corresponds to about 80 light-years at its distance, and it is found in the constellation of Ophiuchus, north of the pincers of Scorpius. Roughly half of the Milky Way's known globular clusters are actually found in the constellations of Sagittarius, Scorpius and Ophiuchus, in the general direction of the centre of the Milky Way. This is because they are all in elongated orbits around the central region and are on average most likely to be seen in this direction. Messier 107 was discovered by Pierre Méchain in April 1782 and it was added to the list of seven Additional Messier Objects that were originally not included in the final version of Messier's catalogue, which was published the previous year. On 12 May 1793, it was independently rediscovered by William Herschel, who was able to resolve this globular cluster into stars for the first time. But it was not until 1947 that this globular cluster finally took its place in Messier's catalogue as M107, making it the most recent star cluster to be added to this famous list. This image is composed from exposures taken through the blue, green and near-infrared filters by the Wide Field Camera (WFI) on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. Notes [1] Fibre Large Array Multi-Element Spectrograph More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

ESO's early history, 1953 - 1975. V. Earliest developments in Chile; 24 March 1966: the road on La Silla dedicated.

NASA Astrophysics Data System (ADS)

Blaauw, A.

1989-12-01

While - as described in the previous article - in Europe Directorate and Council established ESO's administrative basis, and the first telescopes were built or acquired under the guidance of the Instrumentation Committee, work in Chile proceeded equally energetically. Under the leadership of Andre Muller, since January 1, 1964 Superintendent for Chile, a great variety of tasks had to be taken up: building up staff for administration and construction, organizing office facilities, setting up temporary camps as basis for the activities on and around La Silla, learning to know the Chilean world of government and Drovincial authorities-and of contractors, etc. A challenging but demanding assignment! For it is one thing to build up an organization in one's own country with its well-known legal structure and social traditions - but another one to do so in a foreign country with unfamiliar language, different customs and different rules.

Obituary: Jürgen Stock 1923-2004

NASA Astrophysics Data System (ADS)

Lorenzen, D. H.

2004-09-01

On April 19, 2004 Jürgen Stock passed away at the age of 80. Jürgen Stock was never on the payroll of ESO, but he had tremendous impact on the early years of the organisation. In 1951 Stock did his PhD in Hamburg - his supervisor was Otto Heckmann, who later became the first Director General of ESO. After some years in Cleveland - and with a one year interval at Boyden Observatory, South Africa - Stock was asked by Gerard Kuiper to do a site test in Chile. The University of Chicago looked for a mountain in the Santiago area to put up a 1.5-m-telescope in the southern hemisphere. Stock accepted and took off for Chile within days. The trip, that was supposed to last a few weeks, lasted more than three years. "As a result, the world's largest collection of astronomical instruments is now in Chile", recalled Jürgen Stock four decades later.

VLT Unit Telescopes Named at Paranal Inauguration

NASA Astrophysics Data System (ADS)

1999-03-01

This has been a busy, but also a very successful and rewarding week for the European Southern Observatory and its staff. While "First Light" was achieved at the second 8.2-m VLT Unit Telescope (UT2) ahead of schedule, UT1 produced its sharpest image so far. This happened at a moment of exceptional observing conditions in the night between March 4 and 5, 1999. During a 6-min exposure of the majestic spiral galaxy, NGC 2997 , stellar images of only 0.25 arcsec FWHM (full-width half-maximum) were recorded. This and two other frames of nearly the same quality have provided the base for the beautiful colour-composite shown above. At this excellent angular resolution, individual star forming regions are well visible along the spiral arms. Of particular interest is the peculiar, twisted shape of the long spiral arm to the right. The Paranal Inauguration The official inauguration of the Paranal Observatory took place in the afternoon of March 5, 1999, in the presence of His Excellency, the President of the Republic of Chile, Don Eduardo Frei Ruiz-Tagle, and ministers of his cabinet, as well the Ambassadors to Chile of the ESO member states and many other distinguished guests. The President of the ESO Council, Mr. Henrik Grage, and the ESO Director General, Professor Riccardo Giacconi, were the foremost representatives of the ESO organisation; most members of the ESO Council and ESO staff also participated. A substantial number of media representatives from Europe and Chile were present and reported - often live - from Paranal during the afternoon and evening. The guests were shown the impressive installations at the new observatory, including the first and second 8.2-m VLT Unit Telescopes; the latter having achieved "First Light" just four days before. A festive ceremony took place in the dome of UT2, under the large telescope structure that had been tilted towards the horizon to make place for the numerous participants. After an introductory address by the ESO Director General, speeches were delivered by the President of the ESO Council and the President of Chile. The speakers praised the great achievement of bringing the very complex, high-technology VLT project this far so successfully and also the wonderful new opportunities for front-line research with this new facility. This would not have been possible without excellent cooperation between the many parties to this project, individuals as well as research institutes, companies and governments, all working towards a common goal. The ceremony was concluded with a discourse on "Understanding the Universe" by Physics Nobel Prize winner, Professor Carlo Rubbia, former Director of CERN. At the end of the day, the President of the ESO Council, the ESO Director General and the Heads of Delegations had the opportunity to witness an observing session with the UT1 from the VLT Control Room. The 300 other guests followed this event via internal video broadcast. Mapuche names for the Unit Telescopes It had long been ESO's intention to provide "real" names to the four VLT Unit Telescopes, to replace the current, somewhat dry and technical designations as UT1 to UT4. Four meaningful names of objects in the sky in the Mapuche language were chosen. This indigeneous people lives mostly in the area south of Santiago de Chile. An essay contest was arranged in this connection among schoolchildren of the Chilean II Region of which Antofagasta is the capital to write about the implications of these names. It drew many excellent entries dealing with the rich cultural heritage of ESO's host country. The jury was unanimous in its choice of the winning essay. This was submitted by 17-year old Jorssy Albanez Castilla from Chuquicamata near the city of Calama. She received the prize, an amateur telescope, during the Paranal Inauguration. Henceforth, the four Unit Telescopes will be known as ANTU (UT1; pronounced an-too ; The Sun), KUEYEN (UT2; qua-yen , like in "quake"; The Moon), MELIPAL (UT3; me-li-pal ; The Southern Cross) and YEPUN (UT4; ye-poon ; Sirius), respectively. An audio sequence with these names pronounced by a native speaker is available below: [RealMedia - Audio only - 164k] "First Light" of UT2 Following the installation of the main mirror in its cell and a 20-hour working session to put the complex secondary mirror and its support in place, the UT2, now Kueyen , achieved (technical) first light in the morning of March 1, 1999, when an image was obtained of a bright star. It showed this telescope to be in good optical shape and further adjustments of the optical and mechanical systems are expected soon to result in some "astronomical" images. The announcement of this important event was made by the ESO Director during the opening session of the VLT Symposium that was held in Antofagasta during March 1-4, 1999. This meeting attracted over 250 scientists from all over world. It provided a most useful opportunity to discuss future scientific programmes with the VLT and other large telescopes. The participants were left with the impression of mounting expectations, just four weeks before the first VLT Unit Telescope, Antu (UT1), will receive the first visiting astronomers. More images from UT1 ESO PR Photo 17c/99 ESO PR Photo 17c/99 [Preview - JPEG: 400 x 667 pix - 332k] [Normal - JPEG: 800 x 1334 pix - 1.3M] [High-Res - JPEG: 2108 x 3450 pix - 2.8M] Caption to PR Photo 17c/99 : This colour composite photo of the Chamaeleon I area is based on six 1-min exposures obtained with VLT UT1 + FORS1 in the V, R and I bands. The sky field measures 6.8 x 11.2 arcmin 2 ; North is up and East is left [1]. Despite the extensive preparations for the Paranal Inguration and the VLT Symposium, excellent progress is being made during the final tuning of Antu (UT1) and its instruments for the "hand-over" to the astronomers on April 1, 1999. This involves exposures in many different modes and of different sky regions. Another impressive photo is shown here that was obtained some nights ago. It displays a sky area near the Chamaeleon I complex of bright nebulae and hot stars in the constellation of the same name, close to the southern celestial pole. Note: [1]: The photos in this Press Release were prepared at Paranal immediately following the Inauguration event and have only been subject to minimal image processing. To reduce the file size, the high-resolution versions carry no identifying text How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../ ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

Discarded candidate companions to low-mass members of Chamaeleon I

NASA Astrophysics Data System (ADS)

Comerón, F.

2012-01-01

Context. Direct detections of brown dwarfs and planetary-mass companions to members of nearby star-forming regions provide important clues about the process of star formation, core fragmentation, and protoplanetary disk evolution. Aims: We study two faint objects at a very small angular distance from the low-mass star ESO-Hα-558 and the possible massive brown dwarf ESO-Hα-566, both of which are members of the Chamaeleon I star-forming region, to establish whether they are physical companions to those sources. If they are, their low luminosities should imply L or T spectral types, which have clearly detectable spectral features. Methods: Adaptive optics-assisted imaging and spectroscopy of both faint candidate companions has been obtained with the NACO instrument at the Very Large Telescope (VLT). Results: Photometry shows that the colors of both objects are compatible with them being moderately reddened, normal stars in the background of the Chamaeleon I clouds. This interpretation is confirmed spectroscopically, as the spectrum between 1.4 and 2.4 μm of both objects has a featureless, monotonic slope lacking the strong H2O absorption features that dominate cool stellar and substellar spectra in that domain. Conclusions: We demonstrate that the two faint sources seen very close to ESO-Hα-558 and ESO-Hα-566 are unrelated background stars, instead of giant planetary-mass companions as might be expected based on their faintness and angular proximity. Based on observations collected with the Very Large Telescope (VLT) at the European Southern Observatory, Paranal, Chile, under observing programmes 075.C-0809(B) and 078.C-0429(C).

BOOK REVIEW: Geheimnisvolles Universum - Europas Astronomen entschleiern das Weltall

NASA Astrophysics Data System (ADS)

Duerbeck, H. W.; Lorenzen, D. H.

2002-12-01

The 25th birthday of ESO, in 1987, was celebrated by the publication of an illustrated popular book, "Exploring the Southern Sky" (Springer-Verlag 1987), which also saw editions in Danish, English, French, German, and Spanish. Written and illustrated by the ESO staff members Svend Laustsen, Claus Madsen and Richard M. West, its many pictures were mainly taken with the ESO 3.6m and Schmidt telescopes. The structure of the book - perhaps at that time somewhat unusual - started with things far away (Universe and galaxies), zoomed in to the Milky Way, and finally reached the Solar System (with a concluding chapter dealing with the La Silla observatory). Now, with the 4 units of the Very Large Telescope in full operation, and on the occasion of ESO's 40th birthday, another jubilee book has appeared: "Geheimnisvolles Universum: Europas Astronomen entschleiern das Weltall", written by the science journalist Dirk H. Lorenzen, of Hamburg, Germany, and prefaced by Catherine Cesarsky, Director General of ESO. Presumably, this book will also soon become available in more languages spoken in ESO member countries. Thus it may be worthwhile to review the first edition, although some readers may like to wait for more easily accessible editions. Before going into details, let me first mention that I find this a very impressing book, great to look at and refreshing to read. With ESO seen through the eyes of a visitor, things gain a perspective that is quite different from that of the previous book, and at least as attractive. It comes as no surprise that the book starts with a visit of ESO's showcase, the Paranal Observatory, and the writer not only notes down his own impressions, but also cites statements of some of the many people that keep Paranal going - technicians and staff astronomers. This mixture of texts provides a good impression of the operations at a large observatory for the general reader. The two more 'astronomical' parts that follow deal with star and planet formation, stellar death and dust formation, as well as with the Universe, its beginnings and contents (focussing on quasars and SN Ia); like the previous chapters, they contain many quotations of astronomers involved in these types of research (I suppose they are taken from interviews); these blocks, each composed of three chapters, are separated by a more technical part, two chapters dealing with interferometry and adaptive optics. The last third of the book is then dedicated almost exclusively to ESO's "prehistory", and here the reviewer starts to frown. This is a very extensive report on Juergen Stock's early site testing work for US astronomers, first for Gerard Kuiper and the University of Texas, and then for the Association of Universities for Research in Astronomy (AURA), to find an suitable place for a projected telescope and then for the AURA southern observatory, with page-long excerpts from his notebooks (or the printed "Stock reports"). It also deals with Stock's later activities in Chile and Venezuela. Finally, there are a few pages on the foundation of ESO and the choice of a Chilean site, as well as another few pages on future projects of ESO. The decision of ESO to go to Chile is treated very briefly, much shorter than in Blaauw's 1991 book "ESO's Early History"; the reasons for the early focussing on a site in South Africa, and the relatively quick jump on the "Chilean bandwagon" remain quite obscure. Compared to that, the 25 pages of "Stock reports" written to help the decision making of the site of the AURA observatory, contain a lot of not-too-relevant details like prices and names of horses and mules employed in Stock's site testing survey. It is fun reading, but does not penetrate under the surface, and the author's somewhat desperate attempt to join together the ends of the threat, "also the VLT is a consequence of Juergen Stock's activities in Chile", appears not very convincing. I do not want at all to diminish Stock's immense work that made Chile to the "golden land of astronomy" in the late decades of the 20th century. Stock was sent by the US astronomers, and they became active because of Kuiper's enthusiasm, that was triggered by a visit of Federico Rutlland, director of the Astronomy Department of the Universidad de Chile - the former Chilean National Observatory, whose founding was triggered by the activities of a US astronomical expedition in the mid-19th century, headed by James Gilliss; and Gilliss was inspired by an astronomical proposition made in 1847 by Christian Gerling, a mathematics professor of Marburg. And besides this line of events, there have been other astronomical expeditions and observing stations in the north of Chile in the late 19th and early 20th century. What is the true first cause of the presently florishing astronomical activity in Chile? Certainly not the "Stock report"! At times ESO's development resembled more a random walk than a strategic process, that - given enough time and money - finally culminated in a very successful research institution. This very pretty and informative book, whose author - intentionally or unintentionally - had the courage to neglect important things, and to include irrelevant things, is not a book that tells the whole story (and actually no book can achieve this goal!). Even a book like Lorenzen's that is composed of huge fragments that do not quite fit into the story, can make fascinating reading. However, besides the publisher's logo, this book carries the ESO logo, and therefore becomes something like an "official" ESO publication. And this is why one wonders why so much space is used up to describe activities which have hardly any relation to ESO's history, a history that really deserves to be communicated to the interested general public. If this book would encourage some of the early players of ESO to pen down their memoirs and make them available to science writers and historians, a story at least as colorful as that of Juergen Stock would emerge! And only then it would be possible to write a more balanced history of ESO.

The ESO Survey of Non-Publishing Programmes

NASA Astrophysics Data System (ADS)

Patat, F.; Boffin, H. M. J.; Bordelon, D.; Grothkopf, U.; Meakins, S.; Mieske, S.; Rejkuba, M.

2017-12-01

One of the classic ways to measure the success of a scientific facility is the publication return, which is defined as the refereed papers produced per unit of allocated resources (for example, telescope time or proposals). The recent studies by Sterzik et al. (2015, 2016) have shown that 30–50 % of the programmes allocated time at ESO do not produce a refereed publication. While this may be inherent to the scientific process, this finding prompted further investigation. For this purpose, ESO conducted a Survey of Non-Publishing Programmes (SNPP) within the activities of the Time Allocation Working Group, similar to the monitoring campaign that was recently implemented at ALMA (Stoehr et al., 2016). The SNPP targeted 1278 programmes scheduled between ESO Periods 78 and 90 (October 2006 to March 2013) that had not published a refereed paper as of April 2016. The poll was launched on 6 May 2016, remained open for four weeks, and returned 965 valid responses. This article summarises and discusses the results of this survey, the first of its kind at ESO.

VizieR Online Data Catalog: Light curves of WASP-52 (Mancini+, 2017)

NASA Astrophysics Data System (ADS)

Mancini, L.; Southworth, J.; Raia, G.; Tregloan-Reed, J.; Molliere, P.; Bozza, V.; Bretton, M.; Bruni, I.; Ciceri, S.; D'Ago, G.; Dominik, M.; Hinse, T. C.; Hundertmark, M.; Jorgensen, U. G.; Korhonen, H.; Rabus, M.; Rahvar, S.; Starkey, D.; Calchi Novati, S.; Figuera Jaimes, R.; Henning, T.; Juncher, D.; Haugbolle, T.; Kains, N.; Popovas, A.; Schmidt, R. W.; Skottfelt, J.; Snodgrass, C.; Surdej, J.; Wertz, O.

2018-03-01

Light curves of transit events of the extrasolar planet WASP-52b. One of the datasets was obtained using the Cassini 1.52m Telescope (Gunn r) at the Astronomical Observatory of Bologna in Loiano (Italy). Three of the datasets were obtained using the Zeiss 1.23m telescope (Cousins R and Cousins I) at the German-Spanish Astronomical Centre at Calar Alto (Spain). Four of the datasets were obtained using the MPG 2.2m telescope (Sloan g, Sloan r, Sloan i, Sloan z) at the ESO Observatory in La Silla (Chile). Four of the datasets were obtained using the 1.54m Danish Telescope at the ESO Observatory in La Silla (Chile). (2 data files).

On the Trail of a Cosmic Cat

NASA Astrophysics Data System (ADS)

2010-01-01

ESO has just released a stunning new image of the vast cloud known as the Cat's Paw Nebula or NGC 6334. This complex region of gas and dust, where numerous massive stars are born, lies near the heart of the Milky Way galaxy, and is heavily obscured by intervening dust clouds. Few objects in the sky have been as well named as the Cat's Paw Nebula, a glowing gas cloud resembling the gigantic pawprint of a celestial cat out on an errand across the Universe. British astronomer John Herschel first recorded NGC 6334 in 1837 during his stay in South Africa. Despite using one of the largest telescopes in the world at the time, Herschel seems to have only noted the brightest part of the cloud, seen here towards the lower left. NGC 6334 lies about 5500 light-years away in the direction of the constellation Scorpius (the Scorpion) and covers an area on the sky slightly larger than the full Moon. The whole gas cloud is about 50 light-years across. The nebula appears red because its blue and green light are scattered and absorbed more efficiently by material between the nebula and Earth. The red light comes predominantly from hydrogen gas glowing under the intense glare of hot young stars. NGC 6334 is one of the most active nurseries of massive stars in our galaxy and has been extensively studied by astronomers. The nebula conceals freshly minted brilliant blue stars - each nearly ten times the mass of our Sun and born in the last few million years. The region is also home to many baby stars that are buried deep in the dust, making them difficult to study. In total, the Cat's Paw Nebula could contain several tens of thousands of stars. Particularly striking is the red, intricate bubble in the lower right part of the image. This is most likely either a star expelling large amount of matter at high speed as it nears the end of its life or the remnant of a star that already has exploded. This new portrait of the Cat's Paw Nebula was created from images taken with the Wide Field Imager (WFI) instrument at the 2.2-metre MPG/ESO telescope at the La Silla Observatory in Chile, combining images taken through blue, green and red filters, as well as a special filter designed to let through the light of glowing hydrogen. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

NGC 4945: The Milky Way's not-so-distant Cousin

NASA Astrophysics Data System (ADS)

2009-09-01

ESO has released a striking new image of a nearby galaxy that many astronomers think closely resembles our own Milky Way. Though the galaxy is seen edge-on, observations of NGC 4945 suggest that this hive of stars is a spiral galaxy much like our own, with swirling, luminous arms and a bar-shaped central region. These resemblances aside, NGC 4945 has a brighter centre that likely harbours a supermassive black hole, which is devouring reams of matter and blasting energy out into space. As NGC 4945 is only about 13 million light-years away in the constellation of Centaurus (the Centaur), a modest telescope is sufficient for skygazers to spot this remarkable galaxy. NGC 4945's designation comes from its entry number in the New General Catalogue compiled by the Danish-Irish astronomer John Louis Emil Dreyer in the 1880s. James Dunlop, a Scottish astronomer, is credited with originally discovering NGC 4945 in 1826 from Australia. Today's new portrait of NGC 4945 comes courtesy of the Wide Field Imager (WFI) instrument at the 2.2-metre MPG/ESO telescope at the La Silla Observatory in Chile. NGC 4945 appears cigar-shaped from our perspective on Earth, but the galaxy is actually a disc many times wider than it is thick, with bands of stars and glowing gas spiralling around its centre. With the use of special optical filters to isolate the colour of light emitted by heated gases such as hydrogen, the image displays sharp contrasts in NGC 4945 that indicate areas of star formation. Other observations have revealed that NGC 4945 has an active galactic nucleus, meaning its central bulge emits far more energy than calmer galaxies like the Milky Way. Scientists classify NGC 4945 as a Seyfert galaxy after the American astronomer Carl K. Seyfert, who wrote a study in 1943 describing the odd light signatures emanating from some galactic cores. Since then, astronomers have come to suspect that supermassive black holes cause the turmoil in the centre of Seyfert galaxies. Black holes gravitationally draw gas and dust into them, accelerating and heating this attracted matter until it emits high-energy radiation, including X-rays and ultraviolet light. Most large, spiral galaxies, including the Milky Way, host a black hole in their centres, though many of these dark monsters no longer actively "feed" at this stage in galactic development. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Core network infrastructure supporting the VLT at ESO Paranal in Chile

NASA Astrophysics Data System (ADS)

Reay, Harold

2000-06-01

In October 1997 a number of projects were started at ESO's Paranal Observatory at Cerro Paranal in Chile to upgrade the communications infrastructure in place at the time. The planned upgrades were to internal systems such as computer data networks and telephone installations and also data links connecting Paranal to other ESO sites. This paper details the installation work carried out on the Paranal Core Network (PCN) during the period of October 1997 to December 1999. These installations were to provide both short term solutions to the requirement for reliable high bandwidth network connectivity between Paranal and ESO HQ in Garching, Germany in time for UTI (Antu) first light and perhaps more importantly, to provide the core systems necessary for a site moving towards operational status. This paper explains the reasons for using particular cable types, network topology, and fiber backbone design and implementation. We explain why it was decided to install the PCN in two distinct stages and how equipment used in temporary installations was re-used in the Very Large Telescope networks. Finally we describe the tools used to monitor network and satellite link performance and will discuss whether network backbone bandwidth meets the expected utilization and how this bandwidth can easily be increased in the future should there be a requirement.

R Coronae Australis: A Cosmic Watercolour

NASA Astrophysics Data System (ADS)

2010-06-01

This magnificent view of the region around the star R Coronae Australis was created from images taken with the Wide Field Imager (WFI) at ESO's La Silla Observatory in Chile. R Coronae Australis lies at the heart of a nearby star-forming region and is surrounded by a delicate bluish reflection nebula embedded in a huge dust cloud. The image reveals surprising new details in this dramatic area of sky. The star R Coronae Australis lies in one of the nearest and most spectacular star-forming regions. This portrait was taken by the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. The image is a combination of twelve separate pictures taken through red, green and blue filters. This image shows a section of sky that spans roughly the width of the full Moon. This is equivalent to about four light-years at the distance of the nebula, which is located some 420 light-years away in the small constellation of Corona Australis (the Southern Crown). The complex is named after the star R Coronae Australis, which lies at the centre of the image. It is one of several stars in this region that belong to the class of very young stars that vary in brightness and are still surrounded by the clouds of gas and dust from which they formed. The intense radiation given off by these hot young stars interacts with the gas surrounding them and is either reflected or re-emitted at a different wavelength. These complex processes, determined by the physics of the interstellar medium and the properties of the stars, are responsible for the magnificent colours of nebulae. The light blue nebulosity seen in this picture is mostly due to the reflection of starlight off small dust particles. The young stars in the R Coronae Australis complex are similar in mass to the Sun and do not emit enough ultraviolet light to ionise a substantial fraction of the surrounding hydrogen. This means that the cloud does not glow with the characteristic red colour seen in many star-forming regions. The huge dust cloud in which the reflection nebula is embedded is here shown in impressively fine detail. The subtle colours and varied textures of the dust clouds make this image resemble an impressionist painting. A prominent dark lane crosses the image from the centre to the bottom left. Here the visible light emitted by the stars that are forming inside the cloud is completely absorbed by the dust. These objects could only be detected by observing at longer wavelengths, by using a camera that can detect infrared radiation. R Coronae Australis itself is not visible to the unaided eye, but the tiny, tiara-shaped constellation in which it lies is easily spotted from dark sites due to its proximity on the sky to the larger constellation of Sagittarius and the rich star clouds towards the centre of our own galaxy, the Milky Way. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

The Milky Way's Tiny but Tough Galactic Neighbour

NASA Astrophysics Data System (ADS)

2009-10-01

Today ESO announces the release of a stunning new image of one of our nearest galactic neighbours, Barnard's Galaxy, also known as NGC 6822. The galaxy contains regions of rich star formation and curious nebulae, such as the bubble clearly visible in the upper left of this remarkable vista. Astronomers classify NGC 6822 as an irregular dwarf galaxy because of its odd shape and relatively diminutive size by galactic standards. The strange shapes of these cosmic misfits help researchers understand how galaxies interact, evolve and occasionally "cannibalise" each other, leaving behind radiant, star-filled scraps. In the new ESO image, Barnard's Galaxy glows beneath a sea of foreground stars in the direction of the constellation of Sagittarius (the Archer). At the relatively close distance of about 1.6 million light-years, Barnard's Galaxy is a member of the Local Group, the archipelago of galaxies that includes our home, the Milky Way. The nickname of NGC 6822 comes from its discoverer, the American astronomer Edward Emerson Barnard, who first spied this visually elusive cosmic islet using a 125-millimetre aperture refractor in 1884. Astronomers obtained this latest portrait using the Wide Field Imager (WFI) attached to the 2.2-metre MPG/ESO telescope at ESO's La Silla Observatory in northern Chile. Even though Barnard's Galaxy lacks the majestic spiral arms and glowing, central bulge that grace its big galactic neighbours, the Milky Way, the Andromeda and the Triangulum galaxies, this dwarf galaxy has no shortage of stellar splendour and pyrotechnics. Reddish nebulae in this image reveal regions of active star formation, where young, hot stars heat up nearby gas clouds. Also prominent in the upper left of this new image is a striking bubble-shaped nebula. At the nebula's centre, a clutch of massive, scorching stars send waves of matter smashing into the surrounding interstellar material, generating a glowing structure that appears ring-like from our perspective. Other similar ripples of heated matter thrown out by feisty young stars are dotted across Barnard's Galaxy. At only about a tenth of the Milky Way's size, Barnard's Galaxy fits its dwarfish classification. All told, it contains about 10 million stars - a far cry from the Milky Way's estimated 400 billion. In the Local Group, as elsewhere in the Universe, however, dwarf galaxies outnumber their larger, shapelier cousins. Irregular dwarf galaxies like Barnard's Galaxy get their random, blob-like forms from close encounters with or "digestion" by other galaxies. Like everything else in the Universe, galaxies are in motion, and they often make close passes or even go through one another. The density of stars in galaxies is quite low, meaning that few stars physically collide during these cosmic dust-ups. Gravity's fatal attraction, however, can dramatically warp and scramble the shapes of the passing or crashing galaxies. Whole bunches of stars are pulled or flung from their galactic home, in turn forming irregularly shaped dwarf galaxies like NGC 6822. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

ESO unveils an amazing, interactive, 360-degree panoramic view of the entire night sky

NASA Astrophysics Data System (ADS)

2009-09-01

The first of three images of ESO's GigaGalaxy Zoom project - a new magnificent 800-million-pixel panorama of the entire sky as seen from ESO's observing sites in Chile - has just been released online. The project allows stargazers to explore and experience the Universe as it is seen with the unaided eye from the darkest and best viewing locations in the world. This 360-degree panoramic image, covering the entire celestial sphere, reveals the cosmic landscape that surrounds our tiny blue planet. This gorgeous starscape serves as the first of three extremely high-resolution images featured in the GigaGalaxy Zoom project, launched by ESO within the framework of the International Year of Astronomy 2009 (IYA2009). GigaGalaxy Zoom features a web tool that allows users to take a breathtaking dive into our Milky Way. With this tool users can learn more about many different and exciting objects in the image, such as multicoloured nebulae and exploding stars, just by clicking on them. In this way, the project seeks to link the sky we can all see with the deep, "hidden" cosmos that astronomers study on a daily basis. The wonderful quality of the images is a testament to the splendour of the night sky at ESO's sites in Chile, which are the most productive astronomical observatories in the world. The plane of our Milky Way Galaxy, which we see edge-on from our perspective on Earth, cuts a luminous swath across the image. The projection used in GigaGalaxy Zoom place the viewer in front of our Galaxy with the Galactic Plane running horizontally through the image - almost as if we were looking at the Milky Way from the outside. From this vantage point, the general components of our spiral galaxy come clearly into view, including its disc, marbled with both dark and glowing nebulae, which harbours bright, young stars, as well as the Galaxy's central bulge and its satellite galaxies. The painstaking production of this image came about as a collaboration between ESO, the renowned French writer and astrophotographer Serge Brunier and his fellow Frenchman Frédéric Tapissier. Brunier spent several weeks during the period between August 2008 and February 2009 capturing the sky, mostly from ESO observatories at La Silla and Paranal in Chile. In order to cover the full Milky Way, Brunier also made a week-long trip to La Palma, one of the Canary Islands, to photograph the northern skies [1]. Once the raw photographs were in hand, image processing by Tapissier and ESO experts helped to convey accurately the night sky as our eyes behold it [2]. The resulting image, now available on GigaGalaxy Zoom, is composed of almost 300 fields each individually captured by Brunier four times, adding up to nearly 1200 photos that encompass the entire night sky. "I wanted to show a sky that everyone can relate to - with its constellations, its thousands of stars, with names familiar since childhood, its myths shared by all civilisations since Homo became Sapiens," says Brunier. "The image was therefore made as man sees it, with a regular digital camera under the dark skies in the Atacama Desert and on La Palma." As photographing extended over several months, objects from the Solar System came and went through the star fields, with bright planets such as Venus and Jupiter. A brilliant, emerald-green comet also flew by, although spotting it among a background of tens of millions of stars will be difficult (but rewarding). Overall, the creators of the GigaGalaxy Zoom project hope that these tremendous efforts in bringing the night sky as observed under the best conditions on the planet to stargazers everywhere will inspire awe for the beautiful, immense Universe that we live in. "The vision of the IYA2009 is to help people rediscover their place in the Universe through the day- and night-time sky, and this is exactly what the GigaGalaxy Zoom project is all about," says project coordinator Henri Boffin. The second dramatic GigaGalaxy Zoom image will be revealed next week, on 21 September 2009. Notes [1] During his quest, Brunier used a Nikon D3 digital camera. The apparent motion of the sky caused by Earth's rotation was corrected for using a small, precise equatorial mount moving in the opposite direction, which made a whole circle in 23 hours 56 minutes around the Earth's axis of rotation. Each photo required a six-minute exposure, for a total exposure time of more than 120 hours. [2] The data processing, using software called Autopano Pro Giga, took great care in respecting the colours and "texture" of the Milky Way. Frédéric Tapissier needed about 340 computing hours on a powerful PC to complete the task. More information As part of the IYA2009, ESO is participating in several remarkable outreach activities, in line with its world-leading rank in the field of astronomy. ESO is hosting the IYA2009 Secretariat for the International Astronomical Union, which coordinates the Year globally. ESO is one of the Organisational Associates of IYA2009, and was also closely involved in the resolution submitted to the United Nations (UN) by Italy, which led to the UN's 62nd General Assembly proclaiming 2009 the International Year of Astronomy. In addition to a wide array of activities planned both at the local and international level, ESO is leading three of the twelve global Cornerstone Projects. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky". Serge Brunier is a French journalist, photographer and writer who specialises in popularising astronomy. He is a regular contributor to Science & Vie magazine, and to the France Info radio station. He has written numerous popular astronomy books, translated into over ten languages, and is a prize-winning photographer, who has captured images of solar eclipses from the most amazing places in the world. A life-long quest for the best skies in the world led him to Chile. This whole sky panorama was presented from 25 August till 13 September 2009 in the exhibition "Un ciel pour la planète" (A sky for the planet) in the Atrium of the Monte-Carlo Casino, Monaco. With a giant print of 12 times 6 metres, the exhibition was under the Patronage of The Prince Albert II of Monaco, and showed with images and videos the making of this unique ESO project.

The President and the Galaxy

NASA Astrophysics Data System (ADS)

2004-12-01

On December 9-10, 2004, the ESO Paranal Observatory was honoured with an overnight visit by His Excellency the President of the Republic of Chile, Ricardo Lagos and his wife, Mrs. Luisa Duran de Lagos. The high guests were welcomed by the ESO Director General, Dr. Catherine Cesarsky, ESO's representative in Chile, Mr. Daniel Hofstadt, and Prof. Maria Teresa Ruiz, Head of the Astronomy Department at the Universidad de Chile, as well as numerous ESO staff members working at the VLT site. The visit was characterised as private, and the President spent a considerable time in pleasant company with the Paranal staff, talking with and getting explanations from everybody. The distinguished visitors were shown the various high-tech installations at the observatory, including the Interferometric Tunnel with the VLTI delay lines and the first Auxiliary Telescope. Explanations were given by ESO astronomers and engineers and the President, a keen amateur astronomer, gained a good impression of the wide range of exciting research programmes that are carried out with the VLT. President Lagos showed a deep interest and impressed everyone present with many, highly relevant questions. Having enjoyed the spectacular sunset over the Pacific Ocean from the Residence terrace, the President met informally with the Paranal employees who had gathered for this unique occasion. Later, President Lagos visited the VLT Control Room from where the four 8.2-m Unit Telescopes and the VLT Interferometer (VLTI) are operated. Here, the President took part in an observing sequence of the spiral galaxy NGC 1097 (see PR Photo 35d/04) from the console of the MELIPAL telescope. After one more visit to the telescope platform at the top of Paranal, the President and his wife left the Observatory in the morning of December 10, 2004, flying back to Santiago. ESO PR Photo 35e/04 ESO PR Photo 35e/04 President Lagos Meets with ESO Staff at the Paranal Residencia [Preview - JPEG: 400 x 267pix - 144k] [Normal - JPEG: 640 x 427 pix - 240k] ESO PR Photo 35f/04 ESO PR Photo 35f/04 The Presidential Couple with Professor Maria Teresa Ruiz and the ESO Director General [Preview - JPEG: 500 x 400 pix - 224k] [Normal - JPEG: 1000 x 800 pix - 656k] [FullRes - JPEG: 1575 x 1260 pix - 1.0M] ESO PR Photo 35g/04 ESO PR Photo 35g/04 President Lagos with ESO Staff [Preview - JPEG: 500 x 400 pix - 192k] [Normal - JPEG: 1000 x 800 pix - 592k] [FullRes - JPEG: 1575 x 1200 pix - 1.1M] Captions: ESO PR Photo 35e/04 was obtained during President Lagos' meeting with ESO Staff at the Paranal Residencia. On ESO PR Photo 35f/04, President Lagos and Mrs. Luisa Duran de Lagos are seen at a quiet moment during the visit to the VLT Control Room, together with Prof. Maria Teresa Ruiz (far right), Head of the Astronomy Department at the Universidad de Chile, and the ESO Director General. ESO PR Photo 35g/04 shows President Lagos with some ESO staff members in the Paranal Residencia. VLT obtains a splendid photo of a unique galaxy, NGC 1097 ESO PR Photo 35d/04 ESO PR Photo 35d/04 Spiral Galaxy NGC 1097 (Melipal + VIMOS) [Preview - JPEG: 400 x 525 pix - 181k] [Normal - JPEG: 800 x 1049 pix - 757k] [FullRes - JPEG: 2296 x 3012 pix - 7.9M] Captions: ESO PR Photo 35d/04 is an almost-true colour composite based on three images made with the multi-mode VIMOS instrument on the 8.2-m Melipal (Unit Telescope 3) of ESO's Very Large Telescope. They were taken on the night of December 9-10, 2004, in the presence of the President of the Republic of Chile, Ricardo Lagos. Details are available in the Technical Note below. A unique and very beautiful image was obtained with the VIMOS instrument with President Lagos at the control desk. Located at a distance of about 45 million light-years in the southern constellation Fornax (the Furnace), NGC 1097 is a relatively bright, barred spiral galaxy of type SBb, seen face-on. At magnitude 9.5, and thus just 25 times fainter than the faintest object that can be seen with the unaided eye, it appears in small telescopes as a bright, circular disc. ESO PR Photo 35d/04, taken on the night of December 9 to 10, 2004 with the VIsible Multi-Object Spectrograph ("VIMOS), a four-channel multiobject spectrograph and imager attached to the 8.2-m VLT Melipal telescope, shows that the real structure is much more complicated. NGC 1097 is indeed a most interesting object in many respects. As this striking image reveals, NGC 1097 presents a centre that consists of a broken ring of bright knots surrounding the galaxy's nucleus. The sizes of these knots - presumably gigantic bubbles of hydrogen atoms having lost one electron (HII regions) through the intense radiation from luminous massive stars - range from roughly 750 to 2000 light-years. The presence of these knots suggests that an energetic burst of star formation has recently occurred. NGC 1097 is also known as an example of the so-called LINER (Low-Ionization Nuclear Emission Region Galaxies) class. Objects of this type are believed to be low-luminosity examples of Active Galactic Nuclei (AGN), whose emission is thought to arise from matter (gas and stars) falling into oblivion in a central black hole. There is indeed much evidence that a supermassive black hole is located at the very centre of NGC 1097, with a mass of several tens of million times the mass of the Sun. This is at least ten times more massive than the central black hole in our own Milky Way. However, NGC 1097 possesses a comparatively faint nucleus only, and the black hole in its centre must be on a very strict "diet": only a small amount of gas and stars is apparently being swallowed by the black hole at any given moment. A turbulent past As can be clearly seen in the upper part of PR Photo 35d/04, NGC 1097 also has a small galaxy companion; it is designated NGC 1097A and is located about 42,000 light-years away from the centre of NGC 1097. This peculiar elliptical galaxy is 25 times fainter than its big brother and has a "box-like" shape, not unlike NGC 6771, the smallest of the three galaxies that make up the famous Devil's Mask, cf. ESO PR Photo 12/04. There is evidence that NGC 1097 and NGC 1097A have been interacting in the recent past. Another piece of evidence for this galaxy's tumultuous past is the presence of four jets - not visible on this image - discovered in the 1970's on photographic plates. These jets are now believed to be the captured remains of a disrupted dwarf galaxy that passed through the inner part of the disc of NGC 1097. Moreover, another interesting feature of this active galaxy is the fact that no less than two supernovae were detected inside it within a time span of only four years. SN 1999eu was discovered by Japanese amateur Masakatsu Aoki (Toyama, Japan) on November 5, 1999. This 17th-magnitude supernova was a peculiar Type II supernova, the end result of the core collapse of a very massive star. And in the night of January 5 to 6, 2003, Reverend Robert Evans (Australia) discovered another Type II supernova of 15th magnitude. Also visible in this very nice image which was taken during very good sky conditions - the seeing was well below 1 arcsec - are a multitude of background galaxies of different colours and shapes. Given the fact that the total exposure time for this three-colour image was just 11 min, it is a remarkable feat, demonstrating once again the very high efficiency of the VLT.

The Inauguration of the Atacama Large Millimeter/submillimeter Array

NASA Astrophysics Data System (ADS)

Testi, L.; Walsh, J.

2013-06-01

On 13 March 2013 the official inauguration of the Atacama Large Millimeter/submillimeter Array (ALMA) took place at the Operations Support Facility in northern Chile. A report of the event and the preceding press conference is presented and the texts of the speeches by the President of Chile, Sebastián Piñera, and the Director General of ESO, Tim de Zeeuw, are included.

ASASSN-18gq: Discovery of A Low-Luminosity Transient Towards Very Nearby ( 3.4 Mpc) Galaxy ESO 325- G?011

NASA Astrophysics Data System (ADS)

Nicholls, B.; Brimacombe, J.; Vallely, P.; Dong, Subo; Stanek, K. Z.; Kochanek, C. S.; Brown, J. S.; Shields, J.; Thompson, T. A.; Shappee, B. J.; Holoien, T. W.-S.; Prieto, J. L.; Bersier, D.; Bose, S.; Chen, Ping; Stritzinger, M.; Holmbo, S.

2018-04-01

During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014), using data from the quadruple 14-cm "Payne-Gaposchkin" telescope in Sutherland, South Africa, and the quadruple 14-cm "Cassius" and "Paczynski" telescopes in Cerro Tololo, Chile, we discovered a new transient source, most likely a supernova, in the low surface brightness galaxy ESO 325- G?011.

Close to the Sky

NASA Astrophysics Data System (ADS)

2007-11-01

Today, a new ALMA outreach and educational book was publicly presented to city officials of San Pedro de Atacama in Chile, as part of the celebrations of the anniversary of the Andean village. ESO PR Photo 50a/07 ESO PR Photo 50a/07 A Useful Tool for Schools Entitled "Close to the sky: Biological heritage in the ALMA area", and edited in English and Spanish by ESO in Chile, the book collects unique on-site observations of the flora and fauna of the ALMA region performed by experts commissioned to investigate it and to provide key initiatives to protect it. "I thank the ALMA project for providing us a book that will surely be a good support for the education of children and youngsters of San Pedro de Atacama. Thanks to this publication, we expect our rich flora and fauna to be better known. I invite teachers and students to take advantage of this educational resource, which will be available in our schools", commented Ms. Sandra Berna, the Mayor of San Pedro de Atacama, who was given the book by representatives of the ALMA global collaboration project. Copies of the book 'Close to the sky' will be donated to all schools in the area, as a contribution to the education of students and young people in northern Chile. "From the very beginning of the project, ALMA construction has had a firm commitment to environment and local culture, protecting unique flora and fauna species and preserving old estancias belonging to the Likan Antai culture," said Jacques Lassalle, who represented ALMA at the hand-over. "Animals like the llama, the fox or the condor do not only live in the region where ALMA is now being built, but they are also key elements of the ancient Andean constellations. In this sense they are part of the same sky that will be explored by ALMA in the near future." ESO PR Photo 50c/07 ESO PR Photo 50c/07 Presentation of the ALMA book The ALMA Project is a giant, international observatory currently under construction on the high-altitude Chajnantor site in Chile. ALMA will be composed initially of 66 high-precision telescopes, operating at wavelengths of 0.3 to 9.6 mm. The ALMA antennas will be electronically combined and will provide astronomical observations which are equivalent to those from a single large telescope of tremendous size and resolution. Chajnantor was selected as the ideal spot for ALMA, following several years of atmospheric and meteorology studies. The high elevation, stable atmosphere, and low humidity make it one of the best locations in the world for radio astronomy. To protect the outstanding conditions of Chajnantor, the Government of Chile declared a major portion of the area a scientific reserve. The publication is available in PDF format. It is the second book on ALMA for the general public, following the previous launch of "Footprints in the Desert", also available on the Internet in PDF format in Spanish. ALMA is a partnership between Europe, East Asia and North America in cooperation with the Republic of Chile. It is funded in Europe by ESO, in East Asia by the National Institutes of Natural Sciences of Japan in cooperation with the Academia Sinica in Taiwan and in North America by the U.S. National Science Foundation in cooperation with the National Research Council of Canada. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of East Asia by the National Astronomical Observatory of Japan and on behalf of North America by the National Radio Astronomy Observatory, which is managed by Associated Universities, Inc.

Ambitious Survey Spots Stellar Nurseries

NASA Astrophysics Data System (ADS)

2010-08-01

Astronomers scanning the skies as part of ESO's VISTA Magellanic Cloud survey have now obtained a spectacular picture of the Tarantula Nebula in our neighbouring galaxy, the Large Magellanic Cloud. This panoramic near-infrared view captures the nebula itself in great detail as well as the rich surrounding area of sky. The image was obtained at the start of a very ambitious survey of our neighbouring galaxies, the Magellanic Clouds, and their environment. The leader of the survey team, Maria-Rosa Cioni (University of Hertfordshire, UK) explains: "This view is of one of the most important regions of star formation in the local Universe - the spectacular 30 Doradus star-forming region, also called the Tarantula Nebula. At its core is a large cluster of stars called RMC 136, in which some of the most massive stars known are located." ESO's VISTA telescope [1] is a new survey telescope at the Paranal Observatory in Chile (eso0949). VISTA is equipped with a huge camera that detects light in the near-infrared part of the spectrum, revealing a wealth of detail about astronomical objects that gives us insight into the inner workings of astronomical phenomena. Near-infrared light has a longer wavelength than visible light and so we cannot see it directly for ourselves, but it can pass through much of the dust that would normally obscure our view. This makes it particularly useful for studying objects such as young stars that are still enshrouded in the gas and dust clouds from which they formed. Another powerful aspect of VISTA is the large area of the sky that its camera can capture in each shot. This image is the latest view from the VISTA Magellanic Cloud Survey (VMC). The project will scan a vast area - 184 square degrees of the sky (corresponding to almost one thousand times the apparent area of the full Moon) including our neighbouring galaxies the Large and Small Magellanic Clouds. The end result will be a detailed study of the star formation history and three-dimensional geometry of the Magellanic system. Chris Evans from the VMC team adds: "The VISTA images will allow us to extend our studies beyond the inner regions of the Tarantula into the multitude of smaller stellar nurseries nearby, which also harbour a rich population of young and massive stars. Armed with the new, exquisite infrared images, we will be able to probe the cocoons in which massive stars are still forming today, while also looking at their interaction with older stars in the wider region." The wide-field image shows a host of different objects. The bright area above the centre is the Tarantula Nebula itself, with the RMC 136 cluster of massive stars in its core. To the left is the NGC 2100 star cluster. To the right is the tiny remnant of the supernova SN1987A (eso1032). Below the centre are a series of star-forming regions including NGC 2080 - nicknamed the "Ghost Head Nebula" - and the NGC 2083 star cluster. The VISTA Magellanic Cloud Survey is one of six huge near-infrared surveys of the southern sky that will take up most of the first five years of operations of VISTA. Notes [1] VISTA ― the Visible and Infrared Survey Telescope for Astronomy ― is the newest telescope at ESO's Paranal Observatory in northern Chile. VISTA is a survey telescope working at near-infrared wavelengths and is the world's largest survey telescope. Its large mirror, wide field of view and very sensitive detectors will reveal a completely new view of the southern sky. The telescope is housed on the peak adjacent to the one hosting ESO's Very Large Telescope (VLT) and shares the same exceptional observing conditions. VISTA has a main mirror that is 4.1 m across. In photographic terms it can be thought of as a 67-megapixel digital camera with a 13 000 mm f/3.25 mirror lens. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

VizieR Online Data Catalog: HD 176986 HARPS + HARPS-N data (Suarez Mascareno+, 2018)

NASA Astrophysics Data System (ADS)

Suarez Mascareno, A.; Gonzalez Hernandez, J. I.; Rebolo, R.; Velasco, S.; Toledo-Padron, B.; Udry, S.; Motalebi, F.; Segransan, D.; Wyttenbach, A.; Mayor, M.; Pepe, F.; Lovis, C.; Santos, N. C.; Figueira, P.; Esposito, M.

2017-11-01

HD 176986 has been extensively monitored since mid-2004 with HARPS and HARPS-N. The star was followed first in the HARPS planet-search programme on Guaranteed Time Observations (GTO, PI: M. Mayor) on-going for 6 years between autumn 2003 and spring 2009. The observations were then continued within the ESO Large Programs 183.C-0972+183.C-1005 (PI: S. Udry). Then it was observed with HARPS-N from 2014 onwards as part of the RoPES project using a nightly-cadence observation strategy aimed at the detection of very low-mass planets in close orbits of quiet G and K-type stars. HARPS Mayor2003 and HARPS-N Cosentino2012 are two fibre-fed high resolution echelle spectrographs installed at the 3.6m ESO telescope in La Silla Observatory (Chile) and at the Telescopio Nazionale Galileo in the Roque de los Muchachos Observatory (Spain), respectively. During the HARPS campaigns our star was typically observed once per night using an exposure time of 900s, with just a few exceptions. In the HARPS-N campaign the star was always observed using 3x300s exposures per visit, having one visit per night during the first years and two visits separated by a few hours during the 2016 and 2017 campaigns. The data is then re-sampled and averaged into 1 hour bins. The combination of both observational programmes provided 156 HARPS observations and 103 HARPS-N newly acquired observations, coming from 234 individual nights, during 13.2 years of observations. (1 data file).

VISTA Views the Sculptor Galaxy

NASA Astrophysics Data System (ADS)

2010-06-01

A spectacular new image of the Sculptor Galaxy (NGC 253) has been taken with the ESO VISTA telescope at the Paranal Observatory in Chile as part of one of its first major observational campaigns. By observing in infrared light VISTA's view is less affected by dust and reveals a myriad of cooler stars as well as a prominent bar of stars across the central region. The VISTA image provides much new information on the history and development of the galaxy. The Sculptor Galaxy (NGC 253) lies in the constellation of the same name and is one of the brightest galaxies in the sky. It is prominent enough to be seen with good binoculars and was discovered by Caroline Herschel from England in 1783. NGC 253 is a spiral galaxy that lies about 13 million light-years away. It is the brightest member of a small collection of galaxies called the Sculptor Group, one of the closest such groupings to our own Local Group of galaxies. Part of its visual prominence comes from its status as a starburst galaxy, one in the throes of rapid star formation. NGC 253 is also very dusty, which obscures the view of many parts of the galaxy (eso0902). Seen from Earth, the galaxy is almost edge on, with the spiral arms clearly visible in the outer parts, along with a bright core at its centre. VISTA, the Visible and Infrared Survey Telescope for Astronomy, the latest addition to ESO's Paranal Observatory in the Chilean Atacama Desert, is the world's largest survey telescope. After being handed over to ESO at the end of 2009 (eso0949) the telescope was used for two detailed studies of small sections of the sky before it embarked on the much larger surveys that are now in progress. One of these "mini surveys" was a detailed study of NGC 253 and its environment. As VISTA works at infrared wavelengths it can see right through most of the dust that is such a prominent feature of the Sculptor Galaxy when viewed in visible light. Huge numbers of cooler stars that are barely detectable with visible-light telescopes are now also seen. The VISTA view reveals most of what was hidden by the thick dust clouds in the central part of the disc and allows a clear view of a prominent bar of stars across the nuclear region - a feature that is not seen in visible light pictures. The majestic spiral arms now spread over the whole disc of the galaxy. The spectacular viewing conditions VISTA shares with ESO's Very Large Telescope (VLT), located on the next mountain peak, also allow VISTA images to be exceptionally sharp for a ground-based telescope. With this powerful instrument at their command astronomers wanted to peel away some of the mysteries of the Sculptor Galaxy. They are studying the myriad of cool red giant stars in the halo that surrounds the galaxy, measuring the composition of some of NGC 253's small dwarf satellite galaxies, and searching for as yet undiscovered new objects such as globular clusters and ultra-compact dwarf galaxies that would otherwise be invisible without the deep VISTA infrared images. Using the unique VISTA data they plan to map how the galaxy formed and has evolved. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Light, Wind and Fire - Beautiful Image of a Cosmic Sculpture

NASA Astrophysics Data System (ADS)

2010-02-01

Today ESO has released a dramatic new image of NGC 346, the brightest star-forming region in our neighbouring galaxy, the Small Magellanic Cloud, 210 000 light-years away towards the constellation of Tucana (the Toucan). The light, wind and heat given off by massive stars have dispersed the glowing gas within and around this star cluster, forming a surrounding wispy nebular structure that looks like a cobweb. NGC 346, like other beautiful astronomical scenes, is a work in progress, and changes as the aeons pass. As yet more stars form from loose matter in the area, they will ignite, scattering leftover dust and gas, carving out great ripples and altering the face of this lustrous object. NGC 346 spans approximately 200 light-years, a region of space about fifty times the distance between the Sun and its nearest stellar neighbours. Astronomers classify NGC 346 as an open cluster of stars, indicating that this stellar brood all originated from the same collapsed cloud of matter. The associated nebula containing this clutch of bright stars is known as an emission nebula, meaning that gas within it has been heated up by stars until the gas emits its own light, just like the neon gas used in electric store signs. Many stars in NGC 346 are relatively young in cosmic terms with their births dating back only a few million years or so (eso0834). Powerful winds thrown off by a massive star set off this recent round of star birth by compressing large amounts of matter, the first critical step towards igniting new stars. This cloud of material then collapses under its own gravity, until some regions become dense and hot enough to roar forth as a brilliantly shining, nuclear fusion-powered furnace - a star, illuminating the residual debris of gas and dust. In sufficiently congested regions like NGC 346, with high levels of recent star birth, the result is a glorious, glowing vista for our telescopes to capture. NGC 346 is in the Small Magellanic Cloud, a dwarf galaxy some 210 000 light-years away from Earth and in close proximity to our home, the much larger Milky Way Galaxy. Like its sister the Large Magellanic Cloud, the Small Magellanic Cloud is visible with the unaided eye from the southern hemisphere and has served as an extragalactic laboratory for astronomers studying the dynamics of star formation. This particular image was obtained using the Wide Field Imager (WFI) instrument at the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. Images like this help astronomers chronicle star birth and evolution, while offering glimpses of how stellar development influences the appearance of the cosmic environment over time. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory, and VISTA the largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

An Eagle of Cosmic Proportions

NASA Astrophysics Data System (ADS)

2009-07-01

Today ESO has released a new and stunning image of the sky around the Eagle Nebula, a stellar nursery where infant star clusters carve out monster columns of dust and gas. Located 7000 light-years away, towards the constellation of Serpens (the Snake), the Eagle Nebula is a dazzling stellar nursery, a region of gas and dust where young stars are currently being formed and where a cluster of massive, hot stars, NGC 6611, has just been born. The powerful light and strong winds from these massive new arrivals are shaping light-year long pillars, seen in the image partly silhouetted against the bright background of the nebula. The nebula itself has a shape vaguely reminiscent of an eagle, with the central pillars being the "talons". The star cluster was discovered by the Swiss astronomer, Jean Philippe Loys de Chéseaux, in 1745-46. It was independently rediscovered about twenty years later by the French comet hunter, Charles Messier, who included it as number 16 in his famous catalogue, and remarked that the stars were surrounded by a faint glow. The Eagle Nebula achieved iconic status in 1995, when its central pillars were depicted in a famous image obtained with the NASA/ESA Hubble Space Telescope. In 2001, ESO's Very Large Telescope (VLT) captured another breathtaking image of the nebula in the near-infrared, giving astronomers a penetrating view through the obscuring dust, and clearly showing stars being formed in the pillars. The newly released image, obtained with the Wide-Field Imager camera attached to the MPG/ESO 2.2-metre telescope at La Silla, Chile, covers an area on the sky as large as the full Moon, and is about 15 times more extensive than the previous VLT image, and more than 200 times more extensive than the iconic Hubble visible-light image. The whole region around the pillars can now be seen in exquisite detail. The "Pillars of Creation" are in the middle of the image, with the cluster of young stars, NGC 6611, lying above and to the right. The "Spire" - another pillar captured by Hubble - is at the centre left of the image. Finger-like features protrude from the vast cloud wall of cold gas and dust, not unlike stalagmites rising from the floor of a cave. Inside the pillars, the gas is dense enough to collapse under its own weight, forming young stars. These light-year long columns of gas and dust are being simultaneously sculpted, illuminated and destroyed by the intense ultraviolet light from massive stars in NGC 6611, the adjacent young stellar cluster. Within a few million years - a mere blink of the universal eye - they will be gone forever. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Irish Team Wins SEA & SPACE Super Prize

NASA Astrophysics Data System (ADS)

1998-09-01

A secondary school team from Ireland has won a trip to Europe's Spaceport in Kourou, French Guyana, and to ESO's Very Large Telescope (VLT) at Cerro Paranal, Chile. The trip is the Super-Prize for the Sea & Space Newspaper Competition , organised within the framework of the European Week for Scientific and Technological Culture. ESO PR Photo 33/98 ESO PR Photo 33/98 [Preview - JPEG: 800 x 434 pix - 568k] [High-Res - JPEG: 3000 x 1627 pix - 6.7Mb] The presentation of prize certificates to the winning Irish team (right) in Lisbon, on August 31, 1998, by ESO, ESA and EAAE representatives. Stephen Kearney, Cian Wilson (both aged 16 years), Eamonn McKeogh (aged 17 years) together with their teacher, John Daly of Blackrock College in Dublin, prepared their newspaper, Infinitus , on marine and space themes, and came first in the national round of the competition. Together with other students from all over Europe, they were invited to present their winning newspaper to a jury consisting of representatives of the organisers, during a special programme of events at the Gulbenkian Planetarium and EXPO '98 in Lisbon, from 28-31 August, 1998. The Irish team scored highly in all categories of the judging, which included scientific content and originality and creativity of the articles. Their look at Irish contributions to sea and space research also proved popular in a ballot by fellow student competitors. This vote was also taken into account by the judges. The jury was very impressed by the high quality of the national entries and there were several close runners-up. The width and depth was amazing and the variety of ideas and formats presented by the sixteen teams was enormous. A poster competition was organised for younger students, aged 10 to 13 and winning entries at national level are on display at the Oceanophilia Pavilion at EXPO '98. The SEA & SPACE project is a joint initiative of the European Space Agency (ESA) , the European Southern Observatory (ESO) , and the European Association for Astronomy Education (EAAE) , in cooperation with the German National Research Centre for Information Technology (GMD). It builds on these organisations' several years' successful participation in the European Week for Scientific and Technological Culture organised by the European Commission . Note: [1] This press release is published jointly by ESA, ESO and EAAE. More information about the background of SEA & SPACE is available in ESO PR 02/98 (January 22, 1998) and ESA Press Release N 03-98 (23 January 1998). SEA & SPACE webpages are available at these URL's: * http://www.esrin.esa.int/seaspace * http://www.eso.org/seaspace , and * http://www.algonet.se/~sirius/eaae/seaspace How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

Jupiter's Spot Seen Glowing - Scientists Get First Look at Weather Inside the Solar System's Biggest Storm

NASA Astrophysics Data System (ADS)

2010-03-01

New ground-breaking thermal images obtained with ESO's Very Large Telescope and other powerful ground-based telescopes show swirls of warmer air and cooler regions never seen before within Jupiter's Great Red Spot, enabling scientists to make the first detailed interior weather map of the giant storm system linking its temperature, winds, pressure and composition with its colour. "This is our first detailed look inside the biggest storm of the Solar System," says Glenn Orton, who led the team of astronomers that made the study. "We once thought the Great Red Spot was a plain old oval without much structure, but these new results show that it is, in fact, extremely complicated." The observations reveal that the reddest colour of the Great Red Spot corresponds to a warm core within the otherwise cold storm system, and images show dark lanes at the edge of the storm where gases are descending into the deeper regions of the planet. The observations, detailed in a paper appearing in the journal Icarus, give scientists a sense of the circulation patterns within the solar system's best-known storm system. Sky gazers have been observing the Great Red Spot in one form or another for hundreds of years, with continuous observations of its current shape dating back to the 19th century. The spot, which is a cold region averaging about -160 degrees Celsius, is so wide that about three Earths could fit inside its boundaries. The thermal images were mostly obtained with the VISIR [1] instrument attached to ESO's Very Large Telescope in Chile, with additional data coming from the Gemini South telescope in Chile and the National Astronomical Observatory of Japan's Subaru Telescope in Hawaii. The images have provided an unprecedented level of resolution and extended the coverage provided by NASA's Galileo spacecraft in the late 1990s. Together with observations of the deep cloud structure by the 3-metre NASA Infrared Telescope Facility in Hawaii, the level of thermal detail observed from these giant observatories is for the first time comparable to visible-light images from the NASA/ESA Hubble Space Telescope. VISIR allows the astronomers to map the temperature, aerosols and ammonia within and surrounding the storm. Each of these parameters tells us how the weather and circulation patterns change within the storm, both spatially (in 3D) and with time. The years of VISIR observations, coupled with those from the other observatories, reveals how the storm is incredibly stable despite turbulence, upheavals and close encounters with other anticyclones that affect the edge of the storm system. "One of the most intriguing findings shows the most intense orange-red central part of the spot is about 3 to 4 degrees warmer than the environment around it," says lead author Leigh Fletcher. This temperature difference might not seem like a lot, but it is enough to allow the storm circulation, usually counter-clockwise, to shift to a weak clockwise circulation in the very middle of the storm. Not only that, but on other parts of Jupiter, the temperature change is enough to alter wind velocities and affect cloud patterns in the belts and zones. "This is the first time we can say that there's an intimate link between environmental conditions - temperature, winds, pressure and composition - and the actual colour of the Great Red Spot," says Fletcher. "Although we can speculate, we still don't know for sure which chemicals or processes are causing that deep red colour, but we do know now that it is related to changes in the environmental conditions right in the heart of the storm." Notes [1] VISIR stands for VLT Imager and Spectrometer for mid Infrared (eso0417). It is a complex multi-mode instrument designed to operate in the 10 and 20 micron atmospheric windows, i.e. at wavelengths up to about 40 times longer than visible light, and to provide images as well as spectra. More information This research was presented in a paper to appear in Icarus ("Thermal Structure and Composition of Jupiter's Great Red Spot from High-Resolution Thermal Imaging", by L. Fletcher et al.). The team is composed of Leigh N. Fletcher and P. G. J. Irwin (University of Oxford, UK), G. S. Orton, P. Yanamandra-Fisher, and B. M. Fisher (Jet Propulsion Laboratory, California Institute of Technology, USA), O. Mousis (Observatoire de Besançon, France, and University of Arizona, Tucson, USA), P. D. Parrish (University of Edinburgh, UK), L. Vanzi (Pontificia Universidad Catolica de Chile, Santiago, Chile), T. Fujiyoshi and T. Fuse (Subaru Telescope, National Astronomical Observatory of Japan, Hawaii, USA), A.A. Simon-Miller (NASA/Goddard Spaceflight Center, Greenbelt, Maryland, USA), E. Edkins (University of California, Santa Barbara, USA), T.L. Hayward (Gemini Observatory, La Serena, Chile), and J. De Buizer (SOFIA - USRA, NASA Ames Research Center, Moffet Field, CA 94035, USA). Leigh Fletcher was working at JPL during the study. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Astronomer's new guide to the galaxy: largest map of cold dust revealed

NASA Astrophysics Data System (ADS)

2009-07-01

Astronomers have unveiled an unprecedented new atlas of the inner regions of the Milky Way, our home galaxy, peppered with thousands of previously undiscovered dense knots of cold cosmic dust -- the potential birthplaces of new stars. Made using observations from the APEX telescope in Chile, this survey is the largest map of cold dust so far, and will prove an invaluable map for observations made with the forthcoming ALMA telescope, as well as the recently launched ESA Herschel space telescope. ESO PR Photo 24a/09 View of the Galactic Plane from the ATLASGAL survey (annotated and in five sections) ESO PR Photo 24b/09 View of the Galactic Plane from the ATLASGAL survey (annotated) ESO PR Photo 24c/09 View of the Galactic Plane from the ATLASGAL survey (in five sections) ESO PR Photo 24d/09 View of the Galactic Plane from the ATLASGAL survey ESO PR Photo 24e/09 The Galactic Centre and Sagittarius B2 ESO PR Photo 24f/09 The NGC 6357 and NGC 6334 nebulae ESO PR Photo 24g/09 The RCW120 nebula ESO PR Video 24a/09 Annotated pan as seen by the ATLASGAL survey This new guide for astronomers, known as the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) shows the Milky Way in submillimetre-wavelength light (between infrared light and radio waves [1]). Images of the cosmos at these wavelengths are vital for studying the birthplaces of new stars and the structure of the crowded galactic core. "ATLASGAL gives us a new look at the Milky Way. Not only will it help us investigate how massive stars form, but it will also give us an overview of the larger-scale structure of our galaxy", said Frederic Schuller from the Max Planck Institute for Radio Astronomy, leader of the ATLASGAL team. The area of the new submillimetre map is approximately 95 square degrees, covering a very long and narrow strip along the galactic plane two degrees wide (four times the width of the full Moon) and over 40 degrees long. The 16 000 pixel-long map was made with the LABOCA submillimetre-wave camera on the ESO-operated APEX telescope. APEX is located at an altitude of 5100 m on the arid plateau of Chajnantor in the Chilean Andes -- a site that allows optimal viewing in the submillimetre range. The Universe is relatively unexplored at submillimetre wavelengths, as extremely dry atmospheric conditions and advanced detector technology are required for such observations. The interstellar medium -- the material between the stars -- is composed of gas and grains of cosmic dust, rather like fine sand or soot. However, the gas is mostly hydrogen and relatively difficult to detect, so astronomers often search for these dense regions by looking for the faint heat glow of the cosmic dust grains. Submillimetre light allows astronomers to see these dust clouds shining, even though they obscure our view of the Universe at visible light wavelengths. Accordingly, the ATLASGAL map includes the denser central regions of our galaxy, in the direction of the constellation of Sagittarius -- home to a supermassive black hole (ESO 46/08) -- that are otherwise hidden behind a dark shroud of dust clouds. The newly released map also reveals thousands of dense dust clumps, many never seen before, which mark the future birthplaces of massive stars. The clumps are typically a couple of light-years in size, and have masses of between ten and a few thousand times the mass of our Sun. In addition, ATLASGAL has captured images of beautiful filamentary structures and bubbles in the interstellar medium, blown by supernovae and the winds of bright stars. Some striking highlights of the map include the centre of the Milky Way, the nearby massive and dense cloud of molecular gas called Sagittarius B2, and a bubble of expanding gas called RCW120, where the interstellar medium around the bubble is collapsing and forming new stars (see ESO 40/08). "It's exciting to get our first look at ATLASGAL, and we will be increasing the size of the map over the next year to cover all of the galactic plane visible from the APEX site on Chajnantor, as well as combining it with infrared observations to be made by the ESA Herschel Space Observatory. We look forward to new discoveries made with these maps, which will also serve as a guide for future observations with ALMA", said Leonardo Testi from ESO, who is a member of the ATLASGAL team and the European Project Scientist for the ALMA project. Note [1] The map was constructed from individual APEX observations in radiation at 870 µm (0.87 mm) wavelength. More information: The ATLASGAL observations are presented in a paper by Frederic Schuller et al., ATLASGAL -- The APEX Telescope Large Area Survey of the Galaxy at 870 µm, published in Astronomy & Astrophysics. ATLASGAL is a collaboration between the Max Planck Institute for Radio Astronomy, the Max Planck Institute for Astronomy, ESO, and the University of Chile. LABOCA (Large APEX Bolometer Camera), one of APEX's major instruments, is the world's largest bolometer camera (a "thermometer camera", or thermal camera that measures and maps the tiny changes in temperature that occur when sub-millimetre wavelength light falls on its absorbing surface; see ESO 35/07). LABOCA's large field of view and high sensitivity make it an invaluable tool for imaging the "cold Universe". LABOCA was built by the Max Planck Institute for Radio Astronomy. The Atacama Pathfinder Experiment (APEX) telescope is a 12-metre telescope, located at 5100 m altitude on the arid plateau of Chajnantor in the Chilean Andes. APEX operates at millimetre and submillimetre wavelengths. This wavelength range is a relatively unexplored frontier in astronomy, requiring advanced detectors and an extremely high and dry observatory site, such as Chajnantor. APEX, the largest submillimetre-wave telescope operating in the southern hemisphere, is a collaboration between the Max Planck Institute for Radio Astronomy, the Onsala Space Observatory and ESO. Operation of APEX at Chajnantor is entrusted to ESO. APEX is a "pathfinder" for ALMA -- it is based on a prototype antenna constructed for the ALMA project, it is located on the same plateau and will find many targets that ALMA will be able to study in extreme detail. The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ESO is the European partner in ALMA. ALMA, the largest astronomical project in existence, is a revolutionary telescope, comprising an array of 66 giant 12-metre and 7-metre diameter antennas observing at millimetre and submillimetre wavelengths. ALMA will start scientific observations in 2011. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Participant Perspectives on the ESO Astronomy Camp Programme

NASA Astrophysics Data System (ADS)

Olivotto, C.; Cenadelli, D.; Gamal, M.; Grossmann, D.; Teller, L. A. I.; Marta, A. S.; Matoni, C. L.; Taillard, A.

2015-09-01

This article describes the experience of attending the European Southern Observatory (ESO) Astronomy Camp from the perspective of its participants - students aged between 16 and 18 years old from around the world. The students shared a week together during the winter of 2014 in the Alpine village of Saint-Barthelemy, Italy. The camp was organised by ESO in collaboration with Sterrenlab and the Astronomical Observatory of the Autonomous Region of the Aosta Valley and offered a rich programme of astronomy and leisure activities. This article focuses on the concept of astronomy camps, and their role as a unique tool to complement formal classroom education, rather than on the astronomy activities and the scientific programme. Thus, it is not an academic review of the implemented methodologies, but rather a reflection on the overall experience. The article was brought together from collaborative accounts by some of the participants who were asked to reflect on the experience. The participants who contributed to this article represent the diversity of the ESO Astronomy Camp's alumni community.

VLT Data Flow System Begins Operation

NASA Astrophysics Data System (ADS)

1999-06-01

Building a Terabyte Archive at the ESO Headquarters The ESO Very Large Telescope (VLT) is the sum of many sophisticated parts. The site at Cerro Paranal in the dry Atacama desert in Northern Chile is one of the best locations for astronomical observations from the surface of the Earth. Each of the four 8.2-m telescopes is a technological marvel with self-adjusting optics placed in a gigantic mechanical structure of the utmost precision, continuously controlled by advanced soft- and hardware. A multitude of extremely complex instruments with sensitive detectors capture the faint light from distant objects in the Universe and record the digital data fast and efficiently as images and spectra, with a minimum of induced noise. And now the next crucial link in this chain is in place. A few nights ago, following an extended test period, the VLT Data Flow System began providing the astronomers with a steady stream of high-quality, calibrated image and spectral data, ready to be interpreted. The VLT project has entered into a new phase with a larger degree of automation. Indeed, the first 8.2-m Unit Telescope, ANTU, with the FORS1 and ISAAC instruments, has now become a true astronomy machine . A smooth flow of data through the entire system ESO PR Photo 25a/99 ESO PR Photo 25a/99 [Preview - JPEG: 400 x 292 pix - 104k] [Normal - JPEG: 800 x 584 pix - 264k] [High-Res - JPEG: 3000 x 2189 pix - 1.5M] Caption to ESO PR Photo 25a/99 : Simplified flow diagramme for the VLT Data Flow System . It is a closed-loop software system which incorporates various subsystems that track the flow of data all the way from the submission of proposals to storage of the acquired data in the VLT Science Archive Facility. The DFS main components are: Program Handling, Observation Handling, Telescope Control System, Science Archive, Pipeline and Quality Control. Arrows indicate lines of feedback. Already from the start of this project more than ten years ago, the ESO Very Large Telescope was conceived as a complex digital facility to explore the Universe. In order for astronomers to be able to use this marvellous research tool in the most efficient manner possible, the VLT computer software and hardware systems must guarantee a smooth flow of scientific information through the entire system. This process starts when the astronomers submit well-considered proposals for observing time and it ends with large volumes of valuable astronomical data being distributed to the international astronomical community. For this, ESO has produced an integrated collection of software and hardware, known as the VLT Data Flow System (DFS) , that manages and facilitates the flow of scientific information within the VLT Observatory. Early information about this new concept was published as ESO Press Release 12/96 and extensive tests were first carried out at ESOs 3.5-m New Technology Telescope (NTT) at La Silla, cf. ESO Press Release 03/97 [1]. The VLT DFS is a complete (end-to-end) system that guarantees the highest data quality by optimization of the observing process and repeated checks that identify and eliminate any problems. It also introduces automatic calibration of the data, i.e. the removal of external effects introduced by the atmospheric conditions at the time of the observations, as well as the momentary state of the telescope and the instruments. From Proposals to Observations In order to obtain observing time with ESO telescopes, also with the VLT, astronomers must submit a detailed observing proposal to the ESO Observing Programmes Committee (OPC) . It meets twice a year and ranks the proposals according to scientific merit. More than 1000 proposals are submitted each year, mostly by astronomers from the ESO members states and Chile; the competition is fierce and only a fraction of the total demand for observing time can be fulfilled. During the submission of observing proposals, DFS software tools available over the World Wide Web enable the astronomers to simulate their proposed observations and provide accurate estimates of the amount of telescope time they will need to complete their particular scientific programme. Once the proposals have been reviewed by the OPC and telescope time is awarded by the ESO management according to the recommendation by this Committee, the successful astronomers begin to assemble detailed descriptions of their intended observations (e.g. position in the sky, time and duration of the observation, the instrument mode, etc.) in the form of computer files called Observation Blocks (OBs) . The software to make OBs is distributed by ESO and used by the astronomers at their home institutions to design their observing programs well before the observations are scheduled at the telescope. The OBs can then be directly executed by the VLT and result in an increased efficiency in the collection of raw data (images, spectra) from the science instruments on the VLT. The activation (execution) of OBs can be done by the astronomer at the telescope on a particular set of dates ( visitor mode operation) or it can be done by ESO science operations astronomers at times which are optimally suited for the particular scientific programme ( service mode operation). An enormous VLT Data Archive ESO PR Photo 25b/99 ESO PR Photo 25b/99 [Preview - JPEG: 400 x 465 pix - 160k] [Normal - JPEG: 800 x 929 pix - 568k] [High-Res - JPEG: 3000 x 3483 pix - 5.5M] Caption to ESO PR Photo 25b/99 : The first of several DVD storage robot at the VLT Data Archive at the ESO headquarters include 1100 DVDs (with a total capacity of about 16 Terabytes) that may be rapidly accessed by the archive software system, ensuring fast availbility of the requested data. The raw data generated at the telescope are stored by an archive system that sends these data regularly back to ESO headquarters in Garching (Germany) in the form of CD and DVD ROM disks. While the well-known Compact Disks (CD ROMs) store about 600 Megabytes (600,000,000 bytes) each, the new Digital Versatile Disks (DVD ROMs) - of the same physical size - can store up 3.9 Gigabytes (3,900,000,000 bytes) each, or over 6 times more. The VLT will eventually produce more than 20 Gigabytes (20,000,000,000 bytes) of astronomical data every night, corresponding to about 10 million pages of text [2]. Some of these data also pass through "software pipelines" that automatically remove the instrumental effects on the data and deliver data products to the astronomer that can more readily be turned into scientific results. Ultimately these data are stored in a permanent Science Archive Facility at ESO headquarters which is jointly operated by ESO and the Space Telescope European Coordinating Facility (ST-ECF). From here, data are distributed to astronomers on CD ROMs and over the World Wide Web. The archive facility is being developed to enable astronomers to "mine" the large volumes of data that will be collected from the VLT in the coming years. Within the first five years of operations the VLT is expected to produce around 100 Terabytes (100,000,000,000,000 bytes) of data. It is difficult to visualize this enormous amount of information. However, it corresponds to the content of 50 million books of 1000 pages each; they would occupy some 2,500 kilometres of bookshelves! The VLT Data Flow System enters into operation ESO PR Photo 25c/99 ESO PR Photo 25c/99 [Preview - JPEG: 400 x 444 pix - 164k] [Normal - JPEG: 800 x 887 pix - 552k] [High-Res - JPEG: 3000 x 3327 pix - 6.4M] Caption to ESO PR Photo 25c/99 : Astronomers from ESO Data Flow Operations Group at work with the VLT Archive. Science operations with the first VLT 8.2-m telescope ( ANTU ) began on April 1, 1999. Following the first call for proposals to use the VLT in October 1998, the OPC met in December and the observing schedule was finalized early 1999. The related Observation Blocks were prepared by the astronomers in February and March. Service-mode observations began in April and by late May the first scientific programs conducted by ESO science operations were completed. Raw data, instrument calibration information and the products of pipeline processing from these programs have now been assembled and packed onto CD ROMs by ESO science operations staff. On June 15 the first CD ROMs were delivered to astronomers in the ESO community. This event marks the closing of the data flow loop at the VLT for the first time and the successful culmination of more than 5 years of hard work by ESO engineers and scientists to implement a system for efficient and effective scientific data flow. This was achieved by a cross-organization science operations team involving staff in Chile and Europe. With the VLT Data Flow System, a wider research community will have access to the enormous wealth of data from the VLT. It will help astronomers to keep pace with the new technologies and extensive capabilities of the VLT and so obtain world-first scientific results and new insights into the universe. Notes [1] A more technical description of the VLT Data Flow System is available in Chapter 10 of the VLT Whitebook. [2] By definition, one "normal printed page" contains 2,000 characters. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../ ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

A Disturbed Galactic Duo

NASA Astrophysics Data System (ADS)

2011-04-01

The galaxies in this cosmic pairing, captured by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile, display some curious features, demonstrating that each member of the duo is close enough to feel the distorting gravitational influence of the other. The gravitational tug of war has warped the spiral shape of one galaxy, NGC 3169, and fragmented the dust lanes in its companion NGC 3166. Meanwhile, a third, smaller galaxy to the lower right, NGC 3165, has a front-row seat to the gravitational twisting and pulling of its bigger neighbours. This galactic grouping, found about 70 million light-years away in the constellation Sextans (The Sextant), was discovered by the English astronomer William Herschel in 1783. Modern astronomers have gauged the distance between NGC 3169 (left) and NGC 3166 (right) as a mere 50 000 light-years, a separation that is only about half the diameter of the Milky Way galaxy. In such tight quarters, gravity can start to play havoc with galactic structure. Spiral galaxies like NGC 3169 and NGC 3166 tend to have orderly swirls of stars and dust pinwheeling about their glowing centres. Close encounters with other massive objects can jumble this classic configuration, often serving as a disfiguring prelude to the merging of galaxies into one larger galaxy. So far, the interactions of NGC 3169 and NGC 3166 have just lent a bit of character. NGC 3169's arms, shining bright with big, young, blue stars, have been teased apart, and lots of luminous gas has been drawn out from its disc. In NGC 3166's case, the dust lanes that also usually outline spiral arms are in disarray. Unlike its bluer counterpart, NGC 3166 is not forming many new stars. NGC 3169 has another distinction: the faint yellow dot beaming through a veil of dark dust just to the left of and close to the galaxy's centre [1]. This flash is the leftover of a supernova detected in 2003 and known accordingly as SN 2003cg. A supernova of this variety, classified as a Type Ia, is thought to occur when a dense, hot star called a white dwarf - a remnant of medium-sized stars like our Sun - gravitationally sucks gas away from a nearby companion star. This added fuel eventually causes the whole star to explode in a runaway fusion reaction. The new image presented here of a remarkable galactic dynamic duo is based on data selected by Igor Chekalin for ESO's Hidden Treasures 2010 astrophotography competition. Chekalin won the first overall prize and this image received the second highest ranking of the nearly 100 contest entries [2]. Notes [1] Other much more noticeable points of light, such as the one toward the left end of the spiral arm running underneath of NGC 3169's core, are stars within the Milky Way that happen to fall by chance very close to the line of sight between our telescopes and the galaxies. [2] ESO's Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO's vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. To find out more about Hidden Treasures, visit http://www.eso.org/public/outreach/hiddentreasures/. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Double Engine for a Nebula

NASA Astrophysics Data System (ADS)

2009-08-01

ESO has just released a stunning new image of a field of stars towards the constellation of Carina (the Keel). This striking view is ablaze with a flurry of stars of all colours and brightnesses, some of which are seen against a backdrop of clouds of dust and gas. One unusual star in the middle, HD 87643, has been extensively studied with several ESO telescopes, including the Very Large Telescope Interferometer (VLTI). Surrounded by a complex, extended nebula that is the result of previous violent ejections, the star has been shown to have a companion. Interactions in this double system, surrounded by a dusty disc, may be the engine fuelling the star's remarkable nebula. The new image, showing a very rich field of stars towards the Carina arm of the Milky Way, is centred on the star HD 87643, a member of the exotic class of B[e] stars [1]. It is part of a set of observations that provide astronomers with the best ever picture of a B[e] star. The image was obtained with the Wide Field Imager (WFI) attached to the MPG/ESO 2.2-metre telescope at the 2400-metre-high La Silla Observatory in Chile. The image shows beautifully the extended nebula of gas and dust that reflects the light from the star. The central star's wind appears to have shaped the nebula, leaving bright, ragged tendrils of gas and dust. A careful investigation of these features seems to indicate that there are regular ejections of matter from the star every 15 to 50 years. A team of astronomers, led by Florentin Millour, has studied the star HD 87643 in great detail, using several of ESO's telescopes. Apart from the WFI, the team also used ESO's Very Large Telescope (VLT) at Paranal. At the VLT, the astronomers used the NACO adaptive optics instrument, allowing them to obtain an image of the star free from the blurring effect of the atmosphere. To probe the object further, the team then obtained an image with the Very Large Telescope Interferometer (VLTI). The sheer range of this set of observations, from the panoramic WFI image to the fine detail of the VLTI observations, corresponds to a zoom-in factor of 60 000 between the two extremes. The astronomers found that HD 87643 has a companion located at about 50 times the Earth-Sun distance and is embedded in a compact dust shell. The two stars probably orbit each other in a period between 20 and 50 years. A dusty disc may also be surrounding the two stars. The presence of the companion could be an explanation for the regular ejection of matter from the star and the formation of the nebula: as the companion moves on a highly elliptical orbit, it would regularly come very close to HD 87643, triggering an ejection. Notes [1]: B[e] stars are stars of spectral type B, with emission lines in their spectra, hence the "e". They are surrounded by a large amount of dust. More information The work on HD 87643 has been published in a paper to appear in Astronomy and Astrophysics: A binary engine fueling HD 87643's complex circumstellar environment using AMBER/VLTI imaging, by F. Millour et al. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

International Workshop on First Decadal Review of the Edgeworth-Kuiper Belt: Toward new Frontiers

NASA Astrophysics Data System (ADS)

Hainaut, O.

2003-06-01

On March 11 to 14, 2003, an international conference on the Minor Bodies in the Outer Solar System was held in Antofagasta, Chile. The conference, which was organized by ESO and Universidad Catolica del Norte (UCN) of Antofagasta, gathered about 70 participants from 20 countries. Originally, it was supposed to take place on the UCN campus. However, a student strike forced us to relocate at the last minute to the Carrera Club Hotel. Thanks to the efforts of A. Lagarini, the conference secretary (and ESO/Chile Science secretary) and to the Hotel staff, this did not cause any disruption. The traditional group photo (opposite) was shot in front of the Geological Museum of UCN. This short summary highlights some of the results presented at this conference; the proceedings, which are currently being edited, will be published as a special issue of “Earth, Moon and Planets.”

The Superwind Galaxy NGC 4666

NASA Astrophysics Data System (ADS)

2010-09-01

The galaxy NGC 4666 takes pride of place at the centre of this new image, made in visible light with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. NGC 4666 is a remarkable galaxy with very vigorous star formation and an unusual "superwind" of out-flowing gas. It had previously been observed in X-rays by the ESA XMM-Newton space telescope, and the image presented here was taken to allow further study of other objects detected in the earlier X-ray observations. The prominent galaxy NGC 4666 in the centre of the picture is a starburst galaxy, about 80 million light-years from Earth, in which particularly intense star formation is taking place. The starburst is thought to be caused by gravitational interactions between NGC 4666 and its neighbouring galaxies, including NGC 4668, visible to the lower left. These interactions often spark vigorous star-formation in the galaxies involved. A combination of supernova explosions and strong winds from massive stars in the starburst region drives a vast flow of gas from the galaxy into space - a so-called "superwind". The superwind is huge in scale, coming from the bright central region of the galaxy and extending for tens of thousands of light-years. As the superwind gas is very hot it emits radiation mostly as X-rays and in the radio part of the spectrum and cannot be seen in visible light images such as the one presented here. This image was made as part of a follow-up to observations made with the ESA XMM-Newton space telescope in X-rays. NGC 4666 was the target of the original XMM-Newton observations, but thanks to the telescope's wide field-of-view many other X-ray sources were also seen in the background. One such serendipitous detection is a faint galaxy cluster seen close to the bottom edge of the image, right of centre. This cluster is much further away from us than NGC 4666, at a distance of about three billion light-years. In order to fully understand the nature of astronomical objects, researchers must study them at several wavelengths. This is because light of different wavelengths can tell us about different physical processes taking place. In this case the Wide Field Imager (WFI) [1] observations were made in visible light to further investigate these serendipitously detected X-ray objects - a good example of how astronomers using different telescopes work together to explore the Universe. Notes [1] The WFI is a joint project between the European Southern Observatory (ESO), the Max-Planck-Institut für Astronomie (MPIA) in Heidelberg (Germany) and the Osservatorio Astronomico di Capodimonte (OAC) in Naples (Italy). More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

A Cosmic Zoo in the Large Magellanic Cloud

NASA Astrophysics Data System (ADS)

2010-06-01

Astronomers often turn their telescopes to the Large Magellanic Cloud (LMC), one of the closest galaxies to our own Milky Way, in their quest to understand the Universe. In this spectacular new image from the Wide Field Imager (WFI) at ESO's La Silla Observatory in Chile, a celestial menagerie of different objects and phenomena in part of the LMC is on display, ranging from vast globular clusters to the remains left by brilliant supernovae explosions. This fascinating observation provides data for a wide variety of research projects unravelling the life and death of stars and the evolution of galaxies. The Large Magellanic Cloud (LMC) is only about 160 000 light-years from our own Milky Way - very close on a cosmic scale. This proximity makes it a very important target as it can be studied in far more detail than more distant systems. The LMC lies in the constellation of Dorado (the Swordfish), deep in the southern sky and well placed for observations from ESO's observatories in Chile. It is one of the galaxies forming the Local Group surrounding the Milky Way [1]. Though enormous on a human scale, the LMC is less than one tenth the mass of our home galaxy and spans just 14 000 light-years compared to about 100 000 light-years for the Milky Way. Astronomers refer to it as an irregular dwarf galaxy [2]. Its irregularity, combined with its prominent central bar of stars suggests to astronomers that tidal interactions with the Milky Way and fellow Local Group galaxy, the Small Magellanic Cloud, could have distorted its shape from a classic barred spiral into its modern, more chaotic form. This image is a mosaic of four pictures from the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile. The image covers a region of sky more than four times as large as the full Moon. The huge field of view of this camera makes it possible to see a very wide range of objects in the LMC in a single picture, although only a small part of the entire galaxy can be included. Dozens of clusters of young stars can be seen as well as traces of glowing gas clouds. Huge numbers of faint stars fill the image from edge to edge and in the background, more galaxies, far beyond the LMC, are visible. Globular clusters are collections of hundreds of thousands to millions of stars bound by gravity into a roughly spherical shape just a few light-years across. Many clusters orbit the Milky Way and most are ancient, over ten billion years old, and composed mainly of old red stars. The LMC also has globular clusters and one is visible as the fuzzy white oval cluster of stars in the upper right part of the image. This is NGC 1978, an unusually massive globular cluster. Unlike most other globular clusters, NGC 1978 is believed to be just 3.5 billion years old. The presence of this kind of object in the LMC leads astronomers to think that the LMC has a more recent history of active star formation than our own Milky Way. As well as being a vigorous region of star birth, the LMC has also seen many spectacular stellar deaths in the form of brilliant supernova explosions. At the top right of the image, the remnant of one such supernova, a strangely shaped wispy cloud called DEM L 190, often also referred to as N 49, can be seen. This giant cloud of glowing gas is the brightest supernova remnant in the LMC, and is about 30 light-years across. At the centre, where the star once burned, now lies a magnetar, a neutron star with an extremely powerful magnetic field. It was only in 1979 that satellites orbiting Earth detected a powerful gamma-ray burst from this object, drawing attention to the extreme properties of this new class of stellar exotica created by supernova explosions. This part of the Large Magellanic Cloud is so packed with star clusters and other objects that astronomers can spend entire careers exploring it. With so much activity, it is easy to see why astronomers are so keen to study the strange creatures in this heavenly zoo. Notes [1] http://en.wikipedia.org/wiki/Local_Group [2] http://en.wikipedia.org/wiki/Galaxy_morphological_classification More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

The sudden appearance of CO emission in LHA 115-S 65

NASA Astrophysics Data System (ADS)

Oksala, M. E.; Kraus, M.; Arias, M. L.; Borges Fernandes, M.; Cidale, L.; Muratore, M. F.; Curé, M.

2012-10-01

Molecular emission has been detected in several Magellanic Cloud B[e] supergiants. In this Letter, we report on the detection of CO band head emission in the B[e] supergiant LHA 115-S 65, and present a K-band near-infrared spectrum obtained with the Spectrograph for INtegral Field Observation in the Near-Infrared (SINFONI; R= 4500) on the ESO VLT UT4 telescope. The observed molecular band head emission in S65 is quite surprising in the light of a previous non-detection by McGregor, Hyland & McGinn, as well as a high-resolution (R= 50 000) Gemini/Phoenix spectrum of this star taken nine months earlier showing no emission. Based on analysis of the optical spectrum by Kraus, Borges Fernandes & de Araújo, we suspect that the sudden appearance of molecular emission could be due to density build-up in an outflowing viscous disc, as seen for Be stars. This new discovery, combined with variability in two other similar evolved massive stars, indicates an evolutionary link between B[e] supergiants and luminous blue variables. Based on observations obtained with ESO telescopes at the La Silla Paranal Observatory under programme ID 088.D-044 and at the Gemini Observatory which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (USA), the Science and Technology Facilities Council (UK), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), under programme ID GS-2010B-Q-31.

The ESO Observing Programmes Committee

NASA Astrophysics Data System (ADS)

Westerlund, B. E.

1982-06-01

Since 1978 the ESO Observing Programmes Committee (OPC) has "the function to inspect and rank the proposals made for observing programmes at La Silla, and thereby to advise the Director General on the distribution of observing time". The members (one from each member country) and their alternates are nominated by the respective national committees for five-year terms (not immediately renewable). The terms are staggered so that each year one or two persons are replaced. The Chairman is appointed annually by the Council. He is invited to attend Council meetings and to report to its members.

Near-InfraRed Planet Searcher to Join HARPS on the ESO 3.6-metre Telescope

NASA Astrophysics Data System (ADS)

Bouchy, F.; Doyon, R.; Artigau, É.; Melo, C.; Hernandez, O.; Wildi, F.; Delfosse, X.; Lovis, C.; Figueira, P.; Canto Martins, B. L..; González Hernández, J. I..; Thibault, S.; Reshetov, V.; Pepe, F.; Santos, N. C.; de Medeiros, J. R..; Rebolo, R.; Abreu, M.; Adibekyan, V. Z.; Bandy, T.; Benz, W.; Blind, N.; Bohlender, D.; Boisse, I.; Bovay, S.; Broeg, C.; Brousseau, D.; Cabral, A.; Chazelas, B.; Cloutier, R.; Coelho, J.; Conod, U.; Cumming, A.; Delabre, B.; Genolet, L.; Hagelberg, J.; Jayawardhana, R.; Käufl, H.-U.; Lafrenière, D.; de Castro Leão, I..; Malo, L.; de Medeiros Martins, A..; Matthews, J. M.; Metchev, S.; Oshagh, M.; Ouellet, M.; Parro, V. C.; Rasilla Piñeiro, J. L..; Santos, P.; Sarajlic, M.; Segovia, A.; Sordet, M.; Udry, S.; Valencia, D.; Vallée, P.; Venn, K.; Wade, G. A.; Saddlemyer, L.

2017-09-01

The Near-InfraRed Planet Searcher (NIRPS) is a new ultra-stable infrared (YJH) spectrograph that will be installed on ESO's 3.6-metre Telescope in La Silla, Chile. Aiming to achieve a precision of 1 m s-1, NIRPS is designed to find rocky planets orbiting M dwarfs, and will operate together with the High Accuracy Radial velocity Planet Searcher (HARPS), also on the 3.6-metre Telescope. In this article we describe the NIRPS science cases and present its main technical characteristics.

Reflected Glory

NASA Astrophysics Data System (ADS)

2011-02-01

The nebula Messier 78 takes centre stage in this image taken with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile, while the stars powering the bright display take a backseat. The brilliant starlight ricochets off dust particles in the nebula, illuminating it with scattered blue light. Igor Chekalin was the overall winner of ESO's Hidden Treasures 2010 astrophotography competition with his image of this stunning object. Messier 78 is a fine example of a reflection nebula. The ultraviolet radiation from the stars that illuminate it is not intense enough to ionise the gas to make it glow - its dust particles simply reflect the starlight that falls on them. Despite this, Messier 78 can easily be observed with a small telescope, being one of the brightest reflection nebulae in the sky. It lies about 1350 light-years away in the constellation of Orion (The Hunter) and can be found northeast of the easternmost star of Orion's belt. This new image of Messier 78 from the MPG/ESO 2.2-metre telescope at the La Silla Observatory is based on data selected by Igor Chekalin in his winning entry to the Hidden Treasures competition [1]. The pale blue tint seen in the nebula in this picture is an accurate representation of its dominant colour. Blue hues are commonly seen in reflection nebulae because of the way the starlight is scattered by the tiny dust particles that they contain: the shorter wavelength of blue light is scattered more efficiently than the longer wavelength red light. This image contains many other striking features apart from the glowing nebula. A thick band of obscuring dust stretches across the image from the upper left to the lower right, blocking the light from background stars. In the bottom right corner, many curious pink structures are also visible, which are created by jets of material being ejected from stars that have recently formed and are still buried deep in dust clouds. Two bright stars, HD 38563A and HD 38563B, are the main powerhouses behind Messier 78. However, the nebula is home to many more stars, including a collection of about 45 low mass, young stars (less than 10 million years old) in which the cores are still too cool for hydrogen fusion to start, known as T Tauri stars. Studying T Tauri stars is important for understanding the early stages of star formation and how planetary systems are created. Remarkably, this complex of nebulae has also changed significantly in the last ten years. In February 2004 the experienced amateur observer Jay McNeil took an image of this region with a 75 mm telescope and was surprised to see a bright nebula - the prominent fan shaped feature near the bottom of this picture - where nothing was seen on most earlier images. This object is now known as McNeil's Nebula and it appears to be a highly variable reflection nebula around a young star. This colour picture was created from many monochrome exposures taken through blue, yellow/green and red filters, supplemented by exposures through an H-alpha filter that shows light from glowing hydrogen gas. The total exposure times were 9, 9, 17.5 and 15.5 minutes per filter, respectively. Notes [1] Igor Chekalin from Russia uncovered the raw data for this image of Messier 78 in ESO's archives in the competition Hidden Treasures (eso1102). He processed the raw data with great skill, claiming first prize in the contest for his final image (Flickr link). ESO's team of in-house image processing experts then independently processed the raw data at full resolution to produce the image shown here. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

The Rose-red Glow of Star Formation

NASA Astrophysics Data System (ADS)

2011-03-01

The vivid red cloud in this new image from ESO's Very Large Telescope is a region of glowing hydrogen surrounding the star cluster NGC 371. This stellar nursery lies in our neighbouring galaxy, the Small Magellanic Cloud. The object dominating this image may resemble a pool of spilled blood, but rather than being associated with death, such regions of ionised hydrogen - known as HII regions - are sites of creation with high rates of recent star birth. NGC 371 is an example of this; it is an open cluster surrounded by a nebula. The stars in open clusters all originate from the same diffuse HII region, and over time the majority of the hydrogen is used up by star formation, leaving behind a shell of hydrogen such as the one in this image, along with a cluster of hot young stars. The host galaxy to NGC 371, the Small Magellanic Cloud, is a dwarf galaxy a mere 200 000 light-years away, which makes it one of the closest galaxies to the Milky Way. In addition, the Small Magellanic Cloud contains stars at all stages of their evolution; from the highly luminous young stars found in NGC 371 to supernova remnants of dead stars. These energetic youngsters emit copious amounts of ultraviolet radiation causing surrounding gas, such as leftover hydrogen from their parent nebula, to light up with a colourful glow that extends for hundreds of light-years in every direction. The phenomenon is depicted beautifully in this image, taken using the FORS1 instrument on ESO's Very Large Telescope (VLT). Open clusters are by no means rare; there are numerous fine examples in our own Milky Way. However, NGC 371 is of particular interest due to the unexpectedly large number of variable stars it contains. These are stars that change in brightness over time. A particularly interesting type of variable star, known as slowly pulsating B stars, can also be used to study the interior of stars through asteroseismology [1], and several of these have been confirmed in this cluster. Variable stars play a pivotal role in astronomy: some types are invaluable for determining distances to far-off galaxies and the age of the Universe. The data for this image were selected from the ESO archive by Manu Mejias as part of the Hidden Treasures competition [2]. Three of Manu's images made the top twenty; his picture of NGC 371 was ranked sixth in the competition. Notes [1] Asteroseismology is the study of the internal structure of pulsating stars by looking at the different frequencies at which they oscillate. This is a similar approach to the study of the structure of the Earth by looking at earthquakes and how their oscillations travel through the interior of the planet. [2] ESO's Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO's vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. Participants submitted nearly 100 entries and ten skilled people were awarded some extremely attractive prizes, including an all expenses paid trip for the overall winner to ESO's Very Large Telescope (VLT) on Cerro Paranal, in Chile, the world's most advanced optical telescope. The ten winners submitted a total of 20 images that were ranked as the highest entries in the competition out of the near 100 images. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

VISTA Captures Celestial Cat's Hidden Secrets

NASA Astrophysics Data System (ADS)

2010-04-01

The Cat's Paw Nebula, NGC 6334, is a huge stellar nursery, the birthplace of hundreds of massive stars. In a magnificent new ESO image taken with the Visible and Infrared Survey Telescope for Astronomy (VISTA) at the Paranal Observatory in Chile, the glowing gas and dust clouds obscuring the view are penetrated by infrared light and some of the Cat's hidden young stars are revealed. Towards the heart of the Milky Way, 5500 light-years from Earth in the constellation of Scorpius (the Scorpion), the Cat's Paw Nebula stretches across 50 light-years. In visible light, gas and dust are illuminated by hot young stars, creating strange reddish shapes that give the object its nickname. A recent image by ESO's Wide Field Imager (WFI) at the La Silla Observatory (eso1003) captured this visible light view in great detail. NGC 6334 is one of the most active nurseries of massive stars in our galaxy. VISTA, the latest addition to ESO's Paranal Observatory in the Chilean Atacama Desert, is the world's largest survey telescope (eso0949). It works at infrared wavelengths, seeing right through much of the dust that is such a beautiful but distracting aspect of the nebula, and revealing objects hidden from the sight of visible light telescopes. Visible light tends to be scattered and absorbed by interstellar dust, but the dust is nearly transparent to infrared light. VISTA has a main mirror that is 4.1 metres across and it is equipped with the largest infrared camera on any telescope. It shares the spectacular viewing conditions with ESO's Very Large Telescope (VLT), which is located on the nearby summit. With this powerful instrument at their command, astronomers were keen to see the birth pains of the big young stars in the Cat's Paw Nebula, some nearly ten times the mass of the Sun. The view in the infrared is strikingly different from that in visible light. With the dust obscuring the view far less, they can learn much more about how these stars form and develop in their first few million years of life. VISTA's very wide field of view allows the whole star-forming region to be imaged in one shot with much greater clarity than ever before. The VISTA image is filled with countless stars of our Milky Way galaxy overlaid with spectacular tendrils of dark dust that are seen here fully for the first time. The dust is sufficiently thick in places to block even the near-infrared radiation to which VISTA's camera is sensitive. In many of the dusty areas, such as those close to the centre of the picture, features that appear orange are apparent - evidence of otherwise hidden active young stars and their accompanying jets. Further out though, slightly older stars are laid bare to VISTA's vision, revealing the processes taking them from their first nuclear fusion along the unsteady path of the first few million years of their lives. The VISTA telescope is now embarking on several big surveys of the southern sky that will take years to complete. The telescope's large mirror, high quality images, sensitive camera and huge field of view make it by far the most powerful infrared survey telescope on Earth. As this striking image shows, VISTA will keep astronomers busy analysing data they could not have otherwise acquired. This cat is out of the bag. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Closing the Loop for ALMA - Three antennas working in unison open new bright year for revolutionary observatory

NASA Astrophysics Data System (ADS)

2010-01-01

The Atacama Large Millimeter/submillimeter Array (ALMA) has passed a key milestone crucial for the high quality images that will be the trademark of this revolutionary new tool for astronomy. Astronomers and engineers have, for the first time, successfully linked three of the observatory's antennas at the 5000-metre elevation observing site in northern Chile. Having three antennas observing in unison paves the way for precise images of the cool Universe at unprecedented resolution, by providing the missing link to correct errors that arise when only two antennas are used. On 20 November 2009 the third antenna for the ALMA observatory was successfully installed at the Array Operations Site, the observatory's "high site" on the Chajnantor plateau, at an altitude of 5000 metres in the Chilean Andes. Later, after a series of technical tests, astronomers and engineers observed the first signals from an astronomical source making use of all three 12-metre diameter antennas linked together, and are now working around the clock to establish the stability and readiness of the system. "The first signal using just two ALMA antennas, observed in October, can be compared to a baby's first babblings," says Leonardo Testi, the European Project Scientist for ALMA at ESO. "Observing with a third antenna represents the moment when the baby says its very first, meaningful word - not yet a full sentence, but overwhelmingly exciting! The linking of three antennas is indeed the first actual step towards our goal of achieving precise and sharp images at submillimetre wavelengths." The successful linking of the antenna trio was a key test of the full electronic and software system now being installed at ALMA, and its success anticipates the future capabilities of the observatory. When complete, ALMA will have at least 66 high-tech antennas operating together as an "interferometer", working as a single, huge telescope probing the sky in the millimetre and submillimetre wavelengths of light. The combination of the signals received at the individual antennas is crucial to achieve images of astronomical sources of unprecedented quality at its designed observing wavelengths. The three-antenna linkup is a critical step towards the observatory's operations as an interferometer. Although the first, successful measurements employing just two antennas were obtained at the ALMA high site from October 2009 (see ESO Announcement) and demonstrated the excellent performance of the instruments, the addition of the third antenna is a leap of vital importance into the future of the observatory. This major milestone for the project is known as "phase closure" and provides an important independent check on the quality of the interferometry. "The use of a network of three (or more) antennas in an interferometer dramatically enhances its performance over a simple pair of antennas," explains Wolfgang Wild, the European ALMA Project Manager. "This gives astronomers control over possible features which degrade the quality of the image, arising due to the instrument or to atmospheric turbulence. By comparing the signals received simultaneously by the three individual antennas, these unwanted effects can be cancelled out - this is completely impossible using only two antennas." To achieve this crucial goal, astronomers observed the light coming from a distant extragalactic source, the quasar QSO B1921-293, well known to astronomers for its bright emission at very long wavelengths, including the millimetre/submillimetre range probed by ALMA. The stability of the signal measured from this object shows that the antennas are working impressively well. Several additional antennas will be installed on the Chajnantor plateau over the next year and beyond, allowing astronomers to start producing early scientific results with the ALMA system around 2011. After this, the interferometer will steadily grow to reach its full scientific potential, with at least 66 antennas. ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. More information The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ESO is the European partner in ALMA. ALMA, the largest astronomical project in existence, is a revolutionary telescope, comprising an array of 66 giant 12-metre and 7-metre diameter antennas observing at millimetre and submillimetre wavelengths. ALMA will start scientific observations in 2011. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory, and VISTA, the world's largest survey telescope. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

VISTA Stares Deeply into the Blue Lagoon

NASA Astrophysics Data System (ADS)

2011-01-01

This new infrared image of the Lagoon Nebula was captured as part of a five-year study of the Milky Way using ESO's VISTA telescope at the Paranal Observatory in Chile. This is a small piece of a much larger image of the region surrounding the nebula, which is, in turn, only one part of a huge survey. Astronomers are currently using ESO's Visible and Infrared Survey Telescope for Astronomy (VISTA) to scour the Milky Way's central regions for variable objects and map its structure in greater detail than ever before. This huge survey is called VISTA Variables in the Via Lactea (VVV) [1]. The new infrared image presented here was taken as part of this survey. It shows the stellar nursery called the Lagoon Nebula (also known as Messier 8, see eso0936), which lies about 4000-5000 light-years away in the constellation of Sagittarius (the Archer). Infrared observations allow astronomers to peer behind the veil of dust that prevents them from seeing celestial objects in visible light. This is because visible light, which has a wavelength that is about the same size as the dust particles, is strongly scattered, but the longer wavelength infrared light can pass through the dust largely unscathed. VISTA, with its 4.1-metre diameter mirror - the largest survey telescope in the world - is dedicated to surveying large areas of the sky at near-infrared wavelengths deeply and quickly. It is therefore ideally suited to studying star birth. Stars typically form in large molecular clouds of gas and dust, which collapse under their own weight. The Lagoon Nebula, however, is also home to a number of much more compact regions of collapsing gas and dust, called Bok globules [2]. These dark clouds are so dense that, even in the infrared, they can block the starlight from background stars. But the most famous dark feature in the nebula, for which it is named, is the lagoon-shaped dust lane that winds its way through the glowing cloud of gas. Hot, young stars, which give off intense ultraviolet light, are responsible for making the nebula glow brightly. But the Lagoon Nebula is also home to much younger stellar infants. Newborn stars have been detected in the nebula that are so young that they are still surrounded by their natal accretion discs. Such new born stars occasionally eject jets of matter from their poles. When this ejected material ploughs into the surrounding gas short-lived bright streaks called Herbig-Haro objects [3] are formed, making the new-borns easy to spot. In the last five years, several Herbig-Haro objects have been detected in the Lagoon Nebula, so the baby boom is clearly still in progress here. Notes [1] This survey, one of six VISTA surveys currently in progress, will image the central parts of the Milky Way many times over a period of five years and will detect huge numbers of new variable objects. [2] Bart Bok was a Dutch-American astronomer who spent most of his long career in the United States and Australia. He first noticed the dark spots that now bear his name, in star formation regions and speculated that they may be associated with the earliest stages of star formation. The hidden baby stars were only observed directly when infrared imaging was possible several decades later. [3] Although not the first to see such objects, the astronomers George Herbig and Guillermo Haro were the first to study the spectra of these strange objects in detail and realise that they were not just clumps of gas and dust that reflected light, or glowed under the influence of the ultraviolet light from young stars, but were a new class of objects associated with star formation. More information The science team for VVV includes Dante Minniti (Universidad Catolica, Chile), Phil Lucas (University of Hertfordshire, UK), Ignacio Toledo (Universidad Catolica) and Maren Hempel (Universidad Catolica). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Atoms-for-Peace: A Galactic Collision in Action

NASA Astrophysics Data System (ADS)

2010-11-01

European Southern Observatory astronomers have produced a spectacular new image of the famous Atoms-for-Peace galaxy (NGC 7252). This galactic pile-up, formed by the collision of two galaxies, provides an excellent opportunity for astronomers to study how mergers affect the evolution of the Universe. Atoms-for-Peace is the curious name given to a pair of interacting and merging galaxies that lie around 220 million light-years away in the constellation of Aquarius. It is also known as NGC 7252 and Arp 226 and is just bright enough to be seen by amateur astronomers as a very faint small fuzzy blob. This very deep image was produced by ESO's Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. A galaxy collision is one of the most important processes influencing how our Universe evolves, and studying them reveals important clues about galactic ancestry. Luckily, such collisions are long drawn-out events that last hundreds of millions of years, giving astronomers plenty of time to observe them. This picture of Atoms-for-Peace represents a snapshot of its collision, with the chaos in full flow, set against a rich backdrop of distant galaxies. The results of the intricate interplay of gravitational interactions can be seen in the shapes of the tails made from streams of stars, gas and dust. The image also shows the incredible shells that formed as gas and stars were ripped out of the colliding galaxies and wrapped around their joint core. While much material was ejected into space, other regions were compressed, sparking bursts of star formation. The result was the formation of hundreds of very young star clusters, around 50 to 500 million years old, which are speculated to be the progenitors of globular clusters. Atoms-for-Peace may be a harbinger of our own galaxy's fate. Astronomers predict that in three or four billion years the Milky Way and the Andromeda Galaxy will collide, much as has happened with Atoms-for-Peace. But don't panic: the distance between stars within a galaxy is vast, so it is unlikely that our Sun will end up in a head-on collision with another star during the merger. The object's curious nickname has an interesting history. In December 1953, President Eisenhower gave a speech that was dubbed Atoms for Peace. The theme was promoting nuclear power for peaceful purposes - a particularly hot topic at the time. This speech and the associated conference made waves in the scientific community and beyond to such an extent that NGC 7252 was named the Atoms-for-Peace galaxy. In many ways, this is oddly appropriate: the curious shape that we can see is the result of two galaxies merging to produce something new and grand, a little like what occurs in nuclear fusion. Furthermore, the giant loops resemble a textbook diagram of electrons orbiting an atomic nucleus. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

The Stars behind the Curtain

NASA Astrophysics Data System (ADS)

2010-02-01

ESO is releasing a magnificent VLT image of the giant stellar nursery surrounding NGC 3603, in which stars are continuously being born. Embedded in this scenic nebula is one of the most luminous and most compact clusters of young, massive stars in our Milky Way, which therefore serves as an excellent "local" analogue of very active star-forming regions in other galaxies. The cluster also hosts the most massive star to be "weighed" so far. NGC 3603 is a starburst region: a cosmic factory where stars form frantically from the nebula's extended clouds of gas and dust. Located 22 000 light-years away from the Sun, it is the closest region of this kind known in our galaxy, providing astronomers with a local test bed for studying intense star formation processes, very common in other galaxies, but hard to observe in detail because of their great distance from us. The nebula owes its shape to the intense light and winds coming from the young, massive stars which lift the curtains of gas and clouds revealing a multitude of glowing suns. The central cluster of stars inside NGC 3603 harbours thousands of stars of all sorts (eso9946): the majority have masses similar to or less than that of our Sun, but most spectacular are several of the very massive stars that are close to the end of their lives. Several blue supergiant stars crowd into a volume of less than a cubic light-year, along with three so-called Wolf-Rayet stars - extremely bright and massive stars that are ejecting vast amounts of material before finishing off in glorious explosions known as supernovae. Using another recent set of observations performed with the SINFONI instrument on ESO's Very Large Telescope (VLT), astronomers have confirmed that one of these stars is about 120 times more massive than our Sun, standing out as the most massive star known so far in the Milky Way [1]. The clouds of NGC 3603 provide us with a family picture of stars in different stages of their life, with gaseous structures that are still growing into stars, newborn stars, adult stars and stars nearing the end of their life. All these stars have roughly the same age, a million years, a blink of an eye compared to our five billion year-old Sun and Solar System. The fact that some of the stars have just started their lives while others are already dying is due to their extraordinary range of masses: high-mass stars, being very bright and hot, burn through their existence much faster than their less massive, fainter and cooler counterparts. The newly released image, obtained with the FORS instrument attached to the VLT at Cerro Paranal, Chile, portrays a wide field around the stellar cluster and reveals the rich texture of the surrounding clouds of gas and dust. Notes [1] The star, NGC 3603-A1, is an eclipsing system of two stars orbiting around each other in 3.77 days. The most massive star has an estimated mass of 116 solar masses, while its companion has a mass of 89 solar masses. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

The Cosmic Bat - An Island of Stars in the Making on the Outskirts of Orion

NASA Astrophysics Data System (ADS)

2010-03-01

The delicate nebula NGC 1788, located in a dark and often neglected corner of the Orion constellation, is revealed in a new and finely nuanced image that ESO is releasing today. Although this ghostly cloud is rather isolated from Orion's bright stars, the latter's powerful winds and light have had a strong impact on the nebula, forging its shape and making it home to a multitude of infant suns. Stargazers all over the world are familiar with the distinctive profile of the constellation of Orion (the Hunter). Fewer know about the nebula NGC 1788, a subtle, hidden treasure just a few degrees away from the bright stars in Orion's belt. NGC 1788 is a reflection nebula, whose gas and dust scatter the light coming from a small cluster of young stars in such a way that the tenuous glow forms a shape reminiscent of a gigantic bat spreading its wings. Very few of the stars belonging to the nebula are visible in this image, as most of them are obscured by the dusty cocoons surrounding them. The most prominent, named HD 293815, can be distinguished as the bright star in the upper part of the cloud, just above the centre of the image and the pronounced dark lane of dust extending through the nebula. Although NGC 1788 appears at first glance to be an isolated cloud, observations covering a field beyond the one presented in this image have revealed that bright, massive stars, belonging to the vast stellar groupings in Orion, have played a decisive role in shaping NGC 1788 and stimulating the formation of its stars. They are also responsible for setting the hydrogen gas ablaze in the parts of the nebula facing Orion, leading to the red, almost vertical rim visible in the left half of the image. All the stars in this region are extremely young, with an average age of only a million years, a blink of an eye compared to the Sun's age of 4.5 billion years. Analysing them in detail, astronomers have discovered that these "preschool" stars fall naturally into three well separated classes: the slightly older ones, located on the left side of the red rim, the fairly young ones, to its right, making up the small cluster enclosed in the nebula and illuminating it, and eventually the very youngest stars, still deeply embedded in their nascent dusty cocoons, further to the right. Although none of the latter are visible in this image because of the obscuring dust, dozens of them have been revealed through observations in the infrared and millimetre wavelengths of light. This fine distribution of stars, with the older ones closer to Orion and the younger ones concentrated on the opposite side, suggests that a wave of star formation, generated around the hot and massive stars in Orion, propagated throughout NGC 1788 and beyond. This image has been obtained using the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Trifid Triple Treat

NASA Astrophysics Data System (ADS)

2009-09-01

Today ESO has released a new image of the Trifid Nebula, showing just why it is a firm favourite of astronomers, amateur and professional alike. This massive star factory is so named for the dark dust bands that trisect its glowing heart, and is a rare combination of three nebula types, revealing the fury of freshly formed stars and presaging more star birth. Smouldering several thousand light-years away in the constellation of Sagittarius (the Archer), the Trifid Nebula presents a compelling portrait of the early stages of a star's life, from gestation to first light. The heat and "winds" of newly ignited, volatile stars stir the Trifid's gas and dust-filled cauldron; in time, the dark tendrils of matter strewn throughout the area will themselves collapse and form new stars. The French astronomer Charles Messier first observed the Trifid Nebula in June 1764, recording the hazy, glowing object as entry number 20 in his renowned catalogue. Observations made about 60 years later by John Herschel of the dust lanes that appear to divide the cosmic cloud into three lobes inspired the English astronomer to coin the name "Trifid". Made with the Wide-Field Imager camera attached to the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in northern Chile, this new image prominently displays the different regions of the Trifid Nebula as seen in visible light. In the bluish patch to the upper left, called a reflection nebula, dusty gas scatters the light from nearby, Trifid-born stars. The largest of these stars shines most brightly in the hot, blue portion of the visible spectrum. This, along with the fact that dust grains and molecules scatter blue light more efficiently than red light - a property that explains why we have blue skies and red sunsets - imbues this portion of the Trifid Nebula with an azure hue. Below, in the round, pink-reddish area typical of an emission nebula, the gas at the Trifid's core is heated by hundreds of scorching young stars until it emits the red signature light of hydrogen, the major component of the gas, just as hot neon gas glows red-orange in illuminated signs all over the world. The gases and dust that crisscross the Trifid Nebula make up the third kind of nebula in this cosmic cloud, known as dark nebulae, courtesy of their light-obscuring effects. (The iconic Horsehead Nebula may be the most famous of these. Within these dark lanes, the remnants of previous star birth episodes continue to coalesce under gravity's inexorable attraction. The rising density, pressure and temperature inside these gaseous blobs will eventually trigger nuclear fusion, and yet more stars will form. In the lower part of this emission nebula, a finger of gas pokes out from the cloud, pointing directly at the central star powering the Trifid. This is an example of an evaporating gaseous globule, or "EGG", also seen in the Eagle Nebula, another star-forming region. At the tip of the finger, which was photographed by Hubble, a knot of dense gas has resisted the onslaught of radiation from the massive star. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Spin-state and thermophysical analysis of the near-Earth asteroid (8567) 1996 HW_1

NASA Astrophysics Data System (ADS)

Rożek, A.; Lowry, S.; Rozitis, B.; Wolters, S.; Hicks, M.; Duddy, S.; Fitzsimmons, A.; Green, S.; Snodgrass, C.; Weissman, P.

2014-07-01

The asteroid (8567) 1996 HW_1 is a near-Earth Amor-class asteroid. It has been a target of visual lightcurve observations during the two apparitions in 2005 [1,2] and 2008 [3]. The lightcurve datasets were complemented by the radar data obtained at Arecibo during the close approach in September 2008 [4]. The data was combined to constrain the shape and spin state of the asteroid. The sidereal spin rate was measured to be P = 8.76243 hours, and pole position expressed in ecliptic coordinates as λ=281°, β = -31°, with a complex rotation state not being ruled out. The shape of the asteroid resembles a contact binary with two components connected by a narrow neck. It was predicted that the asteroid's rotation rate is decreasing due to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect. We aimed to verify the predicted YORP-induced period change [4]. The asteroid (8567) 1996 HW_1 has been selected as one of the targets of an ESO Large Programme led by Dr. S. Lowry. The programme includes photometric monitoring, infrared thermal observations, and visual near-infrared spectroscopy of selected near-Earth asteroids. Within the ESO LP, the asteroid has been observed on six runs between April 2010 and April 2013 with ESO's 3.6-m NTT telescope (Chile) to acquire optical lightcurves, and in September and December 2011 the infrared observations were performed with the VISIR instrument at the ESO's 8.2-m VLT telescope (Chile). The data set is completed by the visual lightcurve observations gathered from supporting programmes at JPL's Table Mountain Observatory (USA), Palomar 200-in telescope (USA), and the 2-m Liverpool Telescope (Spain). The visual lightcurves from our 2010-2013 observing campaign were combined with the previously published lightcurves from 2005-2009, doubling the time span of the observations for the purpose of the potential YORP detection. The shape model developed from radar and lightcurve data [4] has been used in the spin-state analysis. The current spin-state model reproduces the shape of all the lightcurves obtained over the eight years very well. We do not detect any signature of YORP in our data despite the long time base of our observations and the quality of the data obtained. The updated and improved spin-state model was used to determine the rotation phase of thermal fluxes obtained with VISIR very precisely. The thermal data was analysed using the Advanced Thermo-Physical Model (ATPM) [5,6]. The effective diameter is estimated to be 2.18 ± 0.05 km, which is consistent with the radar estimate of 2.02 ± 0.16 km. Thermal inertia is at the level of 170 ± 50 {Jm}^{-2}{K}^{-1}{s}^{-1/2} with roughness fraction above 75 %. The geometric albedo (using H = 15.27) can be constrained to P_ν = 0.29 ± 0.01. The ATPM modelling indicates a small YORP-induced acceleration at a rate of about 2.6 × 10^{-10} {rad} {d}^{-2} and an obliquity change of 0.9° per 10^5 years. The current value of obliquity, around 129.2°, is close to the critical value where the rotational component of YORP disappears. This result is in agreement with the results of our spin-state analysis. The detection of a period change at the predicted level may require a much longer observational time span. We note the difference in the sign between this prediction and the earlier estimates coming from the inclusion of large-scale self-heating in our analysis. For an object with a major concavity, it might occur that some parts of its surface will be irradiated by sunlight reflected off the other parts of the surface. This self-heating can significantly change the outcome of the YORP torque computation [7].

ESO Reflex: a graphical workflow engine for data reduction

NASA Astrophysics Data System (ADS)

Hook, Richard; Ullgrén, Marko; Romaniello, Martino; Maisala, Sami; Oittinen, Tero; Solin, Otto; Savolainen, Ville; Järveläinen, Pekka; Tyynelä, Jani; Péron, Michèle; Ballester, Pascal; Gabasch, Armin; Izzo, Carlo

ESO Reflex is a prototype software tool that provides a novel approach to astronomical data reduction by integrating a modern graphical workflow system (Taverna) with existing legacy data reduction algorithms. Most of the raw data produced by instruments at the ESO Very Large Telescope (VLT) in Chile are reduced using recipes. These are compiled C applications following an ESO standard and utilising routines provided by the Common Pipeline Library (CPL). Currently these are run in batch mode as part of the data flow system to generate the input to the ESO/VLT quality control process and are also exported for use offline. ESO Reflex can invoke CPL-based recipes in a flexible way through a general purpose graphical interface. ESO Reflex is based on the Taverna system that was originally developed within the UK life-sciences community. Workflows have been created so far for three VLT/VLTI instruments, and the GUI allows the user to make changes to these or create workflows of their own. Python scripts or IDL procedures can be easily brought into workflows and a variety of visualisation and display options, including custom product inspection and validation steps, are available. Taverna is intended for use with web services and experiments using ESO Reflex to access Virtual Observatory web services have been successfully performed. ESO Reflex is the main product developed by Sampo, a project led by ESO and conducted by a software development team from Finland as an in-kind contribution to joining ESO. The goal was to look into the needs of the ESO community in the area of data reduction environments and to create pilot software products that illustrate critical steps along the road to a new system. Sampo concluded early in 2008. This contribution will describe ESO Reflex and show several examples of its use both locally and using Virtual Observatory remote web services. ESO Reflex is expected to be released to the community in early 2009.

The Drama of Starbirth - new-born stars wreak havoc in their nursery

NASA Astrophysics Data System (ADS)

2011-03-01

A new image from ESO's Very Large Telescope gives a close-up view of the dramatic effects new-born stars have on the gas and dust from which they formed. Although the stars themselves are not visible, material they have ejected is colliding with the surrounding gas and dust clouds and creating a surreal landscape of glowing arcs, blobs and streaks. The star-forming region NGC 6729 is part of one of the closest stellar nurseries to the Earth and hence one of the best studied. This new image from ESO's Very Large Telescope gives a close-up view of a section of this strange and fascinating region (a wide-field view is available here: eso1027). The data were selected from the ESO archive by Sergey Stepanenko as part of the Hidden Treasures competition [1]. Sergey's picture of NGC 6729 was ranked third in the competition. Stars form deep within molecular clouds and the earliest stages of their development cannot be seen in visible-light telescopes because of obscuration by dust. In this image there are very young stars at the upper left of the picture. Although they cannot be seen directly, the havoc that they have wreaked on their surroundings dominates the picture. High-speed jets of material that travel away from the baby stars at velocities as high as one million kilometres per hour are slamming into the surrounding gas and creating shock waves. These shocks cause the gas to shine and create the strangely coloured glowing arcs and blobs known as Herbig-Haro objects [2]. In this view the Herbig-Haro objects form two lines marking out the probable directions of ejected material. One stretches from the upper left to the lower centre, ending in the bright, circular group of glowing blobs and arcs at the lower centre. The other starts near the left upper edge of the picture and extends towards the centre right. The peculiar scimitar-shaped bright feature at the upper left is probably mostly due to starlight being reflected from dust and is not a Herbig-Haro object. This enhanced-colour picture [3] was created from images taken using the FORS1 instrument on ESO's Very Large Telescope. Images were taken through two different filters that isolate the light coming from glowing hydrogen (shown as orange) and glowing ionised sulphur (shown as blue). The different colours in different parts of this violent star formation region reflect different conditions - for example where ionised sulphur is glowing brightly (blue features) the velocities of the colliding material are relatively low - and help astronomers to unravel what is going on in this dramatic scene. Notes [1] ESO's Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO's vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. Participants submitted nearly 100 entries and ten skilled people were awarded some extremely attractive prizes, including an all expenses paid trip for the overall winner to ESO's Very Large Telescope (VLT) on Cerro Paranal, in Chile, the world's most advanced optical telescope. The ten winners submitted a total of 20 images that were ranked as the highest entries in the competition out of the near 100 images. [2] The astronomers George Herbig and Guillermo Haro were not the first to see one of the objects that now bear their names, but they were the first to study the spectra of these strange objects in detail. They realised that they were not just clumps of gas and dust that reflected light, or glowed under the influence of the ultraviolet light from young stars, but were a new class of objects associated with ejected material in star formation regions. [3] Both the ionised sulphur and hydrogen atoms in this nebula emit red light. To differentiate between them in this image the sulphur emission has been coloured blue. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Catch a Star 2008!

NASA Astrophysics Data System (ADS)

2007-10-01

ESO and the European Association for Astronomy Education have just launched the 2008 edition of 'Catch a Star', their international astronomy competition for school students. Now in its sixth year, the competition offers students the chance to win a once-in-a-lifetime trip to ESO's flagship observatory in Chile, as well as many other prizes. CAS logo The competition includes separate categories - 'Catch a Star Researchers' and 'Catch a Star Adventurers' - to ensure that every student, whatever their level, has the chance to enter and win exciting prizes. In teams, students investigate an astronomical topic of their choice and write a report about it. An important part of the project for 'Catch a Star Researchers' is to think about how ESO's telescopes such as the Very Large Telescope (VLT) or future telescopes such as the Atacama Large Millimeter/submillimeter Array (ALMA) and the European Extremely Large Telescope (E-ELT) could contribute to investigations of the topic. Students may also include practical activities such as observations or experiments. For the artistically minded, 'Catch a Star' also offers an artwork competition, 'Catch a Star Artists'. Last year, hundreds of students from across Europe and beyond took part in 'Catch a Star', submitting astronomical projects and artwork. "'Catch a Star' gets students thinking about the wonders of the Universe and the science of astronomy, with a chance of winning great prizes. It's easy to take part, whether by writing about astronomy or creating astronomically inspired artwork," said Douglas Pierce-Price, Education Officer at ESO. As well as the top prize - a trip to ESO's Very Large Telescope in Chile - visits to observatories in Austria and Spain, and many other prizes, can also be won. 'Catch a Star Researchers' winners will be chosen by an international jury, and 'Catch a Star Adventurers' will be awarded further prizes by lottery. Entries for 'Catch a Star Artists' will be displayed on the web and winners chosen with the help of a public online vote. Detailed entry information and rules can be found at http://www.eso.org/catchastar/cas2008/. The deadline for submitting an entry for the 2008 competition is Friday 29 February 2008, 17:00 Central European Time.

Obituary: Adriaan Blaauw, 1914-2010

NASA Astrophysics Data System (ADS)

de Zeeuw, Tim

2011-12-01

Professor Adriaan Blaauw, one of the most influential astronomers of the twentieth century, passed away on 1 December 2010. Adriaan Blaauw was born in Amsterdam, the Netherlands, on 12 April 1914. He studied astronomy at Leiden University, under de Sitter, Hertzsprung and Oort, and obtained his doctorate (cum laude) with van Rhijn at the Kapteyn Laboratory in Groningen in 1946, on a PhD thesis entitled: A study of the Scorpio-Centaurus Cluster. In this work he used the proper motions of the stars on the sky, deduced by very careful comparison of position measurements taken more than 50 years apart, and demonstrated that most of the bright hot O and B stars in the constellations Scorpius and Centaurus have nearly identical space motions and hence constitute a physical group of stars. This work laid the basis for a career of groundbreaking studies of the properties of these OB associations which still contain the fossil imprint of their star formation history. Perhaps Blaauw's most famous work explained why some OB stars are found in isolation and are traveling unusually rapidly: the so-called run-away stars. During his time at Yerkes, he and Morgan had discovered curious examples such as the OB stars μ Columbae and AE Aurigae which are moving very fast in opposite directions, putting both of them at the location of the Orion Nebula at approximately the same time, 2.6 million years earlier. Blaauw proposed in 1961 that run-away stars had originally been members of binary stars, and when one star in the binary experiences a supernova explosion, its companion suddenly ceases to feel the gravitational pull that keeps it in its orbit and hence it "runs away" at its orbital velocity and rapidly leaves the group it was born in. In addition to his distinguished research career, Blaauw played a decisive role in the creation of the intergovernmental European Organization for Astronomical Research in the Southern Hemisphere, often referred to as the European Southern Observatory, or simply as ESO. In 1953, Baade and Oort proposed the idea of combining European resources to create an astronomical research organisation that could compete in the international arena. Blaauw had returned to Leiden in 1948 at Oort's invitation, had moved to Yerkes Observatory in 1953, becoming its associate director in 1956, and moved back to Groningen in 1957, where he revitalized the institute and initiated a new program in radio astronomy together with van Woerden. Here he was also in a key position to contribute to transforming the idea of Baade and Oort into reality. He was Secretary of the ESO Committee (the proto ESO Council) from 1959 through 1963, a period which included the signing of the ESO Convention on 5 October 1962 by the five founding Member States Belgium, France, Germany, the Netherlands and Sweden. Blaauw became ESO's Scientific Director in 1968. In this position he also provided the decisive push to combine the various national journals for astronomy into Astronomy and Astrophysics, which today is one of the leading astronomy research publications in the world. Blaauw succeeded Heckman as Director General of ESO in 1970, for a five-year term. During this period several telescopes including the ESO 0.5-meter and 1-meter Schmidt telescopes began operating at ESO's first observatory site, La Silla, in Chile, and much work was done on the design and construction of the ESO 3.6-meter telescope, which saw first light in 1976. Blaauw decided that it was crucial for this challenging project to move ESO's Headquarters and the Technical Department from Hamburg to Geneva, to benefit from the presence of the experienced CERN engineering group. After his ESO period, Blaauw returned to Leiden, where he continued to play a very important role in international astronomy. He was President of the International Astronomical Union from 1976 to 1979. During his tenure he used his considerable diplomatic skills to convince China to rejoin the IAU even though Taiwan was also a member. He retired from his Leiden professorship in 1981 and moved back to Groningen, but stayed active in various areas. He organized the historical archives of ESO and of the IAU - a work which resulted in two books, ESO's Early History and History of the IAU. He also served as Chairman of the Scientific Evaluation Committee for the European Space Agency satellite HIPPARCOS, which would measure the proper motions of the 100,000 brightest stars with unprecedented accuracy, and advised on many aspects of its scientific programme. When the data became available in 1996, he was actively involved in the re-analysis of the young stellar groups he had studied during his PhD research, more than fifty years earlier. Blaauw remained keenly interested in developments at ESO. He drove himself from Groningen to Garching and back for a two-day stay in July 2009 in order to take another look at the historical documents in the ESO library. He visited Chile in February 2010 during which he was driven to La Silla and then Paranal by car to enjoy Chile's beautiful landscapes and 'inspect' the telescopes on both these sites. He actively engaged young people in interesting discussions and throughout the visit displayed a crystal clear perspective on the development of astronomy in general and of ESO's program in particular, including the exciting opportunities for the future. The characteristic twinkle in his eye was as bright as always. Blaauw won many academic distinctions, including membership in many academies of science, honorary doctorates from the University of Besancon and from l'Observatoire de Paris and the Bruce Medal of the Astronomical Society of the Pacific. He was well-known for his warm personality, wisdom, humour, legendary patience, and the very rare gift of being able to slow down when the pressure mounts. The personal account of his life entitled My Cruise Through the World of Astronomy, published in the 2004 Annual Reviews of Astronomy and Astrophysics, provides an accurate and inspiring picture of a truly remarkable person, who positively influenced the lives of many others.

"Life in the Universe" Final Event Video Now Available

NASA Astrophysics Data System (ADS)

2002-02-01

ESO Video Clip 01/02 is issued on the web in conjunction with the release of a 20-min documentary video from the Final Event of the "Life in the Universe" programme. This unique event took place in November 2001 at CERN in Geneva, as part of the 2001 European Science and Technology Week, an initiative by the European Commission to raise the public awareness of science in Europe. The "Life in the Universe" programme comprised competitions in 23 European countries to identify the best projects from school students. The projects could be scientific or a piece of art, a theatrical performance, poetry or even a musical performance. The only restriction was that the final work must be based on scientific evidence. Winning teams from each country were invited to a "Final Event" at CERN on 8-11 November, 2001 to present their projects to a panel of International Experts during a special three-day event devoted to understanding the possibility of other life forms existing in our Universe. This Final Event also included a spectacular 90-min webcast from CERN with the highlights of the programme. The video describes the Final Event and the enthusiastic atmosphere when more than 200 young students and teachers from all over Europe met with some of the world's leading scientific experts of the field. The present video clip, with excerpts from the film, is available in four versions: two MPEG files and two streamer-versions of different sizes; the latter require RealPlayer software. Video Clip 01/02 may be freely reproduced. The 20-min video is available on request from ESO, for viewing in VHS and, for broadcasters, in Betacam-SP format. Please contact the ESO EPR Department for more details. Life in the Universe was jointly organised by the European Organisation for Nuclear Research (CERN) , the European Space Agency (ESA) and the European Southern Observatory (ESO) , in co-operation with the European Association for Astronomy Education (EAAE). Other research organisations were associated with the programme, e.g., the European Molecular Biology Laboratory (EMBL) and the European Synchrotron Radiation Facility (ESRF). Detailed information about the "Life in the Universe" programme can be found at the website b>http://www.lifeinuniverse.org and a webcast of this 90-min closing session in one of the large experimental halls at CERN is available on the web via that page. Most of the ESO PR Video Clips at the ESO website provide "animated" illustrations of the ongoing work and events at the European Southern Observatory. The most recent clip was: ESO PR Video Clips 08a-b/01 about The Eagle's EGGs (20 December 2001) . General information is available on the web about ESO videos.

VizieR Online Data Catalog: Collinder 261 Chandra sources & optical counterparts (Vats+, 2017)

NASA Astrophysics Data System (ADS)

Vats, S.; van den Berg, M.

2017-10-01

Cr 261 was observed with the Advanced CCD Imaging Spectrometer (ACIS) on board Chandra starting 2009 November 9 14:50 UTC, for a total exposure time of 53.8ks (ObsID 11308). We retrieved optical images of Cr 261 in the B and V bands from the ESO public archive. These data were taken as part of the ESO Imaging Survey (EIS; program ID 164.O-0561). The observations of Cr 261 were made using the Wide Field Imager (WFI), mounted on the 2.2m MPG/ESO telescope at La Silla, Chile. The Cr 261 data were taken from 2001 June 27 23:55 UTC to 2001 June 28 00:38 UTC, with a total exposure time of 510s in the B and V filter each. (2 data files).

ESO Public Surveys at VISTA: Lessons learned from Cycle 1 Surveys and the start of Cycle 2

NASA Astrophysics Data System (ADS)

Arnaboldi, M.; Delmotte, N.; Gadotti, D.; Hilker, M.; Hussain, G.; Mascetti, L.; Micol, A.; Petr-Gotzens, M.; Rejkuba, M.; Retzlaff, J.; Ivison, R.; Leibundgut, B.; Romaniello, M.

2017-06-01

The ESO Public Surveys on VISTA serve the science goals of the survey teams while increasing the legacy value of ESO programmes, thanks to their homogeneity and the breadth of their sky coverage in multiple bands. These projects address a variety of research areas: from the detection of planets via microlensing, to stars, the Milky Way and Local Group galaxies, to extragalactic astronomy, galaxy evolution, the high-redshift Universe and cosmology. In 2015, as the first generation of imaging surveys was nearing completion, a second call for Public Surveys was opened to define a coherent scientific programme for VISTA until the commissioning of the wide-field multi-fibre spectrograph, 4MOST, in 2020. This article presents the status of the Cycle 1 surveys as well as an overview of the seven new programmes in Cycle 2, including their science goals, coverage on the sky and observing strategies. We conclude with a forward look at the Cycle 2 data releases and the timelines for their release.

GROND followup of ASASSN-17gu/AT2017eip

NASA Astrophysics Data System (ADS)

Chen, Ting-Wan; Chen, Tau

2017-05-01

We observed the field of ASASSN-17gu/AT2017eip (Stone et al, ATel #10431) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2m MPG telescope at the ESO La Silla Observatory (Chile).

Czech Republic to Become Member of ESO

NASA Astrophysics Data System (ADS)

2006-12-01

Today, an agreement was signed in Prague between ESO and the Czech Republic, aiming to make the latter become a full member of ESO as of 1 January 2007. "The future membership of the Czech Republic in ESO opens for the Czech astronomers completely new opportunities and possibilities. It will foster this discipline on the highest quality level and open new opportunities for Czech industry to actively cooperate in research and development of high-tech instruments for astronomical research," said Miroslava Kopicová, Minister of Education, Youth and Sports of the Czech Republic. ESO PR Photo 52/06 ESO PR Photo 52/06 Signing Ceremony "We warmly welcome the Czech Republic as the thirteenth member of ESO," said Catherine Cesarsky, ESO's Director General. "The timing couldn't be better chosen: with the Very Large Telescope, Europe is now at the forefront of ground-based astronomy, and with the construction of ALMA and the final studies for the European Extremely Large Telescope, we will ensure that this will remain so for several decades. We look forward to working together with our Czech colleagues towards these successes." The signing event took place at the Czech Ministry of Education, Youth and Sports in Prague. Following ratification by the Czech Parliament, the Czech Republic with thus join the twelve present member states of ESO, the European Organisation for Astronomical Research in the Southern Hemisphere: Belgium, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. The Czech Republic is the first country from Central and Eastern Europe to join ESO. Astronomy in the Czech Republic has a very long tradition that dates from as far back as 3500 BC. Four centuries ago, Tycho Brahe and Johannes Kepler established themselves in Prague at the invitation of the emperor Rudolph II, laying the ground for the first golden age in astronomy. Later, eminent scientists such as Christian Doppler, Ernst Mach and Albert Einstein stayed in the famous city for periods of time. The Czech capital also played host to the General Assembly of the International Astronomical Union, first in 1967 and, more recently, in August 2006. Astronomy in the Czech Republic is shared between the Astronomical Institute of the Academy of Sciences and several leading universities, in Prague, Brno and Opava, among others. The Astronomical Institute operates the Ondrejov Observatory, with a 2-m optical telescope and a 10-m radio telescope. Czech astronomers are very active in many fields of this science, such as solar and stellar physics, and the study of interstellar matter, galaxies and planetary systems. Created in 1962, ESO, which quite fittingly means 'ace' in the Czech language, provides state-of-the-art research facilities to European astronomers and astrophysicists. ESO's activities cover a wide spectrum including the design and construction of world-class ground-based observational facilities for the member-state scientists, large telescope projects, design of innovative scientific instruments, developing new and advanced technologies, furthering European co-operation and carrying out European educational programmes. Whilst the Headquarters are located in Garching near Munich, Germany, ESO operates three observational sites in the Chilean Atacama desert. The Very Large Telescope (VLT) is located on Paranal, a 2 600m high mountain south of Antofagasta. At La Silla, 600 km north of Santiago de Chile at 2 400m altitude, ESO operates several medium-sized optical telescopes. The third site is the 5 000m high Llano de Chajnantor, near San Pedro de Atacama. Here a new submillimetre telescope (APEX) is in operation, and a giant array of 12-m submillimetre antennas (ALMA) is under development. Over 1 600 proposals are made each year for the use of the ESO telescopes.

New portrait of Omega Nebula's glistening watercolours

NASA Astrophysics Data System (ADS)

2009-07-01

The Omega Nebula, sometimes called the Swan Nebula, is a dazzling stellar nursery located about 5500 light-years away towards the constellation of Sagittarius (the Archer). An active star-forming region of gas and dust about 15 light-years across, the nebula has recently spawned a cluster of massive, hot stars. The intense light and strong winds from these hulking infants have carved remarkable filigree structures in the gas and dust. When seen through a small telescope the nebula has a shape that reminds some observers of the final letter of the Greek alphabet, omega, while others see a swan with its distinctive long, curved neck. Yet other nicknames for this evocative cosmic landmark include the Horseshoe and the Lobster Nebula. Swiss astronomer Jean-Philippe Loys de Chéseaux discovered the nebula around 1745. The French comet hunter Charles Messier independently rediscovered it about twenty years later and included it as number 17 in his famous catalogue. In a small telescope, the Omega Nebula appears as an enigmatic ghostly bar of light set against the star fields of the Milky Way. Early observers were unsure whether this curiosity was really a cloud of gas or a remote cluster of stars too faint to be resolved. In 1866, William Huggins settled the debate when he confirmed the Omega Nebula to be a cloud of glowing gas, through the use of a new instrument, the astronomical spectrograph. In recent years, astronomers have discovered that the Omega Nebula is one of the youngest and most massive star-forming regions in the Milky Way. Active star-birth started a few million years ago and continues through today. The brightly shining gas shown in this picture is just a blister erupting from the side of a much larger dark cloud of molecular gas. The dust that is so prominent in this picture comes from the remains of massive hot stars that have ended their brief lives and ejected material back into space, as well as the cosmic detritus from which future suns form. The newly released image, obtained with the EMMI instrument attached to the ESO 3.58-metre New Technology Telescope (NTT) at La Silla, Chile, shows the central region of the Omega Nebula in exquisite detail. In 2000, another instrument on the NTT, called SOFI, captured another striking image of the nebula (ESO Press Photo 24a/00) in the near-infrared, giving astronomers a penetrating view through the obscuring dust, and clearly showing many previously hidden stars. The NASA/ESA Hubble Space Telescope has also imaged small parts of this nebula (heic0305a and heic0206d) in fine detail. At the left of the image a huge and strangely box-shaped cloud of dust covers the glowing gas. The fascinating palette of subtle colour shades across the image comes from the presence of different gases (mostly hydrogen, but also oxygen, nitrogen and sulphur) that are glowing under the fierce ultraviolet light radiated by the hot young stars. More Information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Astronomy On-Line Programme Enters "hot Week"

NASA Astrophysics Data System (ADS)

1996-11-01

World's Biggest Astronomy WWW-Event Attracts Thousands of Students The Astronomy On-line Programme (See ESO Press Release 09/96 of 18 June 1996) began officially on 1 October and is now about to enter its most intense phase, known as the Hot Week . On 18 - 22 November, an estimated 4000 astronomy-interested, mostly young people in Europe and on four other continents will get together during five days in what - not unexpected - has become the world's biggest astronomy event ever organised on the World Wide Web. This carefully structured Programme is carried out in collaboration between the European Association for Astronomy Education (EAAE), the European Southern Observatory and the European Commission, under the auspices of the Fourth European Week for Scientific and Technological Culture. The Programme has already had a most visible impact on the school education of natural sciences in various countries; for instance, the Internet-connection of schools has been advanced in some, in order to allow groups to participate. There have been numerous contacts among the groups across the borders and there are clear signs that many Astronomy On-line participants have progressed to use the impressive possibilities of the Web in an efficient and structured way. There has been a lively media interest in Astronomy On-line all over Europe and it is expected to increase during the next week. The current status of Astronomy On-line It is obvious that the pilot function of the Astronomy On-line Programme in the use of the Web has been very effective and that the associated dissemination of astronomical knowledge has been successful. At this time, more than 650 groups have registered with Astronomy On-line. Most come from 31 different European countries and a few dozen groups are located in North and South America as well as in Asia and Australia. Together they have experienced the steady build-up of Astronomy On-line over the past weeks, by means of numerous contributions from a large number of teachers, amateur astronomers and others interested in this field of science. The Astronomy On-line concept is that of a well-structured marketplace with a number of different shops which cater to the participants with a great variety of interesting and educational activities. These range from the availability of useful links to educational and scientific Web sites all around the world, collaborative projects where many participants in different countries work together to achieve an astronomical result and, not the least, the possibility to submit observing programmes to a dozen telescopes at 10 major observatories, including La Silla in Chile. In the early phases of Astronomy On-line , coordinated observations were performed of a lunar eclipse on 27 September and a partial solar eclipse on 12 October. Both events attracted many hundreds of observers from groups in almost all European countries and provisional reports have already been published on the Web. Many beautiful photographs and interesting reports about the activities of the individual groups are also available at their special Web sites. The Hot Week will last from Monday to Friday, 18-22 November and the time interval from 15:00-21:00 UT (16:00 - 22:00 Central European Time) will be the busiest. During this period, a variety of activities will take place. For instance, the groups will have the opportunity to contact professional astronomers at many observatories. They will also be invited to follow the other developments, e.g. the astronomical observations. The resulting images will immediately be made available on the Web. There will also be a Final Event involving all the groups. How to obtain more information about Astronomy On-line Astronomy On-line may be accessed through: http://www.eso.org/astronomyonline/ and http://www.algonet.se/~sirius/eaae.htm. National Astronomy On-line Committees have been established in many European countries. They have set up National Astronomy On-line Web-sites which can be reached directly from the sites indicated above. Information about the individual groups, their participants' interests as well as their postal, E-mail and Web addresses are also available, sorted by country. The addresses of the National organisers of Astronomy On-line may be found at these Web sites. A full report about this unique pilot project will become available before the end of this year. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

Promoting Dark Sky Protection in Chile: the Gabriel Mistral IDA Dark Sky Sanctuary and Other AURA Initiatives

NASA Astrophysics Data System (ADS)

Smith, R. Chris; Smith, Malcolm; Pompea, Stephen; Sanhueza, Pedro; AURA-Chile EPO Team

2018-01-01

For over 20 years, AURA has been leading efforts promoting the protection of dark skies in northern Chile. Efforts began in the early 1990s at AURA's Cerro Tololo Inter-American Observatory (CTIO), working in collaboration with other international observatories in Chile including Las Campanas Observatory (LCO) and the European Southern Observatory (ESO). CTIO also partnered with local communities, for example supporting Vicuña's effort to establish the first municipal observatory in Chile. Today we have developed a multifaceted effort of dark sky protection, including proactive government relations at national and local levels, a strong educational and public outreach program, and a program of highlighting international recognition of the dark skies through the IDA Dark Sky Places program. Work on international recognition has included the declaration of the Gabriel Mistral IDA Dark Sky Sanctuary, the first such IDA sanctuary in the world.

ESO Telescope Designer Raymond Wilson Wins Prestigious Kavli Award for Astrophysics

NASA Astrophysics Data System (ADS)

2010-06-01

Raymond Wilson, whose pioneering optics research at ESO made today's giant telescopes possible thanks to "active optics" technology, has been awarded the 2010 Kavli Prize in astrophysics. The founder and original leader of the Optics and Telescopes Group at ESO, Wilson shares the million-dollar prize with two American scientists, Jerry Nelson and Roger Angel. The biennial prize, presented by the Norwegian Academy of Science and Letters, the Kavli Foundation, and the Norwegian Ministry of Education and Research, was instituted in 2008 and is given to researchers who significantly advance knowledge in the fields of nanoscience, neuroscience, and astrophysics, acting as a complement to the Nobel Prize. The award is named for and funded by Fred Kavli, the Norwegian entrepreneur and phi­lanthropist who later founded the Kavlico Corpora­tion in the US - today one of the world's largest suppliers of sensors for aeronautic, automotive and industrial applications. Wilson, who joined ESO in 1972, strived to achieve optical perfection, developing the concept of active optics as a way to enhance the size of telescopic primary mirrors. It is the size of these mirrors that determines the ability of a telescope to gather light and study faint and distant objects. Before active optics, mirrors over six metres in diameter were impossible, being too heavy, costly, and likely to bend from gravity and temperature changes. The use of active optics, which preserves optimal image quality by continually adjusting the mirror's shape during observations, made lighter, thinner so-called "meniscus mirrors" possible. Wilson first led the implementation of active optics in the revolutionary New Technology Telescope at ESO's La Silla Observatory, and continued to develop and improve the technology until his retirement in 1993. Since then, active optics have become a standard part of modern astronomy, applied in every big telescope including ESO's Very Large Telescope (VLT), a telescope array with four individual telescopes with 17.5 cm thick 8.2-metre mirrors. Active optics has contributed towards making the VLT the world's most successful ground-based observatory and will be an integral part of ESO's European Extremely Large Telescope (E-ELT) project. Active optics technology is also part of the twin 10-metre Keck telescopes, the Subaru telescope's 8.2-metre mirror and the two 8.1-metre Gemini telescopes. Co-prize winners Jerry Nelson and Roger Angel respectively pioneered the use of segmentation in telescope primary mirrors - as used on the Keck telescopes, and the development of lightweight mirrors with short focal ratios. A webcast from Oslo, Norway, announcing the prize winners is available at www.kavlifoundation.org and www.kavliprize.no. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

The Gaia-ESO Survey Astrophysical Calibration

NASA Astrophysics Data System (ADS)

Pancino, E.; Gaia-ESO Survey Consortium

2016-05-01

The Gaia-ESO Survey is a wide field spectroscopic survey recently started with the FLAMES@VLT in Cerro Paranal, Chile. It will produce radial velocities more accurate than Gaia's for faint stars (down to V ≃ 18), and astrophysical parameters and abundances for approximately 100 000 stars, belonging to all Galactic populations. 300 nights were assigned in 5 years (with the last year subject to approval after a detailed report). In particular, to connect with other ongoing and planned spectroscopic surveys, a detailed calibration program — for the astrophysical parameters derivation — is planned, including well known clusters, Gaia benchmark stars, and special equatorial calibration fields designed for wide field/multifiber spectrographs.

NGC1300 dynamics - II. The response models

NASA Astrophysics Data System (ADS)

Kalapotharakos, C.; Patsis, P. A.; Grosbøl, P.

2010-10-01

We study the stellar response in a spectrum of potentials describing the barred spiral galaxy NGC1300. These potentials have been presented in a previous paper and correspond to three different assumptions as regards the geometry of the galaxy. For each potential we consider a wide range of Ωp pattern speed values. Our goal is to discover the geometries and the Ωp supporting specific morphological features of NGC1300. For this purpose we use the method of response models. In order to compare the images of NGC1300 with the density maps of our models, we define a new index which is a generalization of the Hausdorff distance. This index helps us to find out quantitatively which cases reproduce specific features of NGC1300 in an objective way. Furthermore, we construct alternative models following a Schwarzschild-type technique. By this method we vary the weights of the various energy levels, and thus the orbital contribution of each energy, in order to minimize the differences between the response density and that deduced from the surface density of the galaxy, under certain assumptions. We find that the models corresponding to Ωp ~ 16 and 22 kms-1kpc-1 are able to reproduce efficiently certain morphological features of NGC1300, with each one having its advantages and drawbacks. Based on observations collected at the European Southern Observatory, Chile: programme ESO 69.A-0021. E-mail: ckalapot@phys.uoa.gr (CK); patsis@academyofathens.gr (PAP); pgrosbol@eso.org (PG)

A Hubble Diagram from Type II Supernovae Based Solely on Photometry: The Photometric Color Method

NASA Astrophysics Data System (ADS)

de Jaeger, T.; González-Gaitán, S.; Anderson, J. P.; Galbany, L.; Hamuy, M.; Phillips, M. M.; Stritzinger, M. D.; Gutiérrez, C. P.; Bolt, L.; Burns, C. R.; Campillay, A.; Castellón, S.; Contreras, C.; Folatelli, G.; Freedman, W. L.; Hsiao, E. Y.; Krisciunas, K.; Krzeminski, W.; Kuncarayakti, H.; Morrell, N.; Olivares E., F.; Persson, S. E.; Suntzeff, N.

2015-12-01

We present a Hubble diagram of SNe II using corrected magnitudes derived only from photometry, with no input of spectral information. We use a data set from the Carnegie Supernovae Project I for which optical and near-infrared light curves were obtained. The apparent magnitude is corrected by two observables, one corresponding to the slope of the plateau in the V band and the second a color term. We obtain a dispersion of 0.44 mag using a combination of the (V - i) color and the r band and we are able to reduce the dispersion to 0.39 mag using our golden sample. A comparison of our photometric color method (PCM) with the standardized candle method (SCM) is also performed. The dispersion obtained for the SCM (which uses both photometric and spectroscopic information) is 0.29 mag, which compares with 0.43 mag from the PCM for the same SN sample. The construction of a photometric Hubble diagram is of high importance in the coming era of large photometric wide-field surveys, which will increase the detection rate of supernovae by orders of magnitude. Such numbers will prohibit spectroscopic follow up in the vast majority of cases, and hence methods must be deployed which can proceed using solely photometric data. This paper includes data gathered with the 6.5 m Magellan Telescopes, with the du Pont and Swope telescopes located at Las Campanas Observatory, Chile, and the Gemini Observatory, Cerro Pachon, Chile (Gemini Program GS-2008B-Q-56). Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile (ESO Programmes 076.A-0156,078.D-0048, 080.A-0516, and 082.A-0526).

VizieR Online Data Catalog: JHK photometry near IRAS 06145+1455 (Brand+, 2007)

NASA Astrophysics Data System (ADS)

Brand, J.; Wouterloot, J. G. A.

2007-09-01

The data presented here were obtained on February 15, 1995, with the ESO 2.2-m telescope at La Silla (Chile). Images in J, H, and K-bands were taken with the IRAC-2 camera and objective C, which resulted in a scale of 0.49"/pixel. (1 data file).

VizieR Online Data Catalog: Proper motions and photometry of stars in NGC 3201 (Sariya+, 2017)

NASA Astrophysics Data System (ADS)

Sariya, D. P.; Jiang, I.-G.; Yadav, R. K. S.

2017-07-01

To determine the PMs of the stars in this work, we used archive images (http://archive.eso.org/eso/esoarchivemain.html) from observations made with the 2.2m ESO/MPI telescope at La Silla, Chile. This telescope contains a mosaic camera called the Wide-Field Imager (WFI), consisting of 4*2 (i.e., 8 CCD chips). Since each CCD has an array of 2048*4096 pixels, WFI ultimately produces images with a 34*33arcmin2 field of view. The observational run of the first epoch contains two images in B,V and I bands, each with 240s exposure time observed on 1999 December 05. In the second epoch, we have 35 images with 40s exposure time each in V filter observed during the period of 2014 April 02-05. Thus the epoch gap between the data is ~14.3 years. (2 data files).

Observing facilities at the European Southern Observatory (ESO) in Chile for cometary observations

NASA Technical Reports Server (NTRS)

Schnur, G. F. O.; Kohoutek, L.; Rahe, J.

1981-01-01

The (ESO) is located on the mountain La Silla (geographical coordinates: 4h42m55s10 west, -29 deg 15' 25".8 south, 2400 m elevation. The size of the telescopes ranges from a 40 cm Astrograph to the 3.6 m Richey-Chretien telescope. Future telescopes are discussed: a 2.2 m RC-Telescope which will be identical with the German 2.2 m telescope on Calor Alto in SE-Spain, and a 3.5 m telescope, the New Technology Telescope. In addition to these telescopes, a great number of auxiliary instrumentation are operational. Because ESO has to serve all requests of the visiting astronomers these instruments are designed for very different applications. The telescopes and auxiliary instruments that are especially suited for cometary observations are discussed. The dicussion is divided into three parts: photography, photometry-polarimetry and spectroscopy.

The Cosmic Christmas Ghost - Two Stunning Pictures of Young Stellar Clusters

NASA Astrophysics Data System (ADS)

2005-12-01

Just like Charles Dickens' Christmas Carol takes us on a journey into past, present and future in the time of only one Christmas Eve, two of ESO' s telescopes captured various stages in the life of a star in a single image. ESO PR Photo 42a/05 shows the area surrounding the stellar cluster NGC 2467, located in the southern constellation of Puppis (" The Stern" ). With an age of a few million years at most, it is a very active stellar nursery, where new stars are born continuously from large clouds of dust and gas. The image, looking like a colourful cosmic ghost or a gigantic celestial Mandrill [1] , contains the open clusters Haffner 18 (centre) and Haffner 19 (middle right: it is located inside the smaller pink region - the lower eye of the Mandrill), as well as vast areas of ionised gas. The bright star at the centre of the largest pink region on the bottom of the image is HD 64315, a massive young star that is helping shaping the structure of the whole nebular region. ESO PR Photo 42a/05 was taken with the Wide-Field Imager camera at the 2.2m MPG/ESO telescope located at La Silla, in Chile. Another image of the central part of this area is shown as ESO PR Photo 42b/05. It was obtained with the FORS2 instrument at ESO' s Very Large Telescope on Cerro Paranal, also in Chile. ESO PR Photo 42b/05 zooms in on the open stellar cluster Haffner 18, perfectly illustrating three different stages of this process of star formation: In the centre of the picture, Haffner 18, a group of mature stars that have already dispersed their birth nebulae, represents the completed product or immediate past of the star formation process. Located at the bottom left of this cluster, a very young star, just come into existence and, still surrounded by its birth cocoon of gas, provides insight into the very present of star birth. Finally, the dust clouds towards the right corner of the image are active stellar nurseries that will produce more new stars in the future. Haffner 18 contains about 50 stars, among which several short lived, massive ones. The massive star still surrounded by a small, dense shell of hydrogen, has the rather cryptic name of FM3060a. The shell is about 2.5 light-years wide and expands at a speed of 20 km/s. It must have been created some 40,000 years ago. The cluster is between 25,000 and 30,000 light-years away from us [2]. Technical information: ESO PR Photo 42a/05 is based on images obtained with the WFI instrument on the ESO/MPG 2.2-m telescope for Rubio/Minniti/Barba/Mendez on December, 2003. The 49 observations were done in six different filters : U (2 hour exposure), B, O III, V, H-alpha and R (1 hour exposure each). The data were extracted from the ESO Science Archive. The raw observations were reduced and combined by Benoî t Vandame (ESO). North is right and East is to the top. The field of view is about 30x30 arcmin. ESO PR Photo 42a/05 is a colour-composite image obtained with the FORS2 multi-mode instrument on Kueyen, the second Unit Telescope of the Very Large Telescope. The data was collected during the commissioning of the instrument in February 2000, through 4 filters: B, V, R and I, for a total exposure time of only 11 minutes. The observations were extracted from the ESO Science Archive and reduced by Henri Boffin (ESO). North is above and East is to the left. Final processing of ESO PR Photo 42a/05 and 42b/05 was done by Kristina Boneva and Haennes Heyer (ESO).

Gruber Prize in Cosmology Awarded for the Discovery of the Accelerated Expansion of the Universe

NASA Astrophysics Data System (ADS)

2007-09-01

Nearly a decade ago astronomers from two competing teams announced that they had found evidence for an accelerated cosmic expansion. The Gruber Prize in Cosmology 2007 honours this achievement and has been awarded to two groups: the Supernova Cosmology Project team, led by Saul Perlmutter (Lawrence Berkeley Laboratory), and the High-z Supernova Search Team, led by Brian Schmidt (Australian National University). Their results were based on the observations of distant Type Ia supernovae and were obtained with the major telescopes at the time (Riess et al. 1998, AJ 116, 1009; Perlmutter et al. 1999, ApJ 517, 565). Both teams used the 3.6-m telescope and the NTT to contribute photometry and spectroscopic classifications of the supernovae. Four people at ESO were directly involved in the two teams and are recognised as co-recipients of the Gruber Prize. Isobel Hook (now at Oxford University) and Chris Lidman (ESO Chile) were ESO Fellows when they contributed to the work of the Super- nova Cosmology Project, while Jason Spyromilio and Bruno Leibundgut (both ESO Garching) participated in the High-z Supernova Search Team.

The ESO Diffuse Interstellar Bands Large Exploration Survey: EDIBLES I. Project description, survey sample and quality assessment.

PubMed

Cox, Nick L J; Cami, Jan; Farhang, Amin; Smoker, Jonathan; Monreal-Ibero, Ana; Lallement, Rosine; Sarre, Peter J; Marshall, Charlotte C M; Smith, Keith T; Evans, Christopher J; Royer, Pierre; Linnartz, Harold; Cordiner, Martin A; Joblin, Christine; van Loon, Jacco Th; Foing, Bernard H; Bhatt, Neil H; Bron, Emeric; Elyajouri, Meriem; de Koter, Alex; Ehrenfreund, Pascale; Javadi, Atefeh; Kaper, Lex; Khosroshadi, Habib G; Laverick, Mike; Le Petit, Franck; Mulas, Giacomo; Roueff, Evelyne; Salama, Farid; Spaans, Marco

2017-10-01

The carriers of the diffuse interstellar bands (DIBs) are largely unidentified molecules ubiquitously present in the interstellar medium (ISM). After decades of study, two strong and possibly three weak near-infrared DIBs have recently been attributed to the [Formula: see text] fullerene based on observational and laboratory measurements. There is great promise for the identification of the over 400 other known DIBs, as this result could provide chemical hints towards other possible carriers. In an effort to systematically study the properties of the DIB carriers, we have initiated a new large-scale observational survey: the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES). The main objective is to build on and extend existing DIB surveys to make a major step forward in characterising the physical and chemical conditions for a statistically significant sample of interstellar lines-of-sight, with the goal to reverse-engineer key molecular properties of the DIB carriers. EDIBLES is a filler Large Programme using the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope at Paranal, Chile. It is designed to provide an observationally unbiased view of the presence and behaviour of the DIBs towards early-spectral type stars whose lines-of-sight probe the diffuse-to-translucent ISM. Such a complete dataset will provide a deep census of the atomic and molecular content, physical conditions, chemical abundances and elemental depletion levels for each sightline. Achieving these goals requires a homogeneous set of high-quality data in terms of resolution ( R ~ 70 000 - 100 000), sensitivity (S/N up to 1000 per resolution element), and spectral coverage (305-1042 nm), as well as a large sample size (100+ sightlines). In this first paper the goals, objectives and methodology of the EDIBLES programme are described and an initial assessment of the data is provided.

The ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES) . I. Project description, survey sample, and quality assessment

NASA Astrophysics Data System (ADS)

Cox, Nick L. J.; Cami, Jan; Farhang, Amin; Smoker, Jonathan; Monreal-Ibero, Ana; Lallement, Rosine; Sarre, Peter J.; Marshall, Charlotte C. M.; Smith, Keith T.; Evans, Christopher J.; Royer, Pierre; Linnartz, Harold; Cordiner, Martin A.; Joblin, Christine; van Loon, Jacco Th.; Foing, Bernard H.; Bhatt, Neil H.; Bron, Emeric; Elyajouri, Meriem; de Koter, Alex; Ehrenfreund, Pascale; Javadi, Atefeh; Kaper, Lex; Khosroshadi, Habib G.; Laverick, Mike; Le Petit, Franck; Mulas, Giacomo; Roueff, Evelyne; Salama, Farid; Spaans, Marco

2017-10-01

The carriers of the diffuse interstellar bands (DIBs) are largely unidentified molecules ubiquitously present in the interstellar medium (ISM). After decades of study, two strong and possibly three weak near-infrared DIBs have recently been attributed to the C60^+ fullerene based on observational and laboratory measurements. There is great promise for the identification of the over 400 other known DIBs, as this result could provide chemical hints towards other possible carriers. In an effort tosystematically study the properties of the DIB carriers, we have initiated a new large-scale observational survey: the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES). The main objective is to build on and extend existing DIB surveys to make a major step forward in characterising the physical and chemical conditions for a statistically significant sample of interstellar lines-of-sight, with the goal to reverse-engineer key molecular properties of the DIB carriers. EDIBLES is a filler Large Programme using the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope at Paranal, Chile. It is designed to provide an observationally unbiased view of the presence and behaviour of the DIBs towards early-spectral-type stars whose lines-of-sight probe the diffuse-to-translucent ISM. Such a complete dataset will provide a deep census of the atomic and molecular content, physical conditions, chemical abundances and elemental depletion levels for each sightline. Achieving these goals requires a homogeneous set of high-quality data in terms of resolution (R 70 000-100 000), sensitivity (S/N up to 1000 per resolution element), and spectral coverage (305-1042 nm), as well as a large sample size (100+ sightlines). In this first paper the goals, objectives and methodology of the EDIBLES programme are described and an initial assessment of the data is provided.

HATS-1b: The First Transiting Planet Discovered by the HATSouth Survey

NASA Astrophysics Data System (ADS)

Penev, K.; Bakos, G. Á.; Bayliss, D.; Jordán, A.; Mohler, M.; Zhou, G.; Suc, V.; Rabus, M.; Hartman, J. D.; Mancini, L.; Béky, B.; Csubry, Z.; Buchhave, L.; Henning, T.; Nikolov, N.; Csák, B.; Brahm, R.; Espinoza, N.; Conroy, P.; Noyes, R. W.; Sasselov, D. D.; Schmidt, B.; Wright, D. J.; Tinney, C. G.; Addison, B. C.; Lázár, J.; Papp, I.; Sári, P.

2013-01-01

We report the discovery of HATS-1b, a transiting extrasolar planet orbiting the moderately bright V = 12.05 G dwarf star GSC 6652-00186, and the first planet discovered by HATSouth, a global network of autonomous wide-field telescopes. HATS-1b has a period of P ≈ 3.4465 days, mass of Mp ≈ 1.86 M J, and radius of Rp ≈ 1.30 R J. The host star has a mass of 0.99 M ⊙ and radius of 1.04 R ⊙. The discovery light curve of HATS-1b has near-continuous coverage over several multi-day timespans, demonstrating the power of using a global network of telescopes to discover transiting planets. The HATSouth network is operated by a collaboration consisting of Princeton University (PU), the Max Planck Institute für Astronomie (MPIA), and the Australian National University (ANU). The station at Las Campanas Observatory (LCO) of the Carnegie Institute, is operated by PU in conjunction with collaborators at the Pontificia Universidad Católica de Chile (PUC), the station at the High Energy Spectroscopic Survey (HESS) site is operated in conjunction with MPIA, and the station at Siding Spring Observatory (SSO) is operated jointly with ANU. Based in part on observations made with the Nordic Optical Telescope, operated on the island of La Palma in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. Based on observations made with the MPG/ESO 2.2 m Telescope at the ESO Observatory in La Silla. FEROS ID programmes: P087.A-9014(A), P088.A-9008(A), P089.A-9008(A), P087.C-0508(A). GROND ID programme: 089.A-9006(A). This paper uses observations obtained with facilities of the Las Cumbres Observatory Global Telescope.

The ESO Diffuse Interstellar Bands Large Exploration Survey: EDIBLES I. Project description, survey sample and quality assessment

PubMed Central

Cox, Nick L. J.; Cami, Jan; Farhang, Amin; Smoker, Jonathan; Monreal-Ibero, Ana; Lallement, Rosine; Sarre, Peter J.; Marshall, Charlotte C. M.; Smith, Keith T.; Evans, Christopher J.; Royer, Pierre; Linnartz, Harold; Cordiner, Martin A.; Joblin, Christine; van Loon, Jacco Th.; Foing, Bernard H.; Bhatt, Neil H.; Bron, Emeric; Elyajouri, Meriem; de Koter, Alex; Ehrenfreund, Pascale; Javadi, Atefeh; Kaper, Lex; Khosroshadi, Habib G.; Laverick, Mike; Le Petit, Franck; Mulas, Giacomo; Roueff, Evelyne; Salama, Farid; Spaans, Marco

2017-01-01

The carriers of the diffuse interstellar bands (DIBs) are largely unidentified molecules ubiquitously present in the interstellar medium (ISM). After decades of study, two strong and possibly three weak near-infrared DIBs have recently been attributed to the C60+ fullerene based on observational and laboratory measurements. There is great promise for the identification of the over 400 other known DIBs, as this result could provide chemical hints towards other possible carriers. In an effort to systematically study the properties of the DIB carriers, we have initiated a new large-scale observational survey: the ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES). The main objective is to build on and extend existing DIB surveys to make a major step forward in characterising the physical and chemical conditions for a statistically significant sample of interstellar lines-of-sight, with the goal to reverse-engineer key molecular properties of the DIB carriers. EDIBLES is a filler Large Programme using the Ultraviolet and Visual Echelle Spectrograph at the Very Large Telescope at Paranal, Chile. It is designed to provide an observationally unbiased view of the presence and behaviour of the DIBs towards early-spectral type stars whose lines-of-sight probe the diffuse-to-translucent ISM. Such a complete dataset will provide a deep census of the atomic and molecular content, physical conditions, chemical abundances and elemental depletion levels for each sightline. Achieving these goals requires a homogeneous set of high-quality data in terms of resolution (R ~ 70 000 – 100 000), sensitivity (S/N up to 1000 per resolution element), and spectral coverage (305–1042 nm), as well as a large sample size (100+ sightlines). In this first paper the goals, objectives and methodology of the EDIBLES programme are described and an initial assessment of the data is provided. PMID:29151608

VizieR Online Data Catalog: GOODS-S CANDELS multiwavelength catalog (Guo+, 2013)

NASA Astrophysics Data System (ADS)

Guo, Y.; Ferguson, H. C.; Giavalisco, M.; Barro, G.; Willner, S. P.; Ashby, M. L. N.; Dahlen, T.; Donley, J. L.; Faber, S. M.; Fontana, A.; Galametz, A.; Grazian, A.; Huang, K.-H.; Kocevski, D. D.; Koekemoer, A. M.; Koo, D. C.; McGrath, E. J.; Peth, M.; Salvato, M.; Wuyts, S.; Castellano, M.; Cooray, A. R.; Dickinson, M. E.; Dunlop, J. S.; Fazio, G. G.; Gardner, J. P.; Gawiser, E.; Grogin, N. A.; Hathi, N. P.; Hsu, L.-T.; Lee, K.-S.; Lucas, R. A.; Mobasher, B.; Nandra, K.; Newman, J. A.; van der Wel, A.

2014-04-01

The Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS; Grogin et al. 2011ApJS..197...35G; Koekemoer et al. 2011ApJS..197...36K) is designed to document galaxy formation and evolution over the redshift range of z=1.5-8. The core of CANDELS is to use the revolutionary near-infrared HST/WFC3 camera, installed on HST in 2009 May, to obtain deep imaging of faint and faraway objects. The GOODS-S field, centered at RAJ2000=03:32:30 and DEJ2000=-27:48:20 and located within the Chandra Deep Field South (CDFS; Giacconi et al. 2002, Cat. J/ApJS/139/369), is a sky region of about 170arcmin2 which has been targeted for some of the deepest observations ever taken by NASA's Great Observatories, HST, Spitzer, and Chandra as well as by other world-class telescopes. The field has been (among others) imaged in the optical wavelength with HST/ACS in F435W, F606W, F775W, and F850LP bands as part of the HST Treasury Program: the Great Observatories Origins Deep Survey (GOODS; Giavalisco et al. 2004, Cat. II/261); in the mid-IR (3.6-24um) wavelength with Spitzer as part of the GOODS Spitzer Legacy Program (PI: M. Dickinson). The CDF-S/GOODS field was observed by the MOSAIC II imager on the CTIO 4m Blanco telescope to obtain deep U-band observations in 2001 September. Another U-band survey in GOODS-S was carried out using the VIMOS instrument mounted at the Melipal Unit Telescope of the VLT at ESO's Cerro Paranal Observatory, Chile. This large program of ESO (168.A-0485; PI: C. Cesarsky) was obtained in service mode observations in UT3 between 2004 August and fall 2006. In the ground-based NIR, imaging observations of the CDFS were carried out in J, H, Ks bands using the ISAAC instrument mounted at the Antu Unit Telescope of the VLT. Data were obtained as part of the ESO Large Programme 168.A-0485 (PI: C. Cesarsky) as well as ESO Programmes 64.O-0643, 66.A-0572, and 68.A-0544 (PI: E. Giallongo) with a total allocation time of ~500 hr from 1999 October to 2007 January. The CANDELS/GOODS-S field was also observed in the NIR as part of the ongoing HAWK-I UDS and GOODS-S survey (HUGS; VLT large program ID 186.A-0898; PI: A. Fontana; A. Fontana et al., in preparation) using the High Acuity Wide field K-band Imager (HAWK-I) on VLT. (1 data file).

A Roof for ALMA

NASA Astrophysics Data System (ADS)

2007-03-01

On 10 March, an official ceremony took place on the 2,900m high site of the Atacama Large Millimeter/submillimeter Array (ALMA) Operations Support Facility, from where the ALMA antennas will be remotely controlled. The ceremony marked the completion of the structural works, while the building itself will be finished by the end of the year. This will become the operational centre of one of the most important ground-based astronomical facilities on Earth. ESO PR Photo 13a/07 ESO PR Photo 13a/07 Cutting the Red Ribbon The ceremony, known as 'Tijerales' in Chile, is the equivalent to the 'roof-topping ceremony' that takes place worldwide, in one form or another, to celebrate reaching the highest level of a construction. It this case, the construction is the unique ALMA Operations Support Facility (OSF), located near the town of San Pedro de Atacama. "The end of this first stage represents an historic moment for ALMA," said Hans Rykaczewski, the European ALMA Project Manager. "Once completed in December 2007, this monumental building of 7,000 square metres will be one of the largest and most important astronomical operation centres in the world." ALMA, located at an elevation of 5,000m in the Atacama Desert of northern Chile, will provide astronomers with the world's most advanced tool for exploring the Universe at millimetre and submillimetre wavelengths. ALMA will detect fainter objects and be able to produce much higher-quality images at these wavelengths than any previous telescope system. The OSF buildings are designed to suit the requirements of this exceptional observatory in a remote, desert location. The facility, which will host about 100 people during operations, consists of three main buildings: the technical building, hosting the control centre of the observatory, the antenna assembly building, including four antenna foundations for testing and maintenance purposes, and the warehouse building, including mechanical workshops. Further secondary buildings are the transporter shelters and the vehicle maintenance facilities as well as the ALMA gate house. The construction started in August 2006 and will be completed in December 2007. ESO PR Photo 13b/07 ESO PR Photo 13b/07 The Ceremony The ceremony took place in the presence of representatives of the regional authorities, members of the Chilean Parliament, and representatives of the local community, including the mayor of San Pedro, Ms. Sandra Berna, who joined more than 40 representatives of ESO, NRAO and NAOJ - the organisations that are, together, building ALMA. "This is certainly a big step in the realisation of the ALMA Project. The completion of this facility will be essential for assembly, testing and adjustment as well as operation and maintenance of all ALMA antennas from Europe, North America and from Japan," said Ryusuke Ogasawara, the representative of NAOJ in Chile. "This is a tremendous achievement and represents a major milestone for the ALMA project," said Adrian Russell, North American Project Manager for ALMA. ESO PR Photo 13c/07 ESO PR Photo 13c/07 The OSF (Artist's View) The first ALMA antennas, the prototypes of which successfully achieved their first combined astronomical observation last week, are expected to arrive at the ALMA site in a few months. These huge antennas will travel in pieces from Europe, USA and Japan and will be assembled next to the OSF building. The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership among Europe, Japan and North America, in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organisation for Astronomical Research in the Southern Hemisphere, in Japan by the National Institutes of Natural Sciences (NINS) in cooperation with the Academia Sinica in Taiwan and in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC). ALMA construction and operations are led on behalf of Europe by ESO, on behalf of Japan by the National Astronomical Observatory of Japan (NAOJ) and on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI)

The Light and Dark Face of a Star-Forming Nebula

NASA Astrophysics Data System (ADS)

2010-03-01

Today, ESO is unveiling an image of the little known Gum 19, a faint nebula that, in the infrared, appears dark on one half and bright on the other. On one side hot hydrogen gas is illuminated by a supergiant blue star called V391 Velorum. New star formation is taking place within the ribbon of luminous and dark material that brackets V391 Velorum's left in this perspective. After many millennia, these fledgling stars, coupled with the explosive demise of V391 Velorum as a supernova, will likely alter Gum 19's present Janus-like appearance. Gum 19 is located in the direction of the constellation Vela (the Sail) at a distance of approximately 22 000 light years. The Gum 19 moniker derives from a 1955 publication by the Australian astrophysicist Colin S. Gum that served as the first significant survey of so-called HII (read "H-two") regions in the southern sky. HII refers to hydrogen gas that is ionised, or energised to the extent that the hydrogen atoms lose their electrons. Such regions emit light at well-defined wavelengths (or colours), thereby giving these cosmic clouds their characteristic glow. And indeed, much like terrestrial clouds, the shapes and textures of these HII regions change as time passes, though over the course of eons rather than before our eyes. For now, Gum 19 has somewhat of a science fiction-esque, "rip in spacetime" look to it in this image, with a narrow, near-vertical bright region slashing across the nebula. Looking at it, you could possibly see a resemblance to a two-toned angelfish or an arrow with a darkened point. This new image of the evocative Gum 19 object was captured by an infrared instrument called SOFI, mounted on ESO's New Technology Telescope (NTT) that operates at the La Silla Observatory in Chile. SOFI stands for Son of ISAAC, after the "father" instrument, ISAAC, that is located at ESO's Very Large Telescope observatory at Paranal to the north of La Silla. Observing this nebula in the infrared allows astronomers to see through at least parts of the dust. The furnace that fuels Gum 19's luminosity is a gigantic, superhot star called V391 Velorum. Shining brightest in the scorching blue range of visible light, V391 Velorum boasts a surface temperature in the vicinity of 30 000 degrees Celsius. This massive star has a temperamental nature, however, and is categorised as a variable star accordingly. V391 Velorum's brightness can fluctuate suddenly as a result of strong activity that can include ejections of shells of matter, which contribute to Gum 19's composition and light emissions. Stars on the grand scale of V391 Velorum do not burn bright for long, and after a relatively short lifetime of about ten million years these titans blow up as supernovae. These explosions, which temporarily rival whole galaxies in their light intensity, blast heated matter in surrounding space, an event that can radically change the colour and shape of its enclosing nebula. As such, V391 Velorum's death throes may well leave Gum 19 unrecognisable. Within the neighbourhood of this fitful supergiant, new stars nonetheless continue to grow. HII regions denote sites of active star formation wherein great quantities of gas and dust have begun to collapse under their own gravity. In several million years - a blink of an eye in cosmic time - these shrinking knots of matter will eventually reach the high density at their centres necessary to ignite nuclear fusion. The fresh outpouring of energy and stellar winds from these newborn stars will also modify the gaseous landscape of Gum 19. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Information on Vinchucas and Chagas disease.

NASA Astrophysics Data System (ADS)

Schenone, H.

1981-12-01

Following a significant increase in the number of vinchucas observed at La Silla during the last summer, the Director-General of ESO asked Prof. Hugo Schenone, Director of the Department of Microbiology and Parasitology of the University of Chile to pay a visit to La Silla to investigate the situation. The following gives a summary of the resulting report.

Dynamical Mass of the O-Type Supergiant in Zeta Orionis A

DTIC Science & Technology

2013-01-01

A. Hummel1, Th. Rivinius2, M.-F. Nieva3,4, O. Stahl5, G. van Belle6, and R. T. Zavala7 1 European Southern Observatory, Karl - Schwarzschild -Str. 2...85748 Garching, Germany e-mail: chummel@eso.org 2 European Southern Observatory, Casilla 19001, Santiago 19, Chile 3 Dr. Karl Remeis–Sternwarte & ECAP

Spectrum of Th-Ar Hollow Cathode Lamps

National Institute of Standards and Technology Data Gateway

SRD 161 NIST Spectrum of Th-Ar Hollow Cathode Lamps (Web, free access)   This atlas presents observations of the infra-red (IR) spectrum of a low current Th-Ar hollow cathode lamp with the 2-m Fourier transform spectrometer (FTS) at NIST. These observations establish more than 2400 lines that are suitable for use as wavelength standards in the range 691 nm to 5804 nm. The observations were made in collaboration with the European Southern Observatory (ESO), in order to provide calibration reference data for new high-resolution Echelle spectrographs, such as the Cryogenic High-Resolution IR Echelle Spectrograph ([CRIRES]), ESO's new IR spectrograph at the Very Large Telescope in Chile.

An Elegant Galaxy in an Unusual Light

NASA Astrophysics Data System (ADS)

2010-09-01

A new image taken with the powerful HAWK-I camera on ESO's Very Large Telescope at Paranal Observatory in Chile shows the beautiful barred spiral galaxy NGC 1365 in infrared light. NGC 1365 is a member of the Fornax cluster of galaxies, and lies about 60 million light-years from Earth. NGC 1365 is one of the best known and most studied barred spiral galaxies and is sometimes nicknamed the Great Barred Spiral Galaxy because of its strikingly perfect form, with the straight bar and two very prominent outer spiral arms. Closer to the centre there is also a second spiral structure and the whole galaxy is laced with delicate dust lanes. This galaxy is an excellent laboratory for astronomers to study how spiral galaxies form and evolve. The new infrared images from HAWK-I are less affected by the dust that obscures parts of the galaxy than images in visible light (potw1037a) and they reveal very clearly the glow from vast numbers of stars in both the bar and the spiral arms. These data were acquired to help astronomers understand the complex flow of material within the galaxy and how it affects the reservoirs of gas from which new stars can form. The huge bar disturbs the shape of the gravitational field of the galaxy and this leads to regions where gas is compressed and star formation is triggered. Many huge young star clusters trace out the main spiral arms and each contains hundreds or thousands of bright young stars that are less than ten million years old. The galaxy is too remote for single stars to be seen in this image and most of the tiny clumps visible in the picture are really star clusters. Over the whole galaxy, stars are forming at a rate of about three times the mass of our Sun per year. While the bar of the galaxy consists mainly of older stars long past their prime, many new stars are born in stellar nurseries of gas and dust in the inner spiral close to the nucleus. The bar also funnels gas and dust gravitationally into the very centre of the galaxy, where astronomers have found evidence for the presence of a super-massive black hole, well hidden among myriads of intensely bright new stars. NGC 1365, including its two huge outer spiral arms, spreads over around 200 000 light-years. Different parts of the galaxy take different times to make a full rotation around the core of the galaxy, with the outer parts of the bar completing one circuit in about 350 million years. NGC 1365 and other galaxies of its type have come to more prominence in recent years with new observations indicating that the Milky Way could also be a barred spiral galaxy. Such galaxies are quite common - two thirds of spiral galaxies are barred according to recent estimates, and studying others can help astronomers understand our own galactic home. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Planet from another galaxy discovered - Galactic cannibalism brings an exoplanet of extragalactic origin within astronomers' reach

NASA Astrophysics Data System (ADS)

2010-11-01

An exoplanet orbiting a star that entered our Milky Way from another galaxy has been detected by a European team of astronomers using the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. The Jupiter-like planet is particularly unusual, as it is orbiting a star nearing the end of its life and could be about to be engulfed by it, giving tantalising clues about the fate of our own planetary system in the distant future. Over the last 15 years, astronomers have detected nearly 500 planets orbiting stars in our cosmic neighbourhood, but none outside our Milky Way has been confirmed [1]. Now, however, a planet with a minimum mass 1.25 times that of Jupiter [2] has been discovered orbiting a star of extragalactic origin, even though the star now finds itself within our own galaxy. It is part of the so-called Helmi stream [3] - a group of stars that originally belonged to a dwarf galaxy that was devoured by our galaxy, the Milky Way, in an act of galactic cannibalism about six to nine billion years ago. The results are published today in Science Express. "This discovery is very exciting," says Rainer Klement of the Max-Planck-Institut für Astronomie (MPIA), who was responsible for the selection of the target stars for this study. "For the first time, astronomers have detected a planetary system in a stellar stream of extragalactic origin. Because of the great distances involved, there are no confirmed detections of planets in other galaxies. But this cosmic merger has brought an extragalactic planet within our reach." The star is known as HIP 13044, and it lies about 2000 light-years from Earth in the southern constellation of Fornax (the Furnace). The astronomers detected the planet, called HIP 13044 b, by looking for the tiny telltale wobbles of the star caused by the gravitational tug of an orbiting companion. For these precise observations, the team used the high-resolution spectrograph FEROS [4] attached to the 2.2-metre MPG/ESO telescope [5] at ESO's La Silla Observatory in Chile. Adding to its claim to fame, HIP 13044 b is also one of the few exoplanets known to have survived the period when its host star expanded massively after exhausting the hydrogen fuel supply in its core - the red giant phase of stellar evolution. The star has now contracted again and is burning helium in its core. Until now, these so-called horizontal branch stars have remained largely uncharted territory for planet-hunters. "This discovery is part of a study where we are systematically searching for exoplanets that orbit stars nearing the end of their lives," says Johny Setiawan, also from MPIA, who led the research. "This discovery is particularly intriguing when we consider the distant future of our own planetary system, as the Sun is also expected to become a red giant in about five billion years." HIP 13044 b is near to its host star. At the closest point in its elliptical orbit, it is less than one stellar diameter from the surface of the star (or 0.055 times the Sun-Earth distance). It completes an orbit in only 16.2 days. Setiawan and his colleagues hypothesise that the planet's orbit might initially have been much larger, but that it moved inwards during the red giant phase. Any closer-in planets may not have been so lucky. "The star is rotating relatively quickly for an horizontal branch star," says Setiawan. "One explanation is that HIP 13044 swallowed its inner planets during the red giant phase, which would make the star spin more quickly." Although HIP 13044 b has escaped the fate of these inner planets so far, the star will expand again in the next stage of its evolution. HIP 13044 b may therefore be about to be engulfed by the star, meaning that it is doomed after all. This could also foretell the demise of our outer planets - such as Jupiter - when the Sun approaches the end of its life. The star also poses interesting questions about how giant planets form, as it appears to contain very few elements heavier than hydrogen and helium - fewer than any other star known to host planets. "It is a puzzle for the widely accepted model of planet formation to explain how such a star, which contains hardly any heavy elements at all, could have formed a planet. Planets around stars like this must probably form in a different way," adds Setiawan. Notes [1] There have been tentative claims of the detection of extragalactic exoplanets through "gravitational microlensing" events, in which the planet passing in front of an even more distant star leads to a subtle, but detectable "flash". However, this method relies on a singular event - the chance alignment of a distant light source, planetary system and observers on Earth - and no such extragalactic planet detection has been confirmed. [2] Using the radial velocity method, astronomers can only estimate a minimum mass for a planet, as the mass estimate also depends on the tilt of the orbital plane relative to the line of sight, which is unknown. From a statistical point of view, this minimum mass is however often close to the real mass of the planet. [3] Astronomers can identify members of the Helmi stream as they have motions (velocity and orbits) that are rather different from the average Milky Way stars. [4] FEROS stands for Fibre-fed Extended Range Optical Spectrograph. [5] The 2.2-metre telescope has been in operation at La Silla since early 1984 and is on indefinite loan to ESO from the Max-Planck Society (Max Planck Gesellschaft or MPG in German). Telescope time is shared between MPG and ESO observing programmes, while the operation and maintenance of the telescope are ESO's responsibility. More information This research was presented in a paper, "A Giant Planet Around a Metal-poor Star of Extragalactic Origin", by J. Setiawan et al., to appear in Science Express on 18 November 2010. The team is composed of J. Setiawan, R. J. Klement, T. Henning, H.-W. Rix, and B. Rochau (Max-Planck-Institut für Astronomie, Heidelberg, Germany), J. Rodmann (European Space Agency, Noordwijk, the Netherlands), and T. Schulze-Hartung (Max-Planck-Institut für Astronomie, Heidelberg, Germany). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Lightest exoplanet yet discovered

NASA Astrophysics Data System (ADS)

2009-04-01

Well-known exoplanet researcher Michel Mayor today announced the discovery of the lightest exoplanet found so far. The planet, "e", in the famous system Gliese 581, is only about twice the mass of our Earth. The team also refined the orbit of the planet Gliese 581 d, first discovered in 2007, placing it well within the habitable zone, where liquid water oceans could exist. These amazing discoveries are the outcome of more than four years of observations using the most successful low-mass-exoplanet hunter in the world, the HARPS spectrograph attached to the 3.6-metre ESO telescope at La Silla, Chile. ESO PR Photo 15a/09 Artist's impression of Gliese 581 e ESO PR Photo 15b/09 A planet in the habitable zone ESO PR Video 15a/09 ESOcast 6 ESO PR Video 15b/09 VNR A-roll ESO PR Video 15c/09 Zoom-in on Gliese 581 e ESO PR Video 15d/09 Artist's impression of Gliese 581 e ESO PR Video 15e/09 Artist's impression of Gliese 581 d ESO PR Video 15f/09 Artist's impression of Gliese 581 system ESO PR Video 15g/09 The radial velocity method ESO PR Video 15h/09 Statement in English ESO PR Video 15i/09 Statement in French ESO PR Video 15j/09 La Silla Observatory "The holy grail of current exoplanet research is the detection of a rocky, Earth-like planet in the ‘habitable zone' -- a region around the host star with the right conditions for water to be liquid on a planet's surface", says Michel Mayor from the Geneva Observatory, who led the European team to this stunning breakthrough. Planet Gliese 581 e orbits its host star - located only 20.5 light-years away in the constellation Libra ("the Scales") -- in just 3.15 days. "With only 1.9 Earth-masses, it is the least massive exoplanet ever detected and is, very likely, a rocky planet", says co-author Xavier Bonfils from Grenoble Observatory. Being so close to its host star, the planet is not in the habitable zone. But another planet in this system appears to be. From previous observations -- also obtained with the HARPS spectrograph at ESO's La Silla Observatory and announced two years ago -- this star was known to harbour a system with a Neptune-sized planet (ESO 30/05) and two super-Earths (ESO 22/07). With the discovery of Gliese 581 e, the planetary system now has four known planets, with masses of about 1.9 (planet e), 16 (planet b), 5 (planet c), and 7 Earth-masses (planet d). The planet furthest out, Gliese 581 d, orbits its host star in 66.8 days. "Gliese 581 d is probably too massive to be made only of rocky material, but we can speculate that it is an icy planet that has migrated closer to the star," says team member Stephane Udry. The new observations have revealed that this planet is in the habitable zone, where liquid water could exist. "‘d' could even be covered by a large and deep ocean -- it is the first serious 'water world' candidate," continued Udry. The gentle pull of an exoplanet as it orbits the host star introduces a tiny wobble in the star's motion -- only about 7 km/hour, corresponding to brisk walking speed -- that can just be detected on Earth with today's most sophisticated technology. Low-mass red dwarf stars such as Gliese 581 are potentially fruitful hunting grounds for low-mass exoplanets in the habitable zone. Such cool stars are relatively faint and their habitable zones lie close in, where the gravitational tug of any orbiting planet found there would be stronger, making the telltale wobble more pronounced. Even so, detecting these tiny signals is still a challenge, and the discovery of Gliese 581 e and the refinement of Gliese 581 d's orbit were only possible due to HARPS's unique precision and stability. "It is amazing to see how far we have come since we discovered the first exoplanet around a normal star in 1995 -- the one around 51 Pegasi," says Mayor. "The mass of Gliese 581 e is 80 times less than that of 51 Pegasi b. This is tremendous progress in just 14 years." The astronomers are confident that they can still do better. "With similar observing conditions an Earth-like planet located in the middle of the habitable zone of a red dwarf star could be detectable," says Bonfils. "The hunt continues." Notes This discovery was announced today at the JENAM conference during the European Week of Astronomy & Space Science, which is taking place at the University of Hertfordshire, UK. The results have also been submitted for publication in the research journal Astronomy & Astrophysics ("The HARPS search for southern extra-solar planets: XVIII. An Earth-mass planet in the GJ 581 planetary system", by Mayor et al., 2009). The team is composed of M. Mayor, S. Udry, C. Lovis, F. Pepe and D. Queloz (Geneva Observatory, Switzerland), X. Bonfils, T. Forveille , X. Delfosse, H. Beust and C. Perrier (LAOG, France), N. C. Santos (Centro de Astrofisica,Universidade de Porto), F. Bouchy (IAP, Paris, France) and J.-L. Bertaux (Service d'Aéronomie du CNRS, Verrières-le-Buisson, France). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in the Atacama Desert region of Chile: La Silla, Paranal and Chajnantor.

World's fastest and most sensitive astronomical camera

NASA Astrophysics Data System (ADS)

2009-06-01

The next generation of instruments for ground-based telescopes took a leap forward with the development of a new ultra-fast camera that can take 1500 finely exposed images per second even when observing extremely faint objects. The first 240x240 pixel images with the world's fastest high precision faint light camera were obtained through a collaborative effort between ESO and three French laboratories from the French Centre National de la Recherche Scientifique/Institut National des Sciences de l'Univers (CNRS/INSU). Cameras such as this are key components of the next generation of adaptive optics instruments of Europe's ground-based astronomy flagship facility, the ESO Very Large Telescope (VLT). ESO PR Photo 22a/09 The CCD220 detector ESO PR Photo 22b/09 The OCam camera ESO PR Video 22a/09 OCam images "The performance of this breakthrough camera is without an equivalent anywhere in the world. The camera will enable great leaps forward in many areas of the study of the Universe," says Norbert Hubin, head of the Adaptive Optics department at ESO. OCam will be part of the second-generation VLT instrument SPHERE. To be installed in 2011, SPHERE will take images of giant exoplanets orbiting nearby stars. A fast camera such as this is needed as an essential component for the modern adaptive optics instruments used on the largest ground-based telescopes. Telescopes on the ground suffer from the blurring effect induced by atmospheric turbulence. This turbulence causes the stars to twinkle in a way that delights poets, but frustrates astronomers, since it blurs the finest details of the images. Adaptive optics techniques overcome this major drawback, so that ground-based telescopes can produce images that are as sharp as if taken from space. Adaptive optics is based on real-time corrections computed from images obtained by a special camera working at very high speeds. Nowadays, this means many hundreds of times each second. The new generation instruments require these corrections to be done at an even higher rate, more than one thousand times a second, and this is where OCam is essential. "The quality of the adaptive optics correction strongly depends on the speed of the camera and on its sensitivity," says Philippe Feautrier from the LAOG, France, who coordinated the whole project. "But these are a priori contradictory requirements, as in general the faster a camera is, the less sensitive it is." This is why cameras normally used for very high frame-rate movies require extremely powerful illumination, which is of course not an option for astronomical cameras. OCam and its CCD220 detector, developed by the British manufacturer e2v technologies, solve this dilemma, by being not only the fastest available, but also very sensitive, making a significant jump in performance for such cameras. Because of imperfect operation of any physical electronic devices, a CCD camera suffers from so-called readout noise. OCam has a readout noise ten times smaller than the detectors currently used on the VLT, making it much more sensitive and able to take pictures of the faintest of sources. "Thanks to this technology, all the new generation instruments of ESO's Very Large Telescope will be able to produce the best possible images, with an unequalled sharpness," declares Jean-Luc Gach, from the Laboratoire d'Astrophysique de Marseille, France, who led the team that built the camera. "Plans are now underway to develop the adaptive optics detectors required for ESO's planned 42-metre European Extremely Large Telescope, together with our research partners and the industry," says Hubin. Using sensitive detectors developed in the UK, with a control system developed in France, with German and Spanish participation, OCam is truly an outcome of a European collaboration that will be widely used and commercially produced. More information The three French laboratories involved are the Laboratoire d'Astrophysique de Marseille (LAM/INSU/CNRS, Université de Provence; Observatoire Astronomique de Marseille Provence), the Laboratoire d'Astrophysique de Grenoble (LAOG/INSU/CNRS, Université Joseph Fourier; Observatoire des Sciences de l'Univers de Grenoble), and the Observatoire de Haute Provence (OHP/INSU/CNRS; Observatoire Astronomique de Marseille Provence). OCam and the CCD220 are the result of five years work, financed by the European commission, ESO and CNRS-INSU, within the OPTICON project of the 6th Research and Development Framework Programme of the European Union. The development of the CCD220, supervised by ESO, was undertaken by the British company e2v technologies, one of the world leaders in the manufacture of scientific detectors. The corresponding OPTICON activity was led by the Laboratoire d'Astrophysique de Grenoble, France. The OCam camera was built by a team of French engineers from the Laboratoire d'Astrophysique de Marseille, the Laboratoire d'Astrophysique de Grenoble and the Observatoire de Haute Provence. In order to secure the continuation of this successful project a new OPTICON project started in June 2009 as part of the 7th Research and Development Framework Programme of the European Union with the same partners, with the aim of developing a detector and camera with even more powerful functionality for use with an artificial laser star. This development is necessary to ensure the image quality of the future 42-metre European Extremely Large Telescope. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

VizieR Online Data Catalog: WASP-22, WASP-41, WASP-42, WASP-55 (Southworth+, 2016)

NASA Astrophysics Data System (ADS)

Southworth, J.; Tregloan-Reed, J.; Andersen, M. I.; Calchi Novati, S.; Ciceri, S.; Colque, J. P.; D'Ago, G.; Dominik, M.; Evans, D. F.; Gu, S.-H.; Herrera-Cordova, A.; Hinse, T. C.; Jorgensen, U. G.; Juncher, D.; Kuffmeier, M.; Mancini, L.; Peixinho, N.; Popovas, A.; Rabus, M.; Skottfelt, J.; Tronsgaard, R.; Unda-Sanzana, E.; Wang, X.-B.; Wertz, O.; Alsubai, K. A.; Andersen, J. M.; Bozza, V.; Bramich, D. M.; Burgdorf, M.; Damerdji, Y.; Diehl, C.; Elyiv, A.; Figuera Jaimes, R.; Haugbolle, T.; Hundertmark, M.; Kains, N.; Kerins, E.; Korhonen, H.; Liebig, C.; Mathiasen, M.; Penny, M. T.; Rahvar, S.; Scarpetta, G.; Schmidt, R. W.; Snodgrass, C.; Starkey, D.; Surdej, J.; Vilela, C.; von Essen, C.; Wang, Y.

2018-05-01

17 light curves of transits of the extrasolar planetary systems WASP-22, WASP-41, WASP-42 and WASP-55 are presented. 13 of the light curves were obtained using the Danish 1.54m telescope at ESO La Silla, Chile, in the Bessell R or Bessell I passbands. The other 4 light curves were obtained using the 84cm telescope at Observatorio Cerro Armazones, Chile, using either an R filter or no filter. The errorbars for each transit have been scaled so the best-fitting model (obtained using the JKTEBOP code) has a reduced chi-squared value of 1.0. (4 data files).

Report on the Third Advanced Chilean School of Astrophysics

NASA Astrophysics Data System (ADS)

Gieren, W.; Zoccali, M.; Saviane, I.; Méndez, R.; Pietrzynski, G.

2007-03-01

During the second week of January 2007, the third Chilean Advanced School of As-trophysics was held at the Universidad de Concepción, the third-largest university in Chile, on “Insights into Galaxy Evolution from Resolved Stellar Populations”. This school, targeted at Ph.D. students main- ly from Chile and South America, but also open to students from other countries, was organised in the framework of the Chilean FONDAP Center of Astrophysics which includes astronomers of the two largest universities in Santiago and the Universidad de Concepción. The school focused on a field of research which is very well represented in the Center. Addi-tional support was kindly offered by the ALMA Committee, ESO Chile, the Católi-ca and Concepción universities, and the Sociedad Chilena de Astronomía.

VizieR Online Data Catalog: PSR J1023+0038 & XSS J12270-4859 VRi polarimetry (Baglio+, 2016)

NASA Astrophysics Data System (ADS)

Baglio, M. C.; D'Avanzo, P.; Campana, S.; Coti Zelati, F.; Covino, S.; Russell, D. M.

2016-05-01

The systems PSR J1023+0038 and XSS J12270-4859 were observed in quiescence on 8 and 9 February 2015 (respectively) with the ESO New Technology Telescope (NTT) located at La Silla (Chile), equipped with the EFOSC2 camera in polarimetric mode, using the B, V, R, i filters. (6 data files).

Eighty nights up a mountain

NASA Astrophysics Data System (ADS)

Ellison, Sara

2002-12-01

A version of this article first appeared in August 2002 in the online publication Next Wave (www.nextwave.org), published by Science Magazine on the occasion of the UK joining ESO. As Sara Ellison describes, she has been a Paranal Fellow for the past two years and is currently in her third year at the Pontificia Universidad Católica de Chile in Santiago.

Milli-magnitude IR Transit Detection: OGLE-TR-113

NASA Astrophysics Data System (ADS)

Ramírez-Alegría, S.; Minniti, D.; Fernández, J. M.; Ruiz, M. T.; Gieren, W.; Pietrzynski, G.; Zoccali, M.; Ivanov, V.

2006-06-01

OGLE-TR-113-b is a giant exoplanet that was discovered independently by Bouchy et al. (2004, A&A, 421, L13), and by Konacki et al. (2004, ApJ, 609, L37). We present high quality near-IR and optical data during the transit of this planet in front of the star OGLE-TR-113 (V=14.42, α =10:52:24.4 and δ =-61:26:48.5). The K-band observations were obtained in May 2005 with SOFI+NTT, located at ESO La Silla (Chile), and the V-band observations were obtained in April 2005 with VIMOS+VLT, located at ESO Paranal (Chile). After the data reduction process and difference image photometry, it was possible to achieve millimagnitude precision for the transit light curves in both bands. The planetary transit is clearly seen for the first time in the K-band, with similar amplitudes A = 0.03 mag in both V, I, and K, confirming the planetary size of the OGLE-TR-113 companion. Our monitoring program for this and other OGLE transit candidates using accurate optical and near-IR photometry allows us to discard false positives (binaries, blends, giants, etc), and to refine the star/planet parameters.

ESO & NOT photometric monitoring of the Cloverleaf quasar

NASA Astrophysics Data System (ADS)

Ostensen, R.; Remy, M.; Lindblad, P. O.; Refsdal, S.; Stabell, R.; Surdej, J.; Barthel, P. D.; Emanuelsen, P. I.; Festin, L.; Gosset, E.; Hainaut, O.; Hakala, P.; Hjelm, M.; Hjorth, J.; Hutsemekers, D.; Jablonski, M.; Kaas, A. A.; Kristen, H.; Larsson, S.; Magain, P.; Pettersson, B.; Pospieszalska-Surdej, A.; Smette, A.; Teuber, J.; Thomsen, B.; van Drom, E.

1997-12-01

The Cloverleaf quasar, H1413+117, has been photometrically monitored at ESO (La Silla, Chile) and with the NOT (La Palma, Spain) during the period 1987--1994. All good quality CCD frames have been successfully analysed using two independent methods (i.e. an automatic image decomposition technique and an interactive CLEAN algorithm). The photometric results from the two methods are found to be very similar, and they show that the four lensed QSO images vary significantly in brightness (by up to 0.45 mag), nearly in parallel. The lightcurve of the $D$ component presents some slight departures from the general trend which are very likely caused by micro-lensing effects. Upper limits, at the 99% confidence level, of 150 days on the absolute value for the time delays between the photometric lightcurves of this quadruply imaged variable QSO, are derived. This is unfortunately too large to constrain the lens model but there is little doubt that a better sampling of the lightcurves should allow to accurately derive these time delays. Pending a direct detection of the lensing galaxy (position and redshift), this system thus constitutes another good candidate for a direct and independent determination of the Hubble parameter. Based on observations collected at the European Southern Observatory (La Silla, Chile) and with the Nordic Optical Telescope (La Palma, Spain). Table 1. Logbook for the ESO and NOT observations together with photometric results for the Cloverleaf quasar. This long table can be accessed on the WWW at the URL address: http://vela.astro.ulg.ac.be/grav_lens/glp_homepage.html}

U.S. and European ALMA Partners Sign Agreement Green Light for World's Most Powerful Radio Observatory

NASA Astrophysics Data System (ADS)

2003-02-01

Dr. Rita Colwell, director of the U.S. National Science Foundation (NSF), and Dr. Catherine Cesarsky, director general of the European Southern Observatory (ESO), today signed a historic agreement jointly to construct and operate ALMA, the Atacama Large Millimeter Array, the world's largest and most powerful radio telescope operating at millimeter and sub-millimeter wavelengths. "With this agreement, we usher in a new age of research in astronomy," said Dr. Colwell. "By working together in this truly global partnership, the international astronomy community will be able to ensure the research capabilities needed to meet the long-term demands of our scientific enterprise, and we will be able to study and understand our Universe in ways that have previously been beyond our vision." ALMA Array Artist's Conception of ALMA Array in Compact Configuration (Click on Image for Larger Version) Other Images Available: Artist's conception of the antennas for the Atacama Large Millimeter Array Moonrise over ALMA test equipment near Cerro Chajnantor, Chile VertexRSI antenna at the VLA test site Dr. Cesarsky also commented, "This agreement signifies the start of a great project of contemporary astronomy and astrophysics. Representing Europe, and in collaboration with many laboratories and institutes on this continent, we together look forward toward wonderful research projects. With ALMA, we may learn how the earliest galaxies in the Universe really looked like, to mention but one of the many eagerly awaited opportunities with this marvelous facility." When complete in 2011, ALMA will be an array of 64, 12-meter radio antennas that will work together as one telescope to study millimeter and sub-millimeter wavelength light from space. These wavelengths of the electromagnetic spectrum, which cross the critical boundary between infrared and microwave radiation, hold the key to understanding such processes as planet and star formation, the formation of early galaxies and galaxy clusters, and the detection of organic and other molecules in space. The ALMA partners will construct the telescope at an altitude of 16,500 feet in the Atacama Desert in the Chilean Andes. This unique site is perhaps the best location on Earth to study millimeter and sub-millimeter light because these wavelengths are absorbed by moisture in the atmosphere. "Astronomers will have a pristine view of that portion of the electromagnetic spectrum from the ALMA site," said Colwell. ALMA is a joint project between Europe and North America. In Europe, ESO is leading on behalf of its ten member countries and Spain. In North America, the NSF executes the project through the National Radio Astronomy Observatory (NRAO), which is operated under cooperative agreement by Associated Universities, Inc. (AUI). The National Research Council of Canada will partner with the NSF in the North American endeavor. "The NRAO is very pleased to have the leading role in this project on behalf of the North American partners," said Dr. Fred K.Y. Lo, director of the NRAO in Charlottesville, Virginia. "ALMA will be one of astronomy's premier tools for studying the Universe," said Nobel Laureate Riccardo Giacconi, president of AUI. "The entire astronomical community is anxious to have the unprecedented power and resolution that ALMA will provide." The President of the ESO Council, Professor Piet van der Kruit, agrees: "ALMA heralds a breakthrough in sub-millimeter and millimeter astronomy, allowing some of the most penetrating studies of the Universe ever made. It is safe to predict that there will be exciting scientific surprises when ALMA enters into operation." By signing this agreement, ESO and the NSF give the green light for the joint construction of the ALMA telescope, which will cost approximately $552 million U.S. (in FY 2000 dollars). To oversee the construction and management of ALMA, a joint ALMA Board has been established by the partners. This board met for the first time on February 24-25, 2003, and witnessed the signing at the NSF headquarters in Arlington, Virginia. Dr. Joseph Bordogna, deputy director of the NSF, represented Dr. Colwell at the actual ceremony. Chile, the host country for ALMA, has shown its support for the telescope by issuing a Presidential decree granting AUI permission to work on the ALMA project, and by signing an agreement between ESO and the government of the Republic of Chile. These actions by the government of Chile were necessary formal steps to secure the telescope site in that country. ESO is an intergovernmental, European organization for astronomical research. It has ten member countries. ESO operates astronomical observatories in Chile and has its headquarters in Garching, near Munich, Germany. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Pulsating Star Mystery Solved

NASA Astrophysics Data System (ADS)

2010-11-01

By discovering the first double star where a pulsating Cepheid variable and another star pass in front of one another, an international team of astronomers has solved a decades-old mystery. The rare alignment of the orbits of the two stars in the double star system has allowed a measurement of the Cepheid mass with unprecedented accuracy. Up to now astronomers had two incompatible theoretical predictions of Cepheid masses. The new result shows that the prediction from stellar pulsation theory is spot on, while the prediction from stellar evolution theory is at odds with the new observations. The new results, from a team led by Grzegorz Pietrzyński (Universidad de Concepción, Chile, Obserwatorium Astronomiczne Uniwersytetu Warszawskiego, Poland), appear in the 25 November 2010 edition of the journal Nature. Grzegorz Pietrzyński introduces this remarkable result: "By using the HARPS instrument on the 3.6-metre telescope at ESO's La Silla Observatory in Chile, along with other telescopes, we have measured the mass of a Cepheid with an accuracy far greater than any earlier estimates. This new result allows us to immediately see which of the two competing theories predicting the masses of Cepheids is correct." Classical Cepheid Variables, usually called just Cepheids, are unstable stars that are larger and much brighter than the Sun [1]. They expand and contract in a regular way, taking anything from a few days to months to complete the cycle. The time taken to brighten and grow fainter again is longer for stars that are more luminous and shorter for the dimmer ones. This remarkably precise relationship makes the study of Cepheids one of the most effective ways to measure the distances to nearby galaxies and from there to map out the scale of the whole Universe [2]. Unfortunately, despite their importance, Cepheids are not fully understood. Predictions of their masses derived from the theory of pulsating stars are 20-30% less than predictions from the theory of the evolution of stars. This embarrassing discrepancy has been known since the 1960s. To resolve this mystery, astronomers needed to find a double star containing a Cepheid where the orbit happened to be seen edge-on from Earth. In these cases, known as eclipsing binaries, the brightness of the two stars dims as one component passes in front of the other, and again when it passes behind the other star. In such pairs astronomers can determine the masses of the stars to high accuracy [3]. Unfortunately neither Cepheids nor eclipsing binaries are common, so the chance of finding such an unusual pair seemed very low. None are known in the Milky Way. Wolfgang Gieren, another member of the team, takes up the story: "Very recently we actually found the double star system we had hoped for among the stars of the Large Magellanic Cloud. It contains a Cepheid variable star pulsating every 3.8 days. The other star is slightly bigger and cooler, and the two stars orbit each other in 310 days. The true binary nature of the object was immediately confirmed when we observed it with the HARPS spectrograph on La Silla." The observers carefully measured the brightness variations of this rare object, known as OGLE-LMC-CEP0227 [4], as the two stars orbited and passed in front of one another. They also used HARPS and other spectrographs to measure the motions of the stars towards and away from the Earth - both the orbital motion of both stars and the in-and-out motion of the surface of the Cepheid as it swelled and contracted. This very complete and detailed data allowed the observers to determine the orbital motion, sizes and masses of the two stars with very high accuracy - far surpassing what had been done before for a Cepheid. The mass of the Cepheid is now known to about 1% and agrees exactly with predictions from the theory of stellar pulsation. However, the larger mass predicted by stellar evolution theory was shown to be significantly in error. The much-improved mass estimate is only one outcome of this work, and the team hopes to find other examples of these remarkably useful pairs of stars to exploit the method further. They also believe that from such binary systems they will eventually be able to pin down the distance to the Large Magellanic Cloud to 1%, which would mean an extremely important improvement of the cosmic distance scale. Notes [1] The first Cepheid variables were spotted in the 18th century and the brightest ones can easily be seen to vary from night to night with the unaided eye. They take their name from the star Delta Cephei in the constellation of Cepheus (the King), which was first seen to vary by John Goodricke in England in 1784. Remarkably, Goodricke was also the first to explain the light variations of another kind of variable star, eclipsing binaries. In this case two stars are in orbit around each other and pass in front of each other for part of their orbits and so the total brightness of the pair drops. The very rare object studied by the current team is both a Cepheid and an eclipsing binary. Classical Cepheids are massive stars, distinct from similar pulsating stars of lower mass that do not share the same evolutionary history. [2] The period luminosity relation for Cepheids, discovered by Henrietta Leavitt in 1908, was used by Edwin Hubble to make the first estimates of the distance to what we now know to be galaxies. More recently Cepheids have been observed with the Hubble Space Telescope and with the ESO VLT on Paranal to make highly accurate distance estimates to many nearby galaxies. [3] In particular, astronomers can determine the masses of the stars to high accuracy if both stars happen to have a similar brightness and therefore the spectral lines belonging to each of the two stars can be seen in the observed spectrum of the two stars together, as is the case for this object. This allows the accurate measurement of the motions of both stars towards and away from Earth as they orbit, using the Doppler effect. [4] The name OGLE-LMC-CEP0227 arises because the star was first discovered to be a variable during the OGLE search for gravitational microlensing. More details about OGLE are available at: http://ogle.astrouw.edu.pl/. More information This research was presented in a paper to appear in the journal Nature on 25 November 2010. The team is composed of G. Pietrzyński (Universidad de Concepción, Chile, Obserwatorium Astronomiczne Uniwersytetu Warszawskiego, Poland), I. B. Thompson (Carnegie Observatories, USA), W. Gieren (Universidad de Concepción, Chile), D. Graczyk (Universidad de Concepción, Chile), G. Bono (INAF-Osservatorio Astronomico di Roma, Universita' di Roma, Italy), A. Udalski (Obserwatorium Astronomiczne Uniwersytetu Warszawskiego, Poland), I. Soszyński (Obserwatorium Astronomiczne Uniwersytetu Warszawskiego, Poland), D. Minniti (Pontificia Universidad Católica de Chile) and B. Pilecki (Universidad de Concepción, Chile, Obserwatorium Astronomiczne Uniwersytetu Warszawskiego, Poland). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Searching for solar siblings among the HARPS data

NASA Astrophysics Data System (ADS)

Batista, S. F. A.; Adibekyan, V. Zh.; Sousa, S. G.; Santos, N. C.; Delgado Mena, E.; Hakobyan, A. A.

2014-04-01

The search for solar siblings has been particularly fruitful in the past few years. At present, there are four plausible candidates reported in the literature: HIP21158, HIP87382, HIP47399, and HIP92831. In this study we conduct a search for solar siblings among the HARPS high-resolution FGK dwarfs sample, which includes precise chemical abundances and kinematics for 1111 stars. Using a new approach based on chemical abundance trends with condensation temperature, kinematics, and ages we found one (additional) potential solar sibling candidate: HIP97507. Based on observations collected at the La Silla Paranal Observatory, ESO (Chile) with the HARPS spectrograph at the 3.6-m telescope (ESO runs ID 72.C-0488, 082.C-0212, and 085.C-0063).

Precision stellar radial velocity measurements with FIDEOS at the ESO 1-m telescope of La Silla

NASA Astrophysics Data System (ADS)

Vanzi, L.; Zapata, A.; Flores, M.; Brahm, R.; Tala Pinto, M.; Rukdee, S.; Jones, M.; Ropert, S.; Shen, T.; Ramirez, S.; Suc, V.; Jordán, A.; Espinoza, N.

2018-07-01

We present results from the commissioning and early science programs of FIbre Dual Echelle Optical Spectrograph (FIDEOS), the new high-resolution echelle spectrograph developed at the Centre of Astro Engineering of Pontificia Universidad Catolica de Chile, and recently installed at the ESO 1-m telescope of La Silla. The instrument provides spectral resolution R ˜ 43 000 in the visible spectral range 420-800 nm, reaching a limiting magnitude of 11 in V band. Precision in the measurement of radial velocity is guaranteed by light feeding with an octagonal optical fibre, suitable mechanical isolation, thermal stabilization, and simultaneous wavelength calibration. Currently the instrument reaches radial velocity stability of ˜8 m s-1 over several consecutive nights of observation.

Spiral Galaxies Stripped Bare

NASA Astrophysics Data System (ADS)

2010-10-01

Six spectacular spiral galaxies are seen in a clear new light in images from ESO's Very Large Telescope (VLT) at the Paranal Observatory in Chile. The pictures were taken in infrared light, using the impressive power of the HAWK-I camera, and will help astronomers understand how the remarkable spiral patterns in galaxies form and evolve. HAWK-I [1] is one of the newest and most powerful cameras on ESO's Very Large Telescope (VLT). It is sensitive to infrared light, which means that much of the obscuring dust in the galaxies' spiral arms becomes transparent to its detectors. Compared to the earlier, and still much-used, VLT infrared camera ISAAC, HAWK-I has sixteen times as many pixels to cover a much larger area of sky in one shot and, by using newer technology than ISAAC, it has a greater sensitivity to faint infrared radiation [2]. Because HAWK-I can study galaxies stripped bare of the confusing effects of dust and glowing gas it is ideal for studying the vast numbers of stars that make up spiral arms. The six galaxies are part of a study of spiral structure led by Preben Grosbøl at ESO. These data were acquired to help understand the complex and subtle ways in which the stars in these systems form into such perfect spiral patterns. The first image shows NGC 5247, a spiral galaxy dominated by two huge arms, located 60-70 million light-years away. The galaxy lies face-on towards Earth, thus providing an excellent view of its pinwheel structure. It lies in the zodiacal constellation of Virgo (the Maiden). The galaxy in the second image is Messier 100, also known as NGC 4321, which was discovered in the 18th century. It is a fine example of a "grand design" spiral galaxy - a class of galaxies with very prominent and well-defined spiral arms. About 55 million light-years from Earth, Messier 100 is part of the Virgo Cluster of galaxies and lies in the constellation of Coma Berenices (Berenice's Hair, named after the ancient Egyptian queen Berenice II). The third image is of NGC 1300, a spiral galaxy with arms extending from the ends of a spectacularly prominent central bar. It is considered a prototypical example of barred spiral galaxies and lies at a distance of about 65 million light-years, in the constellation of Eridanus (the River). The spiral galaxy in the fourth image, NGC 4030, lies about 75 million light-years from Earth, in the constellation of Virgo. In 2007 Takao Doi, a Japanese astronaut who doubles as an amateur astronomer, spotted a supernova - a stellar explosion that is briefly almost as bright as its host galaxy - going off in this galaxy. The fifth image, NGC 2997, is a spiral galaxy roughly 30 million light-years away in the constellation of Antlia (the Air Pump). NGC 2997 is the brightest member of a group of galaxies of the same name in the Local Supercluster of galaxies. Our own Local Group, of which the Milky Way is a member, is itself also part of the Local Supercluster. Last but not least, NGC 1232 is a beautiful galaxy some 65 million light-years away in the constellation of Eridanus (the River). The galaxy is classified as an intermediate spiral galaxy - somewhere between a barred and an unbarred spiral galaxy. An image of this galaxy and its small companion galaxy NGC 1232A in visible light was one of the first produced by the VLT (eso9845). HAWK-I has now returned to NGC 1232 to show a different view of it at near-infrared wavelengths. As this galactic gallery makes clear, HAWK-I lets us see the spiral structures in these six bright galaxies in exquisite detail and with a clarity that is only made possible by observing in the infrared. Notes [1] HAWK-I stands for High-Acuity Wide-field K-band Imager. More technical details about the camera can be found in an earlier press release (eso0736). [2] More information about the VLT instruments can be found at: http://www.eso.org/public/teles-instr/vlt/vlt-instr.html. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

CERN, ESA and ESO Launch "Physics On Stage"

NASA Astrophysics Data System (ADS)

2000-03-01

Physics is everywhere . The laws of physics govern the Universe, the Sun, the Earth and even our own lives. In today's rapidly developing society, we are becoming increasingly dependent on high technology - computers, transport, and communication are just some of the key areas that are the result of discoveries by scientists working in physics. But how much do the citizens of Europe really know about physics? Here is a unique opportunity to learn more about this elusive subject! [Go to Physics On Stage Website] Beginning in February 2000, three major European research organisations are organising a unique Europe-wide programme to raise the public awareness of physics and related sciences. "Physics on Stage" is launched by the European Laboratory for Particle Physics (CERN) , the European Space Agency (ESA) and the European Southern Observatory (ESO) , with support from the European Union. Other partners are the European Physical Society (EPS) and the European Association for Astronomy Education (EAAE). This exciting programme is part of the European Week for Science and Technology and will culminate in a Science Festival during November 6-11, 2000, on the CERN premises at the French-Swiss border near Geneva. Why "Physics on Stage"? The primary goal of "Physics on Stage" is to counteract the current decline in interest and knowledge about physics among Europe's citizens by means of a series of highly visible promotional activities. It will bring together leading scientists and educators, government bodies and the media, to confront the diminishing attraction of physics to young people and to develop strategies to reverse this trend. The objective in the short term is to infuse excitement and to provide new educational materials. In the longer term, "Physics on Stage" will generate new developments by enabling experts throughout Europe to meet, exchange and innovate. "Physics on Stage" in 22 European Countries "Physics on Stage" has been initiated in 22 European countries [2]. In each of these, a dedicated National Steering Committee is being formed which will be responsible for its own national programme. A list of contact addresses is attached below. "Physics on Stage" is based on a series of high-profile physics-related activities that will inform the European public in general and European high school physics teachers and media representatives in particular about innovative ways to convey information about physics. It will stress the intimate connection of this natural science with our daily lives. It will be accompanied by a broad media debate on these subjects. This effort is undertaken in the context of a progressive decline of physics literacy amongst the European population at all levels. Fewer and fewer young people are attracted towards careers in core sciences and technologies - this could potentially lead to a crisis in European technology in the coming decades unless action is taken now. Too few people possess the basic knowledge that is necessary to understand even common physical phenomena. And not enough are able to form their own substantiated opinions about them. What will happen during "Physics on Stage"? During the first phase of "Physics on Stage" , from now until October 2000, the individual National Steering Committees (NSCs) will survey the situation in their respective countries. The NSCs will collaborate with national media to identify new and exciting educational approaches to physics. These may involve demonstrations, interactive experiments, video and CD-Rom presentations, Web applications, virtual reality, theatre performances, etc. Nationally run competitions will select some of the best and most convincing new ideas for presentations and educational materials which will receive development support from "Physics on Stage" . The project will culminate in November 2000, with approximately 400 delegates converging on CERN, in Geneva, for the Physics on Stage Festival . During this event, the national competion winners, science teachers, science communicators, publishers, top scientists and high-level representatives of the ministries and European organisations will brainstorm future solutions to bolster physics' popularity. The programme will also include spectacular demonstrations of new educational tools; the best will be disseminated over the national TV networks and other media to the European public. Why CERN, ESA and ESO? As Europe's principal organisations in physics research (particle physics, space and astronomy), the three recognised their mutual responsibility to address the issue through the creation of a new initiative and the creative use of their own research to attract the public and teachers alike. About the "European Science and Technology Week" [Go to EWST Website] The objective of the European Science and Technology Week is to improve the public's knowledge and understanding of science and technology - including the associated benefits for society as a whole. The Week focuses on the European dimension of research, such as pan-European scientific and technological co-operation. The rationale for holding the Week has its roots in the importance of the role of science and technology in modern societies and the need, therefore, to ensure that the public recognises its significance in our lives. The Week is a framework for special TV programmes, exhibitions, contests, conferences, electronic networking, and other science related activities to promote the public understanding of science and technology. The Week was launched in 1993, on the initiative of the European Commission. Raising public awareness of science and technology is now the subject of a clearly defined action within the Human Potential Programme of the Fifth Framework Programme. Notes [1] This is a joint Press Release by the European Organization for Nuclear Research (CERN) , the European Space Agency (ESA) and the European Southern Observatory (ESO). [1] The 22 countries are the member countries of at least one of the participating organisations or the European Union: Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, the Slovak Republic, Spain, Sweden, Switzerland, United Kingdom. Statements by the Directors General of CERN, ESA and ESO Luciano Maiani (CERN) : "Science is a critical resource for mankind and, among natural sciences, physics will continue to play a crucial role, well into the next century. The young people of Europe deserve the best possible physics teaching. An enormous resource of first class teachers, teaching materials and innovative thinking exists in our countries. The "Physics on Stage" project will bring these together to generate a new interest in physics education which will be to the long term benefit of children all over Europe. CERN is delighted to take part in this collaboration between the European Community and the continent's three leading physics research organizations." Antonio Rodotà (ESA) : "Space has become an integral part of every day life. The immense technological development that has led to this achievement has taken place and might be taken for granted. But now is the time to follow up and form the future on this basis, a future that has to made by the youth and has to give its benefits to the youth. The European Space Agency is dedicated to support the youth in its development to become a space generation. Many activities have been done and are taking place, and many more are planned for the future. Teachers and educational institutions and organisations form a key role in this development. ESA is enthusiastic about co-operating with ESO and CERN to create an opportunity to receiving ideas from the educational society and will perform a dedicated effort in finding ways to support the realisation of those ideas." Catherine Cesarsky (ESO) : "Astronomy and Astrophysics are at the very heart of modern physics. As vibrant research disciplines they use the most advanced technology available to humanity to explore Cosmos. It is also a science of extreme conditions - the largest distances, the longest periods of time, the highest temperatures, the strongest electrical and magnetic fields, the highest and lowest densities and the most extreme energies. Cosmos is indeed the greatest physics laboratory. For years, ESO - Europe's Astronomy Organisation - has been engaged in communicating the outcome of the exciting research programmes carried out at the ESO observatories to a wide audience and in particular to Europe's youth. I warmly welcome the broad international collaboration within "Physics on Stage". I am confident that working together with the European Union and our sister organisations ESA and CERN, as well as teachers' organisations and dedicated individuals in all member countries, this innovative education programme will make a most important contribution towards raising the interest in fundamental research in Europe." About CERN, ESA and ESO CERN , the European Organization for Nuclear Research , has its headquarters in Geneva. At present, its Member States are Austria, Belgium,Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and Unesco have observer status. The European Space Agency (ESA) is an international/intergovernmental organisation made of 15 member states: Austria, Belgium, Denmark, Finland, France, Germany, Ireland, Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. ESA provides and promotes, for peaceful purposes only, cooperation among its member states in space research, technology and their applications. With ESA, Europe shapes and shares space for people, companies and the scientific community. The European Southern Observatory (ESO) is an intergovernmental organisation supported by Belgium, Denmark, France, Germany, Italy, the Netherlands, Sweden and Switzerland. Portugal has an agreement with ESO aiming at full membership. ESO is a major driving force in European astronomy, performing tasks that are beyond the capabilities of the individual member countries. The ESO La Silla observatory (Chile) is one of the largest and best-equipped in the world. ESO's Very Large Telescope Array (VLT) is under construction at Cerro Paranal (Chile). When completed in 2001, the VLT will be the largest optical telescope in the world. Useful Physics On Stage addresses "Physics on Stage" webaddress: http://www.estec.esa.nl/outreach/pos International Steering Committee (ISC) Clovis de Matos (Executive Coordinator) ESA/ESTEC European Space Research and Technology Centre Office for Educational Outreach Activities Keplerlaan 1 Postbus 299 NL-2200 AG Noordwijk The Netherlands email: cdematos@estec.esa.nl Telephone: +31-71-565- 5518 Fax: +31-71-565 5590

The UKIRT Infrated Deep Sky Survey : data access

NASA Astrophysics Data System (ADS)

2005-09-01

ESO - the European Organisation for Astronomical Research in the Southern Hemisphere - and the Sociedad Chilena de Astronomía (SOCHIAS) are organising a Latin American Astronomy Summer School. It will take place from December 8-10, 2005, the week before the Regional Meeting of the International Astronomical Union to be held on December 12-16, 2005 in Pucon, Chile (~ 800 km South of Santiago).

Finland Becomes Eleventh ESO Member State

NASA Astrophysics Data System (ADS)

2004-07-01

Finland has become the eleventh member state of the European Southern Observatory (ESO) [1]. The formal accession procedure was carried through as planned and has now been completed. Following the signing of the corresponding Agreement earlier this year (ESO PR 02/04), acceptance by the Finnish Parliament and ratification by the Finnish President of the Agreement as well as the ESO Convention and the associated protocols in June [2] and the deposit of the instruments of accession today, Finland has now officially joined ESO. ESO warmly welcomes the new member country and its scientific community that is renowned for their expertise in many frontline areas. The related opportunities will contribute to strenghtening of pioneering research with the powerful facilities at ESO's observatories, to the benefit of Astronomy and Astrophysics as well as European science in general. ESO also looks forward to collaboration with the Finnish high-tech industry. For Finland, the membership in ESO is motivated by scientific and technological objectives as well as by the objective of improving the public understanding of science. The Finnish Government is committed to increasing the public research funding in order to improve the quality, impact and internationalisation of research. Membership in ESO offers unique facilities for astronomical research which would not otherwise be available for Finnish astronomers. Finland is also very interested in taking part in technological development projects in fields like ICT, optics and instrumentation. For young scientists and engineers, ESO is a challenging, international working and learning environment. Finland has already taken part in the educational programmes of ESO, and as a member this activity will be broadened and intensified. In Finland there are also several science journalists and a large community of amateur astronomers who will be very happy to take part in ESO's outreach activities.

A Type II Supernova Hubble Diagram from the CSP-I, SDSS-II, and SNLS Surveys

NASA Astrophysics Data System (ADS)

de Jaeger, T.; González-Gaitán, S.; Hamuy, M.; Galbany, L.; Anderson, J. P.; Phillips, M. M.; Stritzinger, M. D.; Carlberg, R. G.; Sullivan, M.; Gutiérrez, C. P.; Hook, I. M.; Howell, D. Andrew; Hsiao, E. Y.; Kuncarayakti, H.; Ruhlmann-Kleider, V.; Folatelli, G.; Pritchet, C.; Basa, S.

2017-02-01

The coming era of large photometric wide-field surveys will increase the detection rate of supernovae by orders of magnitude. Such numbers will restrict spectroscopic follow-up in the vast majority of cases, and hence new methods based solely on photometric data must be developed. Here, we construct a complete Hubble diagram of Type II supernovae (SNe II) combining data from three different samples: the Carnegie Supernova Project-I, the Sloan Digital Sky Survey II SN, and the Supernova Legacy Survey. Applying the Photometric Color Method (PCM) to 73 SNe II with a redshift range of 0.01-0.5 and with no spectral information, we derive an intrinsic dispersion of 0.35 mag. A comparison with the Standard Candle Method (SCM) using 61 SNe II is also performed and an intrinsic dispersion in the Hubble diagram of 0.27 mag, I.e., 13% in distance uncertainties, is derived. Due to the lack of good statistics at higher redshifts for both methods, only weak constraints on the cosmological parameters are obtained. However, assuming a flat universe and using the PCM, we derive the universe’s matter density: {{{Ω }}}m={0.32}-0.21+0.30 providing a new independent evidence for dark energy at the level of two sigma. This paper includes data gathered with the 6.5 m Magellan Telescopes, with the du Pont and Swope telescopes located at Las Campanas Observatory, Chile; and the Gemini Observatory, Cerro Pachon, Chile (Gemini Program N-2005A-Q-11, GN-2005B-Q-7, GN-2006A-Q-7, GS-2005A-Q-11, GS-2005B-Q-6, and GS-2008B-Q-56). Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile (ESO Programmes 076.A-0156,078.D-0048, 080.A-0516, and 082.A-0526).

Supernova 2010ev: A reddened high velocity gradient type Ia supernova

NASA Astrophysics Data System (ADS)

Gutiérrez, Claudia P.; González-Gaitán, Santiago; Folatelli, Gastón; Pignata, Giuliano; Anderson, Joseph P.; Hamuy, Mario; Morrell, Nidia; Stritzinger, Maximilian; Taubenberger, Stefan; Bufano, Filomena; Olivares E., Felipe; Haislip, Joshua B.; Reichart, Daniel E.

2016-05-01

Aims: We present and study the spectroscopic and photometric evolution of the type Ia supernova (SN Ia) 2010ev. Methods: We obtain and analyze multiband optical light curves and optical/near-infrared spectroscopy at low and medium resolution spanning -7 days to +300 days from the B-band maximum. Results: A photometric analysis shows that SN 2010ev is a SN Ia of normal brightness with a light-curve shape of Δm15(B) = 1.12 ± 0.02 and a stretch s = 0.94 ± 0.01 suffering significant reddening. From photometric and spectroscopic analysis, we deduce a color excess of E(B - V) = 0.25 ± 0.05 and a reddening law of Rv = 1.54 ± 0.65. Spectroscopically, SN 2010ev belongs to the broad-line SN Ia group, showing stronger than average Si IIλ6355 absorption features. We also find that SN 2010ev is a high velocity gradient SN with v˙Si = 164 ± 7 km s-1 d-1. The photometric and spectral comparison with other supernovae shows that SN 2010ev has similar colors and velocities to SN 2002bo and SN 2002dj. The analysis of the nebular spectra indicates that the [Fe II]λ7155 and [Ni II]λ7378 lines are redshifted, as expected for a high velocity gradient supernova. All these common intrinsic and extrinsic properties of the high velocity gradient (HVG) group are different from the low velocity gradient (LVG) normal SN Ia population and suggest significant variety in SN Ia explosions. This paper includes data gathered with the Du Pont Telescope at Las Campanas Observatory, Chile; and the Gemini Observatory, Cerro Pachon, Chile (Gemini Program GS-2010A-Q-14). Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (ESO Programme 085.D-0577).

VizieR Online Data Catalog: Transiting planet WASP-50b (Tregloan-Reed+, 2013)

NASA Astrophysics Data System (ADS)

Tregloan-Reed, J.; Southworth, J.

2018-05-01

Two high-quality light curves of transits of the extrasolar planetary system WASP-50 are presented. They were obtained using the 3.6m NTT at ESO La Silla, Chile, in the Gunn r passband. The errorbars for each transit have been scaled so the best-fitting model (obtained using the JKTEBOP code) has a reduced chi-squared value of 1.0. (1 data file).

VISTA Reveals the Secret of the Unicorn

NASA Astrophysics Data System (ADS)

2010-10-01

A new infrared image from ESO's VISTA survey telescope reveals an extraordinary landscape of glowing tendrils of gas, dark clouds and young stars within the constellation of Monoceros (the Unicorn). This star-forming region, known as Monoceros R2, is embedded within a huge dark cloud. The region is almost completely obscured by interstellar dust when viewed in visible light, but is spectacular in the infrared. An active stellar nursery lies hidden inside a massive dark cloud rich in molecules and dust in the constellation of Monoceros. Although it appears close in the sky to the more familiar Orion Nebula it is actually almost twice as far from Earth, at a distance of about 2700 light-years. In visible light a grouping of massive hot stars creates a beautiful collection of reflection nebulae where the bluish starlight is scattered from parts of the dark, foggy outer layers of the molecular cloud. However, most of the new-born massive stars remain hidden as the thick interstellar dust strongly absorbs their ultraviolet and visible light. In this gorgeous infrared image taken from ESO's Paranal Observatory in northern Chile, the Visible and Infrared Survey Telescope for Astronomy (VISTA [1], eso0949) penetrates the dark curtain of cosmic dust and reveals in astonishing detail the folds, loops and filaments sculpted from the dusty interstellar matter by intense particle winds and the radiation emitted by hot young stars. "When I first saw this image I just said 'Wow!' I was amazed to see all the dust streamers so clearly around the Monoceros R2 cluster, as well as the jets from highly embedded young stellar objects. There is such a great wealth of exciting detail revealed in these VISTA images," says Jim Emerson, of Queen Mary, University of London and leader of the VISTA consortium. With its huge field of view, large mirror and sensitive camera, VISTA is ideal for obtaining deep, high quality infrared images of large areas of the sky, such as the Monoceros R2 region. The width of VISTA's field of view is equivalent to about 80 light-years at this distance. Since the dust is largely transparent at infrared wavelengths, many young stars that cannot be seen in visible-light images become apparent. The most massive of these stars are less than ten million years old. The new image was created from exposures taken in three different parts of the near-infrared spectrum. In molecular clouds like Monoceros R2, the low temperatures and relatively high densities allow molecules to form, such as hydrogen, which under certain conditions emit strongly in the near infrared. Many of the pink and red structures that appear in the VISTA image are probably the glows from molecular hydrogen in outflows from young stars. Monoceros R2 has a dense core, no more than two light-years in extent, which is packed with very massive young stars, as well as a cluster of bright infrared sources, which are typically new-born massive stars still surrounded by dusty discs. This region lies at the centre of the image, where a much higher concentration of stars is visible on close inspection and where the prominent reddish features probably indicate emission from molecular hydrogen. The rightmost of the bright clouds in the centre of the picture is NGC 2170, the brightest reflection nebula in this region. In visible light, the nebulae appear as bright, light blue islands in a dark ocean, while in the infrared frenetic factories are revealed in their interiors where hundreds of massive stars are coming into existence. NGC 2170 is faintly visible through a small telescope and was discovered by William Herschel from England in 1784. Stars form in a process that typically lasts few million years and which takes place inside large clouds of interstellar gas and dust, hundreds of light-years across. Because the interstellar dust is opaque to visible light, infrared and radio observations are crucial in the understanding of the earliest stages of the stellar evolution. By mapping the southern sky systematically, VISTA will gather some 300 gigabytes per night, providing a huge amount of information on those regions that will be studied in greater detail by the Very Large Telescope (VLT), the Atacama Large Millimeter/submillimeter Array (ALMA) and, in the future, by the European Extremely Large Telescope (E-ELT). Notes [1] With its 4.1-metre primary mirror, VISTA is the largest survey telescope in the world and is equipped with the largest infrared camera on any telescope, with 67 million pixels. It is dedicated to sky surveys, which began early in 2010. Located on a peak next to Cerro Paranal, the home of the ESO VLT in northern Chile, VISTA shares the same exceptional observing conditions. Due to the remarkable quality of the sky in this area of the Atacama Desert, one of the driest sites on Earth, Cerro Armazones, located only 20 km away from Cerro Paranal, has been recently selected as the site for the future E-ELT. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Britain Approaches ESO about Installation of Major New Telescope at Paranal

NASA Astrophysics Data System (ADS)

2000-02-01

The Executive Board of the UK Visible and Infrared Survey Telescope (VISTA) project announced today [1] that it is aiming at the installation of a new and powerful astronomical telescope at the ESO Paranal Observatory (Chile). This 4-metre telescope is a specialised wide-angle facility equipped with powerful cameras and efficient detectors that will enable it to obtain deep images of large sky areas in short time. These survey observations will be made in several wavebands in the optical and, in particular, the near-infrared region of the electromagnetic spectrum. VISTA will become the largest and most effective telescope of its type when it enters into operation in 2004. It is a project of a consortium of 18 UK universities [2]. Construction is expected to start in spring 2000. Funding of the project was announced in May 1999, as one of the first allocations from the "Joint Infrastructure Fund (JIF)", an initiative of the UK Government's Department of Trade and Industry, the Wellcome Trust, and the Higher Education Funding Council for England. ESO's Director General, Dr. Catherine Cesarsky , is very pleased with this decision. She received a mandate from the ESO Council in December 1999 to negotiate a contract with the UK Particle Physics and Astronomy Research Council (PPARC) , acting on behalf of the VISTA Executive Board, for the installation of VISTA at Paranal and now looks forward to settle the associated legal and operational details with her British counterparts at good pace. "The installation of VISTA at Paranal will be of great benefit to all European astronomers", she says. "The placement of a survey telescope of this size next to ESO's VLT, the world's largest optical telescope, opens a plethora of exciting opportunities for joint research projects. Deep observations with VISTA, especially in infrared wavebands, will provide a most valuable, first census of large regions of space. This will most certainly lead to the discoveries of many new and interesting celestial objects which can then be studied in much more detail with the many specialised instruments at the powerful VLT Unit Telescopes." ESO, the European Southern Observatory, has eight member states, Belgium, Denmark, France, Germany, Italy, the Netherlands, Sweden and Switzerland. The United Kingdom participated actively in the early discussions in the 1950's about the establishment of ESO, but later elected not to join, mainly because of its access to other southern astronomical facilities in Australia and South Africa. ESO already possesses a smaller survey instrument at the La Silla Observatory (Chile), with the optical Wide-Field Imager at the ESO/MPG 2.2-m telescope. In addition, the 2.6-m VLT Survey Telescope (VST) with the 16kx16k OmegaCam camera will be installed at Paranal in 2002. It will operate in the visual region of the spectrum and, together with VISTA's infrared capability, ensure unequalled sky- and wavelength coverage from one observing site. Notes [1] The announcement was made in a PPARC Press Release, available at http://www.pparc.ac.uk and at the AlphaGalileo site. [2] Universities in the VISTA Consortium are (in alphabetical order) Birmingham, Cambridge, Cardiff, Durham, Edinburgh, Hertfordshire, Keele, Central Lancashire, Leicester, Liverpool John Moores, Nottingham, Oxford, Queen Mary & Westfield College, Queen's University Belfast, St Andrews, Southampton, Sussex, University College London.

A new mix of power for the ESO installations in Chile: greener, more reliable, cheaper

NASA Astrophysics Data System (ADS)

Filippi, G.; Tamai, R.; Kalaitzoglou, D.; Wild, W.; Delorme, A.; Rioseco, D.

2016-07-01

The highest sky quality demands for astronomical research impose to locate observatories often in areas not easily reached by the existing power infrastructures. At the same time, availability and cost of power is a primary factor for sustainable operations. Power may also be a potential source for CO2 pollution. As part of its green initiatives, ESO is in the process of replacing the power sources for its own, La Silla and Paranal-Armazones, and shared, ALMA, installations in Chile in order to provide them with more reliable, affordable, and smaller CO2 footprint power solutions. The connectivity to the Chilean interconnected power systems (grid) which is to extensively use Non-Conventional Renewable Energy (NCRE) as well as the use of less polluting fuels wherever self-generation cannot be avoided are key building blocks for the solutions selected for every site. In addition, considerations such as the environmental impact and - if required - the partnership with other entities have also to be taken into account. After years of preparatory work to which the Chilean Authorities provided great help and support, ESO has now launched an articulated program to upgrade the existing agreements/facilities in i) the La Silla Observatory, from free to regulated grid client status due to an agreement with a Solar Farm private initiative, in ii) the Paranal-Armazones Observatory, from local generation using liquefied petroleum gas (LPG) to connection to the grid which is to extensively use NCRE, and last but not least, in iii) the ALMA Observatory where ESO participates together with North American and East Asian partners, from replacing the LPG as fuel for the turbine local generation system with the use of less polluting natural gas (NG) supplied by a pipe connection to eliminate the pollution caused by the LPG trucks (currently 1 LPG truck from the VIII region, Bio Bio, to the II region, ALMA and back every day, for a total of 3000km). The technologies used and the status of completion of the different projects, as well as the expected benefits are discussed in this paper.

First Giant Mirror for the ESO VLT Ready at REOSC

NASA Astrophysics Data System (ADS)

1995-11-01

The REOSC Contract In 1989, the European Southern Observatory (ESO), the European Organisation for Astronomy, awarded to REOSC, a subsidiary of the SFIM Group and located in Saint Pierre du Perray (France), a comprehensive contract for the polishing of four 8.2-metre diameter mirrors for the unit telescopes of the ESO Very Large Telescope (VLT) project. These mirrors are the largest ever manufactured and polished. This contract comprises not only the polishing and high-precision optical testing of each giant mirror, but also the safe condition of transportation of the blanks which were manufactured by Schott Glaswerke in Mainz (Germany). In order to fulfill the contract, REOSC conceived, built and equipped a novel, high-tech workshop which would allow to polish and test the mirrors, each of which has a surface area of more than 50 square metres. First 8.2-Metre Mirror is Ready and within Specifications The REOSC polishing facility for giant mirrors was built in Saint Pierre du Perray, just south of Paris. It is equipped with two machines: one for grinding and the other for polishing the mirrors, and both with 150-actuator systems that support the thin and flexible mirrors. All equipment is computer controlled. State-of-the-art interferometers probe the accuracy of the mirror surface as the polishing proceeds; they are installed at the top level of the facility in a 30-metre high tower, at the centre of the mirror's radius of curvature. The success of the work at REOSC is now evident by the fact that careful measurements of the first mirror earlier this month have shown that the final optical surface is correct to within 0.00005 millimetres. For illustration, this corresponds to an accuracy of only 1 millimetre deviation over a surface with a diameter of 165 kilometres (equivalent to the entire Paris area)! ESO Receives the First VLT Mirror After having been carefully placed in a special transport box designed by REOSC, the first mirror blank, weighing 23.5 tons and with a replacement value of about 20 million DEM, was transported from Mainz to Saint Pierre du Perray in July 1993. The shaping and polishing phases lasted two years and were completed in October 1995. After one month's hard work, dedicated to optical and mechanical verifications by ESO and REOSC, the mirror's various characteristics have now been found to be in accordance with the contract specifications. Following the technical acceptance, the first mirror was re-installed in its transport container on November 13, 1995. It will thereafter be formally handed over to ESO during a ceremony at REOSC on Tuesday, November 21, 1995. The mirror will be stored at the REOSC facility until its future departure to ESO's VLT Observatory on Cerro Paranal, a 2650 m high summit in the Andean Cordillera in northern Chile. Here it will be installed in the first VLT unit telescope, soon after the assembly of the mechanical parts has been completed. Future Plans at REOSC The polishing of the second VLT mirror, as well as the grinding of the third mirror which was transported from Mainz to Saint Pierre du Perray at the beginning of October 1995, have already started. The transport of the fourth blank will take place in March 1996. With the construction, in a subsequent phase, of a workshop of more than 6000 square metres and mostly dedicated to space and astronomy, the SFIM group will have invested more than 50 million French Francs at the Saint Pierre du Perray site alone. The group is also involved in the contract related to the actuator support system; this is a clear indication of its determination to maintain its position within this scientific-technological market. In addition to the ESO VLT mirrors, REOSC will also polish the two 8.2-metre diameter mirrors of the Gemini programme of the Association of Universities for Research in Astronomy (AURA) in the United States. This important work was entrusted REOSC, following an international call for tenders, in which also US firms participated. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

Protecting the Local Dark-Sky Areas around the International Observatories in Chile.

NASA Astrophysics Data System (ADS)

Smith, M. G.

2001-12-01

This report covers efforts by IAU Commission 50's new Working Group on Light Pollution to slow or halt the spread of incipient light pollution near the VLT, the Magellan 6.5m telescopes, Gemini South, SOAR, Blanco and many smaller telescopes in Chile. An effort has just begun to protect the ALMA site in Northern Chile from RFI. Such work includes extensive outreach programs to the local population, schools and industry as well as to local, regional and national levels of government in Chile. The group is working internationally with such organizations as the IDA; one member has recently led the production of "The first world atlas of the artificial night-sky brightness". These efforts have resulted in the first national-level environmental legislation covering dark skies as part of a government effort to protect the environment. Chilean manufacturers are now producing competitive, full-cut-off, street lighting designed specifically to comply with the new legislation. The Chilean national tourism agency is supporting "Astronomical Tourism" based on the dark, clear skies of Chile. An international conference on Controlling Light Pollution and RFI will be held in La Serena, Chile on 5-7 March, 2002, backed up by a parallel meeting of Chilean amateur astronomers. Much work remains to be done. Most of this work is supported by funding from the US National Science Foundation through CTIO, and from ESO, OCIW and CONAMA.

From SEST to ALMA, from NTT to OWL: of vision, dreams and realities. Perspectives from the Directors General, past and present: Harry van der Laan, ESO Director General, 1988 - 1992

NASA Astrophysics Data System (ADS)

van der Laan, Harry

2002-09-01

ESO has come a long way since in 1987 the first rocks were blasted at the NTT site on La Silla. Those were exciting days, when SEST came online and soon after the VLT programme was getting up to speed upon its approval in December 1987. It was not an easy time for staff or management: taking up the role of main contractor for its own design and construction programme rather than finding an industrial consultant to do so was an enormous challenge. It was not obvious that it could be done, for more than ninety per cent of ESO's staff capacity was occupied with running La Silla, operating Headquarter services and constructing the NTT. The VLT Blue Book and the bag of money Council had allocated to its realization were necessary but by no means sufficient. For the new, formidable task, manpower had to be found and trained, manpower both reassigned and newly recruited.

Second Chance Programmes: A Response to Educational Needs in Compulsory Education

ERIC Educational Resources Information Center

Asin, Antonio Sanchez; Peinado, Jose Luis Boix

2008-01-01

This paper asks whether the integrated training provision currently offered through the different Spanish Second Chance Programmes (SCPs) constitutes a valid response to the educational needs and deficits known to exist among those young people who do not satisfactorily complete the Compulsory Secondary Education stage (ESO). The objectives of the…

ESO PR Highlights in 2007

NASA Astrophysics Data System (ADS)

2008-01-01

Another great year went by for ESO, the European Organisation for Astronomical Research in the Southern Hemisphere. From 1 January 2007, with the official joining of the Czech Republic, ESO has 13 member states, and since September, ESO has a new Director General, Tim de Zeeuw (ESO 03/07 and 38/07). Many scientific discoveries were made possible with ESO's telescopes. Arguably, the most important is the discovery of the first Earth-like planet in the habitable zone of a low-mass red dwarf (ESO 22/07). If there is water on this planet, then it should be liquid! ESO PR Highlights 2007 This is a clickable map. These are only some of the press releases issued by ESO in 2007. For a full listing, please go to ESO 2007 page. In our own Solar System also, astronomers made stunning breakthroughs with ESO's telescopes, observing the effect of the light from the Sun on an asteroid's rotation (ESO 11/07), describing in unprecedented detail the double asteroid Antiope (ESO 18/07), peering at the rings of Uranus (ESO 37/07), discovering a warm south pole on Neptune (ESO 41/07), showing a widespread and persistent morning drizzle of methane over the western foothills of Titan's major continent (ESO 47/07), and studying in the greatest details the wonderful Comet McNaught (ESO 05/07 and 07/07). In the study of objects slightly more massive than planets, the VLT found that brown dwarfs form in a similar manner to normal stars (ESO 24/07). The VLT made it also possible to measure the age of a fossil star that was clearly born at the dawn of time (ESO 23/07). Other discoveries included reconstructing the site of a flare on a solar-like star (ESO 53/07), catching a star smoking (ESO 34/07), revealing a reservoir of dust around an elderly star (ESO 43/07), uncovering a flat, nearly edge-on disc of silicates in the heart of the magnificent Ant Nebula (ESO 42/07), finding material around a star before it exploded (ESO 31/07), fingerprinting the Milky Way (ESO 15/07), revealing a rich circular cluster of stars (ESO 12/07), hunting galaxies (ESO 40/07), discovering teenage galaxies (ESO 52/07), and finding the first known triplet of supermassive black holes (ESO 02/07). On the instrumentation side, the VLT has been equipped with a new 'eye' to study the Universe in the near-infrared, Hawk-I (ESO 36/07), while the Laser Guide Star used at the VLT to create an artificial star appears to fulfil all its promises (ESO 27/07 and 33/07). Successful tests were also done of a crucial technology for Extremely Large Telescopes (ESO 19/07). The VLT Rapid Response Mode showed it unique capabilities in the study of gamma-ray bursts (ESO 17/07), as did the REM, a robotic telescope at La Silla, that allowed astronomers to measure for the first time the speed of matter ejected in these tremendous explosions (ESO 26/07). The world's largest bolometer camera for submillimetre astronomy, LABOCA, is now in service at the 12-m APEX telescope (ESO 35/07), while the construction of ALMA moves forwards. Two 12-m ALMA prototype antennas were first linked together as an integrated system to observe an astronomical object (ESO 10/07), the ALMA Operations Support Facility is almost completed (ESO 13/07), and the ALMA transporters were shipped to Chile (ESO 32/07 and 45/07). ESO is also present on the educational front with, for example, its annual international contest for students, Catch a Star (ESO 21/07 and 46/07). In April 2007, ESO organised with its partners the second EIROforum Science on Stage festival, a unique event, showcasing the very best of today's science education and to which participated the European Commissioner for Science and Research, Janez Potočnik. The Commissioner also visited the Paranal observatory (ESO 48/07) and took part in the observation of a beautiful galaxy (ESO 49/07). This was not the only nice image coming out from ESO telescopes. A rather amazing Cosmic Bird - or a gigantic Tinker Bell - was photographed (ESO 55/07), as well as a Purple Rose (ESO 16/07) and a stellar firework (ESO 39/07). And last but least, at the end of the year, the United Nations passed a resolution proclaiming 2009 the International Year of Astronomy (ESO 54/07).

Most Efficient Spectrograph to Shoot the Southern Skies

NASA Astrophysics Data System (ADS)

2009-05-01

ESO's Very Large Telescope -- Europe's flagship facility for ground-based astronomy -- has been equipped with the first of its second generation instruments: X-shooter. It can record the entire spectrum of a celestial object in one shot -- from the ultraviolet to the near-infrared -- with high sensitivity. This unique new instrument will be particularly useful for the study of distant exploding objects called gamma-ray bursts. ESO PR Photo 20a/09 An X-shooter spectrum ESO PR Photo 20b/09 The X-shooter instrument ESO PR Photo 20c/09 First Light of X-shooter "X-shooter offers a capability that is unique among astronomical instruments installed at large telescopes," says Sandro D'Odorico, who coordinated the Europe-wide consortium of scientists and engineers that built this remarkable instrument. "Until now, different instruments at different telescopes and multiple observations were needed to cover this kind of wavelength range, making it very difficult to compare data, which, even though from the same object, could have been taken at different times and under different sky conditions." X-shooter collects the full spectrum from the ultraviolet (300 nm) to the near-infrared (2400 nm) in parallel, capturing up to half of all the light from an object that passes through the atmosphere and the various elements of the telescope. "All in all, X-shooter can save us a factor of three or more in terms of precious telescope time and opens a new window of opportunity for the study of many, still poorly understood, celestial sources," says D'Odorico. The name of the 2.5-ton instrument was chosen to stress its capacity to capture data highly efficiently from a source whose nature and energy distribution are not known in advance of the observation. This property is particularly crucial in the study of gamma-ray bursts, the most energetic explosions known to occur in the Universe (ESO 17/09). Until now, a rough estimate of the distance of the target was needed, so as to know which instrument to use for a detailed study. Thanks to X-shooter, astronomers won't have to go through this first observing step. This is particularly relevant for gamma-ray bursts, which fade away very quickly and where being fast is the key to understanding the nature of these elusive cosmic sources. "I am very confident that X-shooter will discover the most distant gamma-ray bursts in the Universe, or in other words, the first objects that formed in the young Universe," says François Hammer, who leads the French efforts in X-shooter. X-shooter was built by a consortium of 11 institutes in Denmark, France, Italy and the Netherlands, together with ESO. In total 68 person-years of work by engineers, technicians and astronomers and a global budget of six million Euros were required. The development time was remarkably fast for a project of this complexity, which was completed in just over five years, starting from the kick-off meeting held in December 2003. "The success of X-shooter and its relatively short completion time are a tribute to the quality and dedication of the many people involved in the project," says Alan Moorwood, ESO Director of Programmes. The instrument was installed at the telescope at the end of 2008 and the first observations in its full configuration were made on 14 March 2009, demonstrating that the instrument works efficiently over the full spectral range with unprecedented resolution and quality. X-shooter has already proved its full capability by obtaining the complete spectra of low metallicity stars, of X-ray binaries, of distant quasars and galaxies, of the nebulae associated with Eta Carinae and the supernova 1987A, as well as with the observation of a distant gamma-ray burst that coincidently exploded at the time of the commissioning run. X-shooter will be offered to the astronomical community from 1 October 2009. The instrument is clearly answering a need in the scientific community as about 150 proposals were received for the first runs of X-shooter, for a total of 350 observing nights, making it the second most requested instrument at the Very Large Telescope in this period. More information ESO's Very Large Telescope (VLT) is the world's most advanced optical instrument. It is an ensemble of four 8.2-metre telescopes located at the Paranal Observatory on an isolated mountain peak in the Atacama Desert in North Chile. The four 8.2-metre telescopes have a total of 12 focal stations where different instruments for imaging and spectroscopic observations are installed and a special station where the light of the four telescopes is combined for interferometric observations. The first VLT instrument was installed in 1998 and has been followed by 12 more in the last 10 years, distributed at the different focal stations. X-shooter is the first of the second generation of VLT instruments and replaces the workhorse-instrument FORS1, which has been successfully used for more than ten years by hundreds of astronomers. X-shooter operates at the Cassegrain focus of the Kueyen telescope (UT2). In response to an ESO Call for Proposals for second generation VLT instrumentation, ESO received three proposals for an intermediate resolution, high efficiency spectrograph. These were eventually merged into a single proposal around the present concept of X-shooter, which was approved for construction in November 2003. The Final Design Review, at which the instrument design is finalised and declared ready for construction, took place in April 2006. The first observations with the instrument at the telescope in its full configuration were on 14 March 2009. X-shooter is a joint project by Denmark, France, Italy, the Netherlands and ESO. The collaborating institutes in Denmark are the Niels Bohr and the DARK Institutes of the University of Copenhagen and the National Space Institute (Technical University of Denmark); in France GEPI at the Observatoire de Paris and APC at the Université D. Diderot, with contributions from the CEA and the CNRS; in Italy the Osservatorio di Brera, Trieste, Palermo and Catania; and in the Netherlands, the University of Amsterdam, the University of Nijmegen and ASTRON. Beside the participating institutes and ESO, the project was supported by the National Agencies of Italy (INAF), the Italian Ministry for Education, University and Research (MIUR), the Netherlands (NOVA and NWO) and by the Carlsberg Foundation in Denmark. The project was also supported in Denmark and the Netherlands with funds from the EU Descartes prize, the highest European prize for science, awarded in 2002 to the European collaboration on gamma-ray burst research headed by Professor Ed van den Heuvel. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in the Atacama Desert region of Chile: La Silla, Paranal and Chajnantor.

The First School for Young Astronomers Organized by ESO and the Astronomical Council of the USSR Acadeny of Sciences

NASA Astrophysics Data System (ADS)

D'Odorico, S.

1987-12-01

The first international school for young astronomers organized jointly by ESO and the Astronomical Council of the USSR Academy of Sciences took place from the 22nd to the 29th of September at the Byurakan Astrophysical Observatory of the Academy of Sciences of Armenia and was dedicated to "Observations with Large Telescopes". It was appropriately closed with a oneday visit to the Special Astrophysical Observatory at Zelenchukskaja, in northern Caucasus, home of the 6-m telescope, the largest in the world. The lecturers came from ESO and from the Soviet Union; the 45 participants were from ESO member states, from Bulgaria, Czechoslovakia, the German Democratic Republic, Poland, Spain and the USSR. After the welcome addresses by Academician V.A. Ambartsumian and by E. Ye Khachikian, Chairman of the Local Organizing Committee, the school was opened by M. Tarenghi of ESO who spoke on the characteristics of existing ESO telescopes and on the innovative features of the ESO 3.5-m New Technology Telescope, to be erected at La Silla next year. H. A. Abrahamian and J.A. Stepanian of the Byurakan Observatory presented the Byurakan 2.6-m telescope and the 1-m Schmidt respectively, illustrating the scientific programmes carried out in the recent past and presently at these two facilities.

First two ALMA antennas successfully linked

NASA Astrophysics Data System (ADS)

2009-05-01

Scientists and engineers working on the world's largest ground-based astronomical project, the Atacama Large Millimeter/submillimeter Array (ALMA), have achieved another milestone -- the successful linking of two ALMA astronomical antennas, synchronised with a precision of one millionth of a millionth of a second -- to observe the planet Mars. ALMA is under construction by an international partnership in the Chilean Andes. ESO PR Photo 18a/09 The two ALMA antennas On 30 April, the team observed the first "interferometric fringes" of an astronomical source by linking two 12-metre diameter ALMA antennas, together with the other critical parts of the system. Mars was chosen as a suitable target for the observations, which demonstrate ALMA's full hardware functionality and connectivity. This important milestone was achieved at the ALMA Operations Support Facility, high in Chile's Atacama region, at an altitude of 2900 metres. "We're very proud and excited to have made this crucial observation, as it proves that the various hardware components work smoothly together. This brings us another step closer to full operations for ALMA as an astronomical observatory," says Wolfgang Wild, the European ALMA Project Manager. The two antennas used in this test will be part of ALMA's array of 66 giant 12-metre and 7-metre diameter antennas that will observe in unison as a single giant telescope, under construction on the Chajnantor plateau above the Operations Support Facility, at an altitude of 5000 metres. ALMA will operate as an interferometer, capturing millimetre and submillimetre wavelength signals from the sky with multiple antennas, and combining them to create extremely high resolution images, similar to those that would be obtained by a single, giant antenna with a diameter equal to the distance between the antennas used. "This can only be achieved with the perfect synchronisation of the antennas and the electronic equipment: a precision much better than one millionth of a millionth of a second between equipment located many kilometers apart. The extreme environment where the ALMA observatory is located, with its strong winds, high altitude, and wide range of temperatures, just adds to the complexity of the observatory and to the fascinating engineering challenges we face", comments Richard Murowinski, ALMA Project Engineer. The astronomical target in this scientific milestone was the planet Mars. The astronomers measured the distinctive "fringes" -- a regular pattern of alternating strong and weak signals -- detected by the interferometer as the planet moved across the sky. The hardware used in this successful first test included two 12-metre diameter ALMA antennas as well as the complex series of electronic processing components needed to combine the signals. Such pairs of antennas are the basic building blocks of imaging systems that enable radio telescopes to deliver pictures that approach or even exceed the resolving power of visible light telescopes. Each antenna is combined electronically with every other antenna to form a multitude of antenna pairs. Each pair contributes unique information that is used to build a highly detailed image of the astronomical object under observation. When completed in early in the next decade, ALMA's 66 antennas will provide over a thousand such antenna pairings, with distances between antennas up to 16 kilometres. This will enable ALMA to see with a sharpness surpassing that of the best space telescopes, and to complement ground-based optical interferometers such as the ESO Very Large Telescope Interferometer (VLTI). "We are on target to do the first interferometry tests at the 5000-metre high-altitude site by the end of this year, and by the end of 2011 we plan to have at least 16 antennas working together as a single giant telescope," said Thijs de Graauw, ALMA Director. Notes for editors ALMA is a revolutionary astronomical telescope, comprising an array of 66 giant 12-metre and 7-metre diameter antennas observing at millimetre and submillimetre wavelengths. ALMA, which will start scientific observations in 2011, is the most powerful telescope for observing the cool Universe -- molecular gas and dust as well as the relic radiation of the Big Bang. ALMA will study the building blocks of stars, planetary systems, galaxies and life itself, and will address some of the deepest questions of our cosmic origins. ALMA will operate at wavelengths of 0.3 to 9.6 mm. At these wavelengths, a high, dry site is needed for the telescope to be able to see through the Earth's atmosphere. This is why ALMA is being built on the breathtaking 5000-metre-high plateau of Chajnantor in the Atacama region of Chile, the highest astronomy site in the world. ALMA will offer unprecedented sensitivity and resolution. The 12-metre antennas will have reconfigurable baselines ranging from 15 m to 16 km. ALMA will have a resolution ten times better than the Hubble Space Telescope. The ALMA project is a partnership between the scientific communities of East Asia, Europe and North America with Chile. ESO is the European partner in ALMA. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in the Atacama Desert region of Chile: La Silla, Paranal and Chajnantor.

Opening up a Colourful Cosmic Jewel Box

NASA Astrophysics Data System (ADS)

2009-10-01

The combination of images taken by three exceptional telescopes, the ESO Very Large Telescope on Cerro Paranal , the MPG/ESO 2.2-metre telescope at ESO's La Silla observatory and the NASA/ESA Hubble Space Telescope, has allowed the stunning Jewel Box star cluster to be seen in a whole new light. Star clusters are among the most visually alluring and astrophysically fascinating objects in the sky. One of the most spectacular nestles deep in the southern skies near the Southern Cross in the constellation of Crux. The Kappa Crucis Cluster, also known as NGC 4755 or simply the "Jewel Box" is just bright enough to be seen with the unaided eye. It was given its nickname by the English astronomer John Herschel in the 1830s because the striking colour contrasts of its pale blue and orange stars seen through a telescope reminded Herschel of a piece of exotic jewellery. Open clusters [1] such as NGC 4755 typically contain anything from a few to thousands of stars that are loosely bound together by gravity. Because the stars all formed together from the same cloud of gas and dust their ages and chemical makeup are similar, which makes them ideal laboratories for studying how stars evolve. The position of the cluster amongst the rich star fields and dust clouds of the southern Milky Way is shown in the very wide field view generated from the Digitized Sky Survey 2 data. This image also includes one of the stars of the Southern Cross as well as part of the huge dark cloud of the Coal Sack [2]. A new image taken with the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile shows the cluster and its rich surroundings in all their multicoloured glory. The large field of view of the WFI shows a vast number of stars. Many are located behind the dusty clouds of the Milky Way and therefore appear red [3]. The FORS1 instrument on the ESO Very Large Telescope (VLT) allows a much closer look at the cluster itself. The telescope's huge mirror and exquisite image quality have resulted in a brand-new, very sharp view despite a total exposure time of just 5 seconds. This new image is one of the best ever taken of this cluster from the ground. The Jewel Box may be visually colourful in images taken on Earth, but observing from space allows the NASA/ESA Hubble Space Telescope to capture light of shorter wavelengths than can not be seen by telescopes on the ground. This new Hubble image of the core of the cluster represents the first comprehensive far ultraviolet to near-infrared image of an open galactic cluster. It was created from images taken through seven filters, allowing viewers to see details never seen before. It was taken near the end of the long life of the Wide Field Planetary Camera 2 ― Hubble's workhorse camera up until the recent Servicing Mission, when it was removed and brought back to Earth. Several very bright, pale blue supergiant stars, a solitary ruby-red supergiant and a variety of other brilliantly coloured stars are visible in the Hubble image, as well as many much fainter ones. The intriguing colours of many of the stars result from their differing intensities at different ultraviolet wavelengths. The huge variety in brightness of the stars in the cluster exists because the brighter stars are 15 to 20 times the mass of the Sun, while the dimmest stars in the Hubble image are less than half the mass of the Sun. More massive stars shine much more brilliantly. They also age faster and make the transition to giant stars much more quickly than their faint, less-massive siblings. The Jewel Box cluster is about 6400 light-years away and is approximately 16 million years old. Notes [1] Open, or galactic, star clusters are not to be confused with globular clusters ― huge balls of tens of thousands of ancient stars in orbit around our galaxy and others. It seems that most stars, including our Sun, formed in open clusters. [2] The Coal Sack is a dark nebula in the Southern Hemisphere, near the Southern Cross, that can be seen with the unaided eye. A dark nebula is not the complete absence of light, but an interstellar cloud of thick dust that obscures most background light in the visible. [3] If the light from a distant star passes through dust clouds in space the blue light is scattered and absorbed more than the red. As a result the starlight looks redder when it arrives on Earth. The same effect creates the glorious red colours of terrestrial sunsets. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky". The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

ESO and NSF Sign Agreement on ALMA

NASA Astrophysics Data System (ADS)

2003-02-01

Green Light for World's Most Powerful Radio Observatory On February 25, 2003, the European Southern Observatory (ESO) and the US National Science Foundation (NSF) are signing a historic agreement to construct and operate the world's largest and most powerful radio telescope, operating at millimeter and sub-millimeter wavelength. The Director General of ESO, Dr. Catherine Cesarsky, and the Director of the NSF, Dr. Rita Colwell, act for their respective organizations. Known as the Atacama Large Millimeter Array (ALMA), the future facility will encompass sixty-four interconnected 12-meter antennae at a unique, high-altitude site at Chajnantor in the Atacama region of northern Chile. ALMA is a joint project between Europe and North America. In Europe, ESO is leading on behalf of its ten member countries and Spain. In North America, the NSF also acts for the National Research Council of Canada and executes the project through the National Radio Astronomy Observatory (NRAO) operated by Associated Universities, Inc. (AUI). The conclusion of the ESO-NSF Agreement now gives the final green light for the ALMA project. The total cost of approximately 650 million Euro (or US Dollars) is shared equally between the two partners. Dr. Cesarsky is excited: "This agreement signifies the start of a great project of contemporary astronomy and astrophysics. Representing Europe, and in collaboration with many laboratories and institutes on this continent, we together look forward towards wonderful research projects. With ALMA we may learn how the earliest galaxies in the Universe really looked like, to mention but one of the many eagerly awaited opportunities with this marvellous facility". "With this agreement, we usher in a new age of research in astronomy" says Dr. Colwell. "By working together in this truly global partnership, the international astronomy community will be able to ensure the research capabilities needed to meet the long-term demands of our scientific enterprise, and that we will be able to study and understand our universe in ways that have previously been beyond our vision". The recent Presidential decree from Chile for AUI and the agreement signed in late 2002 between ESO and the Government of the Republic of Chile (cf. ESO PR 18/02) recognize the interest that the ALMA Project has for Chile, as it will deepen and strengthen the cooperation in scientific and technological matters between the parties. A joint ALMA Board has been established which oversees the realisation of the ALMA project via the management structure. This Board meets for the first time on February 24-25, 2003, at NSF in Washington and will witness this historic event. ALMA: Imaging the Light from Cosmic Dawn ESO PR Photo 06a/03 ESO PR Photo 06a/03 [Preview - JPEG: 588 x 400 pix - 52k [Normal - JPEG: 1176 x 800 pix - 192k] [Hi-Res - JPEG: 3300 x 2244 pix - 2.0M] ESO PR Photo 06b/03 ESO PR Photo 06b/03 [Preview - JPEG: 502 x 400 pix - 82k [Normal - JPEG: 1003 x 800 pix - 392k] [Hi-Res - JPEG: 2222 x 1773 pix - 3.0M] ESO PR Photo 06c/03 ESO PR Photo 06c/03 [Preview - JPEG: 474 x 400 pix - 84k [Normal - JPEG: 947 x 800 pix - 344k] [Hi-Res - JPEG: 2272 x 1920 pix - 2.0M] ESO PR Photo 06d/03 ESO PR Photo 06d/03 [Preview - JPEG: 414 x 400 pix - 69k [Normal - JPEG: 828 x 800 pix - 336k] [HiRes - JPEG: 2935 x 2835 pix - 7.4k] Captions: PR Photo 06a/03 shows an artist's view of the Atacama Large Millimeter Array (ALMA), with 64 12-m antennae. PR Photo 06b/03 is another such view, with the array arranged in a compact configuration at the high-altitude Chajnantor site. The ALMA VertexRSI prototype antennae is shown in PR Photo 06c/03 on the Antenna Test Facility (ATF) site at the NRAO Very Large Array (VLA) site near Socorro (New Mexico, USA). The future ALMA site at Llano de Chajnantor at 5000 metre altitude, some 40 km East of the village of San Pedro de Atacama (Chile) is seen in PR Photo 06d/03 - this view was obtained at 11 hrs in the morning on a crisp and clear autumn day (more views of this site are available at the Chajnantor Photo Gallery). The Atacama Large Millimeter Array (ALMA) will be one of astronomy's most powerful telescopes - providing unprecedented imaging capabilities and sensitivity in the corresponding wavelength range, many orders of magnitude greater than anything of its kind today. ALMA will be an array of 64 antennae that will work together as one telescope to study millimeter and sub-millimeter wavelength radiation from space. This radiation crosses the critical boundary between infrared and microwave radiation and holds the key to understanding such processes as planet and star formation, the formation of early galaxies and galaxy clusters, and the formation of organic and other molecules in space. "ALMA will be one of astronomy's premier tools for studying the universe" says Nobel Laureate Riccardo Giacconi, President of AUI (and former ESO Director General (1993-1999)). "The entire astronomical community is anxious to have the unprecedented power and resolution that ALMA will provide". The President of the ESO Council, Professor Piet van der Kruit, agrees: "ALMA heralds a break-through in sub-millimeter and millimeter astronomy, allowing some of the most penetrating studies the Universe ever made. It is safe to predict that there will be exciting scientific surprises when ALMA enters into operation". What is millimeter and sub-millimeter wavelength astronomy? Astronomers learn about objects in space by studying the energy emitted by those objects. Our Sun and the other stars throughout the Universe emit visible light. But these objects also emit other kinds of light waves, such as X-rays, infrared radiation, and radio waves. Some objects emit very little or no visible light, yet are strong sources at other wavelengths in the electromagnetic spectrum. Much of the energy in the Universe is present in the sub-millimeter and millimeter portion of the spectrum. This energy comes from the cold dust mixed with gas in interstellar space. It also comes from distant galaxies that formed many billions of years ago at the edges of the known universe. With ALMA, astronomers will have a uniquely powerful facility with access to this remarkable portion of the spectrum and hence, new and wonderful opportunities to learn more about those objects. Current observatories simply do not have anywhere near the necessary sensitivity and resolution to unlock the secrets that abundant sub-millimeter and millimeter wavelength radiation can reveal. It will take the unparalleled power of ALMA to fully study the cosmic emission at this wavelength and better understand the nature of the universe. Scientists from all over the world will use ALMA. They will compete for observing time by submitting proposals, which will be judged by a group of their peers on the basis of scientific merit. ALMA's unique capabilities ALMA's ability to detect remarkably faint sub-millimeter and millimeter wavelength emission and to create high-resolution images of the source of that emission gives it capabilities not found in any other astronomical instruments. ALMA will therefore be able to study phenomena previously out of reach to astronomers and astrophysicists, such as: * Very young galaxies forming stars at the earliest times in cosmic history; * New planets forming around young stars in our galaxy, the Milky Way; * The birth of new stars in spinning clouds of gas and dust; and * Interstellar clouds of gas and dust that are the nurseries of complex molecules and even organic chemicals that form the building blocks of life. How will ALMA work? All of ALMA's 64 antennae will work in concert, taking quick "snapshots" or long-term exposures of astronomical objects. Cosmic radiation from these objects will be reflected from the surface of each antenna and focussed onto highly sensitive receivers cooled to just a few degrees above absolute zero in order to suppress undesired "noise" from the surroundings. There the signals will be amplified many times, digitized, and then sent along underground fiber-optic cables to a large signal processor in the central control building. This specialized computer, called a correlator - running at 16,000 million-million operations per second - will combine all of the data from the 64 antennae to make images of remarkable quality. The extraordinary ALMA site Since atmospheric water vapor absorbs millimeter and (especially) sub-millimeter waves, ALMA must be constructed at a very high altitude in a very dry region of the earth. Extensive tests showed that the sky above the Atacama Desert of Chile has the excellent clarity and stability essential for ALMA. That is why ALMA will be built there, on Llano de Chajnantor at an altitude of 5,000 metres in the Chilean Andes. A series of views of this site, also in high-resolution suitable for reproduction, is available at the Chajnantor Photo Gallery. Timeline for ALMA June 1998: Phase 1 (Research and Development) June 1999: European/American Memorandum of Understanding February 2003: Signature of the bilateral Agreement 2004: Tests of the Prototype System 2007: Initial scientific operation of a partially completed array 2011: End of construction of the array

The ESO Diffuse Interstellar Band Large Exploration Survey (EDIBLES)

NASA Astrophysics Data System (ADS)

Cami, J.; Cox, N. L.; Farhang, A.; Smoker, J.; Elyajouri, M.; Lallement, R.; Bacalla, X.; Bhatt, N. H.; Bron, E.; Cordiner, M. A.; de Koter, A..; Ehrenfreund, P.; Evans, C.; Foing, B. H.; Javadi, A.; Joblin, C.; Kaper, L.; Khosroshahi, H. G.; Laverick, M.; Le Petit, F..; Linnartz, H.; Marshall, C. C.; Monreal-Ibero, A.; Mulas, G.; Roueff, E.; Royer, P.; Salama, F.; Sarre, P. J.; Smith, K. T.; Spaans, M.; van Loon, J. T..; Wade, G.

2018-03-01

The ESO Diffuse Interstellar Band Large Exploration Survey (EDIBLES) is a Large Programme that is collecting high-signal-to-noise (S/N) spectra with UVES of a large sample of O and B-type stars covering a large spectral range. The goal of the programme is to extract a unique sample of high-quality interstellar spectra from these data, representing different physical and chemical environments, and to characterise these environments in great detail. An important component of interstellar spectra is the diffuse interstellar bands (DIBs), a set of hundreds of unidentified interstellar absorption lines. With the detailed line-of-sight information and the high-quality spectra, EDIBLES will derive strong constraints on the potential DIB carrier molecules. EDIBLES will thus guide the laboratory experiments necessary to identify these interstellar “mystery molecules”, and turn DIBs into powerful diagnostics of their environments in our Milky Way Galaxy and beyond. We present some preliminary results showing the unique capabilities of the EDIBLES programme.

Exploring the Milky Way stellar disk. A detailed elemental abundance study of 714 F and G dwarf stars in the solar neighbourhood

NASA Astrophysics Data System (ADS)

Bensby, T.; Feltzing, S.; Oey, M. S.

2014-02-01

Aims: The aim of this paper is to explore and map the age and abundance structure of the stars in the nearby Galactic disk. Methods: We have conducted a high-resolution spectroscopic study of 714 F and G dwarf and subgiant stars in the Solar neighbourhood. The star sample has been kinematically selected to trace the Galactic thin and thick disks to their extremes, the metal-rich stellar halo, sub-structures in velocity space such as the Hercules stream and the Arcturus moving group, as well as stars that cannot (kinematically) be associated with either the thin disk or the thick disk. The determination of stellar parameters and elemental abundances is based on a standard analysis using equivalent widths and one-dimensional, plane-parallel model atmospheres calculated under the assumption of local thermodynamical equilibrium (LTE). The spectra have high resolution (R = 40 000-110 000) and high signal-to-noise (S/N = 150-300) and were obtained with the FEROS spectrograph on the ESO 1.5 m and 2.2 m telescopes, the SOFIN and FIES spectrographs on the Nordic Optical Telescope, the UVES spectrograph on the ESO Very Large Telescope, the HARPS spectrograph on the ESO 3.6 m telescope, and the MIKE spectrograph on the Magellan Clay telescope. The abundances from individual Fe i lines were were corrected for non-LTE effects in every step of the analysis. Results: We present stellar parameters, stellar ages, kinematical parameters, orbital parameters, and detailed elemental abundances for O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Zn, Y, and Ba for 714 nearby F and G dwarf stars. Our data show that there is an old and α-enhanced disk population, and a younger and less α-enhanced disk population. While they overlap greatly in metallicity between -0.7 < [Fe/H] ≲ +0.1, they show a bimodal distribution in [α/Fe]. This bimodality becomes even clearer if stars where stellar parameters and abundances show larger uncertainties (Teff ≲ 5400 K) are discarded, showing that it is important to constrain the data set to a narrow range in the stellar parameters if small differences between stellar populations are to be revealed. In addition, we find that the α-enhanced population has orbital parameters placing the stellar birthplaces in the inner Galactic disk while the low-α stars mainly come from the outer Galactic disk, fully consistent with the recent claims of a short scale-length for the α-enhanced Galactic thick disk. We have also investigated the properties of the Hercules stream and the Arcturus moving group and find that neither of them presents chemical or age signatures that could suggest that they are disrupted clusters or extragalactic accretion remnants from ancient merger events. Instead, they are most likely dynamical features originating within the Galaxy. We have also discovered that a standard 1D, LTE analysis, utilising ionisation and excitation balance of Fe i and Fe ii lines produces a flat lower main sequence. As the exact cause for this effect is unclear we chose to apply an empirical correction. Turn-off stars and more evolved stars appear to be unaffected. This paper includes data gathered with the 6.5 m Magellan Telescopes located at the Las Campanas Observatory, Chile; the Nordic Optical Telescope (NOT) on La Palma, Spain; the Very Large Telescope (VLT) at the European Southern Observatory (ESO) on Paranal, Chile (ESO Proposal ID 69.B-0277 and 72.B-0179); the ESO 1.5 m, 2.2 m, and 3.6 m telescopes on La Silla, Chile (ESO Proposal ID 65.L-0019, 67.B-0108, 76.B-0416, 82.B-0610); and data from the UVES Paranal Observatory Project (ESO DDT Program ID 266.D-5655).Full Tables C.1-C.3 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/562/A71Appendices are available in electronic form at http://www.aanda.org

A factorial-design cluster randomised controlled trial investigating the cost-effectiveness of a nutrition supplement and an exercise programme on pneumonia incidence, walking capacity and body mass index in older people living in Santiago, Chile: the CENEX study protocol

PubMed Central

Dangour, Alan D; Albala, Cecilia; Aedo, Cristian; Elbourne, Diana; Grundy, Emily; Walker, Damian; Uauy, Ricardo

2007-01-01

Background Chile is currently undergoing a period of rapid demographic transition which has led to an increase in the proportion of older people in the population; the proportion aged 60 years and over, for example, increased from 8% of the population in 1980 to 12% in 2005. In an effort to promote healthy ageing and preserve function, the government of Chile has formulated a package of actions into the Programme of Complementary Feeding for the Older Population (PACAM) which has been providing a nutritional supplement to older people since 1998. PACAM distributes micronutrient fortified foods to individuals aged 70 years and over registered at Primary Health Centres and enrolled in the programme. The recommended serving size (50 g/day) of these supplements provides 50% of daily micronutrient requirements and 20% of daily energy requirements of older people. No information is currently available on the cost-effectiveness of the supplementation programme. Aim The aim of the CENEX cluster randomised controlled trial is to evaluate the cost-effectiveness of an ongoing nutrition supplementation programme, and a specially designed physical exercise intervention for older people of low to medium socio-economic status living in Santiago, Chile. Methods The study has been conceptualised as a public health programme effectiveness study and has been designed as a 24-month factorial cluster-randomised controlled trial conducted among 2800 individuals aged 65.0–67.9 years at baseline attending 28 health centres in Santiago. The main outcomes are incidence of pneumonia, walking capacity and change in body mass index over 24 months of intervention. Costing data (user and provider), collected at all levels, will enable the determination of the cost-effectiveness of the two interventions individually and in combination. The study is supported by the Ministry of Health in Chile, which is keen to expand and improve its national programme of nutrition for older people based on sound science-base and evidence for cost-effectiveness. Trial registration ISRCTN48153354 PMID:17615064

Brightness Variations of Sun-like Stars: The Mystery Deepens - Astronomers facing Socratic "ignorance"

NASA Astrophysics Data System (ADS)

2009-12-01

An extensive study made with ESO's Very Large Telescope deepens a long-standing mystery in the study of stars similar to the Sun. Unusual year-long variations in the brightness of about one third of all Sun-like stars during the latter stages of their lives still remain unexplained. Over the past few decades, astronomers have offered many possible explanations, but the new, painstaking observations contradict them all and only deepen the mystery. The search for a suitable interpretation is on. "Astronomers are left in the dark, and for once, we do not enjoy it," says Christine Nicholls from Mount Stromlo Observatory, Australia, lead author of a paper reporting the study. "We have obtained the most comprehensive set of observations to date for this class of Sun-like stars, and they clearly show that all the possible explanations for their unusual behaviour just fail." The mystery investigated by the team dates back to the 1930s and affects about a third of Sun-like stars in our Milky Way and other galaxies. All stars with masses similar to our Sun become, towards the end of their lives, red, cool and extremely large, just before retiring as white dwarfs. Also known as red giants, these elderly stars exhibit very strong periodic variations in their luminosity over timescales up to a couple of years. "Such variations are thought to be caused by what we call 'stellar pulsations'," says Nicholls. "Roughly speaking, the giant star swells and shrinks, becoming brighter and dimmer in a regular pattern. However, one third of these stars show an unexplained additional periodic variation, on even longer timescales - up to five years." In order to find out the origin of this secondary feature, the astronomers monitored 58 stars in our galactic neighbour, the Large Magellanic Cloud, over two and a half years. They acquired spectra using the high resolution FLAMES/GIRAFFE spectrograph on ESO's Very Large Telescope and combined them with images from other telescopes [1], achieving an impressive collection of the properties of these variable stars. Outstanding sets of data like the one collected by Nicholls and her colleagues often offer guidance on how to solve a cosmic puzzle by narrowing down the plethora of possible explanations proposed by the theoreticians. In this case, however, the observations are incompatible with all the previously conceived models and re-open an issue that has been thoroughly debated. Thanks to this study, astronomers are now aware of their own "ignorance" - a genuine driver of the knowledge-seeking process, as the ancient Greek philosopher Socrates is said to have taught. "The newly gathered data show that pulsations are an extremely unlikely explanation for the additional variation," says team leader Peter Wood. "Another possible mechanism for producing luminosity variations in a star is to have the star itself move in a binary system. However, our observations are strongly incompatible with this hypothesis too." The team found from further analysis that whatever the cause of these unexplained variations is, it also causes the giant stars to eject mass either in clumps or as an expanding disc. "A Sherlock Holmes is needed to solve this very frustrating mystery," concludes Nicholls. Notes [1] Precise brightness measurements were made by the MACHO and OGLE collaborations, running on telescopes in Australia and Chile, respectively. The OGLE observations were made at the same time as the VLT observations. More information This research was presented in two papers: one appeared in the November issue of the Monthly Notices of the Royal Astronomical Society ("Long Secondary Periods in Variable Red Giants", by C. P. Nicholls et al.), and the other has just been published in the Astrophysical Journal ("Evidence for mass ejection associated with long secondary periods in red giants", by P. R. Wood and C. P. Nicholls). The team is composed of Christine P. Nicholls and Peter R. Wood (Research School of Astronomy and Astrophysics, Australia National University), Maria-Rosa L. Cioni (Centre for Astrophysics Research, University of Hertfordshire, UK) and Igor Soszyński (Warsaw University Observatory). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

N° 15-2000: ESA, CERN and ESO launch "Physics on Stage"

NASA Astrophysics Data System (ADS)

2000-03-01

But how much do the citizens of Europe really know about physics? Here is a unique opportunity to learn more about this elusive subject! Beginning in February 2000, three major European research establishments [1] are organising a unique Europe-wide programme to raise the public awareness of physics and related sciences. "Physics on Stage" is launched by the European Space Agency (ESA), the European Laboratory for Particle Physics (CERN), and the European Southern Observatory (ESO), with support from the European Union (EU). Other partners include the European Physical Society (EPS) and the European Association for Astronomy Education (EAAE). This exciting programme is part of the European Week for Science and Technology and will culminate in a Science Festival during November 6-11, 2000, at CERN, Geneva. Why "Physics on Stage"? The primary goal of "Physics on Stage" is to counteract the current decline in interest and knowledge of physics among Europe's citizens by means of a series of highly visible promotional activities. It will bring together leading scientists and educators, government bodies and the media, to confront the diminishing attraction of physics to young people and to develop strategies to reverse this trend. The objective in the short term is to infuse excitement and to provide new educational materials. In the longer term, "Physics on Stage" will generate new developments by enabling experts throughout Europe to meet, exchange and innovate. "Physics on Stage" in 22 European Countries. "Physics on Stage" has been initiated in 22 European countries [2]. In each country, a dedicated National Steering Committee (NSC) is being formed which will be responsible for their own national programme. A list of contact addresses is attached below. "Physics on Stage" is based on a series of high-profile physics-related activities that will inform the European public in general, and European high school physics teachers and media representatives in particular, about innovative ways to convey information about physics. It will stress the intimate connection of this natural science with our daily lives. It will be accompanied by a broad media debate on these subjects. This effort is undertaken in the context of a progressive decline in physics literacy amongst the European population at all levels and ages. Fewer and fewer young people are attracted towards careers in core sciences and technologies - this could potentially lead to a crisis in European technology in the coming decades unless action is taken now. Too few people possess the basic knowledge that is necessary to understand even common physical phenomena. And not enough are able to form their own substantiated opinions about them. What will happen during "Physics on Stage"? During the first phase of "Physics on Stage", from now until October 2000, the individual national steering committees (NSC) will survey the situation in their respective countries. The NSCs will collaborate with national media to identify new and exciting educational approaches to physics. These may involve demonstrations, interactive experiments, video and CD-Rom presentations, web applications, virtual reality, theatre performances, etc. Nationally run competitions will select some of the best and most convincing new ideas for presentations and educational materials which will receive development support from "Physics on Stage". The project will culminate in November 2000, with approximately 400 delegates converging on CERN, in Geneva, for the "Physics on Stage" conference. The conference will enable the national competition winners, science teachers, science communicators, publishers, top scientists and high-level representatives of the ministries and European organisations to brainstorm solutions to bolster physics' popularity. The programme will also include spectacular demonstrations of educational tools; the best will be disseminated over the national TV networks and other media to the European public. Why ESA, CERN, and ESO? As Europe's principal organisations in physics research (particle physics, space and astronomy), the three recognised their mutual responsibility to address the issue with the launch of a new initiative and the creative use of their own research to attract the attention of the general public and teachers alike. About the "European Science and Technology Week" The objective of the "European Science and Technology Week" is to improve the public's knowledge and understanding of science and technology - including the associated benefits for society as a whole. The week focuses on the European dimension of research, such as pan-European scientific and technological co-operation. The rationale for holding the Week has its roots in the importance of the role of science and technology in modern societies and the need therefore, to ensure that the public recognises its significance in our lives. The Week is a framework for special TV programmes, exhibitions, contests, conferences, electronic networking, and other science related activities to promote the public understanding of science and technology. The Week was launched in 1993, on the initiative of the European Commission. Raising public awareness of science and technology is now the subject of a clearly defined action within the Human Potential Programme of the Fifth Framework Programme. Notes [1] The same press release is published also by CERN and ESO. [2] The 22 countries are the member countries of at least one of the participating organisations or the European Union: Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, the Slovak Republic, Spain, Sweden, Switzerland, United Kingdom. Statements by the Directors General of ESA, CERN, and ESO Antonio Rodotà (ESA): "Space has become an integral part of every day life. The immense technological development that has led to this achievement has taken place and might be taken for granted. But now is the time to follow up and form the future on this basis, a future that has to be made by the youth and has to give its benefits to the youth. The European Space Agency is dedicated to support the youth in its development to become a space generation. Many activities have been done and are taking place, and many more are planned for the future. Teachers and educational institutions and organisations form a key role in this development. ESA is enthusiastic about co-operating with ESO, CERN and the European Union to create an opportunity to receive ideas from the educational society and will perform a dedicated effort in finding ways to support the realisation of those ideas." Luciano Maiani (CERN): "Science is a critical resource for mankind and, among natural sciences, physics will continue to play a crucial role, well into the next century. The young people of Europe deserve the best possible physics teaching. An enormous resource of first class teachers, teaching materials and innovative thinking exists in our Countries. The "Physics on Stage" project will bring these together to generate a new interest in physics education which will be to the long term benefit of children all over Europe. CERN is delighted to take part in this collaboration between the European Community and the continent's three leading physics research organisations." Catherine Cesarsky (ESO): "Astronomy and Astrophysics are at the very heart of modern physics. As vibrant research disciplines they use the most advanced technology available to humanity to explore Cosmos. It is also a science of extreme conditions - the largest distances, the longest periods of time, the highest temperatures, the strongest electrical and magnetic fields, the highest and lowest densities and the most extreme energies. Cosmos is indeed the greatest physics laboratory. For years, ESO - Europe's Astronomy Organisation - has been engaged in communicating the outcome of the exciting research programmes carried out at the ESO observatories to a wide audience and in particular to Europe's youth. I warmly welcome the broad international collaboration within "Physics on Stage". I am confident that working together with the European Union and our sister organisations ESA and CERN, as well as teachers' organisations and dedicated individuals in all member countries, this innovative education programme will make a most important contribution towards raising the interest in fundamental research in Europe." About ESA, CERN, and ESO The European Space Agency (ESA) is an international/intergovernmental organisation made of 15 member states: Austria, Belgium, Denmark, Finland, France, Germany, Ireland, Italy, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. ESA provides and promotes, for peaceful purposes only, co-operation among its member states in space research, technology and their applications. With ESA, Europe shapes and shares space for people, companies and the scientific community. The European Southern Observatory (ESO) is an intergovernmental organisation supported by Belgium, Denmark, France, Germany, Italy, the Netherlands, Sweden and Switzerland. Portugal has an agreement with ESO aiming at full membership. ESO is a major driving force in European astronomy, performing tasks that are beyond the capabilities of the individual member countries. The ESO observatory La Silla in Chile is one of the largest and best-equipped observatories in the world. ESO's Very Large Telescope Array (VLT), an array of giant telescopes, is under construction at Cerro Paranal in the Chilean Atacama Desert. When completed in 2001, the VLT will be the largest and best optical telescope in the world. The CERN, European Organisation for Nuclear Research, has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Israel, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and Unesco have observer status.

Trio of Neptunes and their Belt

NASA Astrophysics Data System (ADS)

2006-05-01

Using the ultra-precise HARPS spectrograph on ESO's 3.6-m telescope at La Silla (Chile), a team of European astronomers have discovered that a nearby star is host to three Neptune-mass planets. The innermost planet is most probably rocky, while the outermost is the first known Neptune-mass planet to reside in the habitable zone. This unique system is likely further enriched by an asteroid belt. ESO PR Photo 18a/06 ESO PR Photo 18a/06 Planetary System Around HD 69830 (Artist's Impression) "For the first time, we have discovered a planetary system composed of several Neptune-mass planets", said Christophe Lovis, from the Geneva Observatory and lead-author of the paper presenting the results [1]. During more than two years, the astronomers carefully studied HD 69830, a rather inconspicuous nearby star slightly less massive than the Sun. Located 41 light-years away towards the constellation of Puppis (the Stern), it is, with a visual magnitude of 5.95, just visible with the unaided eye. The astronomers' precise radial-velocity measurements [2] allowed them to discover the presence of three tiny companions orbiting their parent star in 8.67, 31.6 and 197 days. "Only ESO's HARPS instrument installed at the La Silla Observatory, Chile, made it possible to uncover these planets", said Michel Mayor, also from Geneva Observatory, and HARPS Principal Investigator. "Without any doubt, it is presently the world's most precise planet-hunting machine" [3]. ESO PR Photo 18d/06 ESO PR Photo 18d/06 Phase Folded Measurements of HD 69830 The detected velocity variations are between 2 and 3 metres per second, corresponding to about 9 km/h! That's the speed of a person walking briskly. Such tiny signals could not have been distinguished from 'simple noise' by most of today's available spectrographs. The newly found planets have minimum masses between 10 and 18 times the mass of the Earth. Extensive theoretical simulations favour an essentially rocky composition for the inner planet, and a rocky/gas structure for the middle one. The outer planet has probably accreted some ice during its formation, and is likely to be made of a rocky/icy core surrounded by a quite massive envelope. Further calculations have also shown that the system is in a dynamically stable configuration. ESO PR Photo 18e/06 ESO PR Photo 18e/06 Formation Process of the Planetary System The outer planet also appears to be located near the inner edge of the habitable zone, where liquid water can exist at the surface of rocky/icy bodies. Although this planet is probably not Earth-like due to its heavy mass, its discovery opens the way to exciting perspectives. "This alone makes this system already exceptional", said Willy Benz, from Bern University, and co-author. "But the recent discovery by the Spitzer Space Telescope that the star most likely hosts an asteroid belt is adding the cherry to the cake." With three roughly equal-mass planets, one being in the habitable zone, and an asteroid belt, this planetary system shares many properties with our own solar system. "The planetary system around HD 69830 clearly represents a Rosetta stone in our understanding of how planets form", said Michel Mayor. "No doubt it will help us better understand the huge diversity we have observed since the first extra-solar planet was found 11 years ago." High resolution images and their captions are available on this page. Video footage and animations are also available on this page.

VizieR Online Data Catalog: Transiting planet WASP-6b (Tregloan-Reed+, 2015)

NASA Astrophysics Data System (ADS)

Tregloan-Reed, J.; Southworth, J.; Burgdorf, M.; Calchi Novati, S.; Dominik, M.; Finet, F.; Jorgensen, U. G.; Maier, G.; Mancini, L.; Prof, S.; Ricci, D.; Snodgrass, C.; Bozza, V.; Browne, P.; Dodds, P.; Gerner, T.; Harpsoe, K.; Hinse, T. C.; Hundertmark, M.; Kains, N.; Kerins, E.; Liebig, C.; Penny, M. T.; Rahvar, S.; Sahu, K.; Scarpetta, G.; Schafer, S.; Schonebeck, F.; Skottfelt, J.; Surdej, J.

2018-05-01

Four light curves of transits of the extrasolar planetary system WASP-6 are presented. They were obtained using the Danish 1.54m telescope at ESO La Silla, Chile, in the Bessell R passband. The errorbars for each transit have been scaled so the best-fitting model (obtained using the JKTEBOP code and without accounting for the presence of starspots) has a reduced chi-squared value of 1.0. (1 data file).

HUBBLE PHOTOGRAPHS WARPED GALAXY AS CAMERA PASSES MILESTONE

NASA Technical Reports Server (NTRS)

2002-01-01

NASA's Hubble Space Telescope has captured an image of an unusual edge-on galaxy, revealing remarkable details of its warped dusty disk and showing how colliding galaxies spawn the formation of new generations of stars. The dust and spiral arms of normal spiral galaxies, like our own Milky Way, appear flat when viewed edge-on. This month's Hubble Heritage image of ESO 510-G13 shows a galaxy that, by contrast, has an unusual twisted disk structure, first seen in ground-based photographs obtained at the European Southern Observatory (ESO) in Chile. ESO 510-G13 lies in the southern constellation Hydra, roughly 150 million light-years from Earth. Details of the structure of ESO 510-G13 are visible because the interstellar dust clouds that trace its disk are silhouetted from behind by light from the galaxy's bright, smooth central bulge. The strong warping of the disk indicates that ESO 510-G13 has recently undergone a collision with a nearby galaxy and is in the process of swallowing it. Gravitational forces distort the structures of the galaxies as their stars, gas, and dust merge together in a process that takes millions of years. Eventually the disturbances will die out, and ESO 510-G13 will become a normal-appearing single galaxy. In the outer regions of ESO 510-G13, especially on the right-hand side of the image, we see that the twisted disk contains not only dark dust, but also bright clouds of blue stars. This shows that hot, young stars are being formed in the disk. Astronomers believe that the formation of new stars may be triggered by collisions between galaxies, as their interstellar clouds smash together and are compressed. The Heritage Team used Hubble's Wide Field Planetary Camera 2 (WFPC2) to observe ESO 510-G13 in April 2001. Pictures obtained through blue, green, and red filters were combined to make this color-composite image, which emphasizes the contrast between the dusty spiral arms, the bright bulge, and the blue star-forming regions. During the observations of ESO 510-G13, WFPC2 passed the milestone of taking its 100,000th image since its installation in the telescope by shuttle astronauts in 1993. Image Credit: NASA and the Hubble Heritage Team (STScI/AURA) Acknowledgment: C. Conselice (U. Wisconsin/STScI)

The cost-effectiveness of adding fluorides to milk-products distributed by the National Food Supplement Programme (PNAC) in rural areas of Chile.

PubMed

Mariño, R; Morgan, M; Weitz, A; Villa, A

2007-06-01

This paper assesses the cost-effectiveness of a community dental caries prevention programme, targeting pre-school children living in non-fluoridated rural areas of Chile. The results of a community trial to measure the effects of using fluoridated powdered milk and milk-cereal to prevent dental caries, together with the cost of running the programmeme, were used to determine its cost-effectiveness when compared to the status-quo alternative. In the experimental community, fluoridated milk products were given to approximately 1,000 children aged between six months and six years, using the standard National Complementary Feeding Programme available in Chile. The control group received the milk products only. Dental caries status was recorded at the beginning and end of the programme in both communities using WHO criteria. The costs that would be incurred by such a programme, using a societal perspective, were identified and measured. Children who received fluoridated products had significantly lower mean levels of dental caries than those who had not. This improvement was achieved with a yearly cost of RCH (1999) $1,839.75 per child (1 US$ = RCH (1999) $527.70). On average, this programme resulted in a net societal savings of RCH (1999) $2,695.61 per diseased tooth averted after four years when compared to the control group. While the analysis has inherent limitations as a result of its reliance on a range of assumptions, the findings suggest that there are important health and economic benefits to be gained from the use of fluoridated milk products in non-fluoridated rural communities in Chile.

School students "Catch a Star"!

NASA Astrophysics Data System (ADS)

2007-04-01

School students from across Europe and beyond have won prizes in an astronomy competition, including the trip of a lifetime to one of the world's most powerful astronomical observatories, on a mountaintop in Chile. ESO, the European Organisation for Astronomical Research in the Southern Hemisphere, together with the European Association for Astronomy Education (EAAE), has just announced the winners of the 2007 "Catch a Star!" competition. ESO PR Photo 21/07 "Catch a Star!" is an international astronomy competition for school students, in which students are invited to 'become astronomers' and explore the Universe. The competition includes two categories for written projects on astronomical themes, to ensure that every student, whatever their level, has the chance to enter and win exciting prizes. For the artistically minded, "Catch a Star!" also includes an astronomy-themed artwork competition. Students from 22 countries submitted hundreds of written projects and pieces of artwork. "The standard of entries was most impressive, and made the jury's task of choosing winners both enjoyable and difficult! We hope that everyone, whether or not they won a prize, had fun taking part, and learnt some exciting things about our Universe", said Douglas Pierce-Price, Education Officer at ESO. The top prize, of a week-long trip to Chile to visit the ESO Very Large Telescope (VLT) on Paranal, was won by students Jan Mestan and Jan Kotek from Gymnazium Pisek in the Czech Republic, together with their teacher Marek Tyle. Their report on "Research and Observation of the Solar Eclipse" told how they had studied solar eclipses, and involved their fellow students in observations of an eclipse from their school in 2006. The team will travel to Chile and visit the ESO VLT - one of the world's most powerful optical/infrared telescopes - where they will meet astronomers and be present during a night of observations on the 2600m high Paranal mountaintop. "It's fantastic that we will see the VLT in action. I'm also looking forward to my first view of the southern sky!" said Jan Mestan. His fellow student is also excited about the trip. "I am very happy that we'll visit the Paranal observatory, because this is one of the best astronomical observatories in the world, in the amazing scenery of the Atacama Desert", said Jan Kotek. "This was a very well written project, and we particularly liked the way in which the students involved the rest of their school.", said Douglas Pierce-Price. The team's hard work was also helped by some good fortune, as it seemed at first that bad weather might block their view of the eclipse. "It was cloudy, overcast, and a strong west wind was blowing in Pisek. The meteorological situation was nearly hopeless, and we thought we might have to cancel the observation. But later, the sky luckily cleared up and we could see the eclipse!", said the students. "I am very glad that my students' work won the top prize in this great competition. I believe that the visit to the VLT will be an important experience in their education." said teacher Marek Tyle. Other "Catch a Star" participants have won exciting trips to observatories across Europe. Emilio Rojas, Angel Sanchez, Javier Ortiz and their teacher Roberto Palmer from Spain have won a trip to Koenigsleiten Observatory in Austria for their project "Jupiter on the radio". Bogumil Giertler, Ammar Ahmed, and their teacher Richard Burt from Italy have won a trip to Wendelstein Observatory in Germany for their project "Determining the relative radiant of the Geminid meteor shower". Victor Raimbault, Remi Takase, Thomas Salez and their teacher Michel Faye from France have won a trip to Calar Alto Observatory in Spain, a prize kindly donated by the Spanish Council for Scientific Research, for their project "Light on Dark Matter". Forty other teams won prizes, which included astronomy software and sets of posters showcasing stunning astronomical images taken with ESO telescopes. In the artwork competition, sixty winning pictures were chosen with the help of a public vote. The beautiful pictures created by students of all ages can be seen in the gallery on the "Catch a Star" website. The full list of winners can also be found on the website. The full list of winners can be found at http://www.eso.org/catchastar/CAS2007/winners.php The gallery can be found at http://www.eso.org/catchastar/CAS2007/gallery.php Further information about the competition can be found at http://www.eso.org/catchastar/CAS2007/

VizieR Online Data Catalog: VEGAS: A VST Early-type GAlaxy Survey (Capaccioli+, 2015)

NASA Astrophysics Data System (ADS)

Capaccioli, M.; Spavone, M.; Grado, A.; Iodice, E.; Limatola, L.; Napolitano, N. R.; Cantiello, M.; Paolillo, M.; Romanowsky, A. J.; Forbes, D. A.; Puzia, T. H.; Raimondo, G.; Schipani, P.

2015-11-01

The VST Elliptical GAlaxies Survey (VEGAS) is a deep multiband (g,r,i) imaging survey of early-type galaxies in the southern hemisphere carried out with VST at the ESO Cerro Paranal Observatory (Chile). The large field of view (FOV) of the OmegaCAM mounted on VST (one square degree matched by pixels 0.21-arcsec wide), together with its high efficiency and spatial resolution (typically better than 1-arcsec; Kuijken, 2011Msngr.146....8K) allows us to map with a reasonable integration time the surface brightness of a galaxy out to isophotes encircling about 95% of the total light. Observations started in October 2011 (ESO Period 88), and since then, the survey has acquired exposures for about 20 bright galaxies (and for a wealth of companion objects in the field), for a totality of ~80h (up to Period 93). (1 data file).

News and Views: Transit events and resources; HST to use transit to probe venusian atmosphere; Now, the space weather forecast; Astronomy writing prize

NASA Astrophysics Data System (ADS)

2012-06-01

TRANSIT Early risers in the UK have the opportunity to see the final stages of the last transit of Venus for more than a century. TRANSIT Researchers interested in the atmosphere of Venus will be using the Hubble Space Telescope and the Moon to examine sunlight passing through the atmosphere during the transit of Venus this month. The technique is the same as that used to determine atmospheric constituents of transiting exoplanets. The Met Office is expanding its services to include operational space-weather forecasts for the UK, working with the research community to expand existing climate models. Further collaborative work will apply the enhanced model to extrasolar planets. The ESO and the STFC are organizing a Europe-wide competition for the very best in astronomy journalism in print, online or broadcast. The winner gets a trip to ESO's Very Large Telescope in Chile.

TOPoS: chemical study of extremely metal-poor stars.

NASA Astrophysics Data System (ADS)

Caffau, E.; Sbordone, L.; Bonifacio, P.; Cayrel, R.; Christlieb, N.; Clark, P.; François, P.; Glover, S.; Klessen, R.; Koch, A.; Ludwig, H.-G.; Monaco, L.; Plez, B.; Spite, F.; Spite, M.; Steffen, M.; Zaggia, S.

The extremely metal-poor (EMP) stars hold in their atmospheres the fossil record of the chemical composition of the early phases of the Galactic evolution. The chemical analysis of such objects provides important constraints on these early phases. EMP stars are very rare objects; to dig them out, large amounts of data have to be processed. With an automatic procedure, we analysed objects with colours of Turn-Off stars from the Sloan Digital Sky Survey to select a sample of good candidate EMP stars. In the latest years, we observed a sample of these candidates with X-Shooter and UVES, and we have an ongoing ESO large programme to use these spectrographs to observe EMP stars. I will report here the results on metallicity and Strontium abundance. Based on observations obtained at ESO Paranal Observatory, programme 189.D-0165(A)

Teachers' Professional Development through University-School Partnerships: Theoretical Standpoints and Evidence from Two Pilot Studies in Chile

ERIC Educational Resources Information Center

Grau, Valeska; Calcagni, Elisa; Preiss, David D.; Ortiz, Dominga

2017-01-01

This paper presents a teacher professional development programme, based on a university-schools partnership and a collective reflection model, addressing the needs of in-service teacher education in Chile. First, the main challenges faced by both teachers and teacher education in Chile are summarised. Then, the foundations of this model are…

Trio of Stellar Occultations by Pluto One Year Prior to New Horizons’ Arrival

DTIC Science & Technology

2016-04-02

7 Department of Astronomy , Williams College, 33 Lab Campus Drive, Williamstown, MA 01267-2565, USA; chs2@williams.edu, bbabcock@williams.edu 8 Cerro...for Research in Astronomy (SARA), the MPI/ESO 2.2 m on La Silla, and the 0.45 m Cerro Calán telescope and 0.36 telescope in Constitución in Chile on...10 Also MIT, Cambridge, MA, USA. 11 Also Keck Northeast Astronomy Consortium Summer Fellow at Williams College, from Middlebury College, Middlebury, VT

The possible astronomical function of the El Molle stone circle at the ESO Observatory La Silla. II: The updated measurement campaign

NASA Astrophysics Data System (ADS)

Bernardi, Gabriella; Vecchiato, Alberto; Bucciarelli, Beatrice

2014-07-01

This paper reviews and updates the accounts of a previous article discussing the possible astronomical significance of a peculiar, man-made circular stone structure, located close to the European Southern Observatory in La Silla, Chile, and attributed to the El Molle culture. Thanks to further, higher-accuracy measurements in situ, we can confirm some of the original hypotheses and dismiss others, upholding the main tenets of the original work.

VizieR Online Data Catalog: SDSS optically selected BL Lac candidates (Kuegler+, 2014)

NASA Astrophysics Data System (ADS)

Kuegler, S. D.; Nilsson, K.; Heidt, J.; Esser, J.; Schultz, T.

2014-11-01

The data that we use for variability and host galaxy analysis were presented in Paper I (Heidt & Nilsson, 2011A&A...529A.162H, Cat. J/A+A/529/A162). Alltogether, 123 targets were observed at the ESO New Technology Telescope (NTT) on La Silla, Chile during Oct. 2-6, 2008 and Mar. 28-Apr. 1, 2009. The observations were made with the EFOSC2 instrument through a Gunn-r filter (#786). (2 data files).

The origin and evolution of the odd-Z iron-peak elements Sc, V, Mn, and Co in the Milky Way stellar disk

NASA Astrophysics Data System (ADS)

Battistini, Chiara; Bensby, Thomas

2015-05-01

Context. Elements heavier than Li are produced in the interiors of stars. However, for many elements the exact production sites and the timescales on which they are dispersed into the interstellar medium are unknown. Having a clear picture on the origins of the elements is important for our ability to trace and understand the formation and chemical evolution of the Milky Way and its stellar populations. Aims: The aim of this study is to investigate the origin and evolution of Sc, V, Mn, and Co for a homogeneous and statistically significant sample of stars probing the different populations of the Milky Way, in particular the thin and thick disks. Methods: Using high-resolution spectra obtained with the MIKE, FEROS, SOFIN, FIES, UVES, and HARPS spectrographs, we determine Sc, V, Mn, and Co abundances for a large sample of F and G dwarfs in the solar neighborhood. The method is based on spectral synthesis and using one-dimensional, plane-parallel, local thermodynamic equilibrium (LTE) model stellar atmospheres calculated with the MARCS 2012 code. The non-LTE (NLTE) corrections from the literature were applied to Mn and Co. Results: We find that the abundance trends derived for Sc (594 stars), V (466 stars), and Co (567 stars) are very similar to what has been observed for the α-elements in the thin and thick disks. On the contrary, Mn (569 stars) is generally underabundant relative to the Sun (i.e., [ Mn/Fe ] < 0) for [ Fe/H ] < 0. In addition, for Mn, when NLTE corrections are applied, the trend changes and is almost flat over the entire metallicity range of the stars in our sample (-2 ≲ [ Fe/H ] ≲ + 0.4). The [Sc/Fe]-[Fe/H] abundance trends show a small separation between the thin and thick disks, while for V and Co they completely overlap. For Mn there is a small difference in [Mn/Fe], but only when NLTE corrections are used. Comparisons with Ti as a reference element show flat trends for all the elements except for Mn that show well separated [Mn/Ti]-[Ti/H] trends for the thin and thick disks. Conclusions: The elements Sc and V present trends compatible with production from type II supernovae (SNII) events. In addition, Sc clearly shows a metallicity dependence for [ Fe/H ] < -1. Instead, Mn is produced in SNII events for [ Fe/H ] ≲ -0.4 and then type Ia supernovae start to produce Mn. Finally, Co appears to be produced mainly in SNII with suggestion of enrichment from hypernovae at low metallicities. This paper includes data gathered with the 6.5 m Magellan Telescopes located at the Las Campanas Observatory, Chile; the Nordic Optical Telescope (NOT) on La Palma, Spain; the Very Large Telescope (VLT) at the European Southern Observatory (ESO) on Paranal, Chile (ESO Proposal ID 69.B-0277 and 72.B-0179); the ESO 1.5-m, 2.2-m. and 3.6-m telescopes on La Silla, Chile (ESO Proposal ID 65.L-0019, 67.B-0108, 76.B-0416, 82.B-0610); and data from UVES Paranal Observatory Project (ESO DDT Program ID 266.D-5655).Full versions of Tables 2 and 5 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/577/A9Appendices are available in electronic form at http://www.aanda.org

Report on the ESO Workshop ''Satellites and Streams in Santiago''

NASA Astrophysics Data System (ADS)

Küpper, A. H. W.; Mieske, S.

2015-09-01

Galactic satellites and tidal streams are arguably the two most direct imprints of hierarchical structure formation in the haloes of galaxies. At this ESO workshop we sought to create the big picture of the galactic accretion process, and shed light on the interplay between satellites and streams in the Milky Way, Andromeda and beyond. The Scientific Organising Committee prepared a well-balanced programme with 60 talks and 30 poster contributions, resulting in a meeting which was greatly enjoyed by the more than 110 participants at the venue, and worldwide via Twitter (#SSS15).

Li depletion in solar analogues with exoplanets. Extending the sample

NASA Astrophysics Data System (ADS)

Delgado Mena, E.; Israelian, G.; González Hernández, J. I.; Sousa, S. G.; Mortier, A.; Santos, N. C.; Adibekyan, V. Zh.; Fernandes, J.; Rebolo, R.; Udry, S.; Mayor, M.

2014-02-01

Aims: We want to study the effects of the formation of planets and planetary systems on the atmospheric Li abundance of planet host stars. Methods: In this work we present new determinations of lithium abundances for 326 main sequence stars with and without planets in the Teff range 5600-5900 K. The 277 stars come from the HARPS sample, the remaining targets were observed with a variety of high-resolution spectrographs. Results: We confirm significant differences in the Li distribution of solar twins (Teff = T⊙ ± 80 K, log g = log g⊙ ± 0.2 and [Fe/H] = [Fe/H]⊙ ± 0.2): the full sample of planet host stars (22) shows Li average values lower than "single" stars with no detected planets (60). If we focus on subsamples with narrower ranges in metallicity and age, we observe indications of a similar result though it is not so clear for some of the subsamples. Furthermore, we compare the observed spectra of several couples of stars with very similar parameters that show differences in Li abundances up to 1.6 dex. Therefore we show that neither age, mass, nor metallicity of a parent star is the only cause for enhanced Li depletion in solar analogues. Conclusions: We conclude that another variable must account for that difference and suggest that this could be the presence of planets that causes additional rotationally induced mixing in the external layers of planet host stars. Moreover, we find indications that the amount of depletion of Li in planet-host solar-type stars is higher when the planets are more massive than Jupiter. Based on observations collected at the La Silla Observatory, ESO (Chile), with the HARPS spectrograph at the 3.6 m ESO telescope, with CORALIE spectrograph at the 1.2 m Euler Swiss telescope and with the FEROS spectrograph at the 1.52 m ESO telescope; at the Paranal Observatory, ESO (Chile), using the UVES spectrograph at the VLT/UT2 Kueyen telescope, and with the FIES, SARG, and UES spectrographs at the 2.5 m NOT, the 3.6 m TNG and the 4.2 WHT, respectively, operated on the island of La Palma in the Spanish Observatorio del Roque de los Muchachos.Table 6 is available in electronic form at http://www.aanda.org

Integration of the instrument control electronics for the ESPRESSO spectrograph at ESO-VLT

NASA Astrophysics Data System (ADS)

Baldini, V.; Calderone, G.; Cirami, R.; Coretti, I.; Cristiani, S.; Di Marcantonio, P.; Mégevand, D.; Riva, M.; Santin, P.

2016-07-01

ESPRESSO, the Echelle SPectrograph for Rocky Exoplanet and Stable Spectroscopic Observations of the ESO - Very Large Telescope site, is now in its integration phase. The large number of functions of this complex instrument are fully controlled by a Beckhoff PLC based control electronics architecture. Four small and one large cabinets host the main electronic parts to control all the sensors, motorized stages and other analogue and digital functions of ESPRESSO. The Instrument Control Electronics (ICE) is built following the latest ESO standards and requirements. Two main PLC CPUs are used and are programmed through the TwinCAT Beckhoff dedicated software. The assembly, integration and verification phase of ESPRESSO, due to its distributed nature and different geographical locations of the consortium partners, is quite challenging. After the preliminary assembling and test of the electronic components at the Astronomical Observatory of Trieste and the test of some electronics and software parts at ESO (Garching), the complete system for the control of the four Front End Unit (FEU) arms of ESPRESSO has been fully assembled and tested in Merate (Italy) at the beginning of 2016. After these first tests, the system will be located at the Geneva Observatory (Switzerland) until the Preliminary Acceptance Europe (PAE) and finally shipped to Chile for the commissioning. This paper describes the integration strategy of the ICE workpackage of ESPRESSO, the hardware and software tests that have been performed, with an overall view of the experience gained during these project's phases.

Abundance study of the two solar-analogue CoRoT targets HD 42618 and HD 43587 from HARPS spectroscopy

NASA Astrophysics Data System (ADS)

Morel, T.; Rainer, M.; Poretti, E.; Barban, C.; Boumier, P.

2013-04-01

We present a detailed abundance study based on spectroscopic data obtained with HARPS of two solar-analogue main targets for the asteroseismology programme of the CoRoT satellite: HD 42618 and HD 43587. The atmospheric parameters and chemical composition are accurately determined through a fully differential analysis with respect to the Sun observed with the same instrumental set-up. Several sources of systematic errors largely cancel out with this approach, which allows us to narrow down the 1-σ error bars to typically 20 K in effective temperature, 0.04 dex in surface gravity, and less than 0.05 dex in the elemental abundances. Although HD 42618 fulfils many requirements for being classified as a solar twin, its slight deficiency in metals and its possibly younger age indicate that, strictly speaking, it does not belong to this class of objects. On the other hand, HD 43587 is slightly more massive and evolved. In addition, marked differences are found in the amount of lithium present in the photospheres of these two stars, which might reveal different mixing properties in their interiors. These results will put tight constraints on the forthcoming theoretical modelling of their solar-like oscillations and contribute to increase our knowledge of the fundamental parameters and internal structure of stars similar to our Sun. Based on observations collected at the La Silla Observatory, ESO (Chile) with the HARPS spectrograph at the 3.6-m telescope, under programme LP185.D-0056.Tables 1 and 2 are available in electronic form at http://www.aanda.org

Prevalence and associated factors of hearing aid use among older adults in Chile.

PubMed

Fuentes-López, Eduardo; Fuente, Adrian; Cardemil, Felipe; Valdivia, Gonzalo; Albala, Cecilia

2017-11-01

The aim of this study was to determine the prevalence of use of hearing aids by older adults in Chile and the influence of some variables such as education level, income level and geographic area of residence on the prevalence of hearing aids. A national cross-sectional survey which was carried out in 2009. A representative sample of 4766 Chilean older adults aged 60 years and above. The percentage of older adults in Chile who self-reported hearing problems and used hearing aids was 8.9%. Such prevalence increased for adults living in urban areas and for those who knew about the new Chilean programme of universal access to health services (AUGE). For older adults who did not know about this programme, significant associations between the use of hearing aids and the variables of age, geographic area of residence, and income level were found. People's knowledge about AUGE programme may positively influence the use of hearing aids, although a direct effect cannot be attributed.

Desert Pathfinder at Work

NASA Astrophysics Data System (ADS)

2005-09-01

The Atacama Pathfinder Experiment (APEX) project celebrates the inauguration of its outstanding 12-m telescope, located on the 5100m high Chajnantor plateau in the Atacama Desert (Chile). The APEX telescope, designed to work at sub-millimetre wavelengths, in the 0.2 to 1.5 mm range, passed successfully its Science Verification phase in July, and since then is performing regular science observations. This new front-line facility provides access to the "Cold Universe" with unprecedented sensitivity and image quality. After months of careful efforts to set up the telescope to work at the best possible technical level, those involved in the project are looking with satisfaction at the fruit of their labour: APEX is not only fully operational, it has already provided important scientific results. "The superb sensitivity of our detectors together with the excellence of the site allow fantastic observations that would not be possible with any other telescope in the world," said Karl Menten, Director of the group for Millimeter and Sub-Millimeter Astronomy at the Max-Planck-Institute for Radio Astronomy (MPIfR) and Principal Investigator of the APEX project. ESO PR Photo 30/05 ESO PR Photo 30/05 Sub-Millimetre Image of a Stellar Cradle [Preview - JPEG: 400 x 627 pix - 200k] [Normal - JPEG: 800 x 1254 pix - 503k] [Full Res - JPEG: 1539 x 2413 pix - 1.3M] Caption: ESO PR Photo 30/05 is an image of the giant molecular cloud G327 taken with APEX. More than 5000 spectra were taken in the J=3-2 line of the carbon monoxide molecule (CO), one of the best tracers of molecular clouds, in which star formation takes place. The bright peak in the north of the cloud is an evolved star forming region, where the gas is heated by a cluster of new stars. The most interesting region in the image is totally inconspicuous in CO: the G327 hot core, as seen in methanol contours. It is a truly exceptional source, and is one of the richest sources of emission from complex organic molecules in the Galaxy (see spectrum at bottom). Credit: Wyrowski et al. (map), Bisschop et al. (spectrum). Millimetre and sub-millimetre astronomy opens exciting new possibility in the study of the first galaxies to have formed in the Universe and of the formation processes of stars and planets. In particular, APEX allows astronomers to study the chemistry and physical conditions of molecular clouds, that is, dense regions of gas and dust in which new stars are forming. Among the first studies made with APEX, astronomers took a first glimpse deep into cradles of massive stars, observing for example the molecular cloud G327 and measuring significant emission in carbon monoxide and complex organic molecules (see ESO PR Photo 30/05). The official inauguration of the APEX telescope will start in San Pedro de Atacama on September, 25th. The Ambassadors in Chile of some of ESO's member states, the Intendente of the Chilean Region II, the Mayor of San Pedro, the Executive Director of the Chilean Science Agency (CONICYT), the Presidents of the Communities of Sequitor and Toconao, as well as representatives of the Ministry of Foreign Affairs and Universities in Chile, will join ESO's Director General, Dr. Catherine Cesarsky, the Chairman of the APEX Board and MPIfR director, Prof. Karl Menten, and the Director of the Onsala Space Observatory, Prof. Roy Booth, in a celebration that will be held in San Pedro de Atacama. The next day, the delegation will visit the APEX base camp in Sequitor, near San Pedro, from where the telescope is operated, as well as the APEX site on the 5100m high Llano de Chajnantor.

ESO Signs Largest-Ever European Industrial Contract For Ground-Based Astronomy Project ALMA

NASA Astrophysics Data System (ADS)

2005-12-01

ESO, the European Organisation for Astronomical Research in the Southern Hemisphere, announced today that it has signed a contract with the consortium led by Alcatel Alenia Space and composed also of European Industrial Engineering (Italy) and MT Aerospace (Germany), to supply 25 antennas for the Atacama Large Millimeter Array (ALMA) project, along with an option for another seven antennas. The contract, worth 147 million euros, covers the design, manufacture, transport and on-site integration of the antennas. It is the largest contract ever signed in ground-based astronomy in Europe. The ALMA antennas present difficult technical challenges, since the antenna surface accuracy must be within 25 microns, the pointing accuracy within 0.6 arc seconds, and the antennas must be able to be moved between various stations on the ALMA site. This is especially remarkable since the antennas will be located outdoor in all weather conditions, without any protection. Moreover, the ALMA antennas can be pointed directly at the Sun. ALMA will have a collecting area of more than 5,600 square meters, allowing for unprecedented measurements of extremely faint objects. The signing ceremony took place on December 6, 2005 at ESO Headquarters in Garching, Germany. "This contract represents a major milestone. It allows us to move forward, together with our American and Japanese colleagues, in this very ambitious and unique project," said ESO's Director General, Dr. Catherine Cesarsky. "By building ALMA, we are giving European astronomers access to the world's leading submillimetre facility at the beginning of the next decade, thereby fulfilling Europe's desire to play a major role in this field of fundamental research." Pascale Sourisse, Chairman and CEO of Alcatel Alenia Space, said: "We would like to thank ESO for trusting us to take on this new challenge. We are bringing to the table not only our recognized expertise in antenna development, but also our long-standing experience in coordinating consortiums in charge of complex, high-performance ground systems." ALMA is an international astronomy facility. It is a partnership between Europe, North America and Japan, in cooperation with the Republic of Chile. The European contribution is funded by ESO and Spain, with the construction and operations being managed by ESO. A matching contribution is being made by the USA and Canada, who will also provide 25 antennas. Japan will provide additional antennas, thus making this a truly worldwide endeavour. ALMA will be located on the 5,000m high Llano de Chajnantor site in the Atacama Desert of Northern Chile. ALMA will consist of a giant array of 12-m antennas separated by baselines of up to 18 km and is expected to start partial operation by 2010-2011. The excellent site, the most sensitive receivers developed so far, and the large number of antennas will allow ALMA to have a sensitivity that is many times better than any other comparable instrument. "ALMA will bring to sub-millimetre astronomy the aperture synthesis techniques of radio astronomy, enabling precision imaging to be done on sub-arcsecond angular scales, and will nicely complement the ESO VLT/VLTI observatory", said Dr. Hans Rykaczewski, the ALMA European Project Manager. Millimetre-wave astronomy is the study of the universe in the spectral region between what is traditionally considered radio waves and infrared radiation. In this realm, ALMA will study the evolution of galaxies, including very early stages, gather crucial data on the formation of stars, proto-planetary discs, and planets, and provide new insights on the familiar objects of our own solar system. A prototype antenna had already been built by Alcatel Alenia Space and European Industrial Engineering and thoroughly tested along with prototypes antennas from Vertex/LSI and Mitsubishi at the ALMA Antenna Test Facility located at the Very Large Array site in Socorro, New Mexico. For more information on the ALMA project, please go to http://www.eso.org/projects/alma/.

"Physics on Stage" Festival Video Now Available

NASA Astrophysics Data System (ADS)

2001-01-01

ESO Video Clip 01/01 is issued on the web in conjunction with the release of an 18-min documentary video from the Science Festival of the "Physics On Stage" programme. This unique event took place during November 6-11, 2000, on the CERN premises at the French-Swiss border near Geneva, and formed part of the European Science and Technology Week 2000, an initiative by the European Commission to raise the public awareness of science in Europe. Physics On Stage and the Science Festival were jointly organised by CERN, ESA and ESO, in collaboration with the European Physical Society (EPS) and the European Association for Astronomy Education (EAAE) and national organisations in about 25 European countries. During this final phase of the yearlong Physics On Stage programme, more than 500 physics teachers, government officials and media representatives gathered at CERN to discuss different aspects of physics education. The meeting was particular timely in view of the current decline of interest in physics and technology by Europe's citizens, especially schoolchildren. It included spectacular demonstrations of new educational materials and methods. An 18-min video is now available that documents this event. It conveys the great enthusiasm of the many participants who spent an extremely fruitful week, meeting and exchanging information with colleagues from all over the continent. It shows the various types of activities that took place, from the central "fair" with national and organisational booths to the exciting performances and other dramatic presentations. Based of the outcome of 13 workshops that focussed on different subject matters, a series of very useful recommendations was passed at the final session. The Science Festival was also visited by several high-ranking officials, including the European Commissioner for Research, Phillipe Busquin. Full reports from the Festival will soon become available from the International Steering Committee..More information is available on the "Physics on Stage" webpages at CERN , ESA and ESO ). Note also the brief account published in the December 2000 issue of the ESO Messenger. The present video clip is available in four versions: two MPEG files and two streamer-versions of different sizes; the latter require RealPlayer software. Video Clip 01/01 may be freely reproduced. Tapes of this video clip and the 18-min video, suitable for transmission and in full professional quality (Betacam, etc.), are available for broadcasters upon request ; please contact the ESO EPR Department for more details. Most of the ESO PR Video Clips at the ESO website provide "animated" illustrations of the ongoing work and events at the European Southern Observatory. The most recent clip was: ESO PR Video Clip 06/00 about Fourth Light at Paranal! (4 September 2000) . General information is available on the web about ESO videos.

Protection of Existing and Potential Astronomical Sites in Chile - an Update.

NASA Astrophysics Data System (ADS)

Smith, M. G.; Sanhueza, P.; Norman, D.; Schwarz, H.; Orellana, D.

2002-12-01

The IAU's Working Group on Controlling Light Pollution (iauwg) has declared Mauna Kea and a wide strip of Northern Chile between Antofagasta and Chajnanator as top priorities for its efforts to protect existing and potential sites in the Northern and Southern hemispheres respectively. This report provides an update on the iauwg's co-ordinated efforts to protect areas around the major international optical observatories in Chile, as well as the "Chilean Special Zone" (CSZ) mentioned above. This zone is of current and potential interest for the installation of extremely large optical telescopes and includes the ALMA radio-astronomy site. The CSZ is potentially vulnerable to adverse effects of mining in the region. Progess has been made in demonstrating to local mining interests within the CSZ the economic advantages of quality lighting. Educational and outreach activities to a variety of target audiences are building on legislation covering dark skies - itself part of work by the Chilean government to protect the natural heritage of Chile. Substantial good will was generated by an international, bilingual conference held last March in Chile. Just in the region around AURA's Observatory in Chile (Gemini South, CTIO and SOAR), a portable planetarium has been used to reach out to over 600 teachers and 65,000 pupils in the RedLaSer schools network within the last three years. This has attracted the direct interest of Chile's Ministry of Education. Videoconferencing over Internet2 is being used for educational purposes between Chile and various sites in the US. The NSF- initiated Mamalluca municipal observatory now receives more visitors than all the international observatories in Chile combined and is the focus of an expanding local industry of astronomical eco-tourism. Most of this work was supported by funding from, or via, the US NSF through CTIO and Gemini, and from ESO, OCIW, CONAMA and the IDA.

HADES RV programme with HARPS-N at TNG. VII. Rotation and activity of M-dwarfs from time-series high-resolution spectroscopy of chromospheric indicators

NASA Astrophysics Data System (ADS)

Mascareño, A. Suárez; Rebolo, R.; González Hernández, J. I.; Toledo-Padrón, B.; Perger, M.; Ribas, I.; Affer, L.; Micela, G.; Damasso, M.; Maldonado, J.; González-Alvarez, E.; Leto, G.; Pagano, I.; Scandariato, G.; Sozzetti, A.; Lanza, A. F.; Malavolta, L.; Claudi, R.; Cosentino, R.; Desidera, S.; Giacobbe, P.; Maggio, A.; Rainer, M.; Esposito, M.; Benatti, S.; Pedani, M.; Morales, J. C.; Herrero, E.; Lafarga, M.; Rosich, A.; Pinamonti, M.

2018-05-01

We aim to investigate the presence of signatures of magnetic cycles and rotation on a sample of 71 early M-dwarfs from the HADES RV programme using high-resolution time-series spectroscopy of the Ca II H&K and Hα chromospheric activity indicators, the radial velocity series, the parameters of the cross correlation function and the V -band photometry. We used mainly HARPS-N spectra, acquired over 4 yr, and add HARPS spectra from the public ESO database and ASAS photometry light-curves as support data, extending the baseline of the observations of some stars up to 12 yr. We provide log10(R'HK) measurements for all the stars in the sample, cycle length measurements for 13 stars, rotation periods for 33 stars and we are able to measure the semi-amplitude of the radial velocity signal induced by rotation in 16 stars. We complement our work with previous results and confirm and refine the previously reported relationships between the mean level of chromospheric emission, measured by the log10(R'HK), with the rotation period, and with the measured semi-amplitude of the activity induced radial velocity signal for early M-dwarfs. We searched for a possible relation between the measured rotation periods and the lengths of the magnetic cycle, finding a weak correlation between both quantities. Using previous v sin i measurements we estimated the inclinations of the star's poles to the line of sight for all the stars in the sample, and estimate the range of masses of the planets GJ 3998 b and c (2.5-4.9 and 6.3-12.5 M⊕), GJ 625 b (2.82 M⊕), GJ 3942 b (7.1-10.0 M⊕) and GJ 15A b (3.1-3.3 M⊕), assuming their orbits are coplanar with the stellar rotation. Based on: observations made with the Italian Telescopio Nazionale Galileo (TNG), operated on the island of La Palma by the INAF - Fundación Galileo Galilei at the Roche de Los Muchachos Observatory of the Instituto de Astrofísica de Canarias (IAC); observations made with the HARPS instrument on the ESO 3.6-m telescope at La Silla Observatory (Chile).

A time series analysis of the rabies control programme in Chile.

PubMed Central

Ernst, S. N.; Fabrega, F.

1989-01-01

The classical time series decomposition method was used to compare the temporal pattern of rabies in Chile before and after the implementation of the control programme. In the years 1950-60, a period without control measures, rabies showed an increasing trend, a seasonal excess of cases in November and December and a cyclic behaviour with outbreaks occurring every 5 years. During 1961-1970 and 1971-86, a 26-year period that includes two different phases of the rabies programme which started in 1961, there was a general decline in the incidence of rabies. The seasonality disappeared when the disease reached a low frequency level and the cyclical component was not evident. PMID:2606167

ESO's First Observatory Celebrates 40th Anniversary

NASA Astrophysics Data System (ADS)

2009-03-01

ESO's La Silla Observatory, which is celebrating its 40th anniversary, became the largest astronomical observatory of its time. It led Europe to the frontline of astronomical research, and is still one of the most scientifically productive in ground-based astronomy. ESO PR Photo 12a/09 La Silla Aerial View ESO PR Photo 12b/09 The ESO New Technology Telescope ESO PR Photo 12c/09 SEST on La Silla ESO PR Photo 12d/09 Looking for the best site ESO PR Video 12a/09 ESOcast 5 With about 300 refereed publications attributable to the work of the observatory per year, La Silla remains at the forefront of astronomy. It has led to an enormous number of scientific discoveries, including several "firsts". The HARPS spectrograph is the world's foremost exoplanet hunter. It detected the system around Gliese 581, which contains what may be the first known rocky planet in a habitable zone, outside the Solar System (ESO 22/07). Several telescopes at La Silla played a crucial role in discovering that the expansion of the Universe is accelerating (ESO 21/98) and in linking gamma-ray bursts -- the most energetic explosions in the Universe since the Big Bang - with the explosions of massive stars (ESO 15/98). Since 1987, the ESO La Silla Observatory has also played an important role in the study and follow-up of the nearest supernova, SN 1987A (ESO 08/07). "The La Silla Observatory continues to offer the astronomical community exceptional capabilities," says ESO Director General, Tim de Zeeuw. "It was ESO's first presence in Chile and as such, it triggered a very long and fruitful collaboration with this country and its scientific community." The La Silla Observatory is located at the edge of the Chilean Atacama Desert, one of the driest and loneliest areas of the world. Like other observatories in this geographical area, La Silla is located far from sources of polluting light and, as the Paranal Observatory that houses the Very Large Telescope, it has one of the darkest and clearest night skies on the Earth. At its peak, La Silla was home to no fewer than 15 telescopes, among them the first -- and, for a very long time, the only -- telescope working in submillimetric waves (the 15-metre SEST) in the southern hemisphere, which paved the way for APEX and ALMA, and the 1-metre Schmidt telescope, which completed the first photographic mapping of the southern sky. The telescopes at La Silla have also supported countless space missions, e.g., by obtaining the last images of comet Shoemaker Levy 9 before it crashed into Jupiter, thereby helping predicting the exact moment when the Galileo spacecraft should observe to capture images of the cosmic collision. "Many of the current generation of astronomers were trained on La Silla where they got their first experience with what were then considered large telescopes," says Bruno Leibundgut, ESO Director for Science. While some of the smaller telescopes have been closed over the years, frontline observations continue with the larger telescopes, aided by new and innovative astronomical instruments. La Silla currently hosts two of the most productive 4-metre class telescopes in the world, the 3.5-metre New Technology Telescope (NTT) and the 3.6-metre ESO telescope. "The NTT broke new ground for telescope engineering and design," says Andreas Kaufer, director of the La Silla Paranal Observatory. The NTT was the first in the world to have a computer-controlled main mirror (active optics), a technology developed at ESO and now applied to the VLT and most of the world's current large telescopes. The ESO 3.6-metre telescope, which was for many years one of the largest European telescopes in operation, is now home to the extrasolar planet hunter, HARPS (High Accuracy Radial velocity Planet Searcher), a spectrograph with unrivalled precision. The infrastructure of La Silla is used by many of the ESO member states for targeted projects such as the Swiss 1.2-metre Euler telescope, the Italian Rapid-Eye Mount (REM) and French TAROT gamma-ray burst chasers as well as more common user facilities such as the 2.2-metre telescope of the German Max Planck Society and the 1.5-metre Danish telescopes. The 67-million pixel Wide Field Imager on the 2.2-metre telescope has taken many amazing images of celestial objects, some of which have now become icons of their own. The La Silla Observatory, north of the town of La Serena, has been a stronghold of the organisation's capabilities since the 1960s. The site was chosen after an initial prospecting expedition -- partly on horseback -- to the Chilean Andes, during 1963 and 1964, by the first ESO Director General, Otto Heckmann, and several senior astronomers. This was done with the help of AURA, which had just chosen to install an observatory at nearby Cerro Tololo. In the following years, the site was developed and the first small and mid-sized telescopes were erected, followed by the 3.6-metre telescope in 1977 and the NTT in 1989. On 25 March 1969, an audience of more than 300 people, including the then Chilean President, Eduardo Frei and the Minister of Education of Sweden, Olof Palme, celebrated the completion of the first phase of the construction programme. "The erection of the La Silla Observatory is not only of vast importance for the future of astronomical research, but also a striking example of what may be achieved through efficient, and truly far-reaching, international cooperation," said Olof Palme at the time. The future of the La Silla Observatory remains bright. In 2007 ESO's Council endorsed a plan that maintains an important role for La Silla, alongside the other large ESO facilities, the VLT, ALMA and the E-ELT. La Silla also plans to host new national telescope projects and visitor instruments -- an option that has already received a strong positive response from the astronomical community.

First Super-Earth Atmosphere Analysed

NASA Astrophysics Data System (ADS)

2010-12-01

The atmosphere around a super-Earth exoplanet has been analysed for the first time by an international team of astronomers using ESO's Very Large Telescope. The planet, which is known as GJ 1214b, was studied as it passed in front of its parent star and some of the starlight passed through the planet's atmosphere. We now know that the atmosphere is either mostly water in the form of steam or is dominated by thick clouds or hazes. The results will appear in the 2 December 2010 issue of the journal Nature. The planet GJ 1214b was confirmed in 2009 using the HARPS instrument on ESO's 3.6-metre telescope in Chile (eso0950) [1]. Initial findings suggested that this planet had an atmosphere, which has now been confirmed and studied in detail by an international team of astronomers, led by Jacob Bean (Harvard-Smithsonian Center for Astrophysics), using the FORS instrument on ESO's Very Large Telescope. "This is the first super-Earth to have its atmosphere analysed. We've reached a real milestone on the road toward characterising these worlds," said Bean. GJ 1214b has a radius of about 2.6 times that of the Earth and is about 6.5 times as massive, putting it squarely into the class of exoplanets known as super-Earths. Its host star lies about 40 light-years from Earth in the constellation of Ophiuchus (the Serpent Bearer). It is a faint star [2], but it is also small, which means that the size of the planet is large compared to the stellar disc, making it relatively easy to study [3]. The planet travels across the disc of its parent star once every 38 hours as it orbits at a distance of only two million kilometres: about seventy times closer than the Earth orbits the Sun. To study the atmosphere, the team observed the light coming from the star as the planet passed in front of it [4]. During these transits, some of the starlight passes through the planet's atmosphere and, depending on the chemical composition and weather on the planet, specific wavelengths of light are absorbed. The team then compared these precise new measurements with what they would expect to see for several possible atmospheric compositions. Before the new observations, astronomers had suggested three possible atmospheres for GJ 1214b. The first was the intriguing possibility that the planet was shrouded by water, which, given the close proximity to the star, would be in the form of steam. The second possibility was that this is a rocky world with an atmosphere consisting mostly of hydrogen, but with high clouds or hazes obscuring the view. The third option was that this exoplanet was like a mini-Neptune, with a small rocky core and a deep hydrogen-rich atmosphere. The new measurements do not show the telltale signs of hydrogen and hence rule out the third option. Therefore, the atmosphere is either rich in steam, or it is blanketed by clouds or hazes, similar to those seen in the atmospheres of Venus and Titan in our Solar System, which hide the signature of hydrogen.. "Although we can't yet say exactly what that atmosphere is made of, it is an exciting step forward to be able to narrow down the options for such a distant world to either steamy or hazy," says Bean. "Follow-up observations in longer wavelength infrared light are now needed to determine which of these atmospheres exists on GJ 1214b." Notes [1] The number of confirmed exoplanets reached 500 on 19 November 2010. Since then, more exoplanets have been confirmed. For the latest count, please visit: http://exoplanet.eu/catalog.php [2] If GJ 1214 were seen at the same distance from us as our Sun, it would appear 300 times fainter. [3] Because the star GJ1214 itself is quite faint - more than 100 times fainter in visible light than the host stars of the two most widely studied hot Jupiter exoplanets - the large collecting area of the Very Large Telescope was critical for acquiring enough signal for these measurements. [4] GJ 1214b's atmospheric composition was studied using the FORS instrument on the Very Large Telescope, which can perform very sensitive spectroscopy of multiple objects in the near-infrared part of the spectrum. FORS was one of the first instruments installed on the Very Large Telescope. More information This research is presented in a paper to appear in Nature on 2 December 2010. The team is composed of Jacob Bean (Harvard-Smithsonian Center for Astrophysics, USA), Eliza Miller-Ricci Kempton (University of California, Santa Cruz, USA) and Derek Homeier (Institute for Astrophysics, Göttingen, Germany). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Astronomers Break Ground on Atacama Large Millimeter Array (ALMA) - World's Largest Millimeter Wavelength Telescope

NASA Astrophysics Data System (ADS)

2003-11-01

Scientists and dignitaries from Europe, North America and Chile are breaking ground today (Thursday, November 6, 2003) on what will be the world's largest, most sensitive radio telescope operating at millimeter wavelengths . ALMA - the "Atacama Large Millimeter Array" - will be a single instrument composed of 64 high-precision antennas located in the II Region of Chile, in the District of San Pedro de Atacama, at the Chajnantor altiplano, 5,000 metres above sea level. ALMA 's primary function will be to observe and image with unprecedented clarity the enigmatic cold regions of the Universe, which are optically dark, yet shine brightly in the millimetre portion of the electromagnetic spectrum. The Atacama Large Millimeter Array (ALMA) is an international astronomy facility. ALMA is an equal partnership between Europe and North America, in cooperation with the Republic of Chile, and is funded in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC), and in Europe by the European Southern Observatory (ESO) and Spain. ALMA construction and operations are led on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI), and on behalf of Europe by ESO. " ALMA will be a giant leap forward for our studies of this relatively little explored spectral window towards the Universe" , said Dr. Catherine Cesarsky , Director General of ESO. "With ESO leading the European part of this ambitious and forward-looking project, the impact of ALMA will be felt in wide circles on our continent. Together with our partners in North America and Chile, we are all looking forward to the truly outstanding opportunities that will be offered by ALMA , also to young scientists and engineers" . " The U.S. National Science Foundation joins today with our North American partner, Canada, and with the European Southern Observatory, Spain, and Chile to prepare for a spectacular new instrument, " stated Dr. Rita Colwell , director of the U.S. National Science Foundation. " ALMA will expand our vision of the Universe with "eyes" that pierce the shrouded mantles of space through which light cannot penetrate." On the occasion of this groundbreaking, the ALMA logo was unveiled. [ALMA Logo] Science with ALMA ALMA will capture millimetre and sub-millimetre radiation from space and produce images and spectra of celestial objects as they appear at these wavelengths. This particular portion of the electromagnetic spectrum, which is less energetic than visible and infrared light, yet more energetic than most radio waves, holds the key to understanding a great variety of fundamental processes, e.g., planet and star formation and the formation and evolution of galaxies and galaxy clusters in the early Universe. The possibility to detect emission from organic and other molecules in space is of particularly high interest. The millimetre and sub-millimetre radiation that ALMA will study is able to penetrate the vast clouds of dust and gas that populate interstellar (and intergalactic) space, revealing previously hidden details about astronomical objects. This radiation, however, is blocked by atmospheric moisture (water molecules) in the Earth's atmosphere. To conduct research with ALMA in this critical portion of the spectrum, astronomers thus need an exceptional observation site that is very dry, and at a very high altitude where the atmosphere above is thinner. Extensive tests showed that the sky above the high-altitude Chajnantor plain in the Atacama Desert has the unsurpassed clarity and stability needed to perform efficient observations with ALMA . ALMA operation ALMA will be the highest-altitude, full-time ground-based observatory in the world, at some 250 metres higher than the peak of Mont Blanc, Europe's tallest mountain. Work at this altitude is difficult. To help ensure the safety of the scientists and engineers at ALMA , operations will be conducted from the Operations Support Facility ( ALMA OSF) , a compound located at a more comfortable altitude of 2,900 metres, between the cities of Toconao and San Pedro de Atacama. Phase 1 of the ALMA Project, which included the design and development, was completed in 2002. The beginning of Phase 2 happened on February 25, 2003, when the European Southern Observatory (ESO) and the US National Science Foundation (NSF) signed a historic agreement to construct and operate ALMA , cf. ESO PR 04/03 . Construction will continue until 2012; however, initial scientific observations are planned already from 2007, with a partial array of the first antennas. ALMA 's operation will progressively increase until 2012 with the installation of the remaining antennas. The entire project will cost approximately 600 million Euros. Earlier this year, the ALMA Board selected Professor Massimo Tarenghi , formerly manager of ESO's VLT Project, to become ALMA Director. He is confident that he and his team will succeed: "We may have a lot of hard work in front of us" , he said, "but all of us in the team are excited about this unique project. We are ready to work for the international astronomical community and to provide them in due time with an outstanding instrument allowing trailblazing research projects in many different fields of modern astrophysics" . How ALMA will work ALMA will be composed of 64 high-precision antennas, each 12 metres in diameter. The ALMA antennas can be repositioned, allowing the telescope to function much like the zoom lens on a camera. At its largest, ALMA will be 14 kilometers across. This will allow the telescope to observe fine-scale details of astronomical objects. At its smallest configuration, approximately 150 meters across, ALMA will be able to study the large-scale structures of these same objects. ALMA will function as an interferometer (according to the same basic principle as the VLT Interferometer (VLTI) at Paranal). This means that it will combine the signals from all its antennas (one pair of antennas at a time) to simulate a telescope the size of the distance between the antennas. With 64 antennas, ALMA will generate 2016 individual antenna pairs ("baselines") during the observations. To handle this enormous amount of data, ALMA will rely on a very powerful, specialized computer (a "correlator"), which will perform 16,000 million million (1.6 x 10 16 ) operations per second. Currently, two prototype ALMA antennas are undergoing rigorous testing at the NRAO's Very Large Array site, near Socorro, New Mexico, USA. International collaboration For this ambitious project, ALMA has become a joint effort among many nations and scientific institutions. In Europe, ESO leads on behalf of its ten member countries (Belgium, Denmark, France, Germany, Italy, The Netherlands, Portugal, Sweden, Switzerland and the United Kingdom) and Spain. Japan may join in 2004, bringing enhancements to the project. Given the participation of North America, this will be the first truly global project of ground-based astronomy, an essential development in view of the increasing technological sophistication and the high costs of front-line astronomy installations. The first submillimeter telescope in the southern hemisphere was the 15-m Swedish-ESO Submillimetre Telescope (SEST) which was installed at the ESO La Silla Observatory in 1987. It has since been used extensively by astronomers, mostly from ESO's member states. SEST has now been decommissioned and a new submillimetre telescope, APEX, is about to commence operations at Chajnantor. APEX, which is a joint project between ESO, the Max Planck Institute for Radio Astronomy in Bonn (Germany), and the Onsala Space Observatory (Sweden), is an antenna comparable to the ALMA antennas.

Cosmic "Dig" Reveals Vestiges of the Milky Way's Building Blocks

NASA Astrophysics Data System (ADS)

2009-11-01

Peering through the thick dust clouds of our galaxy's "bulge" (the myriads of stars surrounding its centre), and revealing an amazing amount of detail, a team of astronomers has unveiled an unusual mix of stars in the stellar grouping known as Terzan 5. Never observed anywhere in the bulge before, this peculiar "cocktail" of stars suggests that Terzan 5 is in fact one of the bulge's primordial building blocks, most likely the relic of a proto-galaxy that merged with the Milky Way during its very early days. "The history of the Milky Way is encoded in its oldest fragments, globular clusters and other systems of stars that have witnessed the entire evolution of our galaxy," says Francesco Ferraro from the University of Bologna, lead author of a paper appearing in this week's issue of the journal Nature. "Our study opens a new window on yet another piece of our galactic past." Like archaeologists, who dig through the dust piling up on top of the remains of past civilisations and unearth crucial pieces of the history of mankind, astronomers have been gazing through the thick layers of interstellar dust obscuring the bulge of the Milky Way and have unveiled an extraordinary cosmic relic. The target of the study is the star cluster Terzan 5. The new observations show that this object, unlike all but a few exceptional globular clusters, does not harbour stars which are all born at the same time - what astronomers call a "single population" of stars. Instead, the multitude of glowing stars in Terzan 5 formed in at least two different epochs, the earliest probably some 12 billion years ago and then again 6 billion years ago. "Only one globular cluster with such a complex history of star formation has been observed in the halo of the Milky Way: Omega Centauri," says team member Emanuele Dalessandro. "This is the first time we see this in the bulge." The galactic bulge is the most inaccessible region of our galaxy for astronomical observations: only infrared light can penetrate the dust clouds and reveal its myriads of stars. "It is only thanks to the outstanding instruments mounted on ESO's Very Large Telescope," says co-author Barbara Lanzoni, "that we have finally been able to 'disperse the fog' and gain a new perspective on the origin of the galactic bulge itself." A technical jewel lies behind the scenes of this discovery, namely the Multi-conjugate Adaptive Optics Demonstrator (MAD), a cutting-edge instrument that allows the VLT to achieve superbly detailed images in the infrared. Adaptive optics is a technique through which astronomers can overcome the blurring that the Earth's turbulent atmosphere inflicts on astronomical images obtained from ground-based telescopes; MAD is a prototype of even more powerful, next-generation adaptive optics instruments [1]. Through the sharp eye of the VLT, the astronomers also found that Terzan 5 is more massive than previously thought: along with the complex composition and troubled star formation history of the system, this suggests that it might be the surviving remnant of a disrupted proto-galaxy, which merged with the Milky Way during its very early stages and thus contributed to form the galactic bulge. "This could be the first of a series of further discoveries shedding light on the origin of bulges in galaxies, which is still hotly debated," concludes Ferraro. "Several similar systems could be hidden behind the bulge's dust: it is in these objects that the formation history of our Milky Way is written." Notes [1] Telescopes on the ground suffer from a blurring effect introduced by atmospheric turbulence. This turbulence causes the stars to twinkle in a way that delights poets but frustrates astronomers, since it smears out the fine details of the images. However, with adaptive optics (AO) techniques, this major drawback can be overcome so that the telescope produces images that are as sharp as theoretically possible, i.e. approaching conditions in space. Adaptive optics systems work by means of a computer-controlled deformable mirror that counteracts the image distortion introduced by atmospheric turbulence. It is based on real-time optical corrections computed at very high speed (many hundreds of times each second) from image data obtained by a wavefront sensor (a special camera) that monitors light from a reference star, Present AO systems can only correct the effect of atmospheric turbulence in a very small region of the sky - typically 15 arcseconds or less - the correction degrading very quickly when moving away from the reference star. Engineers have therefore developed new techniques to overcome this limitation, one of which is multi-conjugate adaptive optics. MAD uses up to three guide stars instead of one as references to remove the blur caused by atmospheric turbulence over a field of view thirty times larger than existing techniques (eso0719). More information This research was presented in a paper that appears in the 26 November 2009 issue of Nature , "The cluster Terzan 5 as a remnant of a primordial building block of the Galactic bulge", by F. R. Ferraro et al.. The team is composed of Francesco Ferraro, Emanuele Dalessandro, Alessio Mucciarelli and Barbara Lanzoni (Department of Astronomy, University of Bologna, Italy), Giacomo Beccari (ESA, Space Science Department, Noordwijk, Netherlands), Mike Rich (Department of Physics and Astronomy, UCLA, Los Angeles, USA), Livia Origlia, Michele Bellazzini and Gabriele Cocozza (INAF - Osservatorio Astronomico di Bologna, Italy), Robert T. Rood (Astronomy Department, University of Virginia, Charlottesville, USA), Elena Valenti (ESO and Pontificia Universidad Catolica de Chile, Departamento de Astronomia, Santiago, Chile) and Scott Ransom (National Radio Astronomy Observatory, Charlottesville, USA). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Shoemaker-Levy 9/JUPITER Collision Update

NASA Astrophysics Data System (ADS)

1994-05-01

There are many signs that the upcoming collision between comet Shoemaker-Levy 9 and giant planet Jupiter is beginning to catch the imagination of the public. Numerous reports in the various media describe the effects expected during this unique event which according to the latest calculations will start in the evening of July 16 and end in the morning of July 22, 1994. (The times in this Press Release are given in Central European Summer Time (CEST), i.e., Universal Time (UT) + 2 hours. The corresponding local time in Chile is CEST - 6 hours.) Astronomers all over the world are now preparing to observe the associated phenomena with virtually all major telescopes. There will be no less than 12 different investigations at the ESO La Silla observatory during this period. This Press Release updates the information published in ESO PR 02/94 (27 January 1994) and provides details about the special services which will be provided by ESO to the media around this rare astronomical event. SCIENTIFIC EXPECTATIONS The nucleus of comet Shoemaker-Levy 9 broke into many smaller pieces during a near passage of Jupiter in July 1992. They are now moving in parallel orbits around this planet and recent calculations show with close to 100 % certainty that they will all collide with it, just two months from now. At some time, more than 20 individual nuclei were observed. This Press Release is accompanied by a photo that shows this formation, the famous "string of pearls", as it looked like in early May 1994. Both Jupiter and these nuclei have been extensively observed during the past months. A large, coordinated observing programme at La Silla has been active since early April and the first results have become available. However, while we now possess more accurate information about the comet's motion and the times of impact, there is still great uncertainty about the effects which may actually be observed at the time of the impacts. This is first of all due to the fact that it has not been possible to measure the sizes and masses of the individual cometary nuclei and thereby to estimate the amount of energy which will be liberated at the collisions. The first object (nucleus "A"; indicated on the photo) will hit the Jovian atmosphere somewhat later than earlier predicted; the best estimate is now at about 22:00 CEST in the evening of Saturday, 16 July, 1994. The second ("B") will follow the next morning at about 05:00. These two nuclei are comparatively faint and therefore presumably also rather small, and it is at this moment still uncertain whether these impacts will actually be observed. The first, relatively large nuclei ("E") will hit Jupiter around 17:00 on 17 July. The brightest nucleus ("Q"; actually a double object, as seen on images obtained with the Hubble Space Telescope) is expected to arrive just before 22:00 on 20 July, and the last in the train ("W") should collide with the planet at about 10:20 on 22 July. The timing uncertainty varies from impact to impact; in the best cases, there is at present a 95% chance that the collision will happen between 40 minutes before and 40 minutes after the indicated time. Further positional observations are being obtained, also at ESO, and it is hoped that this margin can be reduced to about +-15 minutes or better. Despite intensive spectroscopic observations, no gas has yet been detected in any of the nuclei. We only see dust around the nuclei which are completely hidden from our view within these clouds. The amount of the dust has been steadily decreasing; this is because the dust production from the individual nuclei -- which began when the parent body broke up at the time of the near-collision with Jupiter in July 1992 -- is slowly diminishing with time. Some of the smaller nuclei have recently disappeared from view, probably because they have ceased to produce dust. It is not clear, however, whether this also implies that they no longer exist at all, or whether they are just too small to be seen with available telescopes. THE ESO COORDINATED PROGRAMME Together with their colleagues all over the world, several groups of astronomers in the ESO member states are now getting ready to observe this event with the La Silla telescopes. The observers at ESO participate in a coordinated programme and will profit from the simultaneous observations with many different telescopes and observing techniques at one site. Altogether, there are 12 individual programmes at all the major telescopes, including the 3.6-m, the NTT, the SEST, the 2.2-m MPI/ESO, the 1.4-m CAT and the Danish 1.54-m telescopes. It is clear that these observations will be difficult, in particular because of the relatively short time that Jupiter and the comet will be well above the horizon at La Silla, at most a few hours each evening. When Jupiter is very low in the sky, the viewing conditions are less favourable, since the light must traverse a longer distance through the turbulent and absorbing terrestrial atmosphere. However, since Jupiter will be south of the celestial equator, observing conditions will be even worse from observatories located in the Northern hemisphere. To record the best possible data (images, spectra, light curves, etc.), the telescopes must follow the motion of Jupiter very accurately. Due to its orbital motion in the solar system, Jupiter moves rather rapidly in the sky, and the telescope motion must be precisely offset to continuously track the planet without "smearing" the images. This is not a simple task, also since the planet's rate of motion changes with time and new corrections must be made several times each hour. All in all, the observers face a difficult task and must be extremely alert, especially around the predicted moments of impact. This will demand very high concentration and necessitate "training runs" before the real observations begin. Some of these have already taken place -- not surprisingly, various technical problems were uncovered and are now in the process of being resolved. ESO'S SERVICES TO THE MEDIA In view of the unique nature of this event and the associated astronomical observations, ESO has decided to provide special services to the media. In particular, it is the intention to ensure that the media will be able to follow the developments at La Silla closely and in near-real time, and at the same time will be kept informed about the observational results at other observatories all over the world. This service will be available from the ESO Headquarters in Garching near Munich, Germany, but special arrangements will also be made for the media in Chile. Kindly note that in view of the complex and critical nature of these observations, it is not possible to arrange direct access to the La Silla observatory during the observing period. ESO will obtain all new information directly from the observers at La Silla via the permanent satellite link to the ESO Headquarters in Garching (Germany). For this, ESO is setting up the necessary internal communication lines at La Silla which will allow this transfer to be done at the shortest possible notice. While the observers cannot be disturbed during the actual observations, they will communicate their results and observational progress at regular intervals, and very quickly, if and when "dramatic" events are observed. ESO furthermore has complete and permanent access to the world-wide communication net between all observers of this event, especially set up for this purpose. The information available from this source will first of all serve to alert the observers about the results in other places and to warn them about new and unexpected developments. Moreover, the Space Telescope European Coordinating Facility, the ESA/ESO group that is responsible for the Hubble Space Telescope use by European astronomers and which is housed at the ESO Headquarters, will contribute with information regarding the observations with this major observational facility. With these important sources of information at its disposal, ESO will therefore be in a prime position to inform about and comment on the latest developments at the shortest possible notice. SPECIFIC ARRANGEMENTS In practical terms, ESO's service to the media will have the following elements: - Background material in the form of text and images, as well as related video clippings (broadcast quality) will be available at request, 7 - 10 days before the first impact takes place on 16 July. - Beginning a few days before this date, ESO will issue daily bulletins with the latest predictions and other news, related to the preparations of observations at La Silla and elsewhere in the world. - ESO will arrange a Press Conference at the ESO Headquarters in Garching at 20:00 (CEST) on Saturday 16 July, 1994. This will be just before the first impact is expected to happen and will provide an excellent opportunity to inform the media about the very latest developments. Following this in-depth briefing, media representatives are welcome to pass the night at the ESO Headquarters and to follow the first observations at La Silla at distance (food and beverages will be provided). Unexpected and "spectacular" events, should they happen, will be announced and commented as quickly as possible. We will also attempt to contact the La Silla observers by phone immediately after the end of their observations (in the early morning hours at Garching) and request live commentaries about the intial results. At the same time, the latest images will be transferred and made available. - There will be a Press Conference each day at 11:00 (CEST) on 17 - 22 July 1994, summarizing the previous night's results. Selected images obtained at ESO the night before will be available on these occasion. Media representatives, who are interested in participating in the Press Conference in the evening of July 16 and who would like to stay at ESO during the following night, are kindly requested to soonest contact Mrs. E. Voelk of the ESO Information Service (Tel.: +4989-32006276; Fax: +4989-3202362), to obtain a personal invitation. ESO is preparing special arrangements for the Chilean media; they will soon be announced directly to the involved. PHOTO CAPTION ESO PR PHOTO 10/94-1: PORTRAIT OF A DOOMED COMET These two photos from the ESO La Silla observatory show the individual nuclei of comet Shoemaker-Levy 9, now headed for collision with Jupiter on 16 - 22 July 1994. The wide-field photo (below, left) was obtained by Klaus Jockers and Galina Chernova (Max-Planck-Institute fur Aeronomie, Katlenburg, Lindau, Germany) on May 1, 1994. For this 5 min exposure in red light they used a CCD camera at the MPIfAe/Hoher List focal reducer at the ESO 1-metre telescope. The entire nuclear train (the "string of pearls") is very well seen, together with the sunlight-reflecting dust from the nuclei, all on one side. On this date, the comet was 654 million km from the Earth and the angular extension of the train was about 5.3 arcmin, corresponding to a projected length of just over 1 million km. A 15 min CCD image was obtained for astrometric purposes on May 11, 1994, by Jean-Francois Claeskens at the Danish 1.5 m telescope at La Silla; it is here reproduced in close-up to show well the individual nuclei, in particular the fainter ones. The bright object to the upper right is a 10th mag star. Note that the stars in the field are somewhat trailed, since the telescope was set to follow the motion of the comet. The first nucleus to hit Jupiter will be "A", here seen 42 mm from the left edge and 33 mm below the upper edge of the large picture. The last is "W", 43 mm above the lower edge and 9 mm from the right edge. The comet was 657 million km from the Earth and the train was somewhat longer, 5.8 arcmin, i.e. the projected length was now 1.1 million km. Technical information: Wide-Field: pixel size 1.5 arcsec; scale on photo: 5.1 arcsec/mm; field size: 12.2 x 6.6 arcmin; 5 min exposure; gunn-r filtre. Close-Up: pixel size 0.38 arcsec; scale on photo: 1.3 arcsec/mm; field size: 6.4 x 4.4 arcmin; 15 min exposure; V-filtre. On both photos, North is up and East is to the left; both were obtained during moderate seeing conditions.

The extinction law from photometric data: linear regression methods

NASA Astrophysics Data System (ADS)

Ascenso, J.; Lombardi, M.; Lada, C. J.; Alves, J.

2012-04-01

Context. The properties of dust grains, in particular their size distribution, are expected to differ from the interstellar medium to the high-density regions within molecular clouds. Since the extinction at near-infrared wavelengths is caused by dust, the extinction law in cores should depart from that found in low-density environments if the dust grains have different properties. Aims: We explore methods to measure the near-infrared extinction law produced by dense material in molecular cloud cores from photometric data. Methods: Using controlled sets of synthetic and semi-synthetic data, we test several methods for linear regression applied to the specific problem of deriving the extinction law from photometric data. We cover the parameter space appropriate to this type of observations. Results: We find that many of the common linear-regression methods produce biased results when applied to the extinction law from photometric colors. We propose and validate a new method, LinES, as the most reliable for this effect. We explore the use of this method to detect whether or not the extinction law of a given reddened population has a break at some value of extinction. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (ESO programmes 069.C-0426 and 074.C-0728).

Investigation of a sample of carbon-enhanced metal-poor stars observed with FORS and GMOS

NASA Astrophysics Data System (ADS)

Caffau, E.; Gallagher, A. J.; Bonifacio, P.; Spite, M.; Duffau, S.; Spite, F.; Monaco, L.; Sbordone, L.

2018-06-01

Aims: Carbon-enhanced metal-poor (CEMP) stars represent a sizeable fraction of all known metal-poor stars in the Galaxy. Their formation and composition remains a significant topic of investigation within the stellar astrophysics community. Methods: We analysed a sample of low-resolution spectra of 30 dwarf stars, obtained using the visual and near UV FOcal Reducer and low dispersion Spectrograph for the Very Large Telescope (FORS/VLT) of the European Southern Observatory (ESO) and the Gemini Multi-Object Spectrographs (GMOS) at the GEMINI telescope, to derive their metallicity and carbon abundance. Results: We derived C and Ca from all spectra, and Fe and Ba from the majority of the stars. Conclusions: We have extended the population statistics of CEMP stars and have confirmed that in general, stars with a high C abundance belonging to the high C band show a high Ba-content (CEMP-s or -r/s), while stars with a normal C abundance or that are C-rich, but belong to the low C band, are normal in Ba (CEMP-no). Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 099.D-0791.Based on observations obtained at the Gemini Observatory (processed using the Gemini IRAF package), which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), and Ministério da Ciência, Tecnologia e Inovação (Brazil).Tables 1 and 2 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/614/A68

VISIONS - Vista Star Formation Atlas

NASA Astrophysics Data System (ADS)

Meingast, Stefan; Alves, J.; Boui, H.; Ascenso, J.

2017-06-01

In this talk I will present the new ESO public survey VISIONS. Starting in early 2017 we will use the ESO VISTA survey telescope in a 550 h long programme to map the largest molecular cloud complexes within 500 pc in a multi-epoch program. The survey is optimized for measuring the proper motions of young stellar objects invisible to Gaia and mapping the cloud-structure with extinction. VISIONS will address a series of ISM topics ranging from the connection of dense cores to YSOs and the dynamical evolution of embedded clusters to variations in the reddening law on both small and large scales.

ALMA to Help Solving Acute Mountain Sickness Mystery

NASA Astrophysics Data System (ADS)

2007-04-01

The Atacama Large Millimeter/submillimeter Array (ALMA) astronomical project will not only enlarge our knowledge of the vast Universe beyond the imaginable. It will also help scientists learn more about the human body. Located 5000m above sea level, in the Chilean Atacama desert, ALMA is the highest site for ground-based astronomy. This property will be put to good use for academic institutions in Chile and in Europe in order to study the human response to extreme altitude conditions. During a ceremony held on 2 April in Antofagasta, the largest town close to ESO's Very Large Telescope, representatives from ALMA, ESO and the University of Antofagasta have officially launched a collaborative agreement that also involves the University of Chile and the University of Copenhagen (Denmark). The newly established cooperation aims at contributing to the promotion of teaching, scientific research, and the expansion of altitude physiology and medicine or other related areas considered appropriate. ESO PR Photo 20/07 ESO PR Photo 20/07 Working at 5000 metres "An increasing number of people are periodically exposed to brisk changes in altitude, and not only for astronomical research," said Jacques Lassalle, the ALMA Safety Manager. "Short stays at high altitude alternate with short stays at sea level but the corresponding shifts are very often established by agreement, and not based on scientific arguments. With this project, we aim at improving our knowledge and procedures in order to protect the long term health of the operators, engineers, and scientists as well as ALMA visitors of all ages and all physical conditions," he added. Around the world, a large number of people systematically commute between sea level and high altitude, for example when working in mountainous mines. This poses stringent conditions that may affect health, wellbeing and working performance. Some of the factors in question are the shift work regime, the perturbation of circadian rhythms, fatigue, family and social isolation, commuting, intermittent high altitude exposure and other environmental challenges such as low temperatures. "An adequate acclimatisation to 2500m altitude requires around two weeks, and we can thus speculate that going to 5000m would require more than one month to achieve complete acclimatisation," said Professor Juan Silva Urra, from the University of Antofagasta. However, short and long term effects of regular commuting between sea level and high altitude have scarcely been studied in biomedical terms. Scientifically based guidelines for appropriate preventive handling and care under these conditions are lacking and the new study will help bridging this gap. Among the studies to be done, some involve continuous monitoring of the human body through portable devices, including measurements of hormone levels and application of psychometric tests. All measurements at 5000m will be carried out on a voluntary basis, under strict safety protocols, with the presence of a doctor from the investigation team, paramedic personnel form ALMA and an ambulance. The symptoms of Acute Mountain Sickness are headache, sicknesses, gastrointestinal inconveniences, fatigue and insomnia that, depending on their intensities, decrease the capacity to carry out the most routine activities. The valuable data collected will enhance our knowledge of human physiology in extreme environments, generating recommendations that will improve wellbeing and health not only in high-altitude observatories, but also in mining and Antarctic personnel. "We are pleased that ALMA is contributing to other disciplines, like medicine, even before the antennas begin to explore the universe," said Felix Mirabel, ESO's representative in Chile. "This outstanding long-term research that will provide crucial information of human physiology to experts worldwide, has been made possible thanks to the combined effort of Chilean and European universities, in collaboration with ALMA". The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership among Europe, Japan and North America, in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organisation for Astronomical Research in the Southern Hemisphere, in Japan by the National Institutes of Natural Sciences (NINS) in cooperation with the Academia Sinica in Taiwan and in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC). ALMA construction and operations are led on behalf of Europe by ESO, on behalf of Japan by the National Astronomical Observatory of Japan (NAOJ) and on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI).

Spectra of M Asteroids V1.0

NASA Astrophysics Data System (ADS)

Fornasier, S.; Clark, B. E.; Migliorini, A.; Ockert-Bell, M.

2011-08-01

This data set contains reduced composite visual and near-infrared spectra of thirty M-type asteroids, observed over the years 2004-2008 and presented in Fornasier et al. (2010). The spectra were taken with the Dolores and NICS instruments at the Telescopio Nationale Galileo (TNG) in La Palma, with the EMMI and SOFI instruments at the ESO New Technology Telescope (NTT) in Chile, and with the SPeX instrument at the Infrared Telescope Facility (IRTF) in Hawaii. The individual spectra from the various instruments used to produce the composite spectra are also included.

Massive open star clusters using the VVV survey. II. Discovery of six clusters with Wolf-Rayet stars

NASA Astrophysics Data System (ADS)

Chené, A.-N.; Borissova, J.; Bonatto, C.; Majaess, D. J.; Baume, G.; Clarke, J. R. A.; Kurtev, R.; Schnurr, O.; Bouret, J.-C.; Catelan, M.; Emerson, J. P.; Feinstein, C.; Geisler, D.; de Grijs, R.; Hervé, A.; Ivanov, V. D.; Kumar, M. S. N.; Lucas, P.; Mahy, L.; Martins, F.; Mauro, F.; Minniti, D.; Moni Bidin, C.

2013-01-01

Context. The ESO Public Survey "VISTA Variables in the Vía Láctea" (VVV) provides deep multi-epoch infrared observations for an unprecedented 562 sq. degrees of the Galactic bulge, and adjacent regions of the disk. Nearly 150 new open clusters and cluster candidates have been discovered in this survey. Aims: This is the second in a series of papers about young, massive open clusters observed using the VVV survey. We present the first study of six recently discovered clusters. These clusters contain at least one newly discovered Wolf-Rayet (WR) star. Methods: Following the methodology presented in the first paper of the series, wide-field, deep JHKs VVV observations, combined with new infrared spectroscopy, are employed to constrain fundamental parameters for a subset of clusters. Results: We find that the six studied stellar groups are real young (2-7 Myr) and massive (between 0.8 and 2.2 × 103 M⊙) clusters. They are highly obscured (AV ~ 5-24 mag) and compact (1-2 pc). In addition to WR stars, two of the six clusters also contain at least one red supergiant star, and one of these two clusters also contains a blue supergiant. We claim the discovery of 8 new WR stars, and 3 stars showing WR-like emission lines which could be classified WR or OIf. Preliminary analysis provides initial masses of ~30-50 M⊙ for the WR stars. Finally, we discuss the spiral structure of the Galaxy using the six new clusters as tracers, together with the previously studied VVV clusters. Based on observations with ISAAC, VLT, ESO (programme 087.D-0341A), New Technology Telescope at ESO's La Silla Observatory (programme 087.D-0490A) and with the Clay telescope at the Las Campanas Observatory (programme CN2011A-086). Also based on data from the VVV survey (programme 172.B-2002).

Mass, light and colour of the cosmic web in the supercluster SCL2243-0935 (z = 0.447)

NASA Astrophysics Data System (ADS)

Schirmer, M.; Hildebrandt, H.; Kuijken, K.; Erben, T.

2011-08-01

Aims: In archival 2.2 m MPG-ESO/WFI data we discovered several mass peaks through weak gravitational lensing, forming a possible supercluster at redshift 0.45. Through wide-field imaging and spectroscopy we aim to identify the supercluster centre, confirm individual member clusters, and detect possible connecting filaments. Methods: Through multi-colour imaging with CFHT/Megaprime and INT/WFC we identify a population of early-type galaxies and use it to trace the supercluster network. EMMI/NTT multi-object spectroscopy is used to verify the initial shear-selected cluster candidates. We use weak gravitational lensing to obtain mass estimates for the supercluster centre and the filaments. Results: We identified the centre of the SCL2243-0935 supercluster, MACS J2243-0935, which was found independently by Ebeling et al. (2001, 2010). We found 13 more clusters or overdensities embedded in a large filamentary network. Spectroscopic confirmation for about half of them is still pending. Three (5{-15) h70-1} Mpc filaments are detected, and we estimate the global size of SCL2243 to be 45×15×50 h70-1 Mpc, making it one of the largest superclusters known at intermediate redshifts. Weak lensing yields r200=(2.06±0.13) h_{70-1} Mpc and M200 = (1.54 ± 0.29) × 1015 M⊙ for MACS J2243 with M/L = 428 ± 82, very similar to results from size-richness cluster scaling relations. Integrating the weak lensing surface mass density over the supercluster network (defined by increased i-band luminosity or g - i colours), we find (1.53 ± 1.01) × 1015 M⊙ and M/L = 305 ± 201 for the three main filaments, consistant with theoretical predictions. The filaments' projected dimensionless surface mass density κ varies between 0.007 - 0.012, corresponding to ρ/ρcrit = 10 - 100 depending on location and de-projection. The greatly varying density of the cosmic web is also reflected in the mean colour of galaxies, e.g. ⟨ g - i ⟩ = 2.27 mag for the supercluster centre and 1.80 mag for the filaments. Conclusions: SCL2243 is significantly larger and much more richly structured than other known superclusters such as A901/902 or MS0302 studied with weak lensing before. It is a text-book supercluster with little contamination along the line of sight, making it a perfect sandbox for testing new techniques probing the cosmic web. This work is based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii (programme ID: 2008BO01); based on observations made with ESO Telescopes at the La Silla and Paranal Observatories, Chile (ESO Programmes 165.S-0187 and 079.A-0063); based on observations made with the 2.5 m Isaac Newton Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias (programme ID 2008B/C11 and 2009B/C1).Appendices are available in electronic form at http://www.aanda.org

Finland to Join ESO

NASA Astrophysics Data System (ADS)

2004-02-01

Finland will become the eleventh member state of the European Southern Observatory (ESO) [1]. Today, during a ceremony at the ESO Headquarters in Garching (Germany), a corresponding Agreement was signed by the Finnish Minister of Education and Science, Ms. Tuula Haatainen and the ESO Director General, Dr. Catherine Cesarsky, in the presence of other high officials from Finland and the ESO member states (see Video Clip 02/04 below). Following subsequent ratification by the Finnish Parliament of the ESO Convention and the associated protocols [2], it is foreseen that Finland will formally join ESO on July 1, 2004. Uniting European Astronomy ESO PR Photo 03/04 ESO PR Photo 03/04 Caption : Signing of the Finland-ESO Agreement on February 9, 2004, at the ESO Headquarters in Garching (Germany). At the table, the ESO Director General, Dr. Catherine Cesarsky, and the Finnish Minister of Education and Science, Ms. Tuula Haatainen . [Preview - JPEG: 400 x 499 pix - 52k] [Normal - JPEG: 800 x 997 pix - 720k] [Full Res - JPEG: 2126 x 2649 pix - 2.9M] The Finnish Minister of Education and Science, Ms. Tuula Haatainen, began her speech with these words: "On behalf of Finland, I am happy and proud that we are now joining the European Southern Observatory, one of the most successful megaprojects of European science. ESO is an excellent example of the potential of European cooperation in science, and along with the ALMA project, more and more of global cooperation as well." She also mentioned that besides science ESO offers many technological challenges and opportunities. And she added: "In Finland we will try to promote also technological and industrial cooperation with ESO, and we hope that the ESO side will help us to create good working relations. I am confident that Finland's membership in ESO will be beneficial to both sides." Dr. Catherine Cesarsky, ESO Director General, warmly welcomed the Finnish intention to join ESO. "With the accession of their country to ESO, Finnish astronomers, renowned for their expertise in many frontline areas, will have new, exciting opportunities for working on research programmes at the frontiers of modern astrophysics." "This is indeed the right time to join ESO", she added. "The four 8.2-m VLT Unit Telescopes with their many first-class instruments are working with unsurpassed efficiency at Paranal, probing the near and distant Universe and providing European astronomers with a goldmine of unique astronomical data. The implementation of the VLT Interferometer is progressing well and last year we entered into the construction phase of the intercontinental millimetre- and submillimetre-band Atacama Large Millimeter Array. And the continued design studies for gigantic optical/infrared telescopes like OWL are progressing fast. Wonderful horizons are indeed opening for the coming generations of European astronomers!" She was seconded by the President of the ESO Council, Professor Piet van der Kruit, "This is a most important step in the continuing evolution of ESO. By having Finland become a member of ESO, we welcome a country that has put in place a highly efficient and competitive innovation system with one of the fastest growths of research investment in the EU area. I have no doubt that the Finnish astronomers will not only make the best scientific use of ESO facilities but that they will also greatly contribute through their high quality R&D to technological developments which will benefit the whole ESO community. " Notes [1]: Current ESO member countries are Belgium, Denmark, France, Germany, Italy, the Netherlands, Portugal, Sweden, Switzerland and the United Kindgdom. [2]: The ESO Convention was established in 1962 and specifies the goals of ESO and the means to achieve these, e.g., "The Governments of the States parties to this convention... desirous of jointly creating an observatory equipped with powerful instruments in the Southern hemisphere and accordingly promoting and organizing co-operation in astronomical research..." (from the Preamble to the ESO Convention).

VST project: distributed control system overview

NASA Astrophysics Data System (ADS)

Mancini, Dario; Mazzola, Germana; Molfese, C.; Schipani, Pietro; Brescia, Massimo; Marty, Laurent; Rossi, Emilio

2003-02-01

The VLT Survey Telescope (VST) is a co-operative program between the European Southern Observatory (ESO) and the INAF Capodimonte Astronomical Observatory (OAC), Naples, for the study, design, and realization of a 2.6-m wide-field optical imaging telescope to be operated at the Paranal Observatory, Chile. The telescope design, manufacturing and integration are responsibility of OAC. The VST has been specifically designed to carry out stand-alone observations in the UV to I spectral range and to supply target databases for the ESO Very Large Telescope (VLT). The control hardware is based on a large utilization of distributed embedded specialized controllers specifically designed, prototyped and manufactured by the Technology Working Group for VST project. The use of a field bus improves the whole system reliability in terms of high level flexibility, control speed and allow to reduce drastically the plant distribution in the instrument. The paper describes the philosophy and the architecture of the VST control HW with particular reference to the advantages of this distributed solution for the VST project.

Obsolescence of electronics at the VLT

NASA Astrophysics Data System (ADS)

Hüdepohl, Gerhard; Haddad, Juan-Pablo; Lucuix, Christian

2016-07-01

The ESO Very Large Telescope Observatory (VLT) at Cerro Paranal in Chile had its first light in 1998. Most of the telescopes' electronics components were chosen and designed in the mid 1990s and are now around 20 years old. As a consequence we are confronted with increasing failure rates due to aging and lack of spare parts, since many of the components are no longer available on the market. The lifetime of large telescopes is generally much beyond 25 years. Therefore the obsolescence of electronics components and modules becomes an issue sooner or later and forces the operations teams to upgrade the systems to new technology in order to avoid that the telescope becomes inoperable. Technology upgrade is a time and money consuming process, which in many cases is not straightforward and has various types of complications. This paper shows the strategy, analysis, approach, timeline, complications and progress in obsolescence driven electronics upgrades at the ESO Very Large Telescope (VLT) at the Paranal Observatory.

VizieR Online Data Catalog: Fornax Deep Survey with VST. III. LSB galaxies (Venhola+, 2017)

NASA Astrophysics Data System (ADS)

Venhola, A.; Peletier, R.; Laurikainen, E.; Salo, H.; Lisker, T.; Iodice, E.; Capaccioli, M.; Verdoes Kleijn, G.; Valentijn, E.; Mieske, S.; Hilker, M.; Wittmann, C.; van de Ven, G.; Grado, A.; Spavone, M.; Cantiello, M.; Napolitano, N.; Paolillo, M.; Falcon-Barroso, J.

2018-02-01

We use the ongoing Fornax Deep Survey (FDS), which consists of the combined data of the Guaranteed Time Observation Surveys FOCUS (P.I. R. Peletier) and VEGAS (P.I. E. Iodice), dedicated to the Fornax cluster. Both surveys are performed with the ESO VLT Survey Telescope (VST), which is a 2.6-m diameter optical telescope located at Cerro Paranal, Chile. The imaging is done with the OmegaCAM instrument, using the u', g', r' and i'-bands, and 1°x1° field of view. The observations used in this work were gathered in visitor mode runs during November 2013, 2014 and 2015 (ESO P92, P94 and P96, respectively). All the observations were performed in clear (photometric variations <10%) or photometric conditions. The observations in u' and g'-bands were obtained in dark time, and those of the other bands in gray or dark time. (1 data file).

Putting two and two together? Early childhood education, mothers’ employment and care service expansion in Chile and Mexico.

PubMed

Staab, Silke; Gerhard, Roberto

2011-01-01

In recent years, several middle-income countries, including Chile, Mexico and Uruguay, have increased the availability of early childhood education and care (ECEC) services. These developments have received little scholarly attention so far, resulting in the (surely unintended) impression that Latin American social policy is tied to a familialist track, when in reality national and regional trends are more varied and complex. This article looks at recent efforts to expand ECEC services in Chile and Mexico. In spite of similar concerns over low female labour force participation and child welfare, the approaches of the two countries to service expansion have differed significantly. While the Mexican programme aims to kick-start and subsidize home- and community-based care provision, with a training component for childminders, the Chilean programme emphasizes the expansion of professional ECEC services provided in public institutions. By comparing the two programmes, this article shows that differences in policy design have important implications in terms of the opportunities the programmes are able to create for women and children from low-income families, and in terms of the programmes’ impacts on gender and class inequalities. It also ventures some hypotheses about why the two countries may have chosen such different routes.

Deepest Wide-Field Colour Image in the Southern Sky

NASA Astrophysics Data System (ADS)

2003-01-01

LA SILLA CAMERA OBSERVES CHANDRA DEEP FIELD SOUTH ESO PR Photo 02a/03 ESO PR Photo 02a/03 [Preview - JPEG: 400 x 437 pix - 95k] [Normal - JPEG: 800 x 873 pix - 904k] [HiRes - JPEG: 4000 x 4366 pix - 23.1M] Caption : PR Photo 02a/03 shows a three-colour composite image of the Chandra Deep Field South (CDF-S) , obtained with the Wide Field Imager (WFI) camera on the 2.2-m MPG/ESO telescope at the ESO La Silla Observatory (Chile). It was produced by the combination of about 450 images with a total exposure time of nearly 50 hours. The field measures 36 x 34 arcmin 2 ; North is up and East is left. Technical information is available below. The combined efforts of three European teams of astronomers, targeting the same sky field in the southern constellation Fornax (The Oven) have enabled them to construct a very deep, true-colour image - opening an exceptionally clear view towards the distant universe . The image ( PR Photo 02a/03 ) covers an area somewhat larger than the full moon. It displays more than 100,000 galaxies, several thousand stars and hundreds of quasars. It is based on images with a total exposure time of nearly 50 hours, collected under good observing conditions with the Wide Field Imager (WFI) on the MPG/ESO 2.2m telescope at the ESO La Silla Observatory (Chile) - many of them extracted from the ESO Science Data Archive . The position of this southern sky field was chosen by Riccardo Giacconi (Nobel Laureate in Physics 2002) at a time when he was Director General of ESO, together with Piero Rosati (ESO). It was selected as a sky region towards which the NASA Chandra X-ray satellite observatory , launched in July 1999, would be pointed while carrying out a very long exposure (lasting a total of 1 million seconds, or 278 hours) in order to detect the faintest possible X-ray sources. The field is now known as the Chandra Deep Field South (CDF-S) . The new WFI photo of CDF-S does not reach quite as deep as the available images of the "Hubble Deep Fields" (HDF-N in the northern and HDF-S in the southern sky, cf. e.g. ESO PR Photo 35a/98 ), but the field-of-view is about 200 times larger. The present image displays about 50 times more galaxies than the HDF images, and therefore provides a more representative view of the universe . The WFI CDF-S image will now form a most useful basis for the very extensive and systematic census of the population of distant galaxies and quasars, allowing at once a detailed study of all evolutionary stages of the universe since it was about 2 billion years old . These investigations have started and are expected to provide information about the evolution of galaxies in unprecedented detail. They will offer insights into the history of star formation and how the internal structure of galaxies changes with time and, not least, throw light on how these two evolutionary aspects are interconnected. GALAXIES IN THE WFI IMAGE ESO PR Photo 02b/03 ESO PR Photo 02b/03 [Preview - JPEG: 488 x 400 pix - 112k] [Normal - JPEG: 896 x 800 pix - 1.0M] [Full-Res - JPEG: 2591 x 2313 pix - 8.6M] Caption : PR Photo 02b/03 contains a collection of twelve subfields from the full WFI Chandra Deep Field South (WFI CDF-S), centred on (pairs or groups of) galaxies. Each of the subfields measures 2.5 x 2.5 arcmin 2 (635 x 658 pix 2 ; 1 pixel = 0.238 arcsec). North is up and East is left. Technical information is available below. The WFI CDF-S colour image - of which the full field is shown in PR Photo 02a/03 - was constructed from all available observations in the optical B- ,V- and R-bands obtained under good conditions with the Wide Field Imager (WFI) on the 2.2-m MPG/ESO telescope at the ESO La Silla Observatory (Chile), and now stored in the ESO Science Data Archive. It is the "deepest" image ever taken with this instrument. It covers a sky field measuring 36 x 34 arcmin 2 , i.e., an area somewhat larger than that of the full moon. The observations were collected during a period of nearly four years, beginning in January 1999 when the WFI instrument was first installed (cf. ESO PR 02/99 ) and ending in October 2002. Altogether, nearly 50 hours of exposure were collected in the three filters combined here, cf. the technical information below. Although it is possible to identify more than 100,000 galaxies in the image - some of which are shown in PR Photo 02b/03 - it is still remarkably "empty" by astronomical standards. Even the brightest stars in the field (of visual magnitude 9) can hardly be seen by human observers with binoculars. In fact, the area density of bright, nearby galaxies is only half of what it is in "normal" sky fields. Comparatively empty fields like this one provide an unsually clear view towards the distant regions in the universe and thus open a window towards the earliest cosmic times . Research projects in the Chandra Deep Field South ESO PR Photo 02c/03 ESO PR Photo 02c/03 [Preview - JPEG: 400 x 513 pix - 112k] [Normal - JPEG: 800 x 1026 pix - 1.2M] [Full-Res - JPEG: 1717 x 2201 pix - 5.5M] ESO PR Photo 02d/03 ESO PR Photo 02d/03 [Preview - JPEG: 400 x 469 pix - 112k] [Normal - JPEG: 800 x 937 pix - 1.0M] [Full-Res - JPEG: 2545 x 2980 pix - 10.7M] Caption : PR Photo 02c-d/03 shows two sky fields within the WFI image of CDF-S, reproduced at full (pixel) size to illustrate the exceptional information richness of these data. The subfields measure 6.8 x 7.8 arcmin 2 (1717 x 1975 pixels) and 10.1 x 10.5 arcmin 2 (2545 x 2635 pixels), respectively. North is up and East is left. Technical information is available below. Astronomers from different teams and disciplines have been quick to join forces in a world-wide co-ordinated effort around the Chandra Deep Field South. Observations of this area are now being performed by some of the most powerful astronomical facilities and instruments. They include space-based X-ray and infrared observations by the ESA XMM-Newton , the NASA CHANDRA , Hubble Space Telescope (HST) and soon SIRTF (scheduled for launch in a few months), as well as imaging and spectroscopical observations in the infrared and optical part of the spectrum by telescopes at the ground-based observatories of ESO (La Silla and Paranal) and NOAO (Kitt Peak and Tololo). A huge database is currently being created that will help to analyse the evolution of galaxies in all currently feasible respects. All participating teams have agreed to make their data on this field publicly available, thus providing the world-wide astronomical community with a unique opportunity to perform competitive research, joining forces within this vast scientific project. Concerted observations The optical true-colour WFI image presented here forms an important part of this broad, concerted approach. It combines observations of three scientific teams that have engaged in complementary scientific projects, thereby capitalizing on this very powerful combination of their individual observations. The following teams are involved in this work: * COMBO-17 (Classifying Objects by Medium-Band Observations in 17 filters) : an international collaboration led by Christian Wolf and other scientists at the Max-Planck-Institut für Astronomie (MPIA, Heidelberg, Germany). This team used 51 hours of WFI observing time to obtain images through five broad-band and twelve medium-band optical filters in the visual spectral region in order to measure the distances (by means of "photometric redshifts") and star-formation rates of about 10,000 galaxies, thereby also revealing their evolutionary status. * EIS (ESO Imaging Survey) : a team of visiting astronomers from the ESO community and beyond, led by Luiz da Costa (ESO). They observed the CDF-S for 44 hours in six optical bands with the WFI camera on the MPG/ESO 2.2-m telescope and 28 hours in two near-infrared bands with the SOFI instrument at the ESO 3.5-m New Technology Telescope (NTT) , both at La Silla. These observations form part of the Deep Public Imaging Survey that covers a total sky area of 3 square degrees. * GOODS (The Great Observatories Origins Deep Survey) : another international team (on the ESO side, led by Catherine Cesarsky ) that focusses on the coordination of deep space- and ground-based observations on a smaller, central area of the CDF-S in order to image the galaxies in many differerent spectral wavebands, from X-rays to radio. GOODS has contributed with 40 hours of WFI time for observations in three broad-band filters that were designed for the selection of targets to be spectroscopically observed with the ESO Very Large Telescope (VLT) at the Paranal Observatory (Chile), for which over 200 hours of observations are planned. About 10,000 galaxies will be spectroscopically observed in order to determine their redshift (distance), star formation rate, etc. Another important contribution to this large research undertaking will come from the GEMS project. This is a "HST treasury programme" (with Hans-Walter Rix from MPIA as Principal Investigator) which observes the 10,000 galaxies identified in COMBO-17 - and eventually the entire WFI-field with HST - to show the evolution of their shapes with time. Great questions With the combination of data from many wavelength ranges now at hand, the astronomers are embarking upon studies of the many different processes in the universe. They expect to shed more light on several important cosmological questions, such as: * How and when was the first generation of stars born? * When exactly was the neutral hydrogen in the universe ionized the first time by powerful radiation emitted from the first stars and active galactic nuclei? * How did galaxies and groups of galaxies evolve during the past 13 billion years? * What is the true nature of those elusive objects that are only seen at the infrared and submillimetre wavelengths (cf. ESO PR 23/02 )? * Which fraction of galaxies had an "active" nucleus (probably with a black hole at the centre) in their past, and how long did this phase last? Moreover, since these extensive optical observations were obtained in the course of a dozen observing periods during several years, it is also possible to perform studies of certain variable phenomena: * How many variable sources are seen and what are their types and properties? * How many supernovae are detected per time interval, i.e. what is the supernovae frequency at different cosmic epochs? * How do those processes depend on each other? This is just a short and very incomplete list of questions astronomers world-wide will address using all the complementary observations. No doubt that the coming studies of the Chandra Deep Field South - with this and other data - will be most exciting and instructive! Other wide-field images Other wide-field images from the WFI have been published in various ESO press releases during the past four years - they are also available at the WFI Photo Gallery . A collection of full-resolution files (TIFF-format) is available on a WFI CD-ROM . Technical Information The very extensive data reduction and colour image processing needed to produce these images were performed by Mischa Schirmer and Thomas Erben at the "Wide Field Expertise Center" of the Institut für Astrophysik und Extraterrestrische Forschung der Universität Bonn (IAEF) in Germany. It was done by means of a software pipeline specialised for reduction of multiple CCD wide-field imaging camera data. This pipeline is mainly based on publicly available software modules and algorithms ( EIS , FLIPS , LDAC , Terapix , Wifix ). The image was constructed from about 150 exposures in each of the following wavebands: B-band (centred at wavelength 456 nm; here rendered as blue, 15.8 hours total exposure time), V-band (540 nm; green, 15.6 hours) and R-band (652 nm; red, 17.8 hours). Only images taken under sufficiently good observing conditions (defined as seeing less than 1.1 arcsec) were included. In total, 450 images were assembled to produce this colour image, together with about as many calibration images (biases, darks and flats). More than 2 Terabyte (TB) of temporary files were produced during the extensive data reduction. Parallel processing of all data sets took about two weeks on a four-processor Sun Enterprise 450 workstation and a 1.8 GHz dual processor Linux PC. The final colour image was assembled in Adobe Photoshop. The observations were performed by ESO (GOODS, EIS) and the COMBO-17 collaboration in the period 1/1999-10/2002.

ESO PR Highlights in 2004

NASA Astrophysics Data System (ADS)

2005-01-01

Last year proved again a wonderful one for astronomy in general and for ESO in particular. Certainly the most important astronomical event for a large public was the unique Transit of Venus : on June 8, 2004, Venus - the Earth's sister planet - passed in front of the Sun. This rare event - the last one occurred in 1882 - attracted the attention of millions of people all over the world. ESO in cooperation with several other institutes and with support from the European Commission organised through the whole year the Venus Transit 2004 (VT-2004) public education programme that successfully exposed the broad public to a number of fundamental issues at the crucial interface between society and basic science. The web site experienced a record 55 million webhits during a period of 8 hours around the transit. The programme also re-enacted the historical determination of the distance to the Sun (the "Astronomical Unit") by collecting 4550 timings of the four contacts made by more than 1500 participating group of observers and combining them in a calculation of the AU. This resulted in an astonishing accurate value of the Astronomical Unit. More details are available at the VT-2004 website, whose wealth of information will certainly make it a useful tool until the next transit in 2012! For ESO also, 2004 proved a very special year. Finland officially joined as eleventh member state and in December, the Chilean President, Ricardo Lagos, visited the Paranal Observatory. Last year was also the Fifth anniversary of the Very Large Telescope, ESO's flagship facility, as on April 1, 1999 the first 8.2-m VLT Unit Telescope, Antu (UT1), was "handed over" to the astronomers. On this occasion, ESO released several products, including a selection of the best astronomical images taken with the VLT, the VLT Top 20. But there is no doubt that the numerous high quality images published last year are all contenders to top the charts of best astronomical pictures. The year 2004 also saw many new interesting scientific results on the basis of data from ESO telescopes, including several results from the unmatched interferometer mode of the VLT, the VLTI, some of which were highlighted in ESO Press Releases. Certainly worth noting is the possible first ever bona-fide image of an exoplanet and the discovery of the lightest known exoplanet . At the beginning of the year, Paranal welcomed the first Auxiliary Telescope, while on the instrument side as well, 2004 was a good year: we saw the arrival of SINFONI on the VLT, of AMBER on the VLTI, and the installation at the NACO Adaptive Optics instrument of the " Simultaneous Differential Imager (SDI)" to detect exoplanets. And the first prototype of the Astrophysical Virtual Observatory was able to provide unprecedented results on the existence of Type-2 quasars by discovering an entire population of obscured, powerful supermassive black holes. Many of these developments are described in ESO's Press Releases, most with Press Photos, cf. the 2004 PR Index. Some of last year's ESO PR highlights may be accessed directly via the clickable image above.

The MATISSE analysis of large spectral datasets from the ESO Archive

NASA Astrophysics Data System (ADS)

Worley, C.; de Laverny, P.; Recio-Blanco, A.; Hill, V.; Vernisse, Y.; Ordenovic, C.; Bijaoui, A.

2010-12-01

The automated stellar classification algorithm, MATISSE, has been developed at the Observatoire de la Côte d'Azur (OCA) in order to determine stellar temperatures, gravities and chemical abundances for large datasets of stellar spectra. The Gaia Data Processing and Analysis Consortium (DPAC) has selected MATISSE as one of the key programmes to be used in the analysis of the Gaia Radial Velocity Spectrometer (RVS) spectra. MATISSE is currently being used to analyse large datasets of spectra from the ESO archive with the primary goal of producing advanced data products to be made available in the ESO database via the Virtual Observatory. This is also an invaluable opportunity to identify and address issues that can be encountered with the analysis large samples of real spectra prior to the launch of Gaia in 2012. The analysis of the archived spectra of the FEROS spectrograph is currently underway and preliminary results are presented.

ESO Successfully Tests Automation of Telescope Operations

NASA Astrophysics Data System (ADS)

1997-02-01

This week astronomers at the European Southern Observatory have tested a novel approach of doing astronomy from the ground. Inaugurating a new era, the ESO 3.5-metre New Technology Telescope (NTT) at La Silla successfully performed a series of observations under automatic control by advanced computer software developed by the ESO Data Management Division (DMD) for use with the ESO Very Large Telescope (VLT). This move has been made necessary by technological improvements in telescopes and the increasing competition among scientists for these valuable resources. Caption to ESO PR Photo 05/97 [JPG, 184k] This Press Release is accompanied by ESO Press Photo 05/97 of the NTT. New telescopes produce more data Over the past few years, astronomical telescopes and the amount of data they produce have grown rapidly in size. With the advent of increasingly efficient, large digital cameras, the new telescopes with mirrors as large as 8 to 10 metres in diameter will deliver Gigabytes of valuable information each night. There is little doubt that scientific breakthroughs will be made with these telescopes and it should be no surprise that there is fierce competition for precious observing nights among the international astronomical community. Automated observations In order to make sure that the available observing time at the VLT will be used in the best and most efficient way, ESO has been developing advanced computer systems which will automatically schedule observations according to the scientific priorities of astronomers and the prevailing conditions of weather and equipment at the observatory. Once the astronomical data is gathered it is processed automatically at the telescope to provide the astronomer with immediately useful astronomical images and other pertinent information. No longer will the astronomer be required to spend weeks processing data into a form where results can be extracted. The continuous flow of astronomical data made possible with this system is referred to as the VLT Data Flow System , now being perfected by the ESO Data Management Division for use on ESO's Very Large Telescope project. First tests at the NTT On February 5, a team of software engineers and astronomers from ESO used a first version of the new VLT Data Flow System to perform observations on ESO's New Technology Telescope (NTT) at the La Silla Observatory in Chile. A computer file containing a complete description of an observation (for instance, object position in the sky, filtres and exposure time, and other relevant information) prepared in advance by an astronomer was transferred via the satellite link from the ESO Headquarters in Germany to the NTT computers at La Silla and executed on the control system of the telescope. The telescope then moved to the correct position in the sky, the camera was activated and a few minutes later, a processed image a distant galaxy appeared on the screen in front of the observers. The image was saved in an automatic archive system that writes the astronomical data on CD-ROM. The entire process took place automatically and demonstrated that this system is capable of taking high quality data from the sky at the best possible time and delivering the results to the astronomer, efficiently and in the most convenient form. Further developments This is the first time that a ground-based telescope has been operated under the new system. This successful initial test bodes well for the start-up of the VLT. During 1997, ESO will further develop the data flow system in preparation for the beginning of commissioning of the first VLT 8.2-metre unit, less then 12 months from now. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

VizieR Online Data Catalog: ALLSMOG final data release. A new APEX CO survey (Cicone+, 2017)

NASA Astrophysics Data System (ADS)

Cicone, C.; Bothwell, M.; Wagg, J.; Moller, P.; De Breuck, C.; Zhang, Z.; Martin, S.; Maiolino, R.; Severgnini, P.; Aravena, M.; Belfiore, F.; Espada, D.; Flutsch, A.; Impellizzeri, V.; Peng, Y.; Raj, M. A.; Ramirez-Olivencia, N.; Riechers, D.; Schawinski, K.

2017-10-01

ALLSMOG is an ESO Large Programme for the Atacama Pathfinder EXperiment (APEX, project no.: E-192.A-0359, principal investigator (PI): J. Wagg) targeting the CO(2-1) emission line (rest frequency, νCO(2-1)=230.538GHz) in 88 local, low-M* star-forming galaxies. The project was initially allocated 300h of ESO observing time over the course of four semesters, corresponding to 75h per semester throughout periods P92-P95 (October 2013 - September 2015). However, during P94 and P95 there was a slowdown in ALLSMOG observations, mainly due the installation of the visiting instrument Supercam in combination with better-than-average weather conditions - causing other programmes requiring more stringent precipitable water vapour (PWV) constraints to be prioritised. Because of the resulting ~50% time loss for ALLSMOG during two semesters, the ESO observing programmes committee (OPC) granted a one-semester extension of the project, hence allowing us to complete the survey in P96 (March 2016). The final total APEX observing time dedicated to ALLSMOG amounts to 327h, including the overheads due to setup and calibration but not accounting for possible additional time lost because of technical issues. In 2014 a northern component of the ALLSMOG survey was approved at the IRAM 30m telescope (project code: 188-14, PI: S. Martin), aimed at observing the CO(1-0) (rest frequency, νCO(1-0)=115.271GHz) and CO(2-1) emission lines in a sample of nine additional galaxies characterised by stellar masses, M*<109Mȯ. A total of 22h of observations were obtained with the IRAM 30m during two observing runs in November 2014 and May 2015. (5 data files).

GRB 060605: multi-wavelength analysis of the first GRB observed using integral field spectroscopy

NASA Astrophysics Data System (ADS)

Ferrero, P.; Klose, S.; Kann, D. A.; Savaglio, S.; Schulze, S.; Palazzi, E.; Maiorano, E.; Böhm, P.; Grupe, D.; Oates, S. R.; Sánchez, S. F.; Amati, L.; Greiner, J.; Hjorth, J.; Malesani, D.; Barthelmy, S. D.; Gorosabel, J.; Masetti, N.; Roth, M. M.

2009-04-01

The long and relatively faint gamma-ray burst GRB 060605 detected by Swift/BAT lasted about 20 s. Its afterglow could be observed with Swift/XRT for nearly 1 day, while Swift/UVOT could detect the afterglow during the first 6 h after the event. Here, we report on integral field spectroscopy of its afterglow performed with PMAS/PPak mounted at the Calar Alto 3.5 m telescope. In addition, we report on a detailed analysis of XRT and UVOT data and on the results of deep late-time VLT observations that reveal the GRB host galaxy. We find that the burst occurred at a redshift of z = 3.773, possibly associated with a faint, RC = 26.4 ± 0.3 host. Based on the optical and X-ray data, we deduce information on the SED of the afterglow, the position of the cooling frequency in the SED, the nature of the circumburst environment, its collimation factor, and its energetics. We find that the GRB fireball was expanding into a constant-density medium and that the explosion was collimated with a narrow half-opening angle of about 2.4 degrees. The initial Lorentz factor of the fireball was about 250; however, its beaming-corrected energy release in the gamma-ray band was comparably low. The optical, X-ray afterglow, on the other hand, was rather luminous. Finally, we find that the data are consistent within the error bars with an achromatic evolution of the afterglow during the suspected jet break time at about 0.27 days after the burst. Based on observations collected at the German-Spanish Calar Alto Observatory in Spain (Programme F06-3.5-055) and at the European Southern Observatory, La Silla and Paranal, Chile (ESO Programme 177.D-0591).

Stars Just Got Bigger - A 300 Solar Mass Star Uncovered

NASA Astrophysics Data System (ADS)

2010-07-01

Using a combination of instruments on ESO's Very Large Telescope, astronomers have discovered the most massive stars to date, one weighing at birth more than 300 times the mass of the Sun, or twice as much as the currently accepted limit of 150 solar masses. The existence of these monsters - millions of times more luminous than the Sun, losing weight through very powerful winds - may provide an answer to the question "how massive can stars be?" A team of astronomers led by Paul Crowther, Professor of Astrophysics at the University of Sheffield, has used ESO's Very Large Telescope (VLT), as well as archival data from the NASA/ESA Hubble Space Telescope, to study two young clusters of stars, NGC 3603 and RMC 136a in detail. NGC 3603 is a cosmic factory where stars form frantically from the nebula's extended clouds of gas and dust, located 22 000 light-years away from the Sun (eso1005). RMC 136a (more often known as R136) is another cluster of young, massive and hot stars, which is located inside the Tarantula Nebula, in one of our neighbouring galaxies, the Large Magellanic Cloud, 165 000 light-years away (eso0613). The team found several stars with surface temperatures over 40 000 degrees, more than seven times hotter than our Sun, and a few tens of times larger and several million times brighter. Comparisons with models imply that several of these stars were born with masses in excess of 150 solar masses. The star R136a1, found in the R136 cluster, is the most massive star ever found, with a current mass of about 265 solar masses and with a birthweight of as much as 320 times that of the Sun. In NGC 3603, the astronomers could also directly measure the masses of two stars that belong to a double star system [1], as a validation of the models used. The stars A1, B and C in this cluster have estimated masses at birth above or close to 150 solar masses. Very massive stars produce very powerful outflows. "Unlike humans, these stars are born heavy and lose weight as they age," says Paul Crowther. "Being a little over a million years old, the most extreme star R136a1 is already 'middle-aged' and has undergone an intense weight loss programme, shedding a fifth of its initial mass over that time, or more than fifty solar masses." If R136a1 replaced the Sun in our Solar System, it would outshine the Sun by as much as the Sun currently outshines the full Moon. "Its high mass would reduce the length of the Earth's year to three weeks, and it would bathe the Earth in incredibly intense ultraviolet radiation, rendering life on our planet impossible," says Raphael Hirschi from Keele University, who belongs to the team. These super heavyweight stars are extremely rare, forming solely within the densest star clusters. Distinguishing the individual stars - which has now been achieved for the first time - requires the exquisite resolving power of the VLT's infrared instruments [2]. The team also estimated the maximum possible mass for the stars within these clusters and the relative number of the most massive ones. "The smallest stars are limited to more than about eighty times more than Jupiter, below which they are 'failed stars' or brown dwarfs," says team member Olivier Schnurr from the Astrophysikalisches Institut Potsdam. "Our new finding supports the previous view that there is also an upper limit to how big stars can get, although it raises the limit by a factor of two, to about 300 solar masses." Within R136, only four stars weighed more than 150 solar masses at birth, yet they account for nearly half of the wind and radiation power of the entire cluster, comprising approximately 100 000 stars in total. R136a1 alone energises its surroundings by more than a factor of fifty compared to the Orion Nebula cluster, the closest region of massive star formation to Earth. Understanding how high mass stars form is puzzling enough, due to their very short lives and powerful winds, so that the identification of such extreme cases as R136a1 raises the challenge to theorists still further. "Either they were born so big or smaller stars merged together to produce them," explains Crowther. Stars between about 8 and 150 solar masses explode at the end of their short lives as supernovae, leaving behind exotic remnants, either neutron stars or black holes. Having now established the existence of stars weighing between 150 and 300 solar masses, the astronomers' findings raise the prospect of the existence of exceptionally bright, "pair instability supernovae" that completely blow themselves apart, failing to leave behind any remnant and dispersing up to ten solar masses of iron into their surroundings. A few candidates for such explosions have already been proposed in recent years. Not only is R136a1 the most massive star ever found, but it also has the highest luminosity too, close to 10 million times greater than the Sun. "Owing to the rarity of these monsters, I think it is unlikely that this new record will be broken any time soon," concludes Crowther. Notes [1] The star A1 in NGC 3603 is a double star, with an orbital period of 3.77 days. The two stars in the system have, respectively, 120 and 92 times the mass of the Sun, which means that they have formed as stars weighing, respectively, 148 and 106 solar masses. [2] The team used the SINFONI, ISAAC and MAD instruments, all attached to ESO's Very Large Telescope at Paranal, Chile. [3] (note added on 26 July 2010) The "bigger" in the title does not imply that these stars are the biggest observed. Such stars, called red supergiants, can have radii up to about a thousand solar radii, while R136a1, which is blue, is about 35 times as large as the Sun. However, R136a1 is the star with the greatest mass known to date. More information This work is presented in an article published in the Monthly Notices of the Royal Astronomical Society ("The R136 star cluster hosts several stars whose individual masses greatly exceed the accepted 150 Msun stellar mass limit", by P. Crowther et al.). The team is composed of Paul A. Crowther, Richard J. Parker, and Simon P. Goodwin (University of Sheffield, UK), Olivier Schnurr (University of Sheffield and Astrophysikalisches Institut Potsdam, Germany), Raphael Hirschi (Keele University, UK), and Norhasliza Yusof and Hasan Abu Kassim (University of Malaya, Malaysia). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Distant Supernovae Indicate Ever-Expanding Universe

NASA Astrophysics Data System (ADS)

1998-12-01

ESO Astronomers Contribute towards Resolution of Cosmic Puzzle Since the discovery of the expansion of the Universe by American astronomer Edwin Hubble in the 1920's, by measurement of galaxy velocities, astronomers have tried to learn how this expansion changes with time. Until now, most scientists have been considering two possibilities: the expansion rate is slowing down and will ultimately either come to a halt - whereafter the Universe would start to contract, or it will continue to expand forever. However, new studies by two independent research teams, based on observations of exploding stars ( supernovae ) by ESO astronomers [1] with astronomical telescopes at the La Silla Observatory as well as those of their colleagues at other institutions, appear to show that the expansion of the Universe is accelerating . The results take the discovery of the cosmological expansion one step further and challenge recent models of the Universe. If the new measurements are indeed correct, they show that the elusive "cosmological constant" , as proposed by Albert Einstein , contributes significantly to the evolution of the Universe. The existence of a non-zero cosmological constant implies that a repulsive force, counter-acting gravity, currently dominates the universal expansion , and consequently leads to an ever-expanding Universe. This new research is being named as the "Breakthrough of the Year" by the renowned US science journal Science in the December 18, 1998, issue. A Press Release is published by the journal on this occasion. "Fundamental Parameters" of the Universe Three fundamental parameters govern all cosmological models based on the theory of General Relativity. They are 1. the current expansion rate as described by Hubble's constant , i.e. the proportionality factor between expansion velocity and distance 2. the average matter density in the Universe, and 3. the amount of "other energy" present in space. From the measured values of these fundamental parameters, the age of the Universe and the geometry of space can be derived. They have been the focus of a large number of astronomical programmes over the past decades. Many aspects of the currently preferred cosmological model, the Hot Big Bang , have been impressively confirmed by observations of the expansion of the Universe, the cosmic background radiation, and also the explanation of the synthesis of light elements. Still, our knowledge about the dynamical state of the Universe, as well as the early formation of structures, i.e., of galaxies and stars, is far from complete - this remains a field of active research. Possibly, the simplest way to test our present assumptions in this direction is to measure accurate distances and compare them with the expected cosmic scale. This is where the recent results contribute to our understanding of the Universe. The key role of supernovae The two research teams, both with participation from ESO [1], have concentrated on the study of rare stellar explosions, during which certain old stars undergo internal incineration. In this process, explosive nuclear fusion burns matter into the most stable atomic nucleus, iron, and releases a gigantic amount of energy. ESO PR Photo 50a/98 ESO PR Photo 50a/98 [Preview - JPEG: 800 x 648 pix - 768k] [High-Res - JPEG: 3000 x 2431 pix - 8.5Mb] ESO PR Photo 50b/98 ESO PR Photo 50b/98 [Preview - JPEG: 800 x 649 pix - 784k] [High-Res - JPEG: 3000 x 2432 pix - 8.4Mb] These photos illustrate the follow-up observations on which the new results described in this Press Release are based. Sky fields with clusters of galaxies are monitored with the 4-m telescope at Cerro Tololo Interamerican Observatory (CTIO) in Chile and spectra are obtained of suddenly appearing star-like objects that may be supernovae. Confirmed Type Ia supernovae are then monitored by ESO telescopes at La Silla and at other observatories. In PR Photo 50a/98 , a supernova at redshift z = 0.51 [2] (corresponding to a distance of about 10,000 million light-years) is observed on five dates with the SUSI camera at the 3.6-m New Technology Telescope (NTT). The host galaxy is clearly visible and the supernova reaches its maximum brightness around 13 March 1997, after which it fades. In PR Photo 50b/98 of another supernova that was found at the same time, the image of the host galaxy is barely visible, most probably because it is a low surface brightness galaxy . Here, the redshift of the supernova is z = 0.40 (distance 6,000 million light-years) and the brightness peaks around 16 March 1997. Technical information: All images were obtained through an R (red) optical filtre. The image quality varies somewhat from image to image. Exposure times and seeing values: Photo 50a/98 - 11 March (300 sec; 0.73 arcsec); 13 March (600 sec; 0.79 arcsec); 16 March (600 sec; 0.72 arcsec); 29 March (1200 sec; 1.17 arcsec); 5 April (300 sec; 0.55 arcsec) and Photo 50b/98 - 11 March (300 sec; 0.50 arcsec); 13 March (600 sec; 0.81 arcsec); 16 March (600 sec; 0.90 arcsec); 29 March (1200 sec; 0.83 arcsec); 7 April (300 sec; 1.43 arcsec); 7 May (1800 sec; 1.22 arcsec). These explosions, known as Type Ia Supernovae , are distinguished by their very uniform properties, including their intrinsic brightness; this makes them ideal for the measurement of large distances, cf. ESO PR Photos 50a/98 and 50b/98 , as well as ESO Press Release 09/95. It is by means of observations of remote objects of this type that the all-important distances could be determined with sufficient accuracy. In particular, coordinated observing campaigns of Type Ia Supernovae were carried out at several of the world's major observatories. In this way it became possible to secure the crucial data that provide the basis of the new analysis. Distances to Type Ia Supernovae are larger than expected The new observations show that, compared to their nearby twins, distant supernovae appear too dim, even for a Universe which has been freely coasting (i.e. with no change of the expansion velocity) for the last several billion years (corresponding to redshifts of about 0.5). The only reasonable interpretation of these data implies that the measured distances are larger than what they would be in a "non-braking" Universe. This means that the distances to the supernovae must have increased over and above what they would have been if the rate of expansion did not change with time. This is only possible by the effect of additional acceleration , i.e., the rate of expansion of the Universe increases with time. The acceleration comes from a repulsive force . This concept was introduced by Albert Einstein , as the cosmological constant . Implications There are several important implications from this new result. The corresponding, deduced age of the Universe , now about 14,000 - 15,000 million years, no longer conflicts with that of the oldest known stellar objects in globular clusters. Moreover, the spatial geometry of the Universe appears to be "flat" - this is a strong confirmation of inflation (a short phase of very rapid expansion) in the very early Universe. Ordinary matter, which comprises everything we know - from the atom to the stars - is composed of baryonic matter . It has been realized over the last few years that the matter we observe directly is only a fraction of all mass that is actually present in galaxies and clusters of galaxies, as estimated from measurements of internal motions in these objects. This has been referred to as the "dark matter problem" . Following the new measurements, a new component, "dark energy" (i.e., energy of the vacuum), must be added. It appears that this form of energy is dominating the Universe at the current time. There is a profound philosophical repositioning of humankind implied by this result. This follows the first step which was taken by Copernicus who in the mid-sixteenth century dislodged us from the centre of the Universe. Not only does the material from which the visible galaxies, stars, the Earth and its inhabitants are made comprise only a small fration of the gravitating mass in the Universe. There is now a new component, the "dark energy" which joins the "dark matter" in shaping the large-scale geometric and dynamical structure. Clearly, more observations are needed to further support the findings described here. They will soon be forthcoming, especially from new and large telescopes like the ESO Very Large Telescope (VLT) , that has recently delivered its first, impressive results. But already now, on the verge of the new millenium, we are having a first glimpse of extremely exciting and fundamental aspects in the continuing human quest for the deep truths of nature. Notes: [1] The ESO members of the "High-z Supernova Search" team (see URL: http://cfa-www.harvard.edu/cfa/oir/Research/supernova/HighZ.html) are Bruno Leibundgut and Patrick Woudt (ESO HQ, Garching, Germany) and Jason Spyromilio (Paranal Observatory, Chile). Chris Lidman (La Silla Observatory, Chile) and Isobel Hook (formerly ESO HQ, now Royal Observatory, Edinburgh, UK) are members of the "Supernova Cosmology Project" (see URL: http://www-supernova.lbl.gov/). The astronomers mostly used the ESO 3.6-m and 3.6-m NTT telescopes at La Silla for these research programmes. [2] In astronomy, the redshift (z) denotes the fraction by which the lines in the spectrum of an object are shifted towards longer wavelengths. The observed redshift of a distant galaxy or quasar gives a direct estimate of the universal expansion (i.e. the "recession velocity"). Since this expansion rate increases with the distance, the velocity is itself a function (the Hubble relation) of the distance to the object. For instance, a redshift of z = 0.1 corresponds to a velocity of 30,000 km/sec, and assuming a Hubble constant of 20 km/sec per million light-years, to a distance of about 1,500 million light-years. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

Why is the VLT Very Efficient?

NASA Astrophysics Data System (ADS)

Comerón, F.

2009-09-01

The operations model of the ESO Very Large Telescope (VLT) heavily relies on a full-scale implementation of Service Mode observing. In this contribution we review the main features of ESO's approach to Service Mode at the VLT, we outline the advantages offered by this mode, and the challenges faced when implementing it given the wide diversity of instrumentation and instrument modes currently available at the VLT and the VLT Interferometer (VLTI). We give special emphasis to the part of this challenge directly derived from the evolution of the atmospheric conditions, which drive the short-term scheduling of the different scientific programmes competing for the available time.

a Faint and Lonely Brown Dwarf in the Solar Vicinity

NASA Astrophysics Data System (ADS)

1997-04-01

Discovery of KELU-1 Promises New Insights into Strange Objects Brown Dwarfs are star-like objects which are too small to become real stars, yet too large to be real planets. Their mass is too small to ignite those nuclear processes which are responsible for the large energies and high temperatures of stars, but it is much larger than that of the planets we know in our solar system. Until now, very few Brown Dwarfs have been securely identified as such. Two are members of double-star systems, and a few more are located deep within the Pleiades star cluster. Now, however, Maria Teresa Ruiz of the Astronomy Department at Universidad de Chile (Santiago de Chile), using telescopes at the ESO La Silla observatory, has just discovered one that is all alone and apparently quite near to us. Contrary to the others which are influenced by other objects in their immediate surroundings, this new Brown Dwarf is unaffected and will thus be a perfect object for further investigations that may finally allow us to better understand these very interesting celestial bodies. It has been suggested that Brown Dwarfs may constitute a substantial part of the unseen dark matter in our Galaxy. This discovery may therefore also have important implications for this highly relevant research area. Searching for nearby faint stars The story of this discovery goes back to 1987 when Maria Teresa Ruiz decided to embark upon a long-term search (known as the Calan-ESO proper-motion survey ) for another type of unusual object, the so-called White Dwarfs , i.e. highly evolved, small and rather faint stars. Although they have masses similar to that of the Sun, such stars are no larger than the Earth and are therefore extremely compact. They are particularly interesting, because they most probably represent the future end point of evolution of our Sun, some billions of years from now. For this project, the Chilean astronomer obtained large-field photographic exposures with the 1-m ESO Schmidt telescope at La Silla, each covering a sky area of 5 o.5 x 5 o.5. When comparing plates of the same sky field obtained at time intervals of several years [1] , she was able to detect, among the hundreds of thousands of stellar images on the plates, a few faint ones whose positions had changed a little in the meantime. The search technique is based on the fact that such a shift is a good indicator of the object being relatively nearby. It must therefore also be intrinsically faint, i.e. a potential White Dwarf candidate. On every pair of plates, approximately twenty faint moving objects were detected with proper motions [2] of more than 0.25 arcsec per year. Indeed, follow-up spectroscopic observations showed that about 20 percent of these or about four per plate were White Dwarfs. Until now, a total of forty new White Dwarfs have been discovered during this very successful project, i.e. over ten times more than originally expected. And then - a Brown Dwarf! Caption to ESO PR Photo 11/97 [JPEG, 144k] ESO Press Photo 11/97 When checking two plates with a time inverval of 11 years, Maria Teresa Ruiz earlier this year discovered a very faint object in the southern constellation of Hydra (The Water-Snake), moving at 0.35 arcsec per year (cf. ESO Press Photo 11/97). In order to establish its true nature, she obtained its spectrum (in the visual to near-infrared region from wavelengths 450-1000 nm) on March 15 using the ESO 3.6-m telescope and the EFOSC1 spectrograph. Caption to ESO PR Photo 12/97 [GIF, 35k] ESO Press Photo 12/97 To her great surprise, the spectrum was of a type never seen before and certainly not that of a White Dwarf or any other easily identifiable type of star (cf. ESO Press Photo 12/97). In particular, there were no signs of spectral bands of titanium oxide (TiO) or vanadium oxide (VO) which are common in very cool stars, nor of the spectral lines seen in White Dwarfs. On the other hand, an absorption line of the short-lived element lithium was identified, as well as a hydrogen line in emission. However, when the colour of this mysterious object was measured in different wavebands, it was found to be very red and quite similar to that of one of the two known Brown Dwarfs in double star systems. The presence of the lithium line in the spectrum is also an indication that it might be of that type. The astronomer now decided to give the new object the name KELU-1 ; this word means `red' in the language of the Mapuche people, the ancient population in the central part of Chile. Its visual magnitude is 22.3, i.e. more than 3 million times fainter than what can be seen with the unaided eye. In early April, additional infrared observations with the UKIRT (UK Infrared Telescope) on Mauna Kea (Hawaii) by Sandra K. Leggett (Joint Astrophysical Centre, Hilo, Hawaii, USA) confirmed the Brown Dwarf nature of KELU-1, in particular through the unambiguous detection of Methane (CH 4 ) bands in its spectrum. The nature of Brown Dwarfs Brown Dwarfs are first of all characterised by their low mass. When a body of such a small mass is formed in an interstellar cloud and subsequently begins to contract, its temperature at the centre will rise, but it will never reach a level that is sufficient to ignite the nuclear burning of hydrogen to helium, the process that it is main source of energy in the Sun and most other stars. The Brown Dwarf will just continue to contract, more and more slowly, and it will eventually fade from view. This is also the reason that some astronomers consider Brown Dwarfs in the Milky Way and other galaxies as an important component of the `dark matter' whose presence is infered from other indirect measurements but has never been directly observed. It is assumed that the mass limit that separates nuclear-burning stars and slowly contracting Brown Dwarfs is at about 90 times the mass of the giant planet Jupiter, or 8 percent of that of the Sun. KELU-1: a great opportunity for Brown Dwarf studies Assuming that KELU-1 is identical to other known Brown Dwarfs, its measured characteristics indicate that it must be located at a distance of only 10 parsecs, that is about 33 light-years, from the solar system. Its temperature is obviously below 1700 degrees C (where TiO and VO condense as dust grains [3] so that the spectral lines of these molecules are no longer seen). Its mass can be no more than 75 times that of Jupiter, or 6 percent of that of the Sun. During recent years, several Brown Dwarf candidates have been de-masked as low-mass stars and only recently a few Brown Dwarfs were identified in the Pleiades star cluster. Those Brown Dwarfs are quite young and therefore comparatively hotter and brighter. Contrarily, KELU-1 is most probably somewhat older and its unique location so close to us greatly facilitates future investigations. Moreover, it is not at all `disturbed' by the presence of other objects in its immediate surroundings, as this is the case for all other known objects of this type. It will now be important to obtain accurate measurements of KELU-1's parallax , that is, the small annual change of its position in the sky that is caused by the Earth's motion around the Sun and thus the viewing angle of an Earth-based observer. This should be possible within the next year. Moreover, high resolution spectral investigations with large telescope facilities, soon to include the ESO Very Large Telescope at the Paranal observatory in northern Chile, will now for the first time enable us to investigate the processes that take place in the relatively cold upper layers of Brown Dwarfs. For instance, the observed presence of lithium shows that its atmosphere must be different from that of low-mass stars. KELU-1 and the `Dark Matter' From the fact that KELU-1 is so faint that it was barely detectable on the ESO Schmidt plates, it is possible to estimate that the total volume so far surveyed for this type of objects by this research programme is rather small, only about 23 cubic parsecs (800 cubic light-years). A further consideration of the search statistics indicates that less than 10 percent of the Brown Dwarfs present in the surveyed volume would have been found. This translates into a local density of about 0.4 such objects per cubic parsec. Although the mass density of Brown Dwarfs derived from this estimate is insufficient to constitute all the `dark matter' in the Milky Way Galaxy, it is consistent with the most recent estimates of the local mass density, both observed and as infered from dynamical considerations of the motions of stars in the solar neighborhood. Notes: [1] This is done by means of a so-called blink-comparator , an optical device in which the two plates are placed. A tilting mirror allows to view the same sky field alternately on the two plates. Any celestial object that has changed its position will appear to `jump' back and forth and can thus be identified. [2] A proper motion in the sky of 0.25 arcsec/year corresponds to a transversal speed of about 12 km/sec if the object is located at a distance of 10 parsec, or 32.6 light-years. The largest known proper motion of an object outside the solar system is that of Barnard's Star at about 10 arcsec/year. [3] For instance, as the mineral perovskite . How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

Shedding Light on the Cosmic Skeleton

NASA Astrophysics Data System (ADS)

2009-11-01

Astronomers have tracked down a gigantic, previously unknown assembly of galaxies located almost seven billion light-years away from us. The discovery, made possible by combining two of the most powerful ground-based telescopes in the world, is the first observation of such a prominent galaxy structure in the distant Universe, providing further insight into the cosmic web and how it formed. "Matter is not distributed uniformly in the Universe," says Masayuki Tanaka from ESO, who led the new study. "In our cosmic vicinity, stars form in galaxies and galaxies usually form groups and clusters of galaxies. The most widely accepted cosmological theories predict that matter also clumps on a larger scale in the so-called 'cosmic web', in which galaxies, embedded in filaments stretching between voids, create a gigantic wispy structure." These filaments are millions of light years long and constitute the skeleton of the Universe: galaxies gather around them, and immense galaxy clusters form at their intersections, lurking like giant spiders waiting for more matter to digest. Scientists are struggling to determine how they swirl into existence. Although massive filamentary structures have been often observed at relatively small distances from us, solid proof of their existence in the more distant Universe has been lacking until now. The team led by Tanaka discovered a large structure around a distant cluster of galaxies in images they obtained earlier. They have now used two major ground-based telescopes to study this structure in greater detail, measuring the distances from Earth of over 150 galaxies, and, hence, obtaining a three-dimensional view of the structure. The spectroscopic observations were performed using the VIMOS instrument on ESO's Very Large Telescope and FOCAS on the Subaru Telescope, operated by the National Astronomical Observatory of Japan. Thanks to these and other observations, the astronomers were able to make a real demographic study of this structure, and have identified several groups of galaxies surrounding the main galaxy cluster. They could distinguish tens of such clumps, each typically ten times as massive as our own Milky Way galaxy - and some as much as a thousand times more massive - while they estimate that the mass of the cluster amounts to at least ten thousand times the mass of the Milky Way. Some of the clumps are feeling the fatal gravitational pull of the cluster, and will eventually fall into it. "This is the first time that we have observed such a rich and prominent structure in the distant Universe," says Tanaka. "We can now move from demography to sociology and study how the properties of galaxies depend on their environment, at a time when the Universe was only two thirds of its present age." The filament is located about 6.7 billion light-years away from us and extends over at least 60 million light-years. The newly uncovered structure does probably extend further, beyond the field probed by the team, and hence future observations have already been planned to obtain a definite measure of its size. More information This research was presented in a paper published as a letter in the Astronomy & Astrophysics Journal: The spectroscopically confirmed huge cosmic structure at z = 0.55, by Tanaka et al. The team is composed of Masayuki Tanaka (ESO), Alexis Finoguenov (Max-Planck-Institute for Extraterrestrial Physics, Garching, Germany and University of Maryland, Baltimore, USA), Tadayuki Kodama (National Astronomical Observatory of Japan, Tokyo, Japan), Yusei Koyama (Department of Astronomy, University of Tokyo, Japan), Ben Maughan (H.H. Wills Physics Laboratory, University of Bristol, UK) and Fumiaki Nakata (Subaru Telescope, National Astronomical Observatory of Japan). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Pedagogising Poverty Alleviation: A Discourse Analysis of Educational and Social Policies in Argentina and Chile

ERIC Educational Resources Information Center

Rambla, Xavier; Veger, Antoni

2009-01-01

For the past decades international organisations and governments have promoted and implemented analogous education policies on the grounds that education is the key factor to foster development and fight poverty. This article sets the context of these educational programmes and analyses their discourse on poverty in Argentina and Chile. Then, it…

Reviews of National Policies for Education: Quality Assurance in Higher Education in Chile 2013

ERIC Educational Resources Information Center

OECD Publishing (NJ3), 2013

2013-01-01

Growth and diversity have characterised higher education in OECD countries for fifty years. Chile is no exception and has experienced dramatic increases in the number of students, the range of institutions and the programmes that they offer. But wider participation and diversification are only part of the story. Chilean society remains highly…

The Gaia-ESO Survey: Empirical determination of the precision of stellar radial velocities and projected rotation velocities

NASA Astrophysics Data System (ADS)

Jackson, R. J.; Jeffries, R. D.; Lewis, J.; Koposov, S. E.; Sacco, G. G.; Randich, S.; Gilmore, G.; Asplund, M.; Binney, J.; Bonifacio, P.; Drew, J. E.; Feltzing, S.; Ferguson, A. M. N.; Micela, G.; Neguerela, I.; Prusti, T.; Rix, H.-W.; Vallenari, A.; Alfaro, E. J.; Allende Prieto, C.; Babusiaux, C.; Bensby, T.; Blomme, R.; Bragaglia, A.; Flaccomio, E.; Francois, P.; Hambly, N.; Irwin, M.; Korn, A. J.; Lanzafame, A. C.; Pancino, E.; Recio-Blanco, A.; Smiljanic, R.; Van Eck, S.; Walton, N.; Bayo, A.; Bergemann, M.; Carraro, G.; Costado, M. T.; Damiani, F.; Edvardsson, B.; Franciosini, E.; Frasca, A.; Heiter, U.; Hill, V.; Hourihane, A.; Jofré, P.; Lardo, C.; de Laverny, P.; Lind, K.; Magrini, L.; Marconi, G.; Martayan, C.; Masseron, T.; Monaco, L.; Morbidelli, L.; Prisinzano, L.; Sbordone, L.; Sousa, S. G.; Worley, C. C.; Zaggia, S.

2015-08-01

Context. The Gaia-ESO Survey (GES) is a large public spectroscopic survey at the European Southern Observatory Very Large Telescope. Aims: A key aim is to provide precise radial velocities (RVs) and projected equatorial velocities (vsini) for representative samples of Galactic stars, which will complement information obtained by the Gaia astrometry satellite. Methods: We present an analysis to empirically quantify the size and distribution of uncertainties in RV and vsini using spectra from repeated exposures of the same stars. Results: We show that the uncertainties vary as simple scaling functions of signal-to-noise ratio (S/N) and vsini, that the uncertainties become larger with increasing photospheric temperature, but that the dependence on stellar gravity, metallicity and age is weak. The underlying uncertainty distributions have extended tails that are better represented by Student's t-distributions than by normal distributions. Conclusions: Parametrised results are provided, which enable estimates of the RV precision for almost all GES measurements, and estimates of the vsini precision for stars in young clusters, as a function of S/N, vsini and stellar temperature. The precision of individual high S/N GES RV measurements is 0.22-0.26 km s-1, dependent on instrumental configuration. Based on observations collected with the FLAMES spectrograph at VLT/UT2 telescope (Paranal Observatory, ESO, Chile), for the Gaia- ESO Large Public Survey (188.B-3002).Full Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/580/A75

A Long Expected Party — The First Stone Ceremony for the Extremely Large Telescope

NASA Astrophysics Data System (ADS)

de Zeeuw, T.; Comerón, F.; Tamai, R.

2017-06-01

The ceremony to seal the time capsule, signalling the beginning of construction of the dome and main telescope structure for the Extremely Large Telescope, took place at the Paranal Observatory on 26 May 2017, in the presence of the President of Chile, Michelle Bachelet and many international guests. Owing to high winds, the ceremony could not take place as planned on the levelled site on Cerro Armazones, but instead was held at the Paranal Residencia. A brief report of the event and its organisation is presented, and the welcome speech by the ESO Director General is included.

VizieR Online Data Catalog: Stellar mass of brightest cluster galaxies (Bellstedt+, 2016)

NASA Astrophysics Data System (ADS)

Bellstedt, S.; Lidman, C.; Muzzin, A.; Franx, M.; Guatelli, S.; Hill, A. R.; Hoekstra, H.; Kurinsky, N.; Labbe, I.; Marchesini, D.; Marsan, Z. C.; Safavi-Naeini, M.; Sifon, C.; Stefanon, M.; van de Sande, J.; van Dokkum, P.; Weigel, C.

2017-11-01

We utilize a sample of 98 newly imaged galaxy clusters from the RELICS (REd Lens Infrared Cluster Survey) survey within this study. The data were collected during six observing runs on three instruments over a period spanning from 2013 October to 2015 March. The instruments utilized were the SofI2 camera on the New Technology Telescope at the European Southern Observatory (ESO) La Silla Observatory in Chile, WHIRC3 on the WIYN telescope at the Kitt Peak National Observatory and LIRIS4 on the William Herschel Telescope (WHT) in La Palma, Spain. (2 data files).

VizieR Online Data Catalog: Abundances of Population II stars in NGC 6397 (Lind+, 2008)

NASA Astrophysics Data System (ADS)

Lind, K.; Korn, A. J.; Barklem, P. S.; Grundahl, F.

2010-03-01

The target selection for the spectroscopic study is based on Stroemgren uvby photometry. The photometric observations were collected with the DFOSC instrument on the 1.5m telescope on La Silla, Chile, in 1997. Additional BVI photometric data were obtained in 2005. All spectroscopic data were collected in Service Mode, with the fibre-fed, multi-object, medium-high resolution spectrograph FLAMES/GIRAFFE at ESO-VLT. FLAMES allows for 132 objects to be observed simultaneously, with GIRAFFE in MEDUSA mode, between 2005 Mar 23 and Apr 04. (2 data files).

First Temperate Exoplanet Sized Up

NASA Astrophysics Data System (ADS)

2010-03-01

Combining observations from the CoRoT satellite and the ESO HARPS instrument, astronomers have discovered the first "normal" exoplanet that can be studied in great detail. Designated Corot-9b, the planet regularly passes in front of a star similar to the Sun located 1500 light-years away from Earth towards the constellation of Serpens (the Snake). "This is a normal, temperate exoplanet just like dozens we already know, but this is the first whose properties we can study in depth," says Claire Moutou, who is part of the international team of 60 astronomers that made the discovery. "It is bound to become a Rosetta stone in exoplanet research." "Corot-9b is the first exoplanet that really does resemble planets in our solar system," adds lead author Hans Deeg. "It has the size of Jupiter and an orbit similar to that of Mercury." "Like our own giant planets, Jupiter and Saturn, the planet is mostly made of hydrogen and helium," says team member Tristan Guillot, "and it may contain up to 20 Earth masses of other elements, including water and rock at high temperatures and pressures." Corot-9b passes in front of its host star every 95 days, as seen from Earth [1]. This "transit" lasts for about 8 hours, and provides astronomers with much additional information on the planet. This is fortunate as the gas giant shares many features with the majority of exoplanets discovered so far [2]. "Our analysis has provided more information on Corot-9b than for other exoplanets of the same type," says co-author Didier Queloz. "It may open up a new field of research to understand the atmospheres of moderate- and low-temperature planets, and in particular a completely new window in our understanding of low-temperature chemistry." More than 400 exoplanets have been discovered so far, 70 of them through the transit method. Corot-9b is special in that its distance from its host star is about ten times larger than that of any planet previously discovered by this method. And unlike all such exoplanets, the planet has a temperate climate. The temperature of its gaseous surface is expected to be between 160 degrees and minus twenty degrees Celsius, with minimal variations between day and night. The exact value depends on the possible presence of a layer of highly reflective clouds. The CoRoT satellite, operated by the French space agency CNES [3], identified the planet after 145 days of observations during the summer of 2008. Observations with the very successful ESO exoplanet hunter - the HARPS instrument attached to the 3.6-metre ESO telescope at La Silla in Chile - allowed the astronomers to measure its mass, confirming that Corot-9b is indeed an exoplanet, with a mass about 80% the mass of Jupiter. This finding is being published in this week's edition of the journal Nature. Notes [1] A planetary transit occurs when a celestial body passes in front of its host star and blocks some of the star's light. This type of eclipse causes changes in the apparent brightness of the star and enables the planet's diameter to be measured. Combined with radial velocity measurements made by the HARPS spectrograph, it is also possible to deduce the mass and, hence, the density of the planet. It is this combination that allows astronomers to study this object in great detail. The fact that it is transiting - but nevertheless not so close to its star to be a "hot Jupiter" - is what makes this object uniquely well suited for further studies. [2] Temperate gas giants are, so far, the largest known group of exoplanets discovered. [3] The CoRoT (Convection, Rotation and Transits) space telescope was constructed by CNES, with contributions from Austria, Germany, Spain, Belgium, Brazil and the European Space Agency (ESA). It was specifically designed to detect transiting exoplanets and carry out seismological studies of stars. Its results are supplemented by observations with several ground-based telescopes, among them the IAC-80 (Teide Observatory), the Canada France Hawaii Telescope (Hawaii), the Isaac Newton Telescope (Roque de los Muchachos Observatory), Wise Observatory (Israel), the Faulkes North Telescope of the Las Cumbres Observatory Global Telescope Network (Hawaii) and the ESO 3.6-metre telescope (Chile). More information This research was presented in a paper published this week in Nature ("A transiting giant planet with a temperature between 250 K and 430 K"), by H. J. Deeg et al. The team is composed of H.J. Deeg, B. Tingley, J.M. Almenara, and M. Rabus (Instituto de Astrofısica de Canarias, Tenerife, Spain), C. Moutou, P. Barge, A. S. Bonomo, M. Deleuil, J.-C. Gazzano, L. Jorda, and A. Llebaria (Laboratoire d'Astrophysique de Marseille, Université de Provence, CNRS, OAMP, France), A. Erikson, Sz. Csizmadia, J. Cabrera, P. Kabath, H. Rauer (Institute of Planetary Research, German Aerospace Center, Berlin, Germany), H. Bruntt, M. Auvergne, A. Baglin, D. Rouan, and J. Schneider (Observatoire de Paris-Meudon, France), S. Aigrain and F. Pont (University of Exeter, UK), R. Alonso, C. Lovis, M. Mayor, F. Pepe, D. Queloz, and S. Udry (Observatoire de l'Université de Genève, Switzerland), M. Barbieri (Università di Padova, Italia), W. Benz (Universität Bern, Switzerland), P. Bordé, A. Léger, M. Ollivier, and B. Samuel (Institut d'Astrophysique Spatiale, Université Paris XI, Orsay, France), F. Bouchy and G. Hébrard (IAP, Paris, France), L. Carone and M. Pätzold (Rheinisches Institut für Umweltforschung an der Universität zu Köln, Germany), S. Carpano, M. Fridlund, P. Gondoin, and R. den Hartog (ESTEC/ESA, Noordwijk, The Netherlands), D. Ciardi (NASA Exoplanet Science Institute/Caltech, USA), R. Dvorak (University of Vienna, Austria), S. Ferraz-Mello (Universidade de São Paulo, Brasil), D. Gandolfi, E. Guenther, A. Hatzes, G. Wuchterl, B. Stecklum (Thüringer Landessternwarte, Tautenburg, Germany), M. Gillon (University of Liège, Belgium), T. Guillot and M. Havel (Observatoire de la Côte d' Azur, Nice, France), M. Hidas, T. Lister, and R. Street (Las Cumbres Observatory Global Telescope Network, Santa Barbara, USA), H. Lammer and J. Weingrill (Space Research Institute, Austrian Academy of Science), and T. Mazeh and A. Shporer (Tel Aviv University, Israel). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

First Images from VLT Science Verification Programme

NASA Astrophysics Data System (ADS)

1998-09-01

Two Weeks of Intensive Observations Successfully Concluded After a period of technical commissioning tests, the first 8.2-m telescope of the ESO VLT (UT1) has successfully performed an extensive series of "real science" observations , yielding nearly 100 hours of precious data. They concern all possible types of astronomical objects, from distant galaxies and quasars to pulsars, star clusters and solar system objects. This intensive Science Verification (SV) Programme took place as planned from August 17 to September 1, 1998, and was conducted by the ESO SV Team at the VLT Observatory on Paranal (Chile) and at the ESO Headquarters in Garching (Germany). The new giant telescope lived fully up to the high expectations and worked with spectacular efficiency and performance through the entire period. All data will be released by September 30 via the VLT archive and the web (with some access restrictions - see below). The Science Verification period Just before the beginning of the SV period, the 8.2-m primary mirror in its cell was temporarily removed in order to install the "M3 tower" with the tertiary mirror [1]. The reassembly began on August 15 and included re-installation at the Cassegrain focus of the VLT Test Camera that was also used for the "First Light" images in May 1998. After careful optical alignment and various system tests, the UT1 was handed over to the SV Team on August 17 at midnight local time. The first SV observations began immediately thereafter and the SV Team was active 24 hours a day throughout the two-week period. Video-conferences between Garching and Paranal took place every day at about noon Garching time (6 o'clock in the morning on Paranal). Then, while the Paranal observers were sleeping, data from the previous night were inspected and reduced in Garching, with feedback on what was best to do during the following night being emailed to Paranal several hours in advance of the beginning of the observations. The campaign ended in the morning of September 1 when the telescope was returned to the Commissioning Team that has since continued its work. The FORS instrument is now being installed and the first images from this facility are expected shortly. Observational circumstances During the two-week SV period, a total of 154 hours were available for astronomical observations. Of these, 95 hours (62%) were used to collect scientific data, including calibrations, e.g. flat-fielding and photometric standard star observations. 15 hours (10%) were spent to solve minor technical problems, while another 44 hours (29%) were lost due to adverse meteorological conditions (clouds or wind exceeding 15 m/sec). The amount of telescope technical downtime is very small at this moment of the UT1 commissioning. This fact provides an impressive indication of high technical reliability that has been achieved and which will be further consolidated during the next months. The meteorological conditions that were encountered at Paranal during this period were unfortunately below average, when compared to data from the same calendar period in earlier years. There was an excess of bad seeing and fewer good seeing periods than normal; see, however, ESO PR Photo 35c/98 with 0.26 arcsec image quality. Nevertheless, the measured image quality on the acquired frames was often better than the seeing measured outside the enclosure by the Paranal seeing monitor. Part of this very positive effect is due to "active field stabilization" , now performed during all observations by rapid motion (10 - 70 times per second) of the 1.1-m secondary mirror of beryllium (M2) and compensating for the "twinkling" of stars. Science Verification data soon to be released A great amount of valuable data was collected during the SV programme. The available programme time was distributed as follows: Hubble Deep Field - South [HDF-S; NICMOS and STIS Fields] (37.1 hrs); Lensed QSOs (3.2 hrs); High-z Clusters (6.2 hrs); Host Galaxies of Gamma-Ray Bursters (2.1 hrs); Edge-on Galaxies (7.4 hrs); Globular cluster cores (6.7 hrs); QSO Hosts (4.4 hrs); TNOs (3.4 hrs); Pulsars (1.3 hrs); Calibrations (22.7 hrs). All of the SV data are now in the process of being prepared for public release by September 30, 1998 to the ESO and Chilean astronomical communities. It will be possible to retrieve the data from the VLT archive, and a set of CDs will be distributed to all astronomical research institutes within the ESO member states and Chile. Moreover, data obtained on the HDF-S will become publicly available worldwide, and retrievable from the VLT archive. Updated information on this data release can be found on the ESO web site at http://www.eso.org/vltsv/. It is expected that the first scientific results based on the SV data will become available in the course of October and November 1998. First images from the Science Verification programme This Press Release is accompanied by three photos that reproduce some of the images obtained during the SV period. ESO PR Photo 35a/98 ESO PR Photo 35a/98 [Preview - JPEG: 671 x 800 pix - 752k] [High-Res - JPEG: 2518 x 3000 pix - 5.8Mb] This colour composite was constructed from the U+B, R and I Test Camera Images of the Hubble Deep Field South (HDF-S) NICMOS field. These images are displayed as blue, green and red, respectively. The first photo is a colour composite of the HDF-S NICMOS sky field that combines exposures obtained in different wavebands: ultraviolet (U) + blue (B), red (R) and near-infrared (I). For all of them, the image quality is better than 0.9 arcsec. Most of the objects seen in the field are distant galaxies. The image is reproduced in such a way that it shows the faintest features scaled, while rendering the image of the star below the large spiral galaxy approximately white. The spiral galaxy is displayed in such a way that the internal structure is visible. A provisional analysis has shown that limiting magnitudes that were predicted for the HDF-S observations (27.0 - 28.5, depending on the band), were in fact reached. Technical information : Photo 35a/98 is based on 16 U-frames (~370 nm; total exposure time 17800 seconds; mean seeing 0.71 arcsec) and 15 B-frames (~430 nm; 10200 seconds; 0.71 arcsec) were added and combined with 8 R frames (~600 nm; 7200 seconds; 0.49 arcsec) and 12 I-frames (~800 nm; 10150 seconds; 0.59 arcsec) to make this colour composite. Individual frames were flat-fielded and cleaned for cosmics before combination. The field shown measures 1.0 x 1.0 arcmin. North is up; East is to the left. ESO PR Photo 35b/98 ESO PR Photo 35b/98 [Preview - JPEG: 679 x 800 pix - 760k] [High-Res - JPEG: 2518 x 3000 pix - 5.7Mb] The colour composite of the HDF-S NICMOS field constructed by combining VLT Test Camera images in U+B and R bands with a HST NICMOS near-IR H-band exposure. These images are displayed as blue, green and red, respectively. The NICMOS image was smoothed to match the angular resolution of the R-band VLT image. The boundary of the NICMOS image is also shown. The next photo is similar to the first one, but uses a near-IR frame obtained with the Hubble Space Telescope NICMOS instrument instead of the VLT I-frame. The HST image has nearly the same total exposure time as the VLT images. Their combination is meaningful since the VLT and NICMOS images reach similar depths and show more or less the same faint objects. This is the result of several effects compensating each other: while more distant galaxies are redder and therefore better visible at the infrared waveband of the NICMOS image and this image has a better angular resolution than those from the VLT, the collecting area of the UT1 mirror is over 11 times larger than that of the HST. It is interesting to note that all objects in the NICMOS image are also visible in the VLT images, with the exception of the very red object just left of the face-on spiral. The bright red object near the bottom has not before been detected in optical images (to the limit of R ~ 26 mag), but is clearly present in all the VLT Test Camera coadded images, with the exception of the U-band image. Both of these very red objects are possibly extremely distant, elliptical galaxies [2]. The additional information that can be obtained from the combination of the VLT and the infrared NICMOS images has an immediate bearing on the future work with the VLT. When the infrared, multi-mode ISAAC instrument enters into operation in early 1999, it will be able to obtain spectra of such objects and, in general, to deliver very deep infrared images. Thus, the combination of visual (from FORS) and infrared (from ISAAC) images and spectra promises to become an extremely powerful tool that will allow the detection of very red and therefore exceedingly distant galaxies. Moreover, it is obvious that this sky field is not very crowded - much longer exposure times will thus be possible without encountering serious problems of overlapping objects at the "confusion limit". Technical information : Photo 35b/98 is based on 16 U-frames (~370 nm; total exposure time 17800 seconds; mean seeing 0.71 arcsec) and 15 B-frames (~430 nm; 10200 seconds; 0.71 arcsec) were added and combined with 8 R frames (~600 nm; 7200 seconds; 0.49 arcsec) as well as a HST/NICMOS H-band frame(a H-band HST/NICMOS image from the ST-ECF public archive) (~1600 nm; 7040 seconds; 0.2 arcsec) to make this colour composite. Individual frames were flat-fielded and cleaned for cosmics before combination. The field shown measures 1.0 x 1.0 arcmin. North is up; East is to the left. ESO PR Photo 35c/98 ESO PR Photo 35c/98 [Preview - JPEG: 654 x 800 pix - 280k] [High-Res - JPEG: 2489 x 3000 pix - 2.6Mb] Coaddition of two R-band images of edge-on galaxy ESO342-G017 , obtained with 0.26 arcsec image quality. The galaxy ESO342-G017 was observed on August 19, 1998 during a spell of excellent observing conditions. Two exposures, each lasting 120 seconds, were taken through a red filtre to produce this photo. The quality of the original images is excellent, with seeing (FWHM) of only 0.26 arcsec measured on the stars in the frame. ESO342-G017 is an Sc-type spiral galaxy seen edge-on, and the Test Camera was rotated so that the disk of the galaxy appears horizontal in the figure. Thanks to the image quality, the photo shows much detail in the rather flat disk, including a very thin, obscuring dust band and some brighter knots, most probably star-forming regions. This galaxy is located well outside the Milky Way band in the southern constellation of Sagittarius. Its distance is about 400 million light-years (recession velocity about 7,700 km/sec). A number of more distant galaxies are seen in the background on this short exposure. Technical information : Photo 35c/98 is a reproduced from a composite of two 120-second exposures in the red R-band (~600 nm) of the edge-on galaxy ESO342-G017, both with 0.26 arcsec image quality. The frames were flat-fielded and cleaned for cosmics before combination. The field shown measures 1.5 x 1.5 arcmin. North is inclined 38 o clockwise from the top, East is to the left. Notes: [1] The flat and elliptically shaped, tertiary mirror M3 is mounted on top of the M3 Tower that is fixed in the center of the M1 Cell. The tower can rotate along its axis and deflects the light coming from the M2 mirror to the astronomical instruments on either Nasmyth platform. A mechanism at the top of the M3 Tower is used to move the M3 mirror away from the optical path when the instrument at the Cassegrain focus is used, e.g. the Test Camera during the SV observations. [2] This effect is due to the fact that the more distant a galaxy is, the larger is the velocity with which it recedes from us (Hubble's law). The larger the velocity, the further its emitted light will be shifted redwards in the observed spectrum (the Doppler effect) and the redder its image will appear to us. By comparing the brightness of a distant galaxy in different wavebands (measuring its colour), it is therefore in practice possible to estimate its redshift and thus its distance (the " photometric redshift" method). How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

The Araucaria Project: The Distance to the Fornax Dwarf Galaxy from Near-infrared Photometry of RR Lyrae Stars

NASA Astrophysics Data System (ADS)

Karczmarek, Paulina; Pietrzyński, Grzegorz; Górski, Marek; Gieren, Wolfgang; Bersier, David

2017-12-01

We have obtained single-phase near-infrared (NIR) magnitudes in the J and K bands for 77 RR Lyrae (RRL) stars in the Fornax Dwarf Spheroidal Galaxy. We have used different theoretical and empirical NIR period-luminosity-metallicity calibrations for RRL stars to derive their absolute magnitudes, and found a true, reddening-corrected distance modulus of 20.818+/- 0.015{{(statistical)}}+/- 0.116{{(systematic)}} mag. This value is in excellent agreement with the results obtained within the Araucaria Project from the NIR photometry of red clump stars (20.858 ± 0.013 mag), the tip of the red giant branch (20.84+/- 0.04+/- 0.14 mag), as well as with other independent distance determinations to this galaxy. The effect of metallicity and reddening is substantially reduced in the NIR domain, making this method a robust tool for accurate distance determination at the 5% level. This precision is expected to reach the level of 3% once the zero points of distance calibrations are refined thanks to the Gaia mission. NIR period-luminosity-metallicity relations of RRL stars are particularly useful for distance determinations to galaxies and globular clusters up to 300 kpc, that lack young standard candles, like Cepheids. Based on data collected with the VLT/HAWK-I instrument at ESO Paranal Observatory, Chile, as a part of programme 082.D-0123(B).

A Universal Design Approach to Government Service Delivery: The Case of ChileAtiende.

PubMed

Sandoval, Leonardo

2016-01-01

A common challenge for government administrations that aim to improve the delivery of information and services to citizens is to go beyond a government-centred approach. By focusing on citizens and the needs of a wide range of citizens, Universal Design (UD) can help to increase the effectiveness, efficiency and satisfaction of government services. This paper examines the case of an internationally recognised Chilean government service delivery programme inspired by UD principles known as ChileAtiende ("ChileService"). A brief account of its creation and current status is provided.

Exoplanet Caught on the Move

NASA Astrophysics Data System (ADS)

2010-06-01

For the first time, astronomers have been able to directly follow the motion of an exoplanet as it moves from one side of its host star to the other. The planet has the smallest orbit so far of all directly imaged exoplanets, lying almost as close to its parent star as Saturn is to the Sun. Scientists believe that it may have formed in a similar way to the giant planets in the Solar System. Because the star is so young, this discovery proves that gas giant planets can form within discs in only a few million years, a short time in cosmic terms. Only 12 million years old, or less than three-thousandths of the age of the Sun, Beta Pictoris is 75% more massive than our parent star. It is located about 60 light-years away towards the constellation of Pictor (the Painter) and is one of the best-known examples of a star surrounded by a dusty debris disc [1]. Earlier observations showed a warp of the disc, a secondary inclined disc and comets falling onto the star. "Those were indirect, but tell-tale signs that strongly suggested the presence of a massive planet, and our new observations now definitively prove this," says team leader Anne-Marie Lagrange. "Because the star is so young, our results prove that giant planets can form in discs in time-spans as short as a few million years." Recent observations have shown that discs around young stars disperse within a few million years, and that giant planet formation must occur faster than previously thought. Beta Pictoris is now clear proof that this is indeed possible. The team used the NAOS-CONICA instrument (or NACO [2]), mounted on one of the 8.2-metre Unit Telescopes of ESO's Very Large Telescope (VLT), to study the immediate surroundings of Beta Pictoris in 2003, 2008 and 2009. In 2003 a faint source inside the disc was seen (eso0842), but it was not possible to exclude the remote possibility that it was a background star. In new images taken in 2008 and spring 2009 the source had disappeared! The most recent observations, taken during autumn 2009, revealed the object on the other side of the disc after a period of hiding either behind or in front of the star (in which case it is hidden in the glare of the star). This confirmed that the source indeed was an exoplanet and that it was orbiting its host star. It also provided insights into the size of its orbit around the star. Images are available for approximately ten exoplanets, and the planet around Beta Pictoris (designated "Beta Pictoris b") has the smallest orbit known so far. It is located at a distance between 8 and 15 times the Earth-Sun separation - or 8-15 Astronomical Units - which is about the distance of Saturn from the Sun. "The short period of the planet will allow us to record the full orbit within maybe 15-20 years, and further studies of Beta Pictoris b will provide invaluable insights into the physics and chemistry of a young giant planet's atmosphere," says student researcher Mickael Bonnefoy. The planet has a mass of about nine Jupiter masses and the right mass and location to explain the observed warp in the inner parts of the disc. This discovery therefore bears some similarity to the prediction of the existence of Neptune by astronomers Adams and Le Verrier in the 19th century, based on observations of the orbit of Uranus. "Together with the planets found around the young, massive stars Fomalhaut and HR8799, the existence of Beta Pictoris b suggests that super-Jupiters could be frequent byproducts of planet formation around more massive stars," explains Gael Chauvin, a member of the team. Such planets disturb the discs around their stars, creating structures that should be readily observable with the Atacama Large Millimeter/submillimeter Array (ALMA), the revolutionary telescope being built by ESO together with international partners. A few other planetary candidates have been imaged, but they are all located further from their host star than Beta Pictoris b. If located in the Solar System, they all would lie close to or beyond the orbit of the furthest planet, Neptune. The formation processes of these distant planets are likely to be quite different from those in our Solar System and in Beta Pictoris. "The recent direct images of exoplanets - many made by the VLT - illustrate the diversity of planetary systems," says Lagrange. "Among those, Beta Pictoris b is the most promising case of a planet that could have formed in the same way as the giant planets in our Solar System." Notes [1] Debris discs are composed of dust resulting from collisions among larger bodies such as planetary embryos or asteroids. They are larger versions of the zodiacal dust band in our Solar System. The disc around Beta Pictoris was the first to be imaged and is now known to extend up to about 1000 times the distance between the Earth and the Sun. [2] NACO is an adaptive optics instrument attached to ESO's Very Large Telescope, located in Chile. Thanks to adaptive optics, astronomers can remove most of the blurring effect of the atmosphere and obtain very sharp images. More information This research was presented in a paper to appear this week in Science Express ("A Giant Planet Imaged in the disk of the Young Star Beta Pictoris," by A.-M. Lagrange et al.). The team is composed of A.-M. Lagrange, M. Bonnefoy, G. Chauvin, D. Ehrenreich, and D. Mouillet (Laboratoire d'Astrophysique de l'Observatoire de Grenoble, Université Joseph Fourier, CNRS, France), D. Apai (Space Telescope Science Institute, Baltimore, USA), A. Boccaletti, D. Gratadour, D. Rouan, and S. Lacour (LESIA, Observatoire de Paris-Meudon, France), and M. Kasper (ESO). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Ultraviolet to near-infrared spectroscopy of the potentially hazardous, low delta-V asteroid (175706) 1996 FG3. Backup target of the sample return mission MarcoPolo-R

NASA Astrophysics Data System (ADS)

Perna, D.; Dotto, E.; Barucci, M. A.; Fornasier, S.; Alvarez-Candal, A.; Gourgeot, F.; Brucato, J. R.; Rossi, A.

2013-07-01

Context. Primitive near-Earth asteroids (NEAs) are important subjects of study for current planetary research. Their investigation can provide crucial information on topics such as the formation of the solar system, the emergence of life, and the mitigation of the risk of asteroid impact. Sample return missions from primitive asteroids have been scheduled or are being studied by space agencies, including the MarcoPolo-R mission selected for the assessment study phase of ESA M3 missions. Aims: We want to improve our knowledge of the surface composition and physical nature of the potentially hazardous, low delta-V asteroid (175706) 1996 FG3, backup target of MarcoPolo-R. This intriguing object shows an as-yet unexplained spectral variability. Methods: We performed spectroscopic observations of 1996 FG3 using the visible spectrograph DOLORES at the Telescopio Nazionale Galileo (TNG), and the UV-to-NIR X-Shooter instrument at the ESO Very Large Telescope (VLT). Results: We find featureless spectra and we classify 1996 FG3 as a primitive Xc-type in the Bus-DeMeo taxonomy. Based on literature comparison, we confirm the spectral variability of this object at near-infrared (NIR) wavelengths, and find that spectral variations exist also for the visible spectral region. Phase reddening cannot explain such variations. Obtained with the same observational conditions for the whole 0.3-2.2 μm range, our X-Shooter spectrum allowed a proper comparison with the RELAB meteorite database. A very good fit is obtained with the very primitive C2 Tagish Lake carbonaceous chondrite (pressed powder), confirming 1996 FG3 as a suitable target for a sample return mission from primitive NEAs. Conclusions: We hypothesize a compacted/cemented surface for 1996 FG3, like that observed by the Hayabusa mission on (25143) Itokawa, with the possible presence of regions showing different degrees of surface roughness. This variegation could be related to the binary nature of 1996 FG3, but to check this hypothesis further observations are necessary. Based on observations carried out at the European Southern Observatory (ESO), Chile (programme 088.C-0695), and with the Italian Telescopio Nazionale Galileo (TNG) operated on the island of La Palma by the Fundacion Galileo Galilei of the INAF (Istituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias (programme AOT25/TAC13).

Portugal to Accede to ESO

NASA Astrophysics Data System (ADS)

2000-06-01

The Republic of Portugal will become the ninth member state of the European Southern Observatory (ESO) [1]. Today, during a ceremony at the ESO Headquarters in Garching (Germany), a corresponding Agreement was signed by the Portuguese Minister of Science and Technology, José Mariano Gago and the ESO Director General, Catherine Cesarsky , in the presence of other high officials from Portugal and the ESO member states (see Video Clip 05/00 below). Following subsequent ratification by the Portuguese Parliament of the ESO Convention and the associated protocols [2], it is foreseen that Portugal will formally join this organisation on January 1, 2001. Uniting European Astronomy ESO PR Photo 16/00 ESO PR Photo 16/00 [Preview - JPEG: 400 x 405 pix - 160k] [Normal - JPEG: 800 x 809 pix - 408k] Caption : Signing of the Portugal-ESO Agreement on June 27, 2000, at the ESO Headquarters in Garching (Germany). At the table, the ESO Director General, Catherine Cesarsky , and the Portuguese Minister of Science and Technology, José Mariano Gago . In his speech, the Portuguese Minister of Science and Technology, José Mariano Gago , stated that "the accession of Portugal to ESO is the result of a joint effort by ESO and Portugal during the last ten years. It was made possible by the rapid Portuguese scientific development and by the growth and internationalisation of its scientific community." He continued: "Portugal is fully committed to European scientific and technological development. We will devote our best efforts to the success of ESO". Catherine Cesarsky , ESO Director General since 1999, warmly welcomed the Portuguese intention to join ESO. "With the accession of their country to ESO, Portuguese astronomers will have great opportunities for working on research programmes at the frontiers of modern astrophysics." "This is indeed a good time to join ESO", she added. "The four 8.2-m VLT Unit Telescopes with their many first-class instruments are nearly ready, and the VLT Interferometer will soon follow. With a decision about the intercontinental millimetre-band ALMA project expected next year and the first concept studies for gigantic optical/infrared telescopes like OWL now well under way at ESO, there is certainly no lack of perspectives, also for coming generations of European astronomers!" Portuguese astronomy: a decade of progress The beginnings of the collaboration between Portugal and ESO, now culminating in the imminent accession of that country to the European research organisation, were almost exactly ten years ago. On July 10, 1990, the Republic of Portugal and ESO signed a Co-operation Agreement , aimed at full Portuguese membership of the ESO organisation within the next decade. During the interim period, Portuguese astronomers were granted access to ESO facilities while the Portuguese government would provide support towards the development of astronomy and the associated infrastructure in this country. A joint Portuguese/ESO Advisory Body was set up to monitor the development of Portuguese astronomy and its interaction with ESO. Over the years, an increasing number of measures to strengthen the Portuguese research infrastructure within astrophysics and related fields were proposed and funded. More and more, mostly young Portuguese astronomers began to make use of ESO's facilities at the La Silla observatory and recently, of the Very Large Telescope (VLT) at Paranal. Now, ten years later, the Portuguese astronomical community is the youngest in Europe with more than 90% of its PhD's awarded during the last eight years. As expected, the provisional access to ESO telescopes - especially the Very Large Telescope (VLT) with its suite of state-of-the-art instruments for observations at wavelengths ranging from the UV to the mid-infrared - has proven to be a great incentive to the Portuguese scientists. As a clear demonstration of these positive developments, a very successful Workshop entitled "Portugal - ESO - VLT" was held in Lisbon on April 17-18, 2000. It was primarily directed towards young Portuguese scientists and served to inform them about the ESO Very Large Telescope (VLT) and the steadily evolving, exciting research possibilities with this world-class facility. Notes [1]: Current ESO member countries are Belgium, Denmark, France, Germany, Italy, the Netherlands, Sweden and Switzerland. [2]: The ESO Convention was established in 1962 and specifies the goals of ESO and the means to achieve these, e.g., "The Governments of the States parties to this convention... desirous of jointly creating an observatory equipped with powerful instruments in the Southern hemisphere and accordingly promoting and organizing co-operation in astronomical research..." (from the Preamble to the ESO Convention). Video Clip from the Signing Ceremony

Mission Specific Platforms: Past achievements and future developments in European led ocean research drilling.

NASA Astrophysics Data System (ADS)

Cotterill, Carol; McInroy, David; Stevenson, Alan

2013-04-01

Mission Specific Platform (MSP) expeditions are operated by the European Consortium for Ocean Research Drilling (ECORD). Each MSP expedition is unique within the Integrated Ocean Drilling Program (IODP). In order to complement the abilities of the JOIDES Resolution and the Chikyu, the ECORD Science Operator (ESO) must source vessels and technology suitable for each MSP proposal on a case-by-case basis. The result is that ESO can meet scientific requirements in a flexible manner, whilst maintaining the measurements required for the IODP legacy programme. The process of tendering within EU journals for vessels and technology means that the planning process for each MSP Expedition starts many years in advance of the operational phase. Involvement of proposal proponents from this early stage often leads to the recognition for technological research and development to best meet the scientific aims and objectives. One example of this is the planning for the Atlantis Massif proposal, with collaborative development between the British Geological Survey (BGS) and MARUM, University of Bremen, on suitable instruments for seabed drills, with the European Petrophysics Consortium (EPC) driving the development of suitable wireline logging tools that can be used in association with such seabed systems. Other technological developments being undertaken within the European IODP community include in-situ pressure sampling for gas hydrate expeditions, deep biosphere and fluid sampling equipment and CORK technology. This multi-national collaborative approach is also employed by ESO in the operational phase. IODP Expedition 302 ACEX saw vessel and ice management support from Russia and Sweden to facilitate the first drilling undertaken in Arctic sea ice. A review of MSP expeditions past, present and future reveal the significant impact of European led operations and scientific research within the current IODP programme, and also looking forward to the start of the new International Ocean Discovery Programme in October 2013. Key successes encompass technological development, operational procedures in sensitive areas and research into palaeoclimate and shoreline responses to sea level change amongst others. Increased operational flexibility in the new programme only serves to make the future an exciting one for ocean drilling in Europe.

Milky Way's super-efficient particle accelerators caught in the act

NASA Astrophysics Data System (ADS)

2009-06-01

Thanks to a unique "ballistic study" that combines data from ESO's Very Large Telescope and NASA's Chandra X-ray Observatory, astronomers have now solved a long-standing mystery of the Milky Way's particle accelerators. They show in a paper published today on Science Express that cosmic rays from our galaxy are very efficiently accelerated in the remnants of exploded stars. ESO PR Photo 23a/09 The rim of RCW 86 ESO PR Photo 23b/09 DSS + insert, annotated ESO PR Photo 23c/09 DSS image ESO PR Video 23a/09 Zoom-in RCW 86 During the Apollo flights astronauts reported seeing odd flashes of light, visible even with their eyes closed. We have since learnt that the cause was cosmic rays -- extremely energetic particles from outside the Solar System arriving at the Earth, and constantly bombarding its atmosphere. Once they reach Earth, they still have sufficient energy to cause glitches in electronic components. Galactic cosmic rays come from sources inside our home galaxy, the Milky Way, and consist mostly of protons moving at close to the speed of light, the "ultimate speed limit" in the Universe. These protons have been accelerated to energies exceeding by far the energies that even CERN's Large Hadron Collider will be able to achieve. "It has long been thought that the super-accelerators that produce these cosmic rays in the Milky Way are the expanding envelopes created by exploded stars, but our observations reveal the smoking gun that proves it", says Eveline Helder from the Astronomical Institute Utrecht of Utrecht University in the Netherlands, the first author of the new study. "You could even say that we have now confirmed the calibre of the gun used to accelerate cosmic rays to their tremendous energies", adds collaborator Jacco Vink, also from the Astronomical Institute Utrecht. For the first time Helder, Vink and colleagues have come up with a measurement that solves the long-standing astronomical quandary of whether or not stellar explosions produce enough accelerated particles to explain the number of cosmic rays that hit the Earth's atmosphere. The team's study indicates that they indeed do and it directly tells us how much energy is removed from the shocked gas in the stellar explosion and used to accelerate particles. "When a star explodes in what we call a supernova a large part of the explosion energy is used for accelerating some particles up to extremely high energies", says Helder. "The energy that is used for particle acceleration is at the expense of heating the gas, which is therefore much colder than theory predicts". The researchers looked at the remnant of a star that exploded in AD 185, as recorded by Chinese astronomers. The remnant, called RCW 86, is located about 8200 light-years away towards the constellation of Circinus (the Drawing Compass). It is probably the oldest record of the explosion of a star. Using ESO's Very Large Telescope, the team measured the temperature of the gas right behind the shock wave created by the stellar explosion. They measured the speed of the shock wave as well, using images taken with NASA's X-ray Observatory Chandra three years apart. They found it to be moving at between 10 and 30 million km/h, between 1 and 3 percent the speed of light. The temperature of the gas turned out to be 30 million degrees Celsius. This is quite hot compared to everyday standards, but much lower than expected, given the measured shock wave's velocity. This should have heated the gas up to at least half a billion degrees. "The missing energy is what drives the cosmic rays", concludes Vink. More Information This research was presented in a paper to appear in Science: Measuring the cosmic ray acceleration efficiency of a supernova remnant, by E. A. Helder et al. The team is composed of E.A. Helder, J. Vink and F. Verbunt (Astronomical Institute Utrecht, Utrecht University, The Netherlands), C.G. Bassa and J.A.M. Bleeker (SRON, Netherlands Institute for Space Research, The Netherlands), A. Bamba (ISAS/JAXA Department of High Energy Astrophysics, Kanagawa, Japan), S. Funk (Kavli Institute for Particle Astrophysics and Cosmology, Stanford, USA), P. Ghavamian (Space Telescope Science Institute, Baltimore, USA), K. J. van der Heyden (University of Cape Town, South Africa), and R. Yamazaki (Department of Physical Science, Hiroshima University, Japan). C.G. Bassa is also affiliated with the Radboud University Nijmegen, the Netherlands. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

A Planetary Companion around a Metal-Poor Star with Extragalactic Origin

NASA Astrophysics Data System (ADS)

Setiawan, Johny; Klement, Rainer; Henning, Thomas; Rix, Hans-Walter; Rochau, Boyke; Schulze-Hartung, Tim; Rodmann, Jens

2011-03-01

We report the detection of a planetary companion around HIP 13044, a metal-poor star on the red Horizontal Branch. The detection is based on radial velocity observations with FEROS, a high-resolution spectrograph at the 2.2-m MPG/ESO telescope, located at ESO La Silla observatory in Chile. The periodic radial velocity variation of P = 16.2 days can be distinguished from the periods of the stellar activity indicators. We computed a minimum planetary mass of 1.25 MJup and an orbital semi-major axis of 0.116 AU for the planet. This discovery is unique in three aspects: First, it is the first planet detection around a star with a metallicity much lower than few percent of the solar value; second, the planet host star resides in a stellar evolutionary stage that is still unexplored in the exoplanet surveys; third, the star HIP 13044 belongs to one of the most significant stellar halo streams in the solar neighborhood, implying an extragalactic origin of the planetary system HIP 13044 in a disrupted former satellite of the Milky Way.

Seeing a Stellar Explosion in 3D

NASA Astrophysics Data System (ADS)

2010-08-01

Astronomers using ESO's Very Large Telescope have for the first time obtained a three-dimensional view of the distribution of the innermost material expelled by a recently exploded star. The original blast was not only powerful, according to the new results. It was also more concentrated in one particular direction. This is a strong indication that the supernova must have been very turbulent, supporting the most recent computer models. Unlike the Sun, which will die rather quietly, massive stars arriving at the end of their brief life explode as supernovae, hurling out a vast quantity of material. In this class, Supernova 1987A (SN 1987A) in the rather nearby Large Magellanic Cloud occupies a very special place. Seen in 1987, it was the first naked-eye supernova to be observed for 383 years (eso8704), and because of its relative closeness, it has made it possible for astronomers to study the explosion of a massive star and its aftermath in more detail than ever before. It is thus no surprise that few events in modern astronomy have been met with such an enthusiastic response by scientists. SN 1987A has been a bonanza for astrophysicists (eso8711 and eso0708). It provided several notable observational 'firsts', like the detection of neutrinos from the collapsing inner stellar core triggering the explosion, the localisation on archival photographic plates of the star before it exploded, the signs of an asymmetric explosion, the direct observation of the radioactive elements produced during the blast, observation of the formation of dust in the supernova, as well as the detection of circumstellar and interstellar material (eso0708). New observations making use of a unique instrument, SINFONI [1], on ESO's Very Large Telescope (VLT) have provided even deeper knowledge of this amazing event, as astronomers have now been able to obtain the first-ever 3D reconstruction of the central parts of the exploding material. This view shows that the explosion was stronger and faster in some directions than others, leading to an irregular shape with some parts stretching out further into space. The first material to be ejected from the explosion travelled at an incredible 100 million km per hour, which is about a tenth of the speed of light or around 100 000 times faster than a passenger jet. Even at this breakneck speed it has taken 10 years to reach a previously existing ring of gas and dust puffed out from the dying star. The images also demonstrate that another wave of material is travelling ten times more slowly and is being heated by radioactive elements created in the explosion. "We have established the velocity distribution of the inner ejecta of Supernova 1987A," says lead author Karina Kjær. "Just how a supernova explodes is not very well understood, but the way the star exploded is imprinted on this inner material. We can see that this material was not ejected symmetrically in all directions, but rather seems to have had a preferred direction. Besides, this direction is different to what was expected from the position of the ring." Such asymmetric behaviour was predicted by some of the most recent computer models of supernovae, which found that large-scale instabilities take place during the explosion. The new observations are thus the first direct confirmation of such models. SINFONI is the leading instrument of its kind, and only the level of detail it affords allowed the team to draw their conclusions. Advanced adaptive optics systems counteracted the blurring effects of the Earth's atmosphere while a technique called integral field spectroscopy allowed the astronomers to study several parts of the supernova's chaotic core simultaneously, leading to the build-up of the 3D image. "Integral field spectroscopy is a special technique where for each pixel we get information about the nature and velocity of the gas," says Kjær. "This means that besides the normal picture we also have the velocity along the line of sight. Because we know the time that has passed since the explosion, and because the material is moving outwards freely, we can convert this velocity into a distance. This gives us a picture of the inner ejecta as seen straight on and from the side." Notes [1] The team used the SINFONI (Spectrograph for INtegral Field Observations in the Near Infrared) instrument mounted on ESO's Very Large Telescope (VLT). SINFONI is a near-infrared (1.1-2.45 µm) integral field spectrograph fed by an adaptive optics module. More information This research will appear in Astronomy and Astrophysics ("The 3-D Structure of SN 1987A's inner Ejecta", by K. Kjær et al.). The team is composed of Karina Kjær (Queen's University Belfast, UK), Bruno Leibundgut and Jason Spyromilio (ESO), and Claes Fransson and Anders Jerkstrand (Stockholm University, Sweden). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

The Gaia-ESO Survey: open clusters in Gaia-DR1 . A way forward to stellar age calibration

NASA Astrophysics Data System (ADS)

Randich, S.; Tognelli, E.; Jackson, R.; Jeffries, R. D.; Degl'Innocenti, S.; Pancino, E.; Re Fiorentin, P.; Spagna, A.; Sacco, G.; Bragaglia, A.; Magrini, L.; Prada Moroni, P. G.; Alfaro, E.; Franciosini, E.; Morbidelli, L.; Roccatagliata, V.; Bouy, H.; Bravi, L.; Jiménez-Esteban, F. M.; Jordi, C.; Zari, E.; Tautvaišiene, G.; Drazdauskas, A.; Mikolaitis, S.; Gilmore, G.; Feltzing, S.; Vallenari, A.; Bensby, T.; Koposov, S.; Korn, A.; Lanzafame, A.; Smiljanic, R.; Bayo, A.; Carraro, G.; Costado, M. T.; Heiter, U.; Hourihane, A.; Jofré, P.; Lewis, J.; Monaco, L.; Prisinzano, L.; Sbordone, L.; Sousa, S. G.; Worley, C. C.; Zaggia, S.

2018-05-01

Context. Determination and calibration of the ages of stars, which heavily rely on stellar evolutionary models, are very challenging, while representing a crucial aspect in many astrophysical areas. Aims: We describe the methodologies that, taking advantage of Gaia-DR1 and the Gaia-ESO Survey data, enable the comparison of observed open star cluster sequences with stellar evolutionary models. The final, long-term goal is the exploitation of open clusters as age calibrators. Methods: We perform a homogeneous analysis of eight open clusters using the Gaia-DR1 TGAS catalogue for bright members and information from the Gaia-ESO Survey for fainter stars. Cluster membership probabilities for the Gaia-ESO Survey targets are derived based on several spectroscopic tracers. The Gaia-ESO Survey also provides the cluster chemical composition. We obtain cluster parallaxes using two methods. The first one relies on the astrometric selection of a sample of bona fide members, while the other one fits the parallax distribution of a larger sample of TGAS sources. Ages and reddening values are recovered through a Bayesian analysis using the 2MASS magnitudes and three sets of standard models. Lithium depletion boundary (LDB) ages are also determined using literature observations and the same models employed for the Bayesian analysis. Results: For all but one cluster, parallaxes derived by us agree with those presented in Gaia Collaboration (2017, A&A, 601, A19), while a discrepancy is found for NGC 2516; we provide evidence supporting our own determination. Inferred cluster ages are robust against models and are generally consistent with literature values. Conclusions: The systematic parallax errors inherent in the Gaia DR1 data presently limit the precision of our results. Nevertheless, we have been able to place these eight clusters onto the same age scale for the first time, with good agreement between isochronal and LDB ages where there is overlap. Our approach appears promising and demonstrates the potential of combining Gaia and ground-based spectroscopic datasets. Based on observations collected with the FLAMES instrument at VLT/UT2 telescope (Paranal Observatory, ESO, Chile), for the Gaia-ESO Large Public Spectroscopic Survey (188.B-3002, 193.B-0936).Additional tables are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/612/A99

The Diagnostic Potential of Fe Lines Applied to Protostellar Jets

NASA Astrophysics Data System (ADS)

Giannini, T.; Nisini, B.; Antoniucci, S.; Alcalá, J. M.; Bacciotti, F.; Bonito, R.; Podio, L.; Stelzer, B.; Whelan, E. T.

2013-11-01

We investigate the diagnostic capabilities of iron lines for tracing the physical conditions of shock-excited gas in jets driven by pre-main sequence stars. We have analyzed the 3000-25000 Å, X-shooter spectra of two jets driven by the pre-main sequence stars ESO-Hα 574 and Par-Lup 3-4. Both spectra are very rich in [Fe II] lines over the whole spectral range; in addition, lines from [Fe III] are detected in the ESO-Hα 574 spectrum. Non-local thermal equilibrium codes solving the equations of the statistical equilibrium along with codes for the ionization equilibrium are used to derive the gas excitation conditions of electron temperature and density and fractional ionization. An estimate of the iron gas-phase abundance is provided by comparing the iron lines emissivity with that of neutral oxygen at 6300 Å. The [Fe II] line analysis indicates that the jet driven by ESO-Hα 574 is, on average, colder (T e ~ 9000 K), less dense (n e ~ 2 × 104 cm-3), and more ionized (x e ~ 0.7) than the Par-Lup 3-4 jet (T e ~ 13,000 K, n e ~ 6 × 104 cm-3, x e < 0.4), even if the existence of a higher density component (n e ~ 2 × 105 cm-3) is probed by the [Fe III] and [Fe II] ultra-violet lines. The physical conditions derived from the iron lines are compared with shock models suggesting that the shock at work in ESO-Hα 574 is faster and likely more energetic than the Par-Lup 3-4 shock. This latter feature is confirmed by the high percentage of gas-phase iron measured in ESO-Hα 574 (50%-60% of its solar abundance in comparison with less than 30% in Par-Lup 3-4), which testifies that the ESO-Hα 574 shock is powerful enough to partially destroy the dust present inside the jet. This work demonstrates that a multiline Fe analysis can be effectively used to probe the excitation and ionization conditions of the gas in a jet without any assumption on ionic abundances. The main limitation on the diagnostics resides in the large uncertainties of the atomic data, which, however, can be overcome through a statistical approach involving many lines. Based on observations collected with X-shooter at the Very Large Telescope on Cerro Paranal (Chile), operated by the European Southern Observatory (ESO). Program ID: 085.C-0238(A).

Precision engineering for astronomy: historical origins and the future revolution in ground-based astronomy.

PubMed

Cunningham, Colin; Russell, Adrian

2012-08-28

Since the dawn of civilization, the human race has pushed technology to the limit to study the heavens in ever-increasing detail. As astronomical instruments have evolved from those built by Tycho Brahe in the sixteenth century, through Galileo and Newton in the seventeenth, to the present day, astronomers have made ever more precise measurements. To do this, they have pushed the art and science of precision engineering to extremes. Some of the critical steps are described in the evolution of precision engineering from the first telescopes to the modern generation telescopes and ultra-sensitive instruments that need a combination of precision manufacturing, metrology and accurate positioning systems. In the future, precision-engineered technologies such as those emerging from the photonics industries may enable future progress in enhancing the capabilities of instruments, while potentially reducing the size and cost. In the modern era, there has been a revolution in astronomy leading to ever-increasing light-gathering capability. Today, the European Southern Observatory (ESO) is at the forefront of this revolution, building observatories on the ground that are set to transform our view of the universe. At an elevation of 5000 m in the Atacama Desert of northern Chile, the Atacama Large Millimetre/submillimetre Array (ALMA) is nearing completion. The ALMA is the most powerful radio observatory ever and is being built by a global partnership from Europe, North America and East Asia. In the optical/infrared part of the spectrum, the latest project for ESO is even more ambitious: the European Extremely Large Telescope, a giant 40 m class telescope that will also be located in Chile and which will give the most detailed view of the universe so far.

Exploring the crowded central region of ten Galactic globular clusters using EMCCDs. Variable star searches and new discoveries

NASA Astrophysics Data System (ADS)

Figuera Jaimes, R.; Bramich, D. M.; Skottfelt, J.; Kains, N.; Jørgensen, U. G.; Horne, K.; Dominik, M.; Alsubai, K. A.; Bozza, V.; Calchi Novati, S.; Ciceri, S.; D'Ago, G.; Galianni, P.; Gu, S.-H.; Harpsøe, K. B. W.; Haugbølle, T.; Hinse, T. C.; Hundertmark, M.; Juncher, D.; Korhonen, H.; Mancini, L.; Popovas, A.; Rabus, M.; Rahvar, S.; Scarpetta, G.; Schmidt, R. W.; Snodgrass, C.; Southworth, J.; Starkey, D.; Street, R. A.; Surdej, J.; Wang, X.-B.; Wertz, O.

2016-04-01

Aims: We aim to obtain time-series photometry of the very crowded central regions of Galactic globular clusters; to obtain better angular resolution thanhas been previously achieved with conventional CCDs on ground-based telescopes; and to complete, or improve, the census of the variable star population in those stellar systems. Methods: Images were taken using the Danish 1.54-m Telescope at the ESO observatory at La Silla in Chile. The telescope was equipped with an electron-multiplying CCD, and the short-exposure-time images obtained (ten images per second) were stacked using the shift-and-add technique to produce the normal-exposure-time images (minutes). Photometry was performed via difference image analysis. Automatic detection of variable stars in the field was attempted. Results: The light curves of 12 541 stars in the cores of ten globular clusters were statistically analysed to automatically extract the variable stars. We obtained light curves for 31 previously known variable stars (3 long-period irregular, 2 semi-regular, 20 RR Lyrae, 1 SX Phoenicis, 3 cataclysmic variables, 1 W Ursae Majoris-type and 1 unclassified) and we discovered 30 new variables (16 long-period irregular, 7 semi-regular, 4 RR Lyrae, 1 SX Phoenicis and 2 unclassified). Fluxes and photometric measurements for these stars are available in electronic form through the Strasbourg astronomical Data Center. Based on data collected by the MiNDSTEp team with the Danish 1.54m telescope at ESO's La Silla observatory in Chile.Full Table 1 is only available at CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/588/A128

On the origin of stars with and without planets. Tc trends and clues to Galactic evolution

NASA Astrophysics Data System (ADS)

Adibekyan, V. Zh.; González Hernández, J. I.; Delgado Mena, E.; Sousa, S. G.; Santos, N. C.; Israelian, G.; Figueira, P.; Bertran de Lis, S.

2014-04-01

We explore a sample of 148 solar-like stars to search for a possible correlation between the slopes of the abundance trends versus condensation temperature (known as the Tc slope) with stellar parameters and Galactic orbital parameters in order to understand the nature of the peculiar chemical signatures of these stars and the possible connection with planet formation. We find that the Tc slope significantly correlates (at more than 4σ) with the stellar age and the stellar surface gravity. We also find tentative evidence that the Tc slope correlates with the mean galactocentric distance of the stars (Rmean), suggesting that those stars that originated in the inner Galaxy have fewer refractory elements relative to the volatiles. While the average Tc slope for planet-hosting solar analogs is steeper than that of their counterparts without planets, this difference probably reflects the difference in their age and Rmean. We conclude that the age and probably the Galactic birth place are determinant to establish the star's chemical properties. Old stars (and stars with inner disk origin) have a lower refractory-to-volatile ratio. Based on observations collected with the HARPS spectrograph at the 3.6-m telescope (072.C-0488(E)), installed at the La Silla Observatory, ESO (Chile), with the UVES spectrograph at the 8-m Very Large Telescope program IDs: 67.C-0206(A), 074.C-0134(A), 075.D-0453(A), installed at the Cerro Paranal Observatory, ESO (Chile), and with the UES spectrograph at the 4.2-m William Herschel Telescope, installed at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias, on the island of La Palma.Appendix A is available in electronic form at http://www.aanda.org

How Much Mass Makes a Black Hole? - Astronomers Challenge Current Theories

NASA Astrophysics Data System (ADS)

2010-08-01

Using ESO's Very Large Telescope, European astronomers have for the first time demonstrated that a magnetar - an unusual type of neutron star - was formed from a star with at least 40 times as much mass as the Sun. The result presents great challenges to current theories of how stars evolve, as a star as massive as this was expected to become a black hole, not a magnetar. This now raises a fundamental question: just how massive does a star really have to be to become a black hole? To reach their conclusions, the astronomers looked in detail at the extraordinary star cluster Westerlund 1 [1], located 16 000 light-years away in the southern constellation of Ara (the Altar). From previous studies (eso0510), the astronomers knew that Westerlund 1 was the closest super star cluster known, containing hundreds of very massive stars, some shining with a brilliance of almost one million suns and some two thousand times the diameter of the Sun (as large as the orbit of Saturn). "If the Sun were located at the heart of this remarkable cluster, our night sky would be full of hundreds of stars as bright as the full Moon," says Ben Ritchie, lead author of the paper reporting these results. Westerlund 1 is a fantastic stellar zoo, with a diverse and exotic population of stars. The stars in the cluster share one thing: they all have the same age, estimated at between 3.5 and 5 million years, as the cluster was formed in a single star-formation event. A magnetar (eso0831) is a type of neutron star with an incredibly strong magnetic field - a million billion times stronger than that of the Earth, which is formed when certain stars undergo supernova explosions. The Westerlund 1 cluster hosts one of the few magnetars known in the Milky Way. Thanks to its home in the cluster, the astronomers were able to make the remarkable deduction that this magnetar must have formed from a star at least 40 times as massive as the Sun. As all the stars in Westerlund 1 have the same age, the star that exploded and left a magnetar remnant must have had a shorter life than the surviving stars in the cluster. "Because the lifespan of a star is directly linked to its mass - the heavier a star, the shorter its life - if we can measure the mass of any one surviving star, we know for sure that the shorter-lived star that became the magnetar must have been even more massive," says co-author and team leader Simon Clark. "This is of great significance since there is no accepted theory for how such extremely magnetic objects are formed." The astronomers therefore studied the stars that belong to the eclipsing double system W13 in Westerlund 1 using the fact that, in such a system, masses can be directly determined from the motions of the stars. By comparison with these stars, they found that the star that became the magnetar must have been at least 40 times the mass of the Sun. This proves for the first time that magnetars can evolve from stars so massive we would normally expect them to form black holes. The previous assumption was that stars with initial masses between about 10 and 25 solar masses would form neutron stars and those above 25 solar masses would produce black holes. "These stars must get rid of more than nine tenths of their mass before exploding as a supernova, or they would otherwise have created a black hole instead," says co-author Ignacio Negueruela. "Such huge mass losses before the explosion present great challenges to current theories of stellar evolution." "This therefore raises the thorny question of just how massive a star has to be to collapse to form a black hole if stars over 40 times as heavy as our Sun cannot manage this feat," concludes co-author Norbert Langer. The formation mechanism preferred by the astronomers postulates that the star that became the magnetar - the progenitor - was born with a stellar companion. As both stars evolved they would begin to interact, with energy derived from their orbital motion expended in ejecting the requisite huge quantities of mass from the progenitor star. While no such companion is currently visible at the site of the magnetar, this could be because the supernova that formed the magnetar caused the binary to break apart, ejecting both stars at high velocity from the cluster. "If this is the case it suggests that binary systems may play a key role in stellar evolution by driving mass loss - the ultimate cosmic 'diet plan' for heavyweight stars, which shifts over 95% of their initial mass," concludes Clark. Notes [1] The open cluster Westerlund 1 was discovered in 1961 from Australia by Swedish astronomer Bengt Westerlund, who later moved from there to become ESO Director in Chile (1970-74). This cluster is behind a huge interstellar cloud of gas and dust, which blocks most of its visible light. The dimming factor is more than 100 000, and this is why it has taken so long to uncover the true nature of this particular cluster. Westerlund 1 is a unique natural laboratory for the study of extreme stellar physics, helping astronomers to find out how the most massive stars in our Milky Way live and die. From their observations, the astronomers conclude that this extreme cluster most probably contains no less than 100 000 times the mass of the Sun, and all of its stars are located within a region less than 6 light-years across. Westerlund 1 thus appears to be the most massive compact young cluster yet identified in the Milky Way galaxy. All stars so far analysed in Westerlund 1 have masses at least 30-40 times that of the Sun. Because such stars have a rather short life - astronomically speaking - Westerlund 1 must be very young. The astronomers determine an age somewhere between 3.5 and 5 million years. So, Westerlund 1 is clearly a "newborn" cluster in our galaxy. More information The research presented in this ESO Press Release will soon appear in the research journal Astronomy and Astrophysics ("A VLT/FLAMES survey for massive binaries in Westerlund 1: II. Dynamical constraints on magnetar progenitor masses from the eclipsing binary W13", by B. Ritchie et al.). The same team published a first study of this object in 2006 ("A Neutron Star with a Massive Progenitor in Westerlund 1", by M.P. Muno et al., Astrophysical Journal, 636, L41). The team is composed of Ben Ritchie and Simon Clark (The Open University, UK), Ignacio Negueruela (Universidad de Alicante, Spain), and Norbert Langer (Universität Bonn, Germany, and Universiteit Utrecht, the Netherlands). The astronomers used the FLAMES instrument on ESO's Very Large Telescope at Paranal, Chile to study the stars in the Westerlund 1 cluster. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Delivering Cost-Efficient Public Services in Health Care, Education and Housing in Chile. OECD Economics Department Working Papers, No. 606

ERIC Educational Resources Information Center

Moccero, D.

2008-01-01

The Chilean authorities plan to raise budgetary allocations over the medium term for a variety of social programmes, including education, health care and housing. This incremental spending will need to be carried out in a cost-efficient manner to make sure that it yields commensurate improvements in social outcomes. Chile's health indicators show…

Examining the Impact of Academic Development in the Engineering Faculties in Chile: Changes in Teaching Philosophy and Teachers' Competencies

ERIC Educational Resources Information Center

Acosta Peña, Roxana; Tomás-Folch, Marina; Feixas, Mònica

2017-01-01

The Faculties of Engineering Sciences at Universidad Católica del Norte in Chile regard teacher training as a necessary tool for its academics' professional development and as a fundamental way to improve their teaching quality. The Teaching Unit for Innovation in Engineering (UIDIN) has developed a new curriculum and training programme which…

The Most Distant Mature Galaxy Cluster - Young, but surprisingly grown-up

NASA Astrophysics Data System (ADS)

2011-03-01

Astronomers have used an armada of telescopes on the ground and in space, including the Very Large Telescope at ESO's Paranal Observatory in Chile to discover and measure the distance to the most remote mature cluster of galaxies yet found. Although this cluster is seen when the Universe was less than one quarter of its current age it looks surprisingly similar to galaxy clusters in the current Universe. "We have measured the distance to the most distant mature cluster of galaxies ever found", says the lead author of the study in which the observations from ESO's VLT have been used, Raphael Gobat (CEA, Paris). "The surprising thing is that when we look closely at this galaxy cluster it doesn't look young - many of the galaxies have settled down and don't resemble the usual star-forming galaxies seen in the early Universe." Clusters of galaxies are the largest structures in the Universe that are held together by gravity. Astronomers expect these clusters to grow through time and hence that massive clusters would be rare in the early Universe. Although even more distant clusters have been seen, they appear to be young clusters in the process of formation and are not settled mature systems. The international team of astronomers used the powerful VIMOS and FORS2 instruments on ESO's Very Large Telescope (VLT) to measure the distances to some of the blobs in a curious patch of very faint red objects first observed with the Spitzer space telescope. This grouping, named CL J1449+0856 [1], had all the hallmarks of being a very remote cluster of galaxies [2]. The results showed that we are indeed seeing a galaxy cluster as it was when the Universe was about three billion years old - less than one quarter of its current age [3]. Once the team knew the distance to this very rare object they looked carefully at the component galaxies using both the NASA/ESA Hubble Space Telescope and ground-based telescopes, including the VLT. They found evidence suggesting that most of the galaxies in the cluster were not forming stars, but were composed of stars that were already about one billion years old. This makes the cluster a mature object, similar in mass to the Virgo Cluster, the nearest rich galaxy cluster to the Milky Way. Further evidence that this is a mature cluster comes from observations of X-rays coming from CL J1449+0856 made with ESA's XMM-Newton space observatory. The cluster is giving off X-rays that must be coming from a very hot cloud of tenuous gas filling the space between the galaxies and concentrated towards the centre of the cluster. This is another sign of a mature galaxy cluster, held firmly together by its own gravity, as very young clusters have not had time to trap hot gas in this way. As Gobat concludes: "These new results support the idea that mature clusters existed when the Universe was less than one quarter of its current age. Such clusters are expected to be very rare according to current theory, and we have been very lucky to spot one. But if further observations find many more then this may mean that our understanding of the early Universe needs to be revised." Notes [1] The strange name refers to the object's position in the sky. [2] The galaxies appear red in the picture partly because they are thought to be mainly composed of cool, red stars. In addition the expansion of the Universe since the light left these remote systems has increased the wavelength of the light further so that it is mostly seen as infrared radiation when it gets to Earth. [3] The astronomers measured the distance to the cluster by splitting the light up into its component colours in a spectrograph. They then compared this spectrum with one of a similar object in the nearby Universe. This allowed them to measure the redshift of the remote galaxies - how much the Universe has expanded since the light left the galaxies. The redshift was found to be 2.07, which means that the cluster is seen about three billion years after the Big Bang. More information This research was presented in a paper, "A mature cluster with X-ray emission at z = 2.07", by R. Gobat et al., published in the journal Astronomy & Astrophysics. The team is composed of R. Gobat (Laboratoire AIM-Paris-Saclay, France), E. Daddi (AIM-Paris), M. Onodera (ETH Zürich, Switzerland), A. Finoguenov (Max-Planck-Institut für extraterrestrische Physik [MPE], Garching, Germany), A. Renzini (INAF-Osservatorio Astronomico di Padova), N. Arimoto (National Astronomical Observatory of Japan), R. Bouwens (Lick Observatory, Santa Cruz, USA), M. Brusa (MPE), R.-R. Chary (California Institute of Technology, USA), A. Cimatti (Università di Bologna, Italy), M. Dickinson (NOAO, Tucson, USA), X. Kong (University of Science and Technology of China), and M.Mignoli (INAF - Osservatorio Astronomico di Bologna, Italy). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Giant Galaxy Messier 87 finally sized up

NASA Astrophysics Data System (ADS)

2009-05-01

Using ESO's Very Large Telescope, astronomers have succeeded in measuring the size of giant galaxy Messier 87 and were surprised to find that its outer parts have been stripped away by still unknown effects. The galaxy also appears to be on a collision course with another giant galaxy in this very dynamic cluster. ESO PR Photo 19a/09 The Intercluster Light ESO PR Photo 19b/09 Intergalactic Planetary Nebulae ESO PR Photo 19c/09 The Virgo Cluster The new observations reveal that Messier 87's halo of stars has been cut short, with a diameter of about a million light-years, significantly smaller than expected, despite being about three times the extent of the halo surrounding our Milky Way [1]. Beyond this zone only few intergalactic stars are seen. "This is an unexpected result," says co-author Ortwin Gerhard. "Numerical models predict that the halo around Messier 87 should be several times larger than our observations have revealed. Clearly, something must have cut the halo off early on." The team used FLAMES, the super-efficient spectrograph at ESO's Very Large Telescope at the Paranal Observatory in Chile, to make ultra-precise measurements of a host of planetary nebulae in the outskirts of Messier 87 and in the intergalactic space within the Virgo Cluster of galaxies, to which Messier 87 belongs. FLAMES can simultaneously take spectra many sources, spread over an area of the sky about the size of the Moon. The new result is quite an achievement. The observed light from a planetary nebula in the Virgo Cluster is as faint as that from a 30-Watt light bulb at a distance of about 6 million kilometres (about 15 times the Earth-Moon distance). Furthermore, planetary nebulae are thinly spread through the cluster, so even FLAMES's wide field of view could only capture a few tens of nebulae at a time. "It is a little bit like looking for a needle in a haystack, but in the dark", says team member Magda Arnaboldi. "The FLAMES spectrograph on the VLT was the best instrument for the job". At a distance of approximately 50 million light-years, the Virgo Cluster is the nearest galaxy cluster. It is located in the constellation of Virgo (the Virgin) and is a relatively young and sparse cluster. The cluster contains many hundreds of galaxies, including giant and massive elliptical galaxies, as well as more homely spirals like our own Milky Way. The astronomers have proposed several explanations for the discovered "cut-off" of Messier 87's, such as collapse of dark matter nearby in the galaxy cluster. It might also be that another galaxy in the cluster, Messier 84, came much closer to Messier 87 in the past and dramatically perturbed it about a billion years ago. "At this stage, we can't confirm any of these scenarios," says Arnaboldi. "We will need observations of many more planetary nebulae around Messier 87". One thing the astronomers are sure about, however, is that Messier 87 and its neighbour Messier 86 are falling towards each other. "We may be observing them in the phase just before the first close pass", says Gerhard. "The Virgo Cluster is still a very dynamic place and many things will continue to shape its galaxies over the next billion years." More Information Planetary nebulae (PNe) are the spectacular final phase in the life of Sun-like stars, when the star ejects its outer layers into the surrounding space. Their name is a relic of an earlier era: early observers, using only small telescopes, thought that some of these nearby objects, such as the "Helix Nebula" resembled the discs of the giant planets in the Solar System. Planetary nebulae have strong emission lines, which make them relatively easy to detect at great distances, and also allow their radial velocities to be measured precisely. So planetary nebulae can be used to investigate the motions of stars in the faint outer regions of distant galaxies where velocity measurements are otherwise not possible. Moreover, planetary nebulae are representative of the stellar population in general. As they are relatively short-lived (a few tens of thousands of years -- a mere blip on astronomical timescales), astronomers can estimate that one star in about 8000 million of Sun-like stars is visible as a planetary nebula at any given moment. Thus planetary nebulae can provide a unique handle on the number, types of stars and their motions in faint outer galaxy regions that may harbour a substantial amount of mass. These motions contain the fossil record of the history of galaxy interaction and the formation of the galaxy cluster. This research is presented in a paper to appear in Astronomy and Astrophysics: "The Edge of the M87 Halo and the Kinematics of the Diffuse Light in the Virgo Cluster Core," by Michelle Doherty et al. The team is composed of Michelle Doherty and Magda Arnaboldi (ESO), Payel Das and Ortwin Gerhard (Max-Planck-Institute for Extraterrestrial Physics, Garching, Germany), J. Alfonso L. Aguerri (IAC, Tenerife, Spain), Robin Ciardullo (Pennsylvania State University, USA), John J. Feldmeier (Youngstown State University, USA), Kenneth C. Freeman (Mount Stromlo Observatory, Australia), George H. Jacoby (WIYN Observatory, Tucson, AZ, USA), and Giuseppe Murante (INAF, Osservatorio Astronomico di Pino Torinese, Italy). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in the Atacama Desert region of Chile: La Silla, Paranal and Chajnantor.

Black Hole Blows Big Bubble

NASA Astrophysics Data System (ADS)

2010-07-01

Combining observations made with ESO's Very Large Telescope and NASA's Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole. This object, also known as a microquasar, blows a huge bubble of hot gas, 1000 light-years across, twice as large and tens of times more powerful than other known microquasars. The discovery is reported this week in the journal Nature. "We have been astonished by how much energy is injected into the gas by the black hole," says lead author Manfred Pakull. "This black hole is just a few solar masses, but is a real miniature version of the most powerful quasars and radio galaxies, which contain black holes with masses of a few million times that of the Sun." Black holes are known to release a prodigious amount of energy when they swallow matter. It was thought that most of the energy came out in the form of radiation, predominantly X-rays. However, the new findings show that some black holes can release at least as much energy, and perhaps much more, in the form of collimated jets of fast moving particles. The fast jets slam into the surrounding interstellar gas, heating it and triggering an expansion. The inflating bubble contains a mixture of hot gas and ultra-fast particles at different temperatures. Observations in several energy bands (optical, radio, X-rays) help astronomers calculate the total rate at which the black hole is heating its surroundings. The astronomers could observe the spots where the jets smash into the interstellar gas located around the black hole, and reveal that the bubble of hot gas is inflating at a speed of almost one million kilometres per hour. "The length of the jets in NGC 7793 is amazing, compared to the size of the black hole from which they are launched," says co-author Robert Soria [1]. "If the black hole were shrunk to the size of a soccer ball, each jet would extend from the Earth to beyond the orbit of Pluto." This research will help astronomers understand the similarity between small black holes formed from exploded stars and the supermassive black holes at the centres of galaxies. Very powerful jets have been seen from supermassive black holes, but are thought to be less frequent in the smaller microquasar variety. The new discovery suggests that many of them may simply have gone unnoticed so far. The gas-blowing black hole is located 12 million light-years away, in the outskirts of the spiral galaxy NGC 7793 (eso0914b). From the size and expansion velocity of the bubble the astronomers have found that the jet activity must have been ongoing for at least 200 000 years. Note: [1] Astronomers do not have yet any means of measuring the size of the black hole itself. The smallest stellar black hole discovered so far has a radius of about 15 km. An average stellar black hole of about 10 solar masses has a radius of about 30 km, while a "big" stellar black hole may have a radius of up to 300 km. This is still much smaller than the jets, which extend out to 1000 light-years, or about 9000 million million km! More Information: This result appears in a paper published in this week's issue of the journal Nature (A 300 parsec long jet-inflated bubble around a powerful microquasar in the galaxy NGC 7793, by Manfred W. Pakull, Roberto Soria and Christian Motch). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Black Hole Blows Big Bubble

NASA Astrophysics Data System (ADS)

2010-07-01

Combining observations made with ESO's Very Large Telescope and NASA's Chandra X-ray telescope, astronomers have uncovered the most powerful pair of jets ever seen from a stellar black hole. This object, also known as a microquasar, blows a huge bubble of hot gas, 1000 light-years across, twice as large and tens of times more powerful than other known microquasars. The discovery is reported this week in the journal Nature. "We have been astonished by how much energy is injected into the gas by the black hole," says lead author Manfred Pakull. "This black hole is just a few solar masses, but is a real miniature version of the most powerful quasars and radio galaxies, which contain black holes with masses of a few million times that of the Sun." Black holes are known to release a prodigious amount of energy when they swallow matter. It was thought that most of the energy came out in the form of radiation, predominantly X-rays. However, the new findings show that some black holes can release at least as much energy, and perhaps much more, in the form of collimated jets of fast moving particles. The fast jets slam into the surrounding interstellar gas, heating it and triggering an expansion. The inflating bubble contains a mixture of hot gas and ultra-fast particles at different temperatures. Observations in several energy bands (optical, radio, X-rays) help astronomers calculate the total rate at which the black hole is heating its surroundings. The astronomers could observe the spots where the jets smash into the interstellar gas located around the black hole, and reveal that the bubble of hot gas is inflating at a speed of almost one million kilometres per hour. "The length of the jets in NGC 7793 is amazing, compared to the size of the black hole from which they are launched," says co-author Robert Soria [1]. "If the black hole were shrunk to the size of a soccer ball, each jet would extend from the Earth to beyond the orbit of Pluto." This research will help astronomers understand the similarity between small black holes formed from exploded stars and the supermassive black holes at the centres of galaxies. Very powerful jets have been seen from supermassive black holes, but are thought to be less frequent in the smaller microquasar variety. The new discovery suggests that many of them may simply have gone unnoticed so far. The gas-blowing black hole is located 12 million light-years away, in the outskirts of the spiral galaxy NGC 7793 (eso0914b). From the size and expansion velocity of the bubble the astronomers have found that the jet activity must have been ongoing for at least 200 000 years. Notes [1] Astronomers do not have yet any means of measuring the size of the black hole itself. The smallest stellar black hole discovered so far has a radius of about 15 km. An average stellar black hole of about 10 solar masses has a radius of about 30 km, while a "big" stellar black hole may have a radius of up to 300 km. This is still much smaller than the jets, which extend out to several hundreds light years on each side of the black hole, or about several thousand million million km! More information This result appears in a paper published in this week's issue of the journal Nature (A 300 parsec long jet-inflated bubble around a powerful microquasar in the galaxy NGC 7793, by Manfred W. Pakull, Roberto Soria and Christian Motch). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

CaFe interstellar clouds

NASA Astrophysics Data System (ADS)

Bondar, A.; Kozak, M.; Gnaciński, P.; Galazutdinov, G. A.; Beletsky, Y.; Krełowski, J.

2007-07-01

A new kind of interstellar cloud is proposed. These are rare (just a few examples among ~300 lines of sight) objects with the CaI 4227-Å, FeI 3720-Å and 3860-Å lines stronger than those of KI (near 7699 Å) and NaI (near 3302 Å). We propose the name `CaFe' for these clouds. Apparently they occupy different volumes from the well-known interstellar HI clouds where the KI and ultraviolet NaI lines are dominant features. In the CaFe clouds we have not found either detectable molecular features (CH, CN) or diffuse interstellar bands which, as commonly believed, are carried by some complex, organic molecules. We have found the CaFe clouds only along sightlines toward hot, luminous (and thus distant) objects with high rates of mass loss. In principle, the observed gas-phase interstellar abundances reflect the combined effects of the nucleosynthetic history of the material, the depletion of heavy elements into dust grains and the ionization state of these elements which may depend on irradiation by neighbouring stars. Based on data collected using the Maestro spectrograph at the Terskol 2-m telescope, Russia; and on data collected using the ESO Feros spectrograph; and on data obtained from the ESO Science Archive Facility acquired with the UVES spectrograph, Chile. E-mail: `arctur'@rambler.ru (AB); marizak@astri.uni.torun.pl (MK); pg@iftia.univ.gda.pl (PG); gala@boao.re.kr (GAG); ybialets@eso.org (YB); jacek@astri.uni.torun.pl (JK)

VizieR Online Data Catalog: Spectroscopic Indicators in SeisMic Archive (SISMA) (Rainer+, 2016)

NASA Astrophysics Data System (ADS)

Rainer, M.; Poretti, E.; Misto, A.; Panzera, M. R.; Molinaro, M.; Cepparo, F.; Roth, M.; Michel, E.; Monteiro, M. J. P. F. G.

2017-02-01

We created a large database of physical parameters and variability indicators by fully reducing and analyzing the large number of spectra taken to complement the asteroseismic observations of the COnvection, ROtation and planetary Transits (CoRoT) satellite. CoRoT was launched on 2006 December 27 and it was retired on 2013 June 24. 7103 spectra of 261 stars obtained with the ESO echelle spectrograph High Accuracy Radial velocity Planet Searcher (HARPS) have been stored in the VO-compliant database Spectroscopic Indicators in a SeisMic Archive (SISMA; http://sisma.brera.inaf.it/), along with the CoRoT photometric data of the 72 CoRoT asteroseismic targets. The ground-based activities started with the Large Programme 178.D-0361 using the FEROS spectrograph at the 2.2m telescope of the ESO-La Silla Observatory, and continued with the Large Programmes LP182.D-0356 and LP185.D-0056 using the HARPS instrument at the 3.6m ESO telescope. In the framework of the awarded two HARPS Large Programmes, 15 nights were allocated each semester over nine semesters, from 2008 December to 2013 January, for a total of 135 nights. The HARPS spectrograph covers the spectral range from 3780 to 6910Å, distributed over echelle orders 89-161. We usually used it in the high-efficiency mode EGGS, with resolving power R=80000 to obtain high signal-to-noise ratio (S/N) spectroscopic time series. All of the data (reduced spectra, indicators, and photometric series) are stored as either FITS or PDF files in the SISMA archive and can be accessed at http://sisma.brera.inaf.it/. The data can also be accessed through the Seismic Plus portal (http://voparis-spaceinn.obspm.fr/seismic-plus/), developed in the framework of the SpaceInn project in order to gather and help coordinated access to several different solar and stellar seismic data sources. (1 data file).

Development and preliminary evaluation of a behavioural HIV-prevention programme for teenage girls of Latino descent in the USA.

PubMed

Davidson, Tatiana M; Lopez, Cristina M; Saulson, Raelle; Borkman, April L; Soltis, Kathryn; Ruggiero, Kenneth J; de Arellano, Michael; Wingood, Gina M; Diclemente, Ralph J; Danielson, Carla Kmett

2014-01-01

National data suggests that teenage girls of Latino descent in the USA are disproportionately affected by HIV, with the US Centers for Disease Control and Prevention reporting the rate of new infections being approximately four times higher compared to White women of comparable age . This paper highlights the need for an effective single-sex HIV-prevention programme for teenage girls of Latino descent and describes the development and preliminary evaluation of Chicas Healing, Informing, Living and Empowering (CHILE), a culturally-tailored, HIV-prevention programme exclusively for teenage girls of Latino descent that was adapted from Sisters Informing, Healing, Living and Empowering (SiHLE), an evidence-based HIV- prevention program that is culturally tailored for African American young women. Theatre testing, a pre-testing methodology to assess consumer response to a demonstration of a product, was utilised to evaluate the relevance and utility of the HIV programme as well as opportunities for the integration of cultural constructs. Future directions for the evaluation of CHILE are discussed.

The magnetic fields of hot subdwarf stars

NASA Astrophysics Data System (ADS)

Landstreet, J. D.; Bagnulo, S.; Fossati, L.; Jordan, S.; O'Toole, S. J.

2012-05-01

Context. Detection of magnetic fields has been reported in several sdO and sdB stars. Recent literature has cast doubts on the reliability of most of these detections. The situation concerning the occurrence and frequency of magnetic fields in hot subdwarfs is at best confused. Aims: We revisit data previously published in the literature, and we present new observations to clarify the question of how common magnetic fields are in subdwarf stars. Methods: We consider a sample of about 40 hot subdwarf stars. About 30 of them have been observed with the FORS1 and FORS2 instruments of the ESO VLT. Results have been published for only about half of the hot subdwarfs observed with FORS. Here we present new FORS1 field measurements for 17 stars, 14 of which have never been observed for magnetic fields before. We also critically review the measurements already published in the literature, and in particular we try to explain why previous papers based on the same FORS1 data have reported contradictory results. Results: All new and re-reduced measurements obtained with FORS1 are shown to be consistent with non-detection of magnetic fields. We explain previous spurious field detections from data obtained with FORS1 as due to a non-optimal method of wavelength calibration. Field detections in other surveys are found to be uncertain or doubtful, and certainly in need of confirmation. Conclusions: There is presently no strong evidence for the occurrence of a magnetic field in any sdB or sdO star, with typical longitudinal field uncertainties of the order of 2-400 G. It appears that globally simple fields of more than about 1 or 2 kG in strength occur in at most a few percent of hot subdwarfs. Further high-precision surveys, both with high-resolution spectropolarimeters and with instruments similar to FORS1 on large telescopes, would be very valuable. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile under observing programmes 072.D-0290 and 075.D-0352, or obtained from the ESO/ST-ECF Science Archive Facility.

HATS-17b: A Transiting Compact Warm Jupiter in a 16.3 Day Circular Orbit

NASA Astrophysics Data System (ADS)

Brahm, R.; Jordán, A.; Bakos, G. Á.; Penev, K.; Espinoza, N.; Rabus, M.; Hartman, J. D.; Bayliss, D.; Ciceri, S.; Zhou, G.; Mancini, L.; Tan, T. G.; de Val-Borro, M.; Bhatti, W.; Csubry, Z.; Bento, J.; Henning, T.; Schmidt, B.; Rojas, F.; Suc, V.; Lázár, J.; Papp, I.; Sári, P.

2016-04-01

We report the discovery of HATS-17b, the first transiting warm Jupiter of the HATSouth network. HATS-17b transits its bright (V = 12.4) G-type ({M}\\star = 1.131+/- 0.030 {M}⊙ , {R}\\star = {1.091}-0.046+0.070 {R}⊙ ) metal-rich ([Fe/H] = +0.3 dex) host star in a circular orbit with a period of P = 16.2546 days. HATS-17b has a very compact radius of 0.777+/- 0.056 {R}{{J}} given its Jupiter-like mass of 1.338+/- 0.065 {M}{{J}}. Up to 50% of the mass of HATS-17b may be composed of heavy elements in order to explain its high density with current models of planetary structure. HATS-17b is the longest period transiting planet discovered to date by a ground-based photometric survey, and is one of the brightest transiting warm Jupiter systems known. The brightness of HATS-17 will allow detailed follow-up observations to characterize the orbital geometry of the system and the atmosphere of the planet. The HATSouth network is operated by a collaboration consisting of Princeton University (PU), the Max Planck Institute für Astronomie (MPIA), the Australian National University (ANU), and the Pontificia Universidad Católica de Chile (PUC). The station at Las Campanas Observatory (LCO) of the Carnegie Institute is operated by PU in conjunction with PUC, the station at the High Energy Spectroscopic Survey (H.E.S.S.) site is operated in conjunction with MPIA, and the station at Siding Spring Observatory (SSO) is operated jointly with ANU. This paper includes data gathered with the MPG 2.2 m telescope at the ESO Observatory in La Silla and with the 3.9 m AAT in Siding Spring Observatory. This paper uses observations obtained with facilities of the Las Cumbres Observatory Global Telescope. Based on observations taken with the HARPS spectrograph (ESO 3.6 m telescope at La Silla) under programme 097.C-0571.

Supernova 2010as: The Lowest-velocity Member of a Family of Flat-velocity Type IIb Supernovae

NASA Astrophysics Data System (ADS)

Folatelli, Gastón; Bersten, Melina C.; Kuncarayakti, Hanindyo; Olivares Estay, Felipe; Anderson, Joseph P.; Holmbo, Simon; Maeda, Keiichi; Morrell, Nidia; Nomoto, Ken'ichi; Pignata, Giuliano; Stritzinger, Maximilian; Contreras, Carlos; Förster, Francisco; Hamuy, Mario; Phillips, Mark M.; Prieto, José Luis; Valenti, Stefano; Afonso, Paulo; Altenmüller, Konrad; Elliott, Jonny; Greiner, Jochen; Updike, Adria; Haislip, Joshua B.; LaCluyze, Aaron P.; Moore, Justin P.; Reichart, Daniel E.

2014-09-01

We present extensive optical and near-infrared photometric and spectroscopic observations of the stripped-envelope supernova SN 2010as. Spectroscopic peculiarities such as initially weak helium features and low expansion velocities with a nearly flat evolution place this object in the small family of events previously identified as transitional Type Ib/c supernovae (SNe). There is ubiquitous evidence of hydrogen, albeit weak, in this family of SNe, indicating that they are in fact a peculiar kind of Type IIb SNe that we name "flat-velocity Type IIb. The flat-velocity evolution—which occurs at different levels between 6000 and 8000 km s-1 for different SNe—suggests the presence of a dense shell in the ejecta. Despite the spectroscopic similarities, these objects show surprisingly diverse luminosities. We discuss the possible physical or geometrical unification picture for such diversity. Using archival Hubble Space Telescope images, we associate SN 2010as with a massive cluster and derive a progenitor age of ≈6 Myr, assuming a single star-formation burst, which is compatible with a Wolf-Rayet progenitor. Our hydrodynamical modeling, on the contrary, indicates that the pre-explosion mass was relatively low, ≈4 M ⊙. The seeming contradiction between a young age and low pre-SN mass may be solved by a massive interacting binary progenitor. This paper includes data gathered with the following facilities in Chile: the 6.5 m Magellan Telescopes located at Las Campanas Observatory, the Gemini Observatory, Cerro Pachón (Gemini Program GS-2008B-Q-56), and the European Organisation for Astronomical Research in the Southern Hemisphere (ESO Programmes 076.A-0156, 078.D-0048, 080.A-0516, and 082.A-0526). We have also used data from the ESO Science Archive Facility under request number gfolatelli74580 and from the NASA/ESA Hubble Space Telescope, obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA), and the Canadian Astronomy Data Centre (CADC/NRC/CSA).

Massive pre-main-sequence stars in M17

NASA Astrophysics Data System (ADS)

Ramírez-Tannus, M. C.; Kaper, L.; de Koter, A.; Tramper, F.; Bik, A.; Ellerbroek, L. E.; Ochsendorf, B. B.; Ramírez-Agudelo, O. H.; Sana, H.

2017-08-01

The formation process of massive stars is still poorly understood. Massive young stellar objects (mYSOs) are deeply embedded in their parental clouds; these objects are rare, and thus typically distant, and their reddened spectra usually preclude the determination of their photospheric parameters. M17 is one of the best-studied H II regions in the sky, is relatively nearby, and hosts a young stellar population. We have obtained optical to near-infrared spectra of previously identified candidate mYSOs and a few OB stars in this region with X-shooter on the ESO Very Large Telescope. The large wavelength coverage enables a detailed spectroscopic analysis of the photospheres and circumstellar disks of these candidate mYSOs. We confirm the pre-main-sequence (PMS) nature of six of the stars and characterise the O stars. The PMS stars have radii that are consistent with being contracting towards the main sequence and are surrounded by a remnant accretion disk. The observed infrared excess and the double-peaked emission lines provide an opportunity to measure structured velocity profiles in the disks. We compare the observed properties of this unique sample of young massive stars with evolutionary tracks of massive protostars and propose that these mYSOs near the western edge of the H II region are on their way to become main-sequence stars ( 6-20 M⊙) after having undergone high mass accretion rates (Ṁacc 10-4-10-3M⊙yr-1). Their spin distribution upon arrival at the zero age main-sequence is consistent with that observed for young B stars, assuming conservation of angular momentum and homologous contraction. Based on observations collected at the European Southern Observatory at Paranal, Chile (ESO programmes 60.A-9404(A), 085.D-0741, 089.C-0874(A), and 091.C-0934(B)).The full normalised X-shooter spectra are available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/A78

VizieR Online Data Catalog: Radial velocities of 51 Peg (Martins+, 2015)

NASA Astrophysics Data System (ADS)

Martins, J. H. C.; Santos, N. C.; Figueira, P.; Faria, J. P.; Montalto, M.; Boisse, I.; Ehrenreich, D.; Lovis, C.; Mayor, M.; Melo, C.; Pepe, F.; Sousa, S.; Udry, S.; Cunha, D.

2015-04-01

The table contains the radial velocity data for HARPS observations of 51 Peg. This data was collected with the HARPS spectrograph at ESO's 3.6-m Telescope at La Silla-Paranal Observatory, as part of ESO programme 091.C-0271. It consists of 91 spectra observed in seven different nights (2013-06-08, 2013-06-25, 2013-08-02, 2013-08-04, 2013-09-05, 2013-09-09 and 2013-09-30) totalling around 12.5h of observing time. The obtained spectra have a S/N on the 50th order (~5560Å) that varies between 122 and 388. The spectra cover the wavelengths range from roughly 3781Å to 6910Å. (1 data file).

The ELT in 2017: The Year of the Primary Mirror

NASA Astrophysics Data System (ADS)

Cirasuolo, M.; Tamai, R.; Cayrel, M.; Koehler, B.; Biancat Marchet, F..; González, J. C.; Dimmler, M.; Tuti, M.; ELT Team

2018-03-01

The Extremely Large Telescope (ELT) is at the core of ESO's vision to deliver the largest optical and infrared telescope in the world. With its unrivalled sensitivity and angular resolution the ELT will transform our view of the Universe: from exoplanets to resolved stellar populations, from galaxy evolution to cosmology and fundamental physics. This article focuses on one of the most challenging aspects of the entire programme, the 39-metre primary mirror (M1). 2017 was a particularly intense year for M1, the main highlight being the approval by ESO's Council to proceed with construction of the entire mirror. In addition, several contracts have been placed to ensure that the giant primary mirror will be operational at first light.

A Cluster and a Sea of Galaxies

NASA Astrophysics Data System (ADS)

2010-05-01

A new wide-field image released today by ESO displays many thousands of distant galaxies, and more particularly a large group belonging to the massive galaxy cluster known as Abell 315. As crowded as it may appear, this assembly of galaxies is only the proverbial "tip of the iceberg", as Abell 315 - like most galaxy clusters - is dominated by dark matter. The huge mass of this cluster deflects light from background galaxies, distorting their observed shapes slightly. When looking at the sky with the unaided eye, we mostly only see stars within our Milky Way galaxy and some of its closest neighbours. More distant galaxies are just too faint to be perceived by the human eye, but if we could see them, they would literally cover the sky. This new image released by ESO is both a wide-field and long-exposure one, and reveals thousands of galaxies crowding an area on the sky roughly as large as the full Moon. These galaxies span a vast range of distances from us. Some are relatively close, as it is possible to distinguish their spiral arms or elliptical halos, especially in the upper part of the image. The more distant appear just like the faintest of blobs - their light has travelled through the Universe for eight billion years or more before reaching Earth. Beginning in the centre of the image and extending below and to the left, a concentration of about a hundred yellowish galaxies identifies a massive galaxy cluster, designated with the number 315 in the catalogue compiled by the American astronomer George Abell in 1958 [1]. The cluster is located between the faint, red and blue galaxies and the Earth, about two billion light-years away from us. It lies in the constellation of Cetus (the Whale). Galaxy clusters are some of the largest structures in the Universe held together by gravity. But there is more in these structures than the many galaxies we can see. Galaxies in these giants contribute to only ten percent of the mass, with hot gas in between galaxies accounting for another ten percent [2]. The remaining 80 percent is made of an invisible and unknown ingredient called dark matter that lies in between the galaxies. The presence of dark matter is revealed through its gravitational effect: the enormous mass of a galaxy cluster acts on the light from galaxies behind the cluster like a cosmic magnifying glass, bending the trajectory of the light and thus making the galaxies appear slightly distorted [3]. By observing and analysing the twisted shapes of these background galaxies, astronomers can infer the total mass of the cluster responsible for the distortion, even when this mass is mostly invisible. However, this effect is usually tiny, and it is necessary to measure it over a huge number of galaxies to obtain significant results: in the case of Abell 315, the shapes of almost 10 000 faint galaxies in this image were studied in order to estimate the total mass of the cluster, which amounts to over a hundred thousand billion times the mass of our Sun [4]. To complement the enormous range of cosmic distances and sizes surveyed by this image, a handful of objects much smaller than galaxies and galaxy clusters and much closer to Earth are scattered throughout the field: besides several stars belonging to our galaxy, many asteroids are also visible as blue, green or red trails [5]. These objects belong to the main asteroid belt, located between the orbits of Mars and Jupiter, and their dimensions vary from some tens of kilometres, for the brightest ones, to just a few kilometres in the case of the faintest ones. This image has been taken with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. It is a composite of several exposures acquired using three different broadband filters, for a total of almost one hour in the B filter and about one and a half hours in the V and R filters. The field of view is 34 x 33 arcminutes. Notes [1] The Abell catalogue from 1958 comprised 2712 clusters of galaxies, and was integrated with an additional 1361 clusters in 1989. Abell put together this impressive collection by visual inspection of photographic plates of the sky, seeking those areas where more galaxies than average were found at approximately the same distance from us. [2] Ten percent of a galaxy cluster's mass consists of a very hot mixture of protons and electrons (a plasma), with temperatures as high as ten million degrees or more, which makes it visible to X-ray telescopes. [3] Astronomers refer to these slight distortions as weak gravitational lensing, as opposed to strong gravitational lensing, characterised by more spectacular phenomena such as giant arcs, rings and multiple images. [4] A weak lensing study of the galaxy cluster Abell 315 has been published in a paper that appeared in Astronomy & Astrophysics in 2009 ("Weak lensing observations of potentially X-ray underluminous galaxy clusters", by J. Dietrich et al.). [5] The blue, green or red tracks indicate that each asteroid has been detected through one of the three filters, respectively. Each track is composed of several, smaller sub-tracks, reflecting the sequence of several exposures performed in each of the filters; from the length of these sub-tracks, the distance to the asteroid can be calculated. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Light Dawns on Dark Gamma-ray Bursts

NASA Astrophysics Data System (ADS)

2010-12-01

Gamma-ray bursts are among the most energetic events in the Universe, but some appear curiously faint in visible light. The biggest study to date of these so-called dark gamma-ray bursts, using the GROND instrument on the 2.2-metre MPG/ESO telescope at La Silla in Chile, has found that these gigantic explosions don't require exotic explanations. Their faintness is now fully explained by a combination of causes, the most important of which is the presence of dust between the Earth and the explosion. Gamma-ray bursts (GRBs), fleeting events that last from less than a second to several minutes, are detected by orbiting observatories that can pick up their high energy radiation. Thirteen years ago, however, astronomers discovered a longer-lasting stream of less energetic radiation coming from these violent outbursts, which can last for weeks or even years after the initial explosion. Astronomers call this the burst's afterglow. While all gamma-ray bursts [1] have afterglows that give off X-rays, only about half of them were found to give off visible light, with the rest remaining mysteriously dark. Some astronomers suspected that these dark afterglows could be examples of a whole new class of gamma-ray bursts, while others thought that they might all be at very great distances. Previous studies had suggested that obscuring dust between the burst and us might also explain why they were so dim. "Studying afterglows is vital to further our understanding of the objects that become gamma-ray bursts and what they tell us about star formation in the early Universe," says the study's lead author Jochen Greiner from the Max-Planck Institute for Extraterrestrial Physics in Garching bei München, Germany. NASA launched the Swift satellite at the end of 2004. From its orbit above the Earth's atmosphere it can detect gamma-ray bursts and immediately relay their positions to other observatories so that the afterglows could be studied. In the new study, astronomers combined Swift data with new observations made using GROND [2] - a dedicated gamma-ray burst follow-up observation instrument, which is attached to the 2.2-metre MPG/ESO telescope at La Silla in Chile. In doing so, astronomers have conclusively solved the puzzle of the missing optical afterglow. What makes GROND exciting for the study of afterglows is its very fast response time - it can observe a burst within minutes of an alert coming from Swift using a special system called the Rapid Response Mode - and its ability to observe simultaneously through seven filters covering both the visible and near-infrared parts of the spectrum. By combining GROND data taken through these seven filters with Swift observations, astronomers were able to accurately determine the amount of light emitted by the afterglow at widely differing wavelengths, all the way from high energy X-rays to the near-infrared. The astronomers used this information to directly measure the amount of obscuring dust that the light passed through en route to Earth. Previously, astronomers had to rely on rough estimates of the dust content [3]. The team used a range of data, including their own measurements from GROND, in addition to observations made by other large telescopes including the ESO Very Large Telescope, to estimate the distances to nearly all of the bursts in their sample. While they found that a significant proportion of bursts are dimmed to about 60-80 percent of the original intensity by obscuring dust, this effect is exaggerated for the very distant bursts, letting the observer see only 30-50 percent of the light [4]. The astronomers conclude that most dark gamma-ray bursts are therefore simply those that have had their small amount of visible light completely stripped away before it reaches us. "Compared to many instruments on large telescopes, GROND is a low cost and relatively simple instrument, yet it has been able to conclusively resolve the mystery surrounding dark gamma-ray bursts," says Greiner. Notes [1] Gamma-ray bursts lasting longer than two seconds are referred to as long bursts and those with a shorter duration are known as short bursts. Long bursts, which were observed in this study, are associated with the supernova explosions of massive young stars in star-forming galaxies. Short bursts are not well understood, but are thought to originate from the merger of two compact objects such as neutron stars. [2] The Gamma-Ray burst Optical and Near-infrared Detector (GROND) was designed and built at the Max-Planck Institute for Extraterrestrial Physics in collaboration with the Tautenburg Observatory, and has been fully operational since August 2007. [3] Other studies relating to dark gamma-ray bursts have been released. Early this year, astronomers used the Subaru Telescope to observe a single gamma-ray burst, from which they hypothesised that dark gamma-ray bursts may indeed be a separate sub-class that form through a different mechanism, such as the merger of binary stars. In another study published last year using the Keck Telescope, astronomers studied the host galaxies of 14 dark GRBs, and based on the derived low redshifts they infer dust as the likely mechanism to create the dark bursts. In the new work reported here, 39 GRBs were studied, including nearly 20 dark bursts, and it is the only study in which no prior assumptions have been made and the amount of dust has been directly measured. [4] Because the afterglow light of very distant bursts is redshifted due to the expansion of the Universe, the light that left the object was originally bluer than the light we detect when it gets to Earth. Since the reduction of light intensity by dust is greater for blue and ultraviolet light than for red, this means that the overall dimming effect of dust is greater for the more distant gamma-ray bursts. This is why GROND's ability to observe near-infrared radiation makes such a difference. More information This research is presented in a paper to appear in the journal Astronomy & Astrophysics on 16 December 2010 The team is composed of: J. Greiner (Max-Planck-Institut für extraterrestrische Physik [MPE], Germany), T. Krühler (MPE, Universe Cluster, Technische Universität München), S. Klose (Thüringer Landessternwarte, Germany), P. Afonso (MPE), C. Clemens (MPE), R. Filgas (MPE), D.H. Hartmann (Clemson University, USA), A. Küpcü Yoldaş¸ (University of Cambridge, UK), M. Nardini (MPE), F. Olivares E. (MPE), A. Rau (MPE), A. Rossi (Thüringer Landessternwarte, Germany), P. Schady (MPE), and A. Updike (Clemson University, USA) ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

VISTA: Pioneering New Survey Telescope Starts Work

NASA Astrophysics Data System (ADS)

2009-12-01

A new telescope - VISTA (the Visible and Infrared Survey Telescope for Astronomy) - has just started work at ESO's Paranal Observatory and has made its first release of pictures. VISTA is a survey telescope working at infrared wavelengths and is the world's largest telescope dedicated to mapping the sky. Its large mirror, wide field of view and very sensitive detectors will reveal a completely new view of the southern sky. Spectacular new images of the Flame Nebula, the centre of our Milky Way galaxy and the Fornax Galaxy Cluster show that it is working extremely well. VISTA is the latest telescope to be added to ESO's Paranal Observatory in the Atacama Desert of northern Chile. It is housed on the peak adjacent to the one hosting the ESO Very Large Telescope (VLT) and shares the same exceptional observing conditions. VISTA's main mirror is 4.1 metres across and is the most highly curved mirror of this size and quality ever made - its deviations from a perfect surface are less than a few thousandths of the thickness of a human hair - and its construction and polishing presented formidable challenges. VISTA was conceived and developed by a consortium of 18 universities in the United Kingdom [1] led by Queen Mary, University of London and became an in-kind contribution to ESO as part of the UK's accession agreement. The telescope design and construction were project-managed by the Science and Technology Facilities Council's UK Astronomy Technology Centre (STFC, UK ATC). Provisional acceptance of VISTA was formally granted by ESO at a ceremony at ESO's Headquarters in Garching, Germany, attended by representatives of Queen Mary, University of London and STFC, on 10 December 2009 and the telescope will now be operated by ESO. "VISTA is a unique addition to ESO's observatory on Cerro Paranal. It will play a pioneering role in surveying the southern sky at infrared wavelengths and will find many interesting targets for further study by the Very Large Telescope, ALMA and the future European Extremely Large Telescope," says Tim de Zeeuw, the ESO Director General. At the heart of VISTA is a 3-tonne camera containing 16 special detectors sensitive to infrared light, with a combined total of 67 million pixels. Observing at wavelengths longer than those visible with the human eye allows VISTA to study objects that are otherwise impossible to see in visible light because they are either too cool, obscured by dust clouds or because they are so far away that their light has been stretched beyond the visible range by the expansion of the Universe. To avoid swamping the faint infrared radiation coming from space, the camera has to be cooled to -200 degrees Celsius and is sealed with the largest infrared-transparent window ever made. The VISTA camera was designed and built by a consortium including the Rutherford Appleton Laboratory, the UK ATC and the University of Durham in the United Kingdom. Because VISTA is a large telescope that also has a large field of view it can both detect faint sources and also cover wide areas of sky quickly. Each VISTA image captures a section of sky covering about ten times the area of the full Moon and it will be able to detect and catalogue objects over the whole southern sky with a sensitivity that is forty times greater than that achieved with earlier infrared sky surveys such as the highly successful Two Micron All-Sky Survey. This jump in observational power - comparable to the step in sensitivity from the unaided eye to Galileo's first telescope - will reveal vast numbers of new objects and allow the creation of far more complete inventories of rare and exotic objects in the southern sky. "We're delighted to have been able to provide the astronomical community with the VISTA telescope. The exceptional quality of the scientific data is a tribute to all the scientists and engineers who were involved in this exciting and challenging project," adds Ian Robson, Head of the UK ATC. The first released image shows the Flame Nebula (NGC 2024), a spectacular star-forming cloud of gas and dust in the familiar constellation of Orion (the Hunter) and its surroundings. In visible light the core of the object is hidden behind thick clouds of dust, but the VISTA image, taken at infrared wavelengths, can penetrate the murk and reveal the cluster of hot young stars hidden within. The wide field of view of the VISTA camera also captures the glow of NGC 2023 and the ghostly form of the famous Horsehead Nebula. The second image is a mosaic of two VISTA views towards the centre of our Milky Way galaxy in the constellation of Sagittarius (the Archer). Vast numbers of stars are revealed - this single picture shows about one million stars - and the majority are normally hidden behind thick dust clouds and only become visible at infrared wavelengths. For the final image, VISTA has stared far beyond our galaxy to take a family photograph of a cluster of galaxies in the constellation of Fornax (the Chemical Furnace). The wide field allows many galaxies to be captured in a single image including the striking barred-spiral NGC 1365 and the big elliptical galaxy NGC 1399. VISTA will spend almost all of its time mapping the southern sky in a systematic fashion. The telescope is embarking on six major sky surveys with different scientific goals over its first five years. One survey will cover the entire southern sky and others will be dedicated to smaller regions to be studied in greater detail. VISTA's surveys will help our understanding of the nature, distribution and origin of known types of stars and galaxies, map the three-dimensional structure of our galaxy and the neighbouring Magellanic Clouds, and help determine the relation between the structure of the Universe and the mysterious dark energy and dark matter. The huge data volumes - typically 300 gigabytes per night or more than 100 terabytes per year - will flow back into the ESO digital archive and will be processed into images and catalogues at data centres in the United Kingdom at the Universities of Cambridge and Edinburgh. All data will become public and be available to astronomers around the globe. Jim Emerson of Queen Mary, University of London and leader of the VISTA consortium, is looking forward to a rich harvest of science from the new telescope: "History has shown us some of the most exciting results that come out of projects like VISTA are the ones you least expect - and I'm personally very excited to see what these will be!" Notes [1] The VISTA Consortium is led by Queen Mary, University of London and consists of: Queen Mary, University of London; Queen's University of Belfast; University of Birmingham; University of Cambridge; Cardiff University; University of Central Lancashire; University of Durham; The University of Edinburgh; University of Hertfordshire; Keele University; Leicester University; Liverpool John Moores University; University of Nottingham; University of Oxford; University of St Andrews; University of Southampton; University of Sussex and University College London. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

The Atacama Large Millimeter Array (ALMA)

NASA Astrophysics Data System (ADS)

1999-06-01

The Atacama Large Millimeter Array (ALMA) is the new name [2] for a giant millimeter-wavelength telescope project. As described in the accompanying joint press release by ESO and the U.S. National Science Foundation , the present design and development phase is now a Europe-U.S. collaboration, and may soon include Japan. ALMA may become the largest ground-based astronomy project of the next decade after VLT/VLTI, and one of the major new facilities for world astronomy. ALMA will make it possible to study the origins of galaxies, stars and planets. As presently envisaged, ALMA will be comprised of up to 64 12-meter diameter antennas distributed over an area 10 km across. ESO PR Photo 24a/99 shows an artist's concept of a portion of the array in a compact configuration. ESO PR Video Clip 03/99 illustrates how all the antennas will move in unison to point to a single astronomical object and follow it as it traverses the sky. In this way the combined telescope will produce astronomical images of great sharpness and sensitivity [3]. An exceptional site For such observations to be possible the atmosphere above the telescope must be transparent at millimeter and submillimeter wavelengths. This requires a site that is high and dry, and a high plateau in the Atacama desert of Chile, probably the world's driest, is ideal - the next best thing to outer space for these observations. ESO PR Photo 24b/99 shows the location of the chosen site at Chajnantor, at 5000 meters altitude and 60 kilometers east of the village of San Pedro de Atacama, as seen from the Space Shuttle during a servicing mission of the Hubble Space Telescope. ESO PR Photo 24c/99 and ESO PR Photo 24d/99 show a satellite image of the immediate vicinity and the site marked on a map of northern Chile. ALMA will be the highest continuously operated observatory in the world. The stark nature of this extreme site is well illustrated by the panoramic view in ESO PR Photo 24e/99. High sensitivity and sharp images ALMA will be extremely sensitive to radiation at milllimeter and submillimeter wavelengths. The large number of antennas gives a total collecting area of over 7000 square meters, larger than a football field. At the same time, the shape of the surface of each antenna must be extremely precise under all conditions; the overall accuracy over the entire 12-m diameter must be better than 0.025 millimeters (25µm), or one-third of the diameter of a human hair. The combination of large collecting area and high precision results in extremely high sensitivity to faint cosmic signals. The telescope must also be able to resolve the fine details of the objects it detects. In order to do this at millimeter wavelengths the effective diameter of the overall telescope must be very large - about 10 km. As it is impossible to build a single antenna with this diameter, an array of antennas is used instead, with the outermost antennas being 10 km apart. By combining the signals from all antennas together in a large central computer, it is possible to synthesize the effect of a single dish 10 km across. The resulting angular resolution is about 10 milli-arcseconds, less than one-thousandth the angular size of Saturn. Exciting research perspectives The scientific case for this revolutionary telescope is overwhelming. ALMA will make it possible to witness the formation of the earliest and most distant galaxies. It will also look deep into the dust-obscured regions where stars are born, to examine the details of star and planet formation. But ALMA will go far beyond these main science drivers, and will have a major impact on virtually all areas of astronomy. It will be a millimeter-wave counterpart to the most powerful optical/infrared telescopes such as ESO's Very Large Telescope (VLT) and the Hubble Space Telescope, with the additional advantage of being unhindered by cosmic dust opacity. The first galaxies in the Universe are expected to become rapidly enshrouded in the dust produced by the first stars. The dust can dim the galaxies at optical wavelengths, but the same dust radiates brightly at longer wavelengths. In addition, the expansion of the Universe causes the radiation from distant galaxies to be shifted to longer wavelengths. For both reasons, the earliest galaxies at the epoch of first light can be found with ALMA, and the subsequent evolution of galaxies can be mapped over cosmic time. ALMA will be of great importance for our understanding of the origins of stars and planetary systems. Stellar nurseries are completely obscured at optical wavelengths by dense "cocoons" of dust and gas, but ALMA can probe deep into these regions and study the fundamental processes by which stars are assembled. Moreover, it can observe the major reservoirs of biogenic elements (carbon, oxygen, nitrogen) and follow their incorporation into new planetary systems. A particularly exciting prospect for ALMA is to use its exceptionally sharp images to obtain evidence for planet formation by the presence of gaps in dusty disks around young stars, cleared by large bodies coalescing around the stars. Equally fundamental are observations of the dying gasps of stars at the other end of the stellar lifecycle, when they are often surrounded by shells of molecules and dust enriched in heavy elements produced by the nuclear fires now slowly dying. ALMA will offer exciting new views of our solar system. Studies of the molecular content of planetary atmospheres with ALMA's high resolving power will provide detailed weather maps of Mars, Jupiter, and the other planets and even their satellites. Studies of comets with ALMA will be particularly interesting. The molecular ices of these visitors from the outer reaches of the solar system have a composition that is preserved from ages when the solar system was forming. They evaporate when the comet comes close to the sun, and studies of the resulting gases with ALMA will allow accurate analysis of the chemistry of the presolar nebula. The road ahead The three-year design and development phase of the project is now underway as a collaboration between Europe and the U.S., and Japan may also join in this effort. Assuming the construction phase begins about two years from now, limited operations of the array may begin in 2005 and the full array may become operational by 2009. Notes [1] Press Releases about this event have also been issued by some of the other organisations participating in this project: * CNRS (in French) * MPG (in German) * NOVA (in Dutch) * NRAO * NSF (ASCII and HTML versions) * PPARC [2] "ALMA" means "soul" in Spanish. [3] Additional information about ALMA is available on the web: * Articles in the ESO Messenger - "The Large Southern Array" (March 1998), "European Site Testing at Chajnantor" (December 1998) and "The ALMA Project" (June 1999), cf. http://www.eso.org/gen-fac/pubs/messenger/ * ALMA website at ESO at http://www.eso.org/projects/alma/ * ALMA website at the U.S. National Radio Astronomy Observatory (NRAO) at http://www.mma.nrao.edu/ * ALMA website in The Netherlands about the detectors at http://www.sron.rug.nl/alma/ ALMA/Chajnantor Video Clip and Photos ESO PR Video Clip 03/99 [MPEG-version] ESO PR Video Clip 03/99 (2450 frames/1:38 min) [MPEG Video; 160x120 pix; 2.1Mb] [MPEG Video; 320x240 pix; 10.0Mb] [RealMedia; streaming; 700k] [RealMedia; streaming; 2.3M] About ESO Video Clip 03/99 : This video clip about the ALMA project contains two sequences. The first shows a panoramic scan of the Chajnantor plain from approx. north-east to north-west. The Chajnantor mountain passes through the field-of-view and the perfect cone of the Licancabur volcano (5900 m) on the Bolivian border is seen at the end (compare also with ESO PR 24e/99 below. The second is a 52-sec animation with a change of viewing perspective of the array and during which the antennas move in unison. For convenience, the clip is available in four versions: two MPEG files of different sizes and two streamer-versions of different quality that require RealPlayer software. There is no audio. Note that ESO Video News Reel No. 5 with more related scenes and in professional format with complete shot list is also available. ESO PR Photo 24b/99 ESO PR Photo 24b/99 [Preview - JPEG: 400 x 446 pix - 184k] [Normal - JPEG: 800 x 892 pix - 588k] [High-Res - JPEG: 3000 x 3345 pix - 5.4M] Caption to ESO PR Photo 24b/99 : View of Northern Chile, as seen from the NASA Space Shuttle during a servicing mission to the Hubble Space Telescope (partly visible to the left). The Atacama Desert, site of the ESO VLT at Paranal Observatory and the proposed location for ALMA at Chajnantor, is seen from North (foreground) to South. The two sites are only a few hundred km distant from each other. Few clouds are seen in this extremely dry area, due to the influence of the cold Humboldt Stream along the Chilean Pacific coast (right) and the high Andes mountains (left) that act as a barrier. Photo courtesy ESA astronaut Claude Nicollier. ESO PR Photo 24c/99 ESO PR Photo 24c/99 [Preview - JPEG: 400 x 318 pix - 212k] [Normal - JPEG: 800 x 635 pix - 700k] [High-Res - JPEG: 3000 x 2382 pix - 5.9M] Caption to ESO PR Photo 24c/99 : This satellite image of the Chajnantor area was produced in 1998 at Cornell University (USA), by Jennifer Yu, Jeremy Darling and Riccardo Giovanelli, using the Thematic Mapper data base maintained at the Geology Department laboratory directed by Bryan Isacks. It is a composite of three exposures in spectral bands at 1.6 µm (rendered as red), 1.0 µm (green) and 0.5 µm (blue). The horizontal resolution of the false-colour image is about 30 meters. North is at the top of the photo. ESO PR Photo 24d/99 ESO PR Photo 24d/99 [Preview - JPEG: 400 x 381 pix - 108k] [Normal - JPEG: 800 x 762 pix - 240k] [High-Res - JPEG: 2300 x 2191 pix - 984k] Caption to ESO PR Photo 24d/99 : Geographical map with the sites of the VLT and ALMA indicated. ESO PR Photo 24e/99 ESO PR Photo 24e/99 [Preview - JPEG: 400 x 238 pix - 93k] [Normal - JPEG: 800 x 475 pix - 279k] [High-Res - JPEG: 2862 x 1701 pix - 4.2M] Caption to ESO PR Photo 24e/99 : Panoramic view of the proposed site for ALMA at Chajnantor. This high-altitude plain (elevation 5000 m) in the Chilean Andes mountains is an ideal site for ALMA. In this view towards the north, the Chajnantor mountain (5600 m) is in the foreground, left of the centre. The perfect cone of the Licancabur volcano (5900 m) on the Bolivian border is in the background further to the left. This image is a wide-angle composite (140° x 70°) of three photos (Hasselblad 6x6 with SWC 1:4.5/38 mm Biogon), obtained in December 1998. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../ ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

With the VLT Interferometer towards Sharper Vision

NASA Astrophysics Data System (ADS)

2000-05-01

The Nova-ESO VLTI Expertise Centre Opens in Leiden (The Netherlands) European science and technology will gain further strength when the new, front-line Nova-ESO VLTI Expertise Centre (NEVEC) opens in Leiden (The Netherlands) this week. It is a joint venture of the Netherlands Research School for Astronomy (NOVA) (itself a collaboration between the Universities of Amsterdam, Groningen, Leiden, and Utrecht) and the European Southern Observatory (ESO). It is concerned with the Very Large Telescope Interferometer (VLTI). The Inauguration of the new Centre will take place on Friday, May 26, 2000, at the Gorlaeus Laboratory (Lecture Hall no. 1), Einsteinweg 55 2333 CC Leiden; the programme is available on the web. Media representatives who would like to participate in this event and who want further details should contact the Nova Information Centre (e-mail: jacques@astro.uva.nl; Tel: +31-20-5257480 or +31-6-246 525 46). The inaugural ceremony is preceded by a scientific workshop on ground and space-based optical interferometry. NEVEC: A Technology Centre of Excellence As a joint project of NOVA and ESO, NEVEC will develop in the coming years the expertise to exploit the unique interferometric possibilities of the Very Large Telescope (VLT) - now being built on Paranal mountain in Chile. Its primary goals are the * development of instrument modeling, data reduction and calibration techniques for the VLTI; * accumulation of expertise relevant for second-generation VLTI instruments; and * education in the use of the VLTI and related matters. NEVEC will develop optical equipment, simulations and software to enable interferometry with VLT [1]. The new Center provides a strong impulse to Dutch participation in the VLTI. With direct involvement in this R&D work, the scientists at NOVA will be in the front row to do observations with this unique research facility, bound to produce top-level research and many exciting new discoveries. The ESO VLTI at Paranal ESO PR Photo 14a/00 ESO PR Photo 14a/00 [Preview - JPEG: 359 x 400 pix - 120k] [Normal - JPEG: 717 x 800 pix - 416k] [High-Res - JPEG: 2689 x 3000 pix - 6.7M] Caption : A view of the Paranal platform with the four 8.2-m VLT Unit Telescopes (UTs) and the foundations for the 1.8-m VLT Auxiliary Telescopes (ATs) that together will be used as the VLT Interferometer (VLTI). The three ATs will move on rails (yet to be installed) between the thirty observing stations above the holes that provide access to the underlying tunnel system. The light beams from the individual telescopes will be guided towards the centrally located, partly underground Interferometry Laboratory in which the VLTI instruments will be set up. This photo was obtained in December 1999 at which time some construction materials were still present on the platform; they were electronically removed in this reproduction. The ESO VLT facility at Paranal (Chile) consists of four Unit Telescopes with 8.2-m mirrors and several 1.8-m auxiliary telescopes that move on rails, cf. PR Photo 14a/00 . While each of the large telescopes can be used individually for astronomical observations, a prime feature of the VLT is the possibility to combine all of these telescopes into the Very Large Telescope Interferometer (VLTI) . In the interferometric mode, the light beams from the VLT telescopes are brought together at a common focal point in the Interferometry Laboratory that is placed at the centre of the observing platform on top of Paranal. In principle, this can be done in such a way that the resulting (reconstructed) image appears to come from a virtual telescope with a diameter that is equal to the largest distance between two of the individual telescopes, i.e., up to about 200 metres. The theoretically achievable image sharpness of an astronomical telescope is proportional to its diameter (or, for an interferometer, the largest distance between two of its component telescopes). The interferometric observing technique will thus allow the VLTI to produce images as sharp as 0.001 arcsec (at wavelength 1 µm) - this corresponds to viewing the shape of a golfball at more than 8,000 km distance. The VLTI will do even better when this technique is later extended to shorter wavelengths in the visible part of the spectrum - it may ultimately distinguish human-size objects on the surface of the Moon (a 2-metre object at this distance, about 400,000 km, subtends an angle of about 0.001 arcsec). However, interferometry with the VLT demands that the wavefronts of light from the individual telescopes that are up to 200 meters apart must be matched exactly, with less than 1 wavelength of difference. This demands continuous mechanical stability to a fraction of 1 µm (0.001 mm) for the heavy components over such large distances, and is a technically formidable challenge. This is achieved by electronic feed-back loops that measure and adjust the distances during the observations. In addition, continuous and automatic correction of image distortions from air turbulence in the telescopes' field of view is performed by means of adaptive optics [2]. VLTI technology at ESO, industry and institutes The VLT Interferometer is based on front-line technologies introduced and advanced by ESO, and its many parts are now being constructed at various sites in Europe. ESO PR Photo 14b/00 ESO PR Photo 14b/00 [Preview - JPEG: 359 x 400 pix - 72k] [Normal - JPEG: 717 x 800 pix - 200k] [High-Res - JPEG: 2687 x 3000 pix - 1.3M] Caption : Schematic lay-out of the VLT Interferometer. The light from a distant celestial objects enters two of the VLT telescopes and is reflected by the various mirrors into the Interferometric Tunnel, below the observing platform on the top of Paranal. Two Delay Lines with moveable carriages continuously adjust the length of the paths so that the two beams interfere constructively and produce fringes at the interferometric focus in the laboratory. In 1998, Fokker Space (also in Leiden, The Netherlands) was awarded a contract for the delivery of the three Delay Lines of the VLTI. This mechanical-optical system will compensate the optical path differences of the light beams from the individual telescopes. It is necessary to ensure that the light from all telescopes arrives in the same phase at the focal point of the interferometer. Otherwise, the very sharp interferometric images cannot be obtained. More details are available in the corresponding ESO PR 04/98 and recent video sequences, included in ESO Video News Reel No. 9 and Video Clip 04a/00 , cf. below. Also in 1998, the company AMOS (Liège, Belgium) was awarded an ESO contract for the delivery of the three 1.8-m Auxiliary Telescopes (ATs) and of the full set of on-site equipment for the 30 AT observing stations, cf. ESO PR Photos 25a-b/98. This work is now in progress at the factory - various scenes are incorporated into ESO Video News Reel No. 9 and Video Clip 04b/00 . Several instruments for imaging and spectroscopy are currently being developed for the VLTI. The first will be the VLT Interferometer Commissioning Instrument (VINCI) that is the test and first-light instrument for the VLT Interferometer. It is being built by a consortium of French and German institutes under ESO contract. The VLTI Near-Infrared / Red Focal Instrument (AMBER) is a collaborative project between five institutes in France, Germany and Italy, under ESO contract. It will operate with two 8.2-m UTs in the wavelength range between 1 and 2.5 µm during a first phase (2001-2003). The wavelength coverage will be extended in a second phase down to 0.6 µm (600 nm) at the time the ATs become operational. Main scientific objectives are the investigation at very high-angular resolution of disks and jets around young stellar objects and dust tori at active galaxy nuclei with spectroscopic observations. The Phase-Referenced Imaging and Microarcsecond Astrometry (PRIMA) device is managed by ESO and will allow simultaneous interferometric observations of two objects - each with a maximum size of 2 arcsec - and provide exceedingly accurate positional measurements. This will be of importance for many different kinds of astronomical investigations, for instance the search for planetary companions by means of accurate astrometry. The MID-Infrared interferometric instrument (MIDI) is a project collaboration between eight institutes in France, Germany and the Netherlands [1], under ESO contract. The actual design of MIDI is optimized for operation at 10 µm and a possible extension to 20 µm is being considered. Notes [1] The NEVEC Centre is involved in the MIDI project for the VLTI. Another joint project between ESO and NOVA is the Wide-Field Imager OMEGACAM for the VLT Survey Telescope (VST) that will be placed at Paranal. [2] Adaptive Optics systems allow to continuously "re-focus" an astronomical telescope in order to compensate for the atmospheric turbulence and thus to obtain the sharpest possible images. The work at ESO is described on the Adaptive Optics Team Homepage. VLTI-related videos now available In conjunction with the Inauguration of the NEVEC Centre (Leiden, The Netherlands) on May 26, 2000, ESO has issued ESO Video News Reel No. 9 (May 2000) ( "The Sharpest Vision - Interferometry with the VLT" ). Tapes with this VNR, suitable for transmission and in full professional quality (Betacam, etc.), are now available for broadcasters upon request; please contact the ESO EPR Department for more details. Extracts from this VNR are available as ESO Video Clips 04a/00 and 04b/00 . ESO PR Video Clip 04a/00 [160x120 pix MPEG-version] ESO PR Video Clip 04a/00 (2600 frames/1:44 min) [MPEG Video+Audio; 160x120 pix; 2.4Mb] [MPEG Video+Audio; 320x240 pix; 4.8 Mb] [RealMedia; streaming; 33kps] [RealMedia; streaming; 200kps] ESO Video Clip 04a/00 shows some recent tests with the prototype VLT Delay Line carriage at FOKKER Space (Leiden, The Netherlands. This device is crucial for the proper functioning of the VLTI and will be mounted in the main interferometric tunnel at Paranal. Contents: Outside view of the FOKKER site. The carriage on rails. The protecting cover is removed. View towards the cat's eye. The carriage moves on the rails. ESO PR Video Clip 04b/00 [160x120 pix MPEG-version] ESO PR Video Clip 04b/00 (3425 frames/2:17 min) [MPEG Video+Audio; 160x120 pix; 3.2Mb] [MPEG Video+Audio; 320x240 pix; 6.3 Mb] [RealMedia; streaming; 33kps] [RealMedia; streaming; 200kps] ESO Video Clip 04b/00 shows the construction of the 1.8-m VLT Auxiliary Telescopes at AMOS (Liège, Belgium). Contents: External view of the facility. Computer drawing of the mechanics. The 1.8-m mirror (graphics). Construction of the centerpiece of the telescope tube. Mechanical parts. Checking the optical shape of an 1.8-m mirror. Mirror cell with supports for the 1.8-m mirror. Test ramp with rails on which the telescope moves and an "observing station" (the hole). The telescope yoke that will support the telescope tube. Both clips are available in four versions: two MPEG files and two streamer-versions of different sizes; the latter require RealPlayer software. They may be freely reproduced if ESO is mentioned as source. Most of the ESO PR Video Clips at the ESO website provide "animated" illustrations of the ongoing work and events at the European Southern Observatory. The most recent clip was: ESO PR Video Clip 03/00 with a trailer for "Physics on Stage" (2 May 2000). Information is also available on the web about other ESO videos.

"europe Towards the Stars"

NASA Astrophysics Data System (ADS)

1995-06-01

YOUNG EUROPEANS AND THEIR TEACHERS TO OBSERVE WITH SUPER-TELESCOPE With the above title, and following the very successful events of the past two years [1], ESO again organises an "educational adventure" in 1995. It takes place within the framework of the "Third European Week for Scientific and Technological Culture", initiated and supported by the European Commission. This time ESO will invite about fifty 17-18 year old grammar school pupils with their teachers to try their skills at one of the world's most advanced astronomical telescopes. The young people are the winners of a Europe-wide astronomy contest that will take place during the summer and early autumn. The main event involves a free, week-long stay at the Headquarters of the European Southern Observatory in November this year. During this time, the participants will experience modern astronomy and astrophysics at one of the world's foremost international centres and also have the opportunity to perform remote observations via a satellite link with two telescopes at the ESO La Silla observatory in Chile. THE CONTEST This year's programme will begin with national competitions in sixteen European countries. It is devised as a contest between joint teams of pupils and teachers. Each team is expected to consist of (up to) three pupils and their teacher. They can choose between four different subjects requiring either practical or theoretical work. Each subject has a strong scientific and technological component. Here are short descriptions: At the telescope - Catching and interpreting the signals. "You observe with an existing telescope and instrument of your own choice. In your observational report you describe the scientific goal, the capability of your equipment, the execution of the observation. You discuss the observational data including an error analysis, and describe the conclusions." Technology for Science - Building an Instrument. "You build an astronomical instrument (e.g. a photometer or a spectrograph, fitted with the associated detector). In the instrument documentation, you describe the instrument, its design, construction and the test results." A Future Space Mission - Designing an on-board Instrument. "You design an instrument for a future space mission to the outer Solar System. The purpose is to carry out observations of Pluto and Transneptunian Objects. Describe the design, the physical/chemical principles of the instrument and the observations to be made with it. Give examples of some possible results." Theory - Looking into the Future. "You describe a stable planetary system around another star. Your report contains a description of the conditions (inner structure, composition, surface features, atmosphere) of the planets. What are the technical requirements for observing this system from the Earth? Which kind of observations of these objects can be done with available instruments?" None of these subjects are easy to treat, but experience has shown that thanks to very dedicated teachers, the teaching of astronomy takes place at a surprisingly high level at many of Europe's schools. The establishment of the European Association for Astronomy Education (EAAE) last year has also resulted in a Europe-wide, increasing interest in these matters and many EAAE members actively promote the present contest and participate in the organisation. Many good entries are therefore expected. The participation is open to pupils in their last or second-to-last year before baccalaureate. In each country, a National Committee has been established that will organise the contest and evaluate the responses. In most cases, the closing date is early October 1995, and the national award ceremonies will take place in early November. Detailed information about this programme may be obtained from the National Committees at the addresses below. A VISIT TO ESO The members of the winning teams from each country will be invited to spend an exciting and informative week at the ESO Headquarters in Garching near Munich (Germany) in mid-November 1995. Here they will experience front-line science and partake in the daily life of one of Europe's foremost scientific establishments. Assisted by professional astronomers, they will prepare and carry out real astronomical observations with the 1.4-metre CAT (Coude Auxiliary Telescope) and the very advanced 3.5-metre NTT (New Technology Telescope) from ESO's remote control centre. They will also begin the treatment of the registered data and, if possible, arrive at tentative interpretations. The week will undoubtedly be very hectic, but it will of course also include events of a more social character which will further emphasize the pan-European nature of this unique visit. ESO will provide more details about this programme in early November 1995, including the planned media coverage. ADDRESSES OF THE NATIONAL COMMITTEES For further information about the programme "Europe Towards The Stars", please contact the National Committee in your country. Austria: Prof. H. Mucke, Astronomisches Buero, Hasenwartgasse 32, A-1138 Vienna, Tel. 0043-1-8893541 Belgium: Dr. C. Sterken, Vrije Universiteit Brussel, Campus Ofenplein, Pleinlaan 2, B-1050 Brussels, Tel. 0032-2-6293469, Fax 0032-9-3623976, E-mail csterken@is1.vub.ac.be Denmark: Mr. B. F. Joergensen, Tycho Brahe Planetariet, Gl. Kongevej 10, DK-1610 Copenhagen V, Tel. 0045-33-144888, Fax 0045-33-142888, E-mail tycho@inet.uni-c.dk Finland: Mr. M. Hotakainen, Tahtitieteellinen Yhdistys Ursa Ry, Laivanvarustajankatu 9C 54, FIN-00140 Helsinki, Tel. 00358-0-174048, Fax 00358-0-657728 France: Mr. B. Pellequer, Geospace d'Aniane, Boîte Postale 22, F-34150 Aniane, Tel. 0033-6-7034949, Fax 0033-6-7752864 Germany: Dr. K.-H. Lotze, Friedrich-Schiller-Universitaet, Max-Wien-Platz 1, D-07743 Jena, Germany, Tel. +49-3641-635904/636654, Fax +49-3641-636728 Greece: Dr. D. Simopoulos, Eugenides Foundation, Astronomy Department, 387 Sygrou Avenue, Palaio Faliro, GR-175 64 Athens, Tel. 0030-1-941-1181, Fax 0030-1-941-7372 Ireland: Dr I. Elliot, Dunsink Observatory (Dublin Institute for Advanced Studies), Castleknock, Dublin 15, Tel. 00353-1- 838-7911/7959, Fax 00353-1-8387090, E-mail ie@dunsink.dias.ie Italy: Prof. F. Pacini, Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Florence, Tel. 0039-55-2752246, Fax 0039-55-220039, E-mail pacini@arcetri.astro.it Luxemburg: Dr. F. Wagner, Laboratoire de Physique, Lycee de Garcons d'Esch, BP 195, L-4002 Esch/Alzette, Tel. 00352-556285, Fax 00352-570994 The Netherlands: Dr. H. Lamers, Rijksuniversiteit Utrecht, Princetonplein 5, Postbus 80.000, NL-3508 TA Utrecht, Tel. 0031-30-535200, Fax 0031-30531601, email hennyl@sron.ruu.nl Portugal: Dr. T. Lago, Centro de Astrofisico, Universidade do Porto, Rua do Campo Alegre 823, P-4150 Porto, Tel. 00351-2-6007081, Fax 00351-2-6007982, E-mail mtlago@ncc.up.pt Spain: Dr. Asuncion Sanchez/Dr Telmo Fernandez, Planetario de Madrid, Parque Tierno Galvan, E-28045 Madrid, Tel. 0034-1-4673578, Fax 0034-1-4681154, E-mail tfc@vilspa.esa.es Sweden: Dr. Kerstin Loden, Stockholms Observatorium, S-133 36 Saltsjoebaden, Tel. 0046-8-164454, Fax 0046-8-7174719, e-mail lodenk@astro.su.se Switzerland: Mr. M. Wieland, Schweizer Jugend Forscht/La Science Appelle les Jeunes, Technoramastrasse 1, CH-8404 Winterthur, Tel. 0041-52-2424440, Fax 0041-52-2422967 United Kingdom: Dr A. M. Cohen, Dane Valley High School, Jackson Road, Congleton, Cheshire CW12 1NT, England, United Kingdom, Tel. +44-260-273000, Fax +44-260-297352 (until July 1, 1995). The National Committee for the United Kingdom, c/o The Association for Astronomy Education, 9 Hurst Lane, Bollington, Macclesfield, Cheshire SK10 5LN, England (after July 1, 1995). [1] See ESO Press Releases 08/93 of 5 November 1993 and 17/94 of 2 December 1994. ESO Press Information is made available on the World-Wide Web (URL: http://www.hq.eso.org/) and on CompuServe (space science and astronomy area, GO SPACE).

Exoplanets Clue to Sun's Curious Chemistry

NASA Astrophysics Data System (ADS)

2009-11-01

A ground-breaking census of 500 stars, 70 of which are known to host planets, has successfully linked the long-standing "lithium mystery" observed in the Sun to the presence of planetary systems. Using ESO's successful HARPS spectrograph, a team of astronomers has found that Sun-like stars that host planets have destroyed their lithium much more efficiently than "planet-free" stars. This finding does not only shed light on the lack of lithium in our star, but also provides astronomers with a very efficient way of finding stars with planetary systems. "For almost 10 years we have tried to find out what distinguishes stars with planetary systems from their barren cousins," says Garik Israelian, lead author of a paper appearing this week in the journal Nature. "We have now found that the amount of lithium in Sun-like stars depends on whether or not they have planets." Low levels of this chemical element have been noticed for decades in the Sun, as compared to other solar-like stars, and astronomers have been unable to explain the anomaly. The discovery of a trend among planet-bearing stars provides a natural explanation to this long-standing mystery. "The explanation of this 60 year-long puzzle is for us rather simple," adds Israelian. "The Sun lacks lithium because it has planets." This conclusion is based on the analysis of 500 stars, including 70 planet-hosting stars. Most of these stars were monitored for several years with ESO's High Accuracy Radial Velocity Planet Searcher. This spectrograph, better known as HARPS, is attached to ESO's 3.6-metre telescope and is the world's foremost exoplanet hunter. "This is the best possible sample available to date to understand what makes planet-bearing stars unique," says co-author Michel Mayor. The astronomers looked in particular at Sun-like stars, almost a quarter of the whole sample. They found that the majority of stars hosting planets possess less than 1% of the amount of lithium shown by most of the other stars. "Like our Sun, these stars have been very efficient at destroying the lithium they inherited at birth," says team member Nuno Santos. "Using our unique, large sample, we can also prove that the reason for this lithium reduction is not related to any other property of the star, such as its age." Unlike most other elements lighter than iron, the light nuclei of lithium, beryllium and boron are not produced in significant amounts in stars. Instead, it is thought that lithium, composed of just three protons and four neutrons, was mainly produced just after the Big Bang, 13.7 billion years ago. Most stars will thus have the same amount of lithium, unless this element has been destroyed inside the star. This result also provides the astronomers with a new, cost-effective way to search for planetary systems: by checking the amount of lithium present in a star astronomers can decide which stars are worthy of further significant observing efforts. Now that a link between the presence of planets and curiously low levels of lithium has been established, the physical mechanism behind it has to be investigated. "There are several ways in which a planet can disturb the internal motions of matter in its host star, thereby rearrange the distribution of the various chemical elements and possibly cause the destruction of lithium. It is now up to the theoreticians to figure out which one is the most likely to happen," concludes Mayor. More information This research was presented in a paper that appears in the 12 November 2009 issue of Nature (Enhanced lithium depletion in Sun-like stars with orbiting planets, by G. Israelian et al.). The team is composed of Garik Israelian, Elisa Delgado Mena, Carolina Domínguez Cerdeña, and Rafael Rebolo (Instituto de Astrofisíca de Canarias, La Laguna, Tenerife, Spain), Nuno Santos and Sergio Sousa (Centro de Astrofisica, Universidade de Porto, Portugal), Michel Mayor and Stéphane Udry (Observatoire de Genève, Switzerland), and Sofia Randich (INAF, Osservatorio di Arcetri, Firenze, Italy). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

ALMA On the Move - ESO Awards Important Contract for the ALMA Project

NASA Astrophysics Data System (ADS)

2005-12-01

Only two weeks after awarding its largest-ever contract for the procurement of antennas for the Atacama Large Millimeter Array project (ALMA), ESO has signed a contract with Scheuerle Fahrzeugfabrik GmbH, a world-leader in the design and production of custom-built heavy-duty transporters, for the provision of two antenna transporting vehicles. These vehicles are of crucial importance for ALMA. ESO PR Photo 41a/05 ESO PR Photo 41a/05 The ALMA Transporter (Artist's Impression) [Preview - JPEG: 400 x 756 pix - 234k] [Normal - JPEG: 800 x 1512 pix - 700k] [Full Res - JPEG: 1768 x 3265 pix - 2.3M] Caption: Each of the ALMA transporters will be 10 m wide, 4.5 m high and 16 m long. "The timely awarding of this contract is most important to ensure that science operations can commence as planned," said ESO Director General Catherine Cesarsky. "This contract thus marks a further step towards the realization of the ALMA project." "These vehicles will operate in a most unusual environment and must live up to very strict demands regarding performance, reliability and safety. Meeting these requirements is a challenge for us, and we are proud to have been selected by ESO for this task," commented Hans-Jörg Habernegg, President of Scheuerle GmbH. ESO PR Photo 41b/05 ESO PR Photo 41b/05 Signing the Contract [Preview - JPEG: 400 x 572 pix - 234k] [Normal - JPEG: 800 x 1143 pix - 700k] [HiRes - JPEG: 4368 x 3056 pix - 2.3M] Caption: (left to right) Mr Thomas Riek, Vice-President of Scheuerle GmbH, Dr Catherine Cesarsky, ESO Director General and Mr Hans-Jörg Habernegg, President of Scheuerle GmbH. When completed on the high-altitude Chajnantor site in Chile, ALMA is expected to comprise more than 60 antennas, which can be placed in different locations on the plateau but which work together as one giant telescope. Changing the relative positions of the antennas and thus also the configuration of the array allows for different observing modes, comparable to using a zoom lens, offering different degrees of resolution and sky coverage as needed by the astronomers. The ALMA Antenna Transporters allow for moving the antennas between the different pre-defined antenna positions. They will also be used for transporting antennas between the maintenance area at 2900 m elevation and the "high site" at 5000 m above sea level, where the observations are carried out. Given their important functions, both for the scientific work and in transporting high-tech antennas with the required care, the vehicles must live up to very demanding operational requirements. Each transporter has a mass of 150 tonnes and is able to lift and transport antennas of 110 tonnes. They must be able to place the antennas on the docking pads with millimetric precision. At the same time, they must be powerful enough to climb 2000 m reliably and safely with their heavy and valuable load, putting extraordinary demands on the 500 kW diesel engines. This means negotiating a 28 km long high-altitude road with an average slope of 7 %. Finally, as they will be operated at an altitude with significantly reduced oxygen levels, a range of redundant safety devices protect both personnel and equipment from possible mishaps or accidents. The first transporter is scheduled to be delivered in the summer of 2007 to match the delivery of the first antennas to Chajnantor. The ESO contract has a value of approx. 5.5 m Euros.

The First X-shooter Observations of Jets from Young Stars

NASA Astrophysics Data System (ADS)

Bacciotti, F.; Whelan, E. T.; Alcalá, J. M.; Nisini, B.; Podio, L.; Randich, S.; Stelzer, B.; Cupani, G.

2011-08-01

We present the first pilot study of jets from young stars conducted with X-shooter, on the ESO/Very Large Telescope. As it offers simultaneous, high-quality spectra in the range 300-2500 nm, X-shooter is uniquely important for spectral diagnostics in jet studies. We chose to probe the accretion/ejection mechanisms at low stellar masses examining two targets with well-resolved continuous jets lying on the plane of the sky: ESO-HA 574 in Chameleon I and Par-Lup3-4 in Lupus III. The mass of the latter is close to the sub-stellar boundary (M sstarf = 0.13 M sun). A large number of emission lines probing regions of different excitation are identified, position-velocity diagrams are presented, and mass outflow/accretion rates are estimated. Comparison between the two objects is striking. ESO-HA 574 is a weakly accreting star for which we estimate a mass accretion rate of log (\\dot{M}_{acc}) = -10.8 +/- 0.5 (in M sun yr-1), yet it drives a powerful jet with \\dot{M}_{out} ~ 1.5-2.7 × 10-9 M sun yr-1. These values can be reconciled with a magneto-centrifugal jet acceleration mechanism assuming that the presence of the edge-on disk severely depresses the luminosity of the accretion tracers. In comparison, Par-Lup3-4, with stronger mass accretion (log (\\dot{M}_{acc}) = -9.1 +/- 0.4 M sun yr-1), drives a low-excitation jet with about \\dot{M}_{out} ~ 3.2 × 10-10 M sun yr-1 in both lobes. Despite the low stellar mass, \\dot{M}_{out}/\\dot{M}_{acc} for Par-Lup3-4 is at the upper limit of the range usually measured for young objects, but still compatible with a steady magneto-centrifugal wind scenario if all uncertainties are considered. Based on Observations collected with X-shooter at the Very Large Telescope on Cerro Paranal (Chile), operated by the European Southern Observatory (ESO). Program ID: 085.C-0238(A).

Titanic Weather Forecasting

NASA Astrophysics Data System (ADS)

2004-04-01

New Detailed VLT Images of Saturn's Largest Moon Optimizing space missions Titan, the largest moon of Saturn was discovered by Dutch astronomer Christian Huygens in 1655 and certainly deserves its name. With a diameter of no less than 5,150 km, it is larger than Mercury and twice as large as Pluto. It is unique in having a hazy atmosphere of nitrogen, methane and oily hydrocarbons. Although it was explored in some detail by the NASA Voyager missions, many aspects of the atmosphere and surface still remain unknown. Thus, the existence of seasonal or diurnal phenomena, the presence of clouds, the surface composition and topography are still under debate. There have even been speculations that some kind of primitive life (now possibly extinct) may be found on Titan. Titan is the main target of the NASA/ESA Cassini/Huygens mission, launched in 1997 and scheduled to arrive at Saturn on July 1, 2004. The ESA Huygens probe is designed to enter the atmosphere of Titan, and to descend by parachute to the surface. Ground-based observations are essential to optimize the return of this space mission, because they will complement the information gained from space and add confidence to the interpretation of the data. Hence, the advent of the adaptive optics system NAOS-CONICA (NACO) [1] in combination with ESO's Very Large Telescope (VLT) at the Paranal Observatory in Chile now offers a unique opportunity to study the resolved disc of Titan with high sensitivity and increased spatial resolution. Adaptive Optics (AO) systems work by means of a computer-controlled deformable mirror that counteracts the image distortion induced by atmospheric turbulence. It is based on real-time optical corrections computed from image data obtained by a special camera at very high speed, many hundreds of times each second (see e.g. ESO Press Release 25/01 , ESO PR Photos 04a-c/02, ESO PR Photos 19a-c/02, ESO PR Photos 21a-c/02, ESO Press Release 17/02, and ESO Press Release 26/03 for earlier NACO images, and ESO Press Release 11/03 for MACAO-VLTI results.) The southern smile ESO PR Photo 08a/04 ESO PR Photo 08a/04 Images of Titan on November 20, 25 and 26, 2002 Through Five Filters (VLT YEPUN + NACO) [Preview - JPEG: 522 x 400 pix - 40k] [Normal - JPEG: 1043 x 800 pix - 340k] [Hires - JPEG: 2875 x 2205 pix - 1.2M] Caption: ESO PR Photo 08a/04 shows Titan (apparent visual magnitude 8.05, apparent diameter 0.87 arcsec) as observed with the NAOS/CONICA instrument at VLT Yepun (Paranal Observatory, Chile) on November 20, 25 and 26, 2003, between 6.00 UT and 9.00 UT. The median seeing values were 1.1 arcsec and 1.5 arcsec respectively for the 20th and 25th. Deconvoluted ("sharpened") images of Titan are shown through 5 different narrow-band filters - they allow to probe in some detail structures at different altitudes and on the surface. Depending on the filter, the integration time varies from 10 to 100 seconds. While Titan shows its leading hemisphere (i.e. the one observed when Titan moves towards us) on Nov. 20, the trailing side (i.e the one we see when Titan moves away from us in its course around Saturn) - which displays less bright surface features - is observed on the last two dates. ESO PR Photo 08b/04 ESO PR Photo 08b/04 Titan Observed Through Nine Different Filters on November 26, 2002 [Preview - JPEG: 480 x 400 pix - 36k] [Normal - JPEG: 960 x 800 pix - 284k] Caption: ESO PR Photo 08b/04: Images of Titan taken on November 26, 2002 through nine different filters to probe different altitudes, ranging from the stratosphere to the surface. On this night, a stable "seeing" (image quality before adaptive optics correction) of 0.9 arcsec allowed the astronomers to attain the diffraction limit of the telescope (0.032 arcsec resolution). Due to these good observing conditions, Titan's trailing hemisphere was observed with contrasts of about 40%, allowing the detection of several bright features on this surface region, once thought to be quite dark and featureless. ESO PR Photo 08c/04 ESO PR Photo 08c/04 Titan Surface Projections [Preview - JPEG: 601 x 400 pix - 64k] [Normal - JPEG: 1201 x 800 pix - 544k] Caption: ESO PR Photo 08c/04 : Titan images obtained with NACO on November 26th, 2002. Left: Titan's surface projection on the trailing hemisphere as observed at 1.3 μm, revealing a complex brightness structure thanks to the high image contrast of about 40%. Right: a new, possibly meteorological, phenomenon observed at 2.12 μm in Titan's atmosphere, in the form of a bright feature revolving around the South Pole. A team of French astronomers [2] have recently used the NACO state-of-the-art adaptive optics system on the fourth 8.2-m VLT unit telescope, Yepun, to map the surface of Titan by means of near-infrared images and to search for changes in the dense atmosphere. These extraordinary images have a nominal resolution of 1/30th arcsec and show details of the order of 200 km on the surface of Titan. To provide the best possible views, the raw data from the instrument were subjected to deconvolution (image sharpening). Images of Titan were obtained through 9 narrow-band filters, sampling near-infrared wavelengths with large variations in methane opacity. This permits sounding of different altitudes ranging from the stratosphere to the surface. Titan harbours at 1.24 and 2.12 μm a "southern smile", that is a north-south asymmetry, while the opposite situation is observed with filters probing higher altitudes, such as 1.64, 1.75 and 2.17 μm. A high-contrast bright feature is observed at the South Pole and is apparently caused by a phenomenon in the atmosphere, at an altitude below 140 km or so. This feature was found to change its location on the images from one side of the south polar axis to the other during the week of observations. Outlook An additional series of NACO observations of Titan is foreseen later this month (April 2004). These will be a great asset in helping optimize the return of the Cassini/Huygens mission. Several of the instruments aboard the spacecraft depend on such ground-based data to better infer the properties of Titan's surface and lower atmosphere. Although the astronomers have yet to model and interpret the physical and geophysical phenomena now observed and to produce a full cartography of the surface, this first analysis provides a clear demonstration of the marvellous capabilities of the NACO imaging system. More examples of the exciting science possible with this facility will be found in a series of five papers published today in the European research journal Astronomy & Astrophysics (Vol. 47, L1 to L24).

Tracing the evolution of the Galactic bulge with chemodynamical modelling of alpha-elements

NASA Astrophysics Data System (ADS)

Friaça, A. C. S.; Barbuy, B.

2017-02-01

Context. Galactic bulge abundances can be best understood as indicators of bulge formation and nucleosynthesis processes by comparing them with chemo-dynamical evolution models. Aims: The aim of this work is to study the abundances of alpha-elements in the Galactic bulge, including a revision of the oxygen abundance in a sample of 56 bulge red giants. Methods: Literature abundances for O, Mg, Si, Ca and Ti in Galactic bulge stars are compared with chemical evolution models. For oxygen in particular, we reanalysed high-resolution spectra obtained using FLAMES+UVES on the Very Large Telescope, now taking each star's carbon abundances, derived from CI and C2 lines, into account simultaneously. Results: We present a chemical evolution model of alpha-element enrichment in a massive spheroid that represents a typical classical bulge evolution. The code includes multi-zone chemical evolution coupled with hydrodynamics of the gas. Comparisons between the model predictions and the abundance data suggest a typical bulge formation timescale of 1-2 Gyr. The main constraint on the bulge evolution is provided by the O data from analyses that have taken the C abundance and dissociative equilibrium into account. Mg, Si, Ca and Ti trends are well reproduced, whereas the level of overabundance critically depends on the adopted nucleosynthesis prescriptions. Observations collected both at the European Southern Observatory, Paranal, Chile (ESO programmes 71.B-0617A, 73.B0074A, and GTO 71.B-0196)

The astrometric lessons of Gaia-GBOT experiment

NASA Astrophysics Data System (ADS)

Bouquillon, S.; Mendez, R. A.; Altmann, M.

2017-07-01

To ensure the full capabilities of the Gaia's measurements, a programme of daily observations with Earth-based telescopes of the satellite itself - called Ground Based Optical Tracking (GBOT) - was implemented since the beginning of the Gaia mission (for more details concerning GBOT operating see Altmann et al. 2014 and concerning GBOT software facilities see Bouquillon et al. 2014). These observations are carried out mainly with two facilities: the 2.6m VLT Survey Telescope (ESO's VST) at the Cerro Paranal in Chile and the 2.0m Liverpool Telescope (LT) on the Canary Island of La Palma. The constraint of 20 mas on the tracking astrometric quality and the fact that Gaia is a faint and relatively fast moving target (its magnitude in a red passband is around 21 and its apparent speed around 0.04"/s), lead us to rigorously analyse the reachable astrometric precision for CCD observations of this kind of celestial objects. During LARIM 2016, we presented the main results of this study which uses the Cramér-Rao lower bound to characterize the precision limit for the PSF center when drifting in the CCD-frame. This work extends earlier studies dealing with one-dimensional detectors and stationary sources (Mendez et al. 2013 & 2014) firstly to the case of standard two-dimensional CCD sensors, and then, to moving sources. These new results have been submitted for a publication in A&A journal this year (Bouquillon et al. 2017).

Distant World in Peril Discovered from La Silla

NASA Astrophysics Data System (ADS)

2003-01-01

Giant Exoplanet Orbits Giant Star Summary When, in a distant future, the Sun begins to expand and evolves into a "giant" star, the surface temperature on the Earth will rise dramatically and our home planet will eventually be incinerated by that central body. Fortunately for us, this dramatic event is several billion years away. However, that sad fate will befall another planet, just discovered in orbit about the giant star HD 47536, already within a few tens of millions of years. At a distance of nearly 400 light-years from us, it is the second-remotest planetary system discovered to date [1]. This is an interesting side-result of a major research project, now carried out by a European-Brazilian team of astronomers [2]. In the course of a three-year spectroscopic survey, they have observed about 80 giant stars in the southern sky with the advanced FEROS spectrograph on the 1.52-m telescope installed at the ESO La Silla Observatory (Chile). It is one of these stars that has just been found to host a giant planet. This is only the fourth such case known and with a diameter of about 33 million km (or 23.5 times that of our Sun), HD 47536 is by far the largest of those giant stars [1]. The distance of the planet from the star is still of the order of 300 million km (or twice the distance of the Earth from the Sun), a safe margin now, but this will not always be so. The orbital period is 712 days, i.e., somewhat less than two Earth years, and the planet's mass is 5 - 10 times that of Jupiter. The presence of exoplanets in orbit around giant stars, some of which will eventually perish into their central star (be "cannibalized"), provides a possible explanation of the anomalous abundance of certain chemical elements that is observed in the atmospheres of some stars, cf. ESO PR 10/01. This interesting discovery bodes well for coming observations of exoplanetary systems with new, more powerful instruments, like HARPS to be installed next year at the ESO 3.6-m telescope on La Silla, and also the Very Large Telescope Interferometer (VLTI) now being commissioned at Paranal. PR Photo 05a/03: Giant stars observed in this programme (HR-diagram) PR Photo 05b/03: Giant star HD 47536. PR Photo 05c/03: "Velocity curve" of HD 47536. PR Photo 05d/03: Distance distribution of known exoplanets. Stellar evolution The structure and evolution of stars like our Sun are quite well understood. They are born by contraction in immense clouds of dust and gas and when the central density and temperature become high enough, nuclear fusion ignites in their interiors. Then follows a long period of relative calm - the Sun is now in this phase - that ends when the nuclear fuel runs out. A direct result is that the star begins to expand and soon becomes a "giant". During this phase, the surface temperature drops somewhat (but is still several thousand degrees) and the colour of the star changes from yellow to red. In the case of the Sun, this will happen some billion years from now. At some moment, our star will become larger and the surface of our home planet will become exceedingly hot, incinerating whatever remaining lifeforms that cannot protect themselves. Later, the Sun will shred its outer layers into space and a small, hot core will become visible. This final stage of stellar evolution can be observed as beautiful "Planetary Nebulae", e.g. the Dumbbell Nebula of which an impressive VLT photo is available (ESO PR Photos 38a-b/98). A spectroscopic survey of giant stars ESO PR Photo 05a/03 ESO PR Photo 05a/03 [Preview - JPEG: 400 x 467 pix - 128k [Normal - JPEG: 800 x 933 pix - 288k] Caption: PR Photo 05a/03 shows part of the Hertzsprung-Russell (HR) diagram [3] - a very useful way to illustrate stellar evolution. Plotting the temperature of solar-type stars (abscissa; in degrees Kelvin or as a "colour index") against their intrinsic brightness (ordinate; in solar units) reveals a typical distribution (hotter stars are less bright than cooler stars) that reflect their different evolutionary stages. With time, the position of the Sun in this diagram (now at the lower left) will migrate towards the upper right as it expands and becomes brighter. This direction corresponds to increasing radius. The approximately 80 stars plotted here are those that are being spectroscopically observed within the present programme; cf. the text. The positions and names of four giant stars that are known to host planets are marked [1]. The largest and brightest of them is HD 47536, as indicated by its upper-right position, relative to the three others. Since 1999, a European-Brazilian team of astronomers [2] has been studying a selection of comparatively bright giant stars with the goal to learn more about their physical properties. In particular, detailed spectra have been obtained by means of the advanced FEROS spectrograph on the 1.52-m telescope that is installed at the ESO La Silla Observatory in Chile, cf. ESO PR 03/99. About 80 stars have been regularly observed with this instrument, in order to search for possible velocity variations [4]. In PR Photo 05a/03, their temperature and intrinsic brightness are plotted in the so-called Hertzsprung-Russell diagram [3], a very useful way of illustrating stellar evolution. The background for this ambitious research project is that recent observations indicate that some giant stars may undergo small velocity variations with periods from days to years. While short-term variations are likely to be caused by oscillations in their extended and tenous atmospheres, there are at least three possible causes for long-term variations: 1) the gravitational pull of one or more orbiting planets, 2) radial pulsations of the entire star, or 3) variable surface patterns due to stellar activity. Which of these possibilities are behind the observed velocity variations? How many of those stars pulsate? Do some of them possess planets and if so, are planetary systems around giant stars common or not? "These are very fundamental questions" says team leader Johny Setiawan of the Kiepenheuer-Institut in Freiburg (Germany), "and the present discovery was somehow unexpected. Many of our giant stars show similar long-period velocity variations which we suspect are due to stellar activity". A planet around HD 47536 ESO PR Photo 05b/03 ESO PR Photo 05b/03 [Preview - JPEG: 400 x 462 pix - 68k [Normal - JPEG: 800 x 924 pix - 360k] ESO PR Photo 05c/03 ESO PR Photo 05c/03 [Preview - JPEG: 400 x 433 pix - 112k [Normal - JPEG: 800 x 866 pix - 256k] ESO PR Photo 05d/03 ESO PR Photo 05d/03 [Preview - JPEG: 477 x 400 pix - 96k [Normal - JPEG: 953 x 800 pix - 272k] Captions: PR Photo 05b/03 shows a sky area of 10 x 10 arcmin2 around the 6th-magnitude giant star HD 47536 at which a new exoplanet has been found (reproduced from the Digital Sky Survey [STScI Digitized Sky Survey, (C) 1993, 1994, AURA, Inc. all rights reserved - cf. http://archive.eso.org/dss/dss]). The pattern is caused by internal reflections in the telescope from this relatively bright object. PR Photo 05c/03 displays the "velocity curve" of HD 47536, caused by the pull of the orbiting planet during the 712-day period (abscissa: Julian Date - 2,400,000; ordinate: velocity in kilometres per second along the line-of-sight). Error bars indicate the accuracy of the measurements. The fully-drawn curve is the computed velocity curve, corresponding to the best-fitting planetary orbit. The lower part of the diagram displays the deviation of the measurements from this curve - in the mean about 0.025 km/sec, or 25 m/sec. In PR Photo 05d/03, the distribution of the distances of the 100+ known exoplanets is shown, with the planet around HD 47536 at the extreme end. The extensive observations began three years ago, with the main aim to pin down the cause(s) for any possible long-term variations. For this programme to succeed, it was also necessary to monitor other properties of these stars, in particular more rapid changes in the upper atmosphere ("stellar activity"). The first results indicate that about 70% of these stars display velocity variations. Among them, the 6th-magnitude star HD 47536 in the southern constellation of Canis Major (The Great Dog) soon caught the eye of the observers, as the measured velocity variations strongly indicated the presence of a planetary companion. The same FEROS spectra also show that other possible explanations, including stellar activity, are very unlikely to be responsible for those variations. At a distance of 396 light-years, the new exoplanet is the second-most remote one found to date. It moves around HD 47536 in a slightly elongated orbit and one revolution lasts somewhat less than two Earth years (712 days). Depending on the mass of the star (which is not well known yet), the distance of the planet from the star is somewhere between 240 and 337 million km (the mean distance of planet Mars to the Sun is 228 million km) and the new planet has between 4.9 and 9.7 times the mass of planet Jupiter (for assumed stellar mass 1.1 and 3.0 times that of the Sun, respectively). The indicated planetary mass is in any case too small for this object to be a "failed star", it is a bona-fide planet. Implications "We are very excited about this discovery", says Luca Pasquini of ESO, "because it now widens the search for exoplanets towards more massive stars. The observational problem is that most massive stars rotate very rapidly during the first phase of their life. This makes accurate measurements of minute velocity variations caused by the gravitaional pull of accompanying planets virtually impossible. However, in the later phase of their lives when they become giants, they slow down considerably and we then have a much better chance of detecting possible exoplanets in orbit around them." The giant planet in orbit around HD 47536 is now most probably witnessing some of those dramatic events that will happen to the Earth some billions of years from now. Its central star is slowly but steadily expanding and occupies a progressively larger fraction of the sky above the planet. The insolation is becoming more and more intense, with the resulting atmospheric effects - rising temperature and violent winds. Some tens of millions of years from now, the unlucky planet is doomed to lose its gaseous layers entirely and the surface will become burning hot. The discovery has other interesting implications. For years, the present team of astronomers has been studying certain giant stars that are found to contain much lithium. However, this light element is rapidly consumed in such stars and it should really not be there, see also ESO PR 10/01. "No problem now", says team member Licio da Silva from the Observatório Nacional in Rio de Janeiro (Brazil), "one obvious possibility is that those stars have obtained their lithium by recently swallowing a nearby planet. But until recently, this hypothesis was considered rather exotic, because of the lack of evidence of planets in danger". Indeed, with this discovery of a giant planet near a giant star, that explanation is looking quite plausible. Perspectives With over 70 other giant stars still under close scrutiny, the perspectives for the present programme appear very promising. The present discovery comes at a moment when the team is working hard to sift through the many observational data - it is quite possible that they will find other giant stars with planet-induced velocity variations. At the same time, the observational means for this kind of research are getting ever more powerful. Soon, the HARPS very high-precision spectrometer will be installed at the ESO 3.6-m telescope on La Silla. It has been built by the Geneva Observatory in collaboration with ESO and will be dedicated to the search for exoplanets.

ALMA telescope reaches new heights

NASA Astrophysics Data System (ADS)

2009-09-01

The ALMA (Atacama Large Millimeter/submillimeter Array) astronomical observatory has taken another step forward - and upwards. One of its state-of-the-art antennas was carried for the first time to the 5000m plateau of Chajnantor, in the Chilean Andes, on the back of a custom-built giant transporter. The antenna, which weighs about 100 tons and has a diameter of 12 metres, was transported up to the high-altitude Array Operations Site, where the extremely dry and rarefied air is ideal for ALMA's observations of the Universe. The conditions at the Array Operations Site on Chajnantor, while excellent for astronomy, are also very harsh. Only half as much oxygen is available as at sea level, making it very difficult to work there. This is why ALMA's antennas are assembled and tested at the lower 2900 m altitude of the ALMA Operations Support Facility. It was from this relatively hospitable base camp that the ALMA antenna began its journey to the high Chajnantor site. "This is an important moment for ALMA. We are very happy that the first transport of an antenna to the high site went flawlessly. This achievement was only possible through contributions from all international ALMA partners: this particular antenna is provided by Japan, the heavy-lift transporter by Europe, and the receiving electronics inside the antenna by North America, Europe, and Asia", said Wolfgang Wild, European ALMA Project Manager. The trip began when one of the two ALMA transporters, named Otto, lifted the antenna onto its back. It then carried its heavy load along the 28 km road from the Operations Support Facility up to the Array Operations Site. While the transporter is capable of speeds of up to 12 km/hour when carrying an antenna, this first journey was made more slowly to ensure that everything worked as expected, taking about seven hours. The ALMA antennas are the most advanced submillimetre-wavelength antennas ever made. They are designed to operate fully exposed in the harsh conditions of the Array Operations Site. This means surviving strong winds and temperatures between +20 and -20 Celsius whilst being able to point precisely enough that they could pick out a golf ball at a distance of 15 km, and to keep their smooth reflecting surfaces accurate to better than 25 micrometres (less than the typical thickness of a human hair). Once the transporter reached the high plateau it carried the antenna to a concrete pad - a docking station with connections for power and fibre optics - and positioned it with an accuracy of a few millimetres. The transporter is guided by a laser steering system and, just like some cars today, also has ultrasonic collision detectors. These sensors ensure the safety of the state-of-the-art antennas as the transporter drives them across what will soon be a rather crowded plateau. Ultimately, ALMA will have at least 66 antennas distributed over about 200 pads, spread over distances of up to 18.5 km and operating as a single, giant telescope. Even when ALMA is fully operational, the transporters will be used to move the antennas between pads to reconfigure the telescope for different kinds of observations. "Transporting our first antenna to the Chajnantor plateau is a epic feat which exemplifies the exciting times in which ALMA is living. Day after day, our global collaboration brings us closer to the birth of the most ambitious ground-based astronomical observatory in the world", said Thijs de Graauw, ALMA Director. This first ALMA antenna at the high site will soon be joined by others and the ALMA team looks forward to making their first observations from the Chajnantor plateau. They plan to link three antennas by early 2010, and to make the first scientific observations with ALMA in the second half of 2011. ALMA will help astronomers answer important questions about our cosmic origins. The telescope will observe the Universe using light with millimetre and submillimetre wavelengths, between infrared light and radio waves in the electromagnetic spectrum. Light at these wavelengths comes from some of the coldest, but also from some of the most distant objects in the cosmos. These include cold clouds of gas and dust where new stars are being born and remote galaxies towards the edge of the observable universe. The Universe is relatively unexplored at submillimetre wavelengths, as the telescopes need extremely dry atmospheric conditions, such as those at Chajnantor, and advanced detector technology. More information The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ESO is the European partner in ALMA. ALMA, the largest astronomical project in existence, is a revolutionary telescope, comprising an array of 66 giant 12-metre and 7-metre diameter antennas observing at millimetre and submillimetre wavelengths. ALMA will start scientific observations in 2011. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

ALLSMOG, the APEX Low-redshift Legacy Survey for MOlecular Gas

NASA Astrophysics Data System (ADS)

Bothwell, M.; Cicone, C.; Wagg, J.; De Breuck, C..

2017-09-01

We report the completion of the APEX Low-redshift Legacy Survey for MOlecular Gas (ALLSMOG), an ESO Large Programme, carried out with the Atacama Pathfinder EXperiment (APEX) between 2013 and 2016. With a total of 327 hours of APEX observing time, we observed the 12CO(2-1) line in 88 nearby low-mass star-forming galaxies. We briefly outline the ALLSMOG goals and design, and describe a few science highlights that have emerged from the survey so far. We outline future work that will ensure that the ALLSMOG dataset continues to provide scientific value in the coming years. ALLSMOG was designed to be a reference legacy survey and as such all reduced data products are publicly available through the ESO Science Archive Phase 3 interface.

VIMOS Instrument Control Software Design: an Object Oriented Approach

NASA Astrophysics Data System (ADS)

Brau-Nogué, Sylvie; Lucuix, Christian

2002-12-01

The Franco-Italian VIMOS instrument is a VIsible imaging Multi-Object Spectrograph with outstanding multiplex capabilities, allowing to take spectra of more than 800 objects simultaneously, or integral field spectroscopy mode in a 54x54 arcsec area. VIMOS is being installed at the Nasmyth focus of the third Unit Telescope of the European Southern Observatory Very Large Telescope (VLT) at Mount Paranal in Chile. This paper will describe the analysis, the design and the implementation of the VIMOS Instrument Control System, using UML notation. Our Control group followed an Object Oriented software process while keeping in mind the ESO VLT standard control concepts. At ESO VLT a complete software library is available. Rather than applying waterfall lifecycle, ICS project used iterative development, a lifecycle consisting of several iterations. Each iteration consisted in : capture and evaluate the requirements, visual modeling for analysis and design, implementation, test, and deployment. Depending of the project phases, iterations focused more or less on specific activity. The result is an object model (the design model), including use-case realizations. An implementation view and a deployment view complement this product. An extract of VIMOS ICS UML model will be presented and some implementation, integration and test issues will be discussed.

VizieR Online Data Catalog: weak G-band stars abundances (Palacios+, 2016)

NASA Astrophysics Data System (ADS)

Palacios, A.; Jasniewicz, G.; Masseron, T.; Thevenin, F.; Itam-Pasquet, J.; Parthasarathy, M.

2016-05-01

Seventeen southern wGb stars were observed at La Silla, ESO Chile, with the high-efficiency Fiber-fed Extended Range Optical Spectrograph FEROS spectrograph mounted on the 2.2m telescope. FEROS is a bench-mounted, thermally controlled, prism-cross-dispersed echelle spectrograph, providing, in a single spectrogram spread over 39 orders, almost complete spectral coverage from ~350 to ~920nm at a resolution of 48000. The FEROS observations were carried out during an observing run between May 10 and 13, 2012. All these spectra were flat-fielded and calibrated by means of ThArNe exposures using standard processing tools available at ESO. In addition, two northern wGb stars, HD 18474 and HD 166208, were observed in service mode at the Observatoire du Pic du Midi, France, with the NARVAL spectrograph mounted on the Bernard Lyot 2.0m telescope. The NARVAL instrument consists of a bench-mounted cross-dispersed echelle spectrograph, fibre-fed from a Cassegrain-mounted polarimeter unit. It was used in its non-polarimetric mode; it provided almost complete spectral coverage from ~375 to ~1050nm at a resolution of 75000 in a single spectrogram spread over 40 orders. (6 data files).

Live Webcasts from CERN and ESO for European Science and Technology Week

NASA Astrophysics Data System (ADS)

2002-10-01

Visit http://www.cern.ch/sci-tech on 7 - 8 November to find out what modern Europeans can't live without. Seven of Europe's leading Research Organizations [1] are presenting three live Webcasts from CERN in a joint outreach programme for the European Science and Technology Week . The aim of Sci-Tech... couldn't be without it! is to show how today's society couldn't be without cutting-edge scientific research. See also ESO Press Release 05/02. Northern Europeans can't imagine their households without ovens, whereas Southern Europeans identify the refrigerator as the most essential household appliance. In the area of communications, cars and motorbikes are clearly the technologies of choice in Italy, but are regarded as less important in countries like Norway and Germany. For entertainment, the personal computer is a clear winner as the device is considered most essential by all Europeans, followed by the TV and the Internet. This hit parade of technological marvels is the result of a phone and online survey conducted by the Sci-Tech... couldn't be without it! team for this year's European Science and Technology Week on 4-10 November. The technologies Europeans could not be without, form the starting point of three entertaining and informative Webcast shows in Italian (Thursday 7 November at 10:00 CET), French (Thursday 7 November at 15:00 CET) and English (Friday 8 November at 15:00 CET), broadcast live on the Internet from a studio at CERN. During these Webcasts scientists from the seven research Organizations and their industrial partners Sun Microsystems, Siemens, L'Oreal and Luminex will engage - from the CERN studio or from remote locations through teleconference links - an audience of Internauts all over the world. The public will be taken inside their most popular gadgets to discover the science that made them possible and how vital fundamental research has been in the creation of modern technology. Fundamental science will be brought as close as possible to people's daily lives by showing in an entertaining way how the behaviour of electrons in silicon was essential to the development of transistors and thus to computers, for example. How new medicines are developed by looking at the genome of malaria-carrying mosquitoes, and how cancer can be diagnosed and treated with particle beams. People will be amazed to discover how everyday products such as cosmetics are developed using advanced scientific instruments like synchrotron radiation sources. And how fashion and design will be soon revolutionised by a new fabric made of the same optical fibre used for advanced computer networks. The excitement of the Internet audience will be maintained thanks to live quiz shows for 15 to 19 year-old Europeans in the studio and online, with top-tech prizes to win. Sci-tech... couldn't be without it! will show the next generation of technology users how fundamental research is relevant to everyday life, and draw attention to the fascinating opportunities that lie ahead in the world of research and development. WATCH THE LIVE WEBCASTS and take part in the Online quizzes: * Thursday 7 November at 10:00 hrs CET in Italian * Thursday 7 November at 15:00 hrs CET in French * Friday 8 November at 15:00 hrs CET in English on http://www.cern.ch/sci-tech For more information on the webcasts and the Sci-tech... couldn't be without it! project, contact: paola.catapano@cern.ch Catch A Star! Go to the Catch a Star! educational programme Another interesting webcast can be followed on Friday, November 8, 2002, from 13:00 hrs CET (in English) at: http://www.eso.org/public/outreach/eduoff/cas/cas2002/cas-webcast.html Earlier this year, the European Southern Observatory (ESO) and the European Association for Astronomy Education (EAAE) invited all students in Europe's schools to the exciting Catch A Star! web-based educational programme with a competition. It takes place within the context of the EC-sponsored European Week of Science and Technology (EWST) - 2002 . See also ESO Press Release 08/02. This project revolves around a web-based competition and is centred on astronomy. It is specifically conceived to stimulate the interest of young people in various aspects of this well-known field of science, but will also be of interest to the broad public. Three hundred groups of up to four persons (e.g., three students and one teacher) have selected an astronomical object of their choice - a bright star, a distant galaxy, a beautiful comet, a planet or a moon in the solar system, or some other celestial body. They come from 25 countries. Until tomorrow, November 1, 2002, they have to deliver a comprehensive report about their chosen object. All reports have to conform with certain rules and are judged by a jury. Those fulfilling the criteria (explained at the Catch A Star! website) will participate in a lottery with exciting prizes, the first prize being a free trip in early 2003 for the members of the group to the ESO Paranal Observatory in Chile, the site of the ESO Very Large Telescope (VLT) . The lottery drawing will take place at the end of the European Week of Science and Technology, on November 8th, 2002, beginning at 13:00 hrs CET (12:00 UT) . This event will be broadcast by webcast and the outcome will be displayed via a dedicated webpage. All accepted reports (that fulfill the criteria) will be published on the Catch A Star! website soon thereafter.

PESSTO: survey description and products from the first data release by the Public ESO Spectroscopic Survey of Transient Objects

NASA Astrophysics Data System (ADS)

Smartt, S. J.; Valenti, S.; Fraser, M.; Inserra, C.; Young, D. R.; Sullivan, M.; Pastorello, A.; Benetti, S.; Gal-Yam, A.; Knapic, C.; Molinaro, M.; Smareglia, R.; Smith, K. W.; Taubenberger, S.; Yaron, O.; Anderson, J. P.; Ashall, C.; Balland, C.; Baltay, C.; Barbarino, C.; Bauer, F. E.; Baumont, S.; Bersier, D.; Blagorodnova, N.; Bongard, S.; Botticella, M. T.; Bufano, F.; Bulla, M.; Cappellaro, E.; Campbell, H.; Cellier-Holzem, F.; Chen, T.-W.; Childress, M. J.; Clocchiatti, A.; Contreras, C.; Dall'Ora, M.; Danziger, J.; de Jaeger, T.; De Cia, A.; Della Valle, M.; Dennefeld, M.; Elias-Rosa, N.; Elman, N.; Feindt, U.; Fleury, M.; Gall, E.; Gonzalez-Gaitan, S.; Galbany, L.; Morales Garoffolo, A.; Greggio, L.; Guillou, L. L.; Hachinger, S.; Hadjiyska, E.; Hage, P. E.; Hillebrandt, W.; Hodgkin, S.; Hsiao, E. Y.; James, P. A.; Jerkstrand, A.; Kangas, T.; Kankare, E.; Kotak, R.; Kromer, M.; Kuncarayakti, H.; Leloudas, G.; Lundqvist, P.; Lyman, J. D.; Hook, I. M.; Maguire, K.; Manulis, I.; Margheim, S. J.; Mattila, S.; Maund, J. R.; Mazzali, P. A.; McCrum, M.; McKinnon, R.; Moreno-Raya, M. E.; Nicholl, M.; Nugent, P.; Pain, R.; Pignata, G.; Phillips, M. M.; Polshaw, J.; Pumo, M. L.; Rabinowitz, D.; Reilly, E.; Romero-Cañizales, C.; Scalzo, R.; Schmidt, B.; Schulze, S.; Sim, S.; Sollerman, J.; Taddia, F.; Tartaglia, L.; Terreran, G.; Tomasella, L.; Turatto, M.; Walker, E.; Walton, N. A.; Wyrzykowski, L.; Yuan, F.; Zampieri, L.

2015-07-01

Context. The Public European Southern Observatory Spectroscopic Survey of Transient Objects (PESSTO) began as a public spectroscopic survey in April 2012. PESSTO classifies transients from publicly available sources and wide-field surveys, and selects science targets for detailed spectroscopic and photometric follow-up. PESSTO runs for nine months of the year, January - April and August - December inclusive, and typically has allocations of 10 nights per month. Aims: We describe the data reduction strategy and data products that are publicly available through the ESO archive as the Spectroscopic Survey data release 1 (SSDR1). Methods: PESSTO uses the New Technology Telescope with the instruments EFOSC2 and SOFI to provide optical and NIR spectroscopy and imaging. We target supernovae and optical transients brighter than 20.5m for classification. Science targets are selected for follow-up based on the PESSTO science goal of extending knowledge of the extremes of the supernova population. We use standard EFOSC2 set-ups providing spectra with resolutions of 13-18 Å between 3345-9995 Å. A subset of the brighter science targets are selected for SOFI spectroscopy with the blue and red grisms (0.935-2.53 μm and resolutions 23-33 Å) and imaging with broadband JHKs filters. Results: This first data release (SSDR1) contains flux calibrated spectra from the first year (April 2012-2013). A total of 221 confirmed supernovae were classified, and we released calibrated optical spectra and classifications publicly within 24 h of the data being taken (via WISeREP). The data in SSDR1 replace those released spectra. They have more reliable and quantifiable flux calibrations, correction for telluric absorption, and are made available in standard ESO Phase 3 formats. We estimate the absolute accuracy of the flux calibrations for EFOSC2 across the whole survey in SSDR1 to be typically ~15%, although a number of spectra will have less reliable absolute flux calibration because of weather and slit losses. Acquisition images for each spectrum are available which, in principle, can allow the user to refine the absolute flux calibration. The standard NIR reduction process does not produce high accuracy absolute spectrophotometry but synthetic photometry with accompanying JHKs imaging can improve this. Whenever possible, reduced SOFI images are provided to allow this. Conclusions: Future data releases will focus on improving the automated flux calibration of the data products. The rapid turnaround between discovery and classification and access to reliable pipeline processed data products has allowed early science papers in the first few months of the survey. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, as part of programme 188.D-3003 (PESSTO). http://www.pessto.org

Orion in a New Light - VISTA exposes high-speed antics of young stars

NASA Astrophysics Data System (ADS)

2010-02-01

The Orion Nebula reveals many of its hidden secrets in a dramatic image taken by ESO's new VISTA survey telescope. The telescope's huge field of view can show the full splendour of the whole nebula and VISTA's infrared vision also allows it to peer deeply into dusty regions that are normally hidden and expose the curious behaviour of the very active young stars buried there. VISTA - the Visible and Infrared Survey Telescope for Astronomy - is the latest addition to ESO's Paranal Observatory (eso0949). It is the largest survey telescope in the world and is dedicated to mapping the sky at infrared wavelengths. The large (4.1-metre) mirror, wide field of view and very sensitive detectors make VISTA a unique instrument. This dramatic new image of the Orion Nebula illustrates VISTA's remarkable powers. The Orion Nebula [1] is a vast stellar nursery lying about 1350 light-years from Earth. Although the nebula is spectacular when seen through an ordinary telescope, what can be seen using visible light is only a small part of a cloud of gas in which stars are forming. Most of the action is deeply embedded in dust clouds and to see what is really happening astronomers need to use telescopes with detectors sensitive to the longer wavelength radiation that can penetrate the dust. VISTA has imaged the Orion Nebula at wavelengths about twice as long as can be detected by the human eye. As in the many visible light pictures of this object, the new wide field VISTA image shows the familiar bat-like form of the nebula in the centre of the picture as well as the fascinating surrounding area. At the very heart of this region lie the four bright stars forming the Trapezium, a group of very hot young stars pumping out fierce ultraviolet radiation that is clearing the surrounding region and making the gas glow. However, observing in the infrared allows VISTA to reveal many other young stars in this central region that cannot be seen in visible light. Looking to the region above the centre of the picture, curious red features appear that are completely invisible except in the infrared. Many of these are very young stars that are still growing and are seen through the dusty clouds from which they form. These youthful stars eject streams of gas with typical speeds of 700 000 km/hour and many of the red features highlight the places where these gas streams collide with the surrounding gas, causing emission from excited molecules and atoms in the gas. There are also a few faint, red features below the Orion Nebula in the image, showing that stars form there too, but with much less vigour. These strange features are of great interest to astronomers studying the birth and youth of stars. This new image shows the power of the VISTA telescope to image wide areas of sky quickly and deeply in the near-infrared part of the spectrum. The telescope is just starting to survey the sky and astronomers are anticipating a rich harvest of science from this unique ESO facility. Notes [1] The Orion Nebula lies in the sword of the famous celestial hunter and is a favourite target both for casual sky watchers and astrophysicists alike. It is faintly visible to the unaided eye and appeared to early telescopic observers as a small cluster of blue-white stars surrounded by a mysterious grey-green mist. The object was first described in the early seventeenth century although the identity of the discoverer is uncertain. The French comet-hunter Messier made an accurate sketch of its main features in the mid-eighteenth century and gave it the number 42 in his famous catalogue. He also allocated the number 43 to the smaller detached region just above the main part of the nebula. Later William Herschel speculated that the nebula might be "the chaotic material of future suns" and astronomers have since discovered that the mist is indeed gas glowing under the fierce ultraviolet light from young hot stars that have recently formed there. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

VizieR Online Data Catalog: Variable stars in globular clusters (Figuera Jaimes+, 2016)

NASA Astrophysics Data System (ADS)

Figuera Jaimes, R.; Bramich, D. M.; Skottfelt, J.; Kains, N.; Jorgensen, U. G.; Horne, K.; Dominik, M.; Alsubai, K. A.; Bozza, V.; Calchi Novati, S.; Ciceri, S.; D'Ago, G.; Galianni, P.; Gu, S.-H.; W Harpsoe, K. B.; Haugbolle, T.; Hinse, T. C.; Hundertmark, M.; Juncher, D.; Korhonen, H.; Mancini, L.; Popovas, A.; Rabus, M.; Rahvar, S.; Scarpetta, G.; Schmidt, R. W.; Snodgrass, C.; Southworth, J.; Starkey, D.; Street, R. A.; Surdej, J.; Wang, X.-B.; Wertz, O.

2016-02-01

Observations were taken during 2013 and 2014 as part of an ongoing program at the 1.54m Danish telescope at the ESO observatory at La Silla in Chile that was implemented from April to September each year. table1.dat file contains the time-series I photometry for all the variables in the globular clusters studied in this work. We list standard and instrumental magnitudes and their uncertainties corresponding to the variable star identification, filter, and epoch of mid-exposure. For completeness, we also list the reference flux, difference flux, and photometric scale factor, along with the uncertainties on the reference and difference fluxes. (2 data files).

VizieR Online Data Catalog: Variable stars in NGC 6715 (Figuera Jaimes+, 2016)

NASA Astrophysics Data System (ADS)

Figuera Jaimes, R.; Bramich, D. M.; Kains, N.; Skottfelt, J.; Jorgensen, U. G.; Horne, K.; Dominik, M.; Alsubai, K. A.; Bozza, V.; Burgdorf, M. J.; Calchi Novati, S.; Ciceri, S.; D'Ago, G.; Evans, D. F.; Galianni, P.; Gu, S. H.; Harpsoe, K. B. W.; Haugbolle, T.; Hinse, T. C.; Hundertmark, M.; Juncher, D.; Kerins, E.; Korhonen, H.; Kuffmeier, M.; Mancini, L.; Peixinho, N.; Popovas, A.; Rabus, M.; Rahvar, S.; Scarpetta, G.; Schmidt, R. W.; Snodgrass, C.; Southworth, J.; Starkey, D.; Street, R. A.; Surdej, J.; Tronsgaard, R.; Unda-Sanzana, E.; von Essen, C.; Wang, X. B.; Wertz, O.

2016-06-01

Observations were taken during 2013, 2014, and 2015 as part of an ongoing program at the 1.54m Danish telescope at the ESO observatory at La Silla in Chile that was implemented from April to September each year. table1.dat file contains the time-series I photometry for all the variables in NGC 6715 studied in this work. We list standard and instrumental magnitudes and their uncertainties corresponding to the variable star identification, filter, and epoch of mid-exposure. For completeness, we also list the reference flux, difference flux, and photometric scale factor, along with the uncertainties on the reference and difference fluxes. (3 data files).

New and updated stellar parameters for 71 evolved planet hosts. On the metallicity-giant planet connection

NASA Astrophysics Data System (ADS)

Mortier, A.; Santos, N. C.; Sousa, S. G.; Adibekyan, V. Zh.; Delgado Mena, E.; Tsantaki, M.; Israelian, G.; Mayor, M.

2013-09-01

Context. It is still being debated whether the well-known metallicity-giant planet correlation for dwarf stars is also valid for giant stars. For this reason, having precise metallicities is very important. Precise stellar parameters are also crucial to planetary research for several other reasons. Different methods can provide different results that lead to discrepancies in the analysis of planet hosts. Aims: To study the impact of different analyses on the metallicity scale for evolved stars, we compare different iron line lists to use in the atmospheric parameter derivation of evolved stars. Therefore, we use a sample of 71 evolved stars with planets. With these new homogeneous parameters, we revisit the metallicity-giant planet connection for evolved stars. Methods: A spectroscopic analysis based on Kurucz models in local thermodynamic equilibrium (LTE) was performed through the MOOG code to derive the atmospheric parameters. Two different iron line list sets were used, one built for cool FGK stars in general, and the other for giant FGK stars. Masses were calculated through isochrone fitting, using the Padova models. Kolmogorov-Smirnov tests (K-S tests) were then performed on the metallicity distributions of various different samples of evolved stars and red giants. Results: All parameters compare well using a line list set, designed specifically for cool and solar-like stars to provide more accurate temperatures. All parameters derived with this line list set are preferred and are thus adopted for future analysis. We find that evolved planet hosts are more metal-poor than dwarf stars with giant planets. However, a bias in giant stellar samples that are searched for planets is present. Because of a colour cut-off, metal-rich low-gravity stars are left out of the samples, making it hard to compare dwarf stars with giant stars. Furthermore, no metallicity enhancement is found for red giants with planets (log g < 3.0 dex) with respect to red giants without planets. The data presented here are based on observations collected at the La Silla Paranal Observatory, ESO (Chile) with the FEROS spectrograph at the 2.2 m telescope (ESO runs ID 70.C-0084, 088.C-0892, 089.C-0444, and 090.C-0146) and the HARPS spectrograph at the 3.6 m telescope (ESO run ID 72.C-0488); at the Paranal Observatory, ESO (Chile) with the UVES spectrograph at the VLT Kueyen telescope (ESO runs ID 074.C-0134, 079.C-0131, 380.C-0083, and 083.C-0174); at the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias with the FIES spectrograph at the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden (program ID 44-210); and at the Observatoire de Haute-Provence (OHP, CNRS/OAMP), France with the SOPHIE spectrographs at the 1.93 m telescope (program ID 11B.DISC.SOUS).Tables 1, 5, 6 and Appendix A are available in electronic form at http://www.aanda.orgTables 5, 6, and A.1 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/557/A70

A Strange Supernova with a Gamma-Ray Burst

NASA Astrophysics Data System (ADS)

1998-10-01

Important Observations with La Silla Telescopes Several articles appear today in the scientific journal Nature about the strange supernova SN 1998bw that exploded earlier this year in the spiral galaxy ESO184-G82 . These studies indicate that this event was linked to a Gamma-Ray Burst and may thus provide new insights into this elusive phenomenon. Important observations of SN 1998bw have been made with several astronomical telescopes at the ESO La Silla Observatory by some of the co-authors of the Nature articles [1]. The measurements at ESO will continue during the next years. The early observations On April 25, the BeppoSAX satellite detected a Gamma-Ray Burst from the direction of the constellation Telescopium, deep in the southern sky. Although there is now general consensus that they originate in very distant galaxies, the underlying physical causes of these events that release great amounts of energy within seconds are still puzzling astronomers. Immediately after reports about the April 25 Burst had been received, astronomers at La Silla took some images of the sky region where the gamma-rays were observed as a "Target of Opportunity" (ToO) programme. The aim was to check if the visual light of one of the objects in the field had perhaps brightened when compared to exposures made earlier. This would then provide a strong indication of the location of the Gamma-Ray Burst. The digital exposures were transferred to the Italian/Dutch group around BeppoSax that had requested these ToO observations. Astronomers of this group quickly noticed a new, comparatively bright star, right on the arm of a small spiral galaxy. This galaxy was first catalogued in the 1970's during the ESO/Uppsala Survey of the Southern Sky and received the designation ESO184-G82 . It is located at a distance of about 140 million light-years. SN 1998bw ESO PR Photo 39a/98 ESO PR Photo 39a/98 [Preview - JPEG: 800 x 963 pix - 592k] [High-Res - JPEG: 3000 x 3612 pix - 4.1Mb] ESO PR Photo 39b/98 ESO PR Photo 39b/98 [Preview - JPEG: 800 x 987 pix - 432k] [High-Res - JPEG: 3000 x 3703 pix - 2.5Mb] PR Photo 39a/98 (left) shows a colour composite of three images obtained with the EMMI multi-mode instrument at the ESO 3.58-m New Technology Telescope (NTT) at La Silla on May 4, 1998. The short exposures were obtained through V (green), R (red) and I (near-infrared) filtres. SN 1998bw is the very bright, bluish star at the center (indicated with an arrow), located on an arm of spiral galaxy ESO 184-G82 . There are several other galaxies in the field. Compare with Photo 39b/98 (right) that was obtained before the explosion (ESO 1-m Schmidt Telescope; 15 May 1985; 120-min exposure in red light). In both photos, the field of view measures 3.6 x 3.6 arcmin; North is up and East is left. Note that while the brighter objects are more prominent on the long-exposure Schmidt photo (39b/98), considerably more details can be seen on that obtained by the NTT (39a/98). The ESO astronomers at La Silla decided to continue observations of the new star-like object and set up a comprehensive programme with several telescopes at that observatory. During the subsequent weeks and months, they obtained images through various filtres to determine the brightness in different colours, as well as detailed spectra. These observations soon showed the object to be a supernova . This is a heavy star that explodes during a late and fatal evolutionary stage. The new supernova now received the official designation SN 1998bw . From a careful study based on these observations, it has been concluded that SN 1998bw underwent an exceptionally powerful explosion, more violent than most other supernovae observed so far. It was also unusual in the sense that very strong radio emission was observed within a few days after the explosion - normally this only happens after several weeks. In fact, at radio wavelengths, SN 1998bw was the brightest supernova ever observed. The origin of the Gamma-Ray Burst SN 1998bw is obviously an unusual supernova. It is therefore of particular significance that a Gamma-Ray Burst was observed from the same sky region just before it was discovered in optical light. It is very unlikely that these two very rare events would happen in the same region of the sky without being somehow related. Most astronomers therefore tend to believe that the gamma-rays do indeed originate in the supernova explosion. But can a single supernova be sufficiently energetic to produce a powerful Gamma-Ray Burst? New theoretical calculations, also published today in Nature, indicate that this may be so. Moreover, if the Gamma-Ray Burst observed on April 25 did originate in this supernova that is located in a relatively nearby galaxy, it was intrinsically much fainter than some of the other Gamma-Ray Bursts that are known to have taken place in extremely distant galaxies. The main idea is that while the centres of most other supernovae collapse into neutron stars at the moment of explosion, a black hole was created in a very massive star consisting mostly of carbon and oxygen. If so, a very strong shockwave may be produced that is capable of generating the observed gamma rays. A comparison of synthetic spectra from such a supernova model, based on a new spectrum-modelling technique developed by Leon Lucy at the ESA/ESO Space Telescope/European Coordinating Facility (ST/ECF), with the spectra of SN 1998bw observed at La Silla, show good agreement, thus lending credibility to the new models. Future work Much data has already been collected at ESO on the strange supernova SN 1998bw . More observations will be obtained by the astronomers at the ESO observatories in the future during a long-term monitoring programme of SN 1998bw . There is a good chance that this effort will ultimately provide fundamental information on the explosion mechanism and the nature of the progenitor star of this exceptional object. This supernova's connection with a Gamma-Ray Burst will significantly enhance our understanding of the nature of these powerful and enigmatic events. In view of the range in emitted energy, it now seems likely that there may be more than one class of Gamma-Ray Burst. According to some models for Gamma-Ray Bursts that include beaming (emission of the radiation in one prefered direction), it is possible that these events are only detected if they have a favourable angle with respect to the line of sight. In the case of SN 1998bw this is probably not the case, however, and it was only detected in gamma-rays, because it is so relatively nearby. The question of differences in intrinsic brightness and possible different classes of objects is far from settled yet. Note: [1] The ESO astronomers involved in this work are Thomas Augusteijn, Hermann Boehnhardt, James Brewer, Vanessa Doublier, Jean-Francois Gonzalez, Olivier Hainaut, Bruno Leibundgut, Christopher Lidman and Fernando Patat . How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

The European SL-9/JUPITER Workshop

NASA Astrophysics Data System (ADS)

1995-02-01

During the past six months, many astronomers - observational as well theoretical - have been busy interpreting the many data taken during the impacts and thereafter. This is a very labour-intensive task and although the first conclusions have begun to emerge, it has also become obvious that extensive consultations between the various groups are necessary before it will be possible to understand the very complex processes during the impacts and thereafter. In order to further the interaction among the involved scientists, it has been decided to hold a three-day "European SL-9/Jupiter Workshop" at the Headquarters of the European Southern Observatory. More than 100 astronomers will meet on February 13-15, 1995, and close to 100 reports will be delivered on this occasion. Although most come from European countries, the major groups on other continents are also well represented. This meeting will give the participants the opportunity to exchange information about their individual programmes and will serve to establish future collaborative efforts. SL-9/JUPITER PRESS CONFERENCE In this connection, ESO is pleased to invite the media to a Press Conference: Wednesday, February 15, 1995, 17:30 CET ESO Headquarters, Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany This conference will be held at the end of the Workshop and will provide a thorough overview of the latest results, as presented during the meeting. Media representatives who are interested in participating in this Press Conference are requested to register with the ESO Information Service (Mrs. E. Völk, Tel.: +49-89-32006276; Fax: +49-89-3202362), at the latest on Friday, February 10, 1995. ESO Press Information is made available on the World-Wide Web (URL: http://www.hq.eso.org/) and on CompuServe (space science and astronomy area, GO SPACE).

Observing multiple populations in globular clusters with the ESO archive: NGC 6388 reloaded

NASA Astrophysics Data System (ADS)

Carretta, Eugenio; Bragaglia, Angela

2018-06-01

The metal-rich and old bulge globular cluster (GC) NGC 6388 is one of the most massive Galactic GCs (M 106 M⊙). However, the spectroscopic properties of its multiple stellar populations rested only on 32 red giants (only 7 of which observed with UVES, the others with GIRAFFE), given the difficulties in observing a rather distant cluster, heavily contaminated by bulge and disc field stars. We bypassed the problem using the resources of the largest telescope facility ever: the European Southern Observatory (ESO) archive. By selecting member stars identified by other programmes, we derive atmospheric parameters and the full set of abundances for 15 species from high-resolution UVES spectra of another 17 red giant branch stars in NGC 6388. We confirm that no metallicity dispersion is detectable in this GC. About 30% of the stars show the primordial composition of first-generation stars, about 20% present an extremely modified second-generation composition, and 50% have an intermediate composition. The stars are clearly distributed in the Al-O and Na-O planes in three discrete groups. We find substantial hints that more than a single class of polluters is required to reproduce the composition of the intermediate component in NGC 6388. In the heavily polluted component the sum Mg+Al increases as Al increases. The sum Mg+Al+Si is constant, and is the fossil record of hot H-burning at temperatures higher than about 70 MK in the first-generation polluters that contributed to form multiple populations in this cluster. Based on observations collected at ESO telescopes under programmes 073.D-0211 (propr ietary), and 073.D-0760, 381.D-0329, 095.D-0834 (archival).

Press Meeting 20 January 2003: First Light for Europe's Virtual Observatory

NASA Astrophysics Data System (ADS)

2002-12-01

Imagine you are an astronomer with instant, fingertip access to all existing observations of a given object and the opportunity to sift through them at will. In just a few moments, you can have information on all kinds about objects out of catalogues all over the world, including observations taken at different times. Over the next two years this scenario will become reality as Europe's Astrophysical Virtual Observatory (AVO) develops. Established only a year ago (cf. ESO PR 26/01), the AVO already offers astronomers a unique, prototype research tool that will lead the way to many outstanding new discoveries. Journalists are invited to a live demonstration of the capabilities of this exciting new initiative in astronomy. The demonstration will take place at the Jodrell Bank Observatory in Manchester, in the United Kingdom, on 20 January 2003, starting at 11:00. Sophisticated AVO tools will help scientists find the most distant supernovae - objects that reveal the cosmological makeup of our Universe. The tools are also helping astronomers measure the rate of birth of stars in extremely red and distant galaxies. Journalists will also have the opportunity to discuss the project with leading astronomers from across Europe. The new AVO website has been launched today, explaining the progress being made in this European Commission-funded project: URL: http://www.euro-vo.org/ To register your intention to attend the AVO First Light Demonstration, please provide your name and affiliation by January 13, 2003, to: Ian Morison, Jodrell Bank Observatory (full contact details below). Information on getting to the event is included on the webpage above. Programme for the AVO First Light Demonstration 11:00 Welcome, Phil Diamond (University of Manchester/Jodrell Bank Observatory) 11:05 Short introduction to Virtual Observatories, Piero Benvenuti (ESA/ST-ECF) 11:15 Q&A 11:20 Short introduction to the Astrophysical Virtual Observatory, Peter Quinn (ESO) 11:30 Q&A 11:35 Screening of Video News Release 11:40 Demonstration of the AVO prototype, Nicholas Walton (University of Cambridge) 12:00 Q&A, including interview possibilities with the scientists 12:30-13:45 Buffet lunch, including individual hands-on demos 14:00 Science Demo (also open to interested journalists) For more information about Virtual Observatories and the AVO, see the website or the explanation below. Notes to editors The AVO involves several partner organisations led by the European Southern Observatory (ESO). The other partner organisations are the European Space Agency (ESA), AstroGrid (funded by PPARC as part of the UK's E-Science programme), the CNRS-supported Centre de Données Astronomiques de Strasbourg (CDS), the University Louis Pasteur in Strasbourg, France, the CNRS-supported TERAPIX astronomical data centre at the Institut d'Astrophysique in Paris, France, and the Jodrell Bank Observatory of the Victoria University of Manchester, United Kingdom. Note [1]: This is a joint Press Release issued by the European Southern Observatory (ESO), the Hubble European Space Agency Information Centre, AstroGrid, CDS, TERAPIX/CNRS and the University of Manchester. Science Contacts Peter J. Quinn European Southern Observatory (ESO) Garching, Germany Tel: +49-89-3200 -6509 email: pjq@eso.org Phil Diamond University of Manchester/Jodrell Bank Observatory United Kingdom Tel: +44-147-757-26-25 (0147 in the United Kingdom) email: pdiamond@jb.man.ac.uk Press contacts Ian Morison University of Manchester/Jodrell Bank Observatory United Kingdom Tel: +44-147-757-26-10 (0147 in the United Kingdom) E-mail: email: im@jb.man.ac.uk Lars Lindberg Christensen Hubble European Space Agency Information Centre Garching, Germany Tel: +49-89-3200-6306 (089 in Germany) Cellular (24 hr): +49-173-3872-621 (0173 in Germany) email: lars@eso.org Richard West (ESO EPR Dept.) ESO EPR Dept. Garching, Germany Phone: +49-89-3200-6276 email: rwest@eso.org Background information What is a Virtual Observatory? - A short introduction The Virtual Observatory is an international astronomical community-based initiative. It aims to allow global electronic access to the available astronomical data archives of space and ground-based observatories, sky survey databases. It also aims to enable data analysis techniques through a coordinating entity that will provide common standards, wide-network bandwidth, and state-of-the-art analysis tools. It is now possible to have powerful and expensive new observing facilities at wavelengths from the radio to the X-ray and gamma-ray regions. Together with advanced instrumentation techniques, a vast new array of astronomical data sets will soon be forthcoming at all wavelengths. These very large databases must be archived and made accessible in a systematic and uniform manner to realise the full potential of the new observing facilities. The Virtual Observatory aims to provide the framework for global access to the various data archives by facilitating the standardisation of archiving and data-mining protocols. The AVO will also take advantage of state-of-the-art advances in data-handling software in astronomy and in other fields. The Virtual Observatory initiative is currently aiming at a global collaboration of the astronomical communities in Europe, North and South America, Asia, and Australia under the auspices of the recently formed International Virtual Observatory Alliance. The Astrophysical Virtual Observatory - An Introduction The breathtaking capabilities and ultrahigh efficiency of new ground and space observatories have led to a 'data explosion' calling for innovative ways to process, explore, and exploit these data. Researchers must now turn to the GRID paradigm of distributed computing and resources to solve complex, front-line research problems. To implement this new IT paradigm, you have to join existing astronomical data centres and archives into an interoperating and single unit. This new astronomical data resource will form a Virtual Observatory (VO) so that astronomers can explore the digital Universe in the new archives across the entire spectrum. Similarly to how a real observatory consists of telescopes, each with a collection of unique astronomical instruments, the VO consists of a collection of data centres each with unique collections of astronomical data, software systems, and processing capabilities. The Astrophysical Virtual Observatory Project (AVO) will conduct a research and demonstration programme on the scientific requirements and technologies necessary to build a VO for European astronomy. The AVO has been jointly funded by the European Commission (under FP5 - Fifth Framework Programme) with six European organisations participating in a three year Phase-A work programme, valued at 5 million Euro. The partner organisations are the European Southern Observatory (ESO) in Munich, Germany, the European Space Agency (ESA), AstroGrid (funded by PPARC as part of the UK's E-Science programme), the CNRS-supported Centre de Données Astronomiques de Strasbourg (CDS), the University Louis Pasteur in Strasbourg, France, the CNRS-supported TERAPIX astronomical data centre at the Institut d'Astrophysique in Paris, France, and the Jodrell Bank Observatory of the Victoria University of Manchester, United Kingdom. The Phase A program will focus its effort in the following areas: * A detailed description of the science requirements for the AVO will be constructed, following the experience gained in a smaller-scale science demonstration program called ASTROVIRTEL (Accessing Astronomical Archives as Virtual Telescopes). * The difficult issue of data and archive interoperability will be addressed by new standards definitions for astronomical data and trial programmes of "joins" between specific target archives within the project team. * The necessary GRID and database technologies will be assessed and tested for use within a full AVO implementation. The AVO project is currently working in conjunction with other international VO efforts in the United States and Asia-Pacific region. This is part of an International Virtual Observatory Alliance to define essential new data standards so that the VO concept can have a global dimension. The AVO partners will join with all astronomical data centres in Europe to put forward an FP6 IST (Sixth Framework Programme - Information Society Technologies Programme) Integrated Project proposal to make a European VO fully operational by the end of 2007.

Rubble-Pile Minor Planet Sylvia and Her Twins

NASA Astrophysics Data System (ADS)

2005-08-01

VLT NACO Instrument Helps Discover First Triple Asteroid One of the thousands of minor planets orbiting the Sun has been found to have its own mini planetary system. Astronomer Franck Marchis (University of California, Berkeley, USA) and his colleagues at the Observatoire de Paris (France) [1] have discovered the first triple asteroid system - two small asteroids orbiting a larger one known since 1866 as 87 Sylvia [2]. "Since double asteroids seem to be common, people have been looking for multiple asteroid systems for a long time," said Marchis. "I couldn't believe we found one." The discovery was made with Yepun, one of ESO's 8.2-m telescopes of the Very Large Telescope Array at Cerro Paranal (Chile), using the outstanding image' sharpness provided by the adaptive optics NACO instrument. Via the observatory's proven "Service Observing Mode", Marchis and his colleagues were able to obtain sky images of many asteroids over a six-month period without actually having to travel to Chile. ESO PR Photo 25a/05 ESO PR Photo 25a/05 Orbits of Twin Moonlets around 87 Sylvia [Preview - JPEG: 400 x 516 pix - 145k] [Normal - JPEG: 800 x 1032 pix - 350k] ESO PR Photo 25b/05 ESO PR Photo 25b/05 Artist's impression of the triple asteroid system [Preview - JPEG: 420 x 400 pix - 98k] [Normal - JPEG: 849 x 800 pix - 238k] [Full Res - JPEG: 4000 x 3407 pix - 3.7M] [Full Res - TIFF: 4000 x 3000 pix - 36.0M] Caption: ESO PR Photo 25a/05 is a composite image showing the positions of Remus and Romulus around 87 Sylvia on 9 different nights as seen on NACO images. It clearly reveals the orbits of the two moonlets. The inset shows the potato shape of 87 Sylvia. The field of view is 2 arcsec. North is up and East is left. ESO PR Photo 25b/05 is an artist rendering of the triple system: Romulus, Sylvia, and Remus. ESO Video Clip 03/05 ESO Video Clip 03/05 Asteroid Sylvia and Her Twins [Quicktime Movie - 50 sec - 384 x 288 pix - 12.6M] Caption: ESO PR Video Clip 03/05 is an artist rendering of the triple asteroid system showing the large asteroid 87 Sylvia spinning at a rapid rate and surrounded by two smaller asteroids (Remus and Romulus) in orbit around it. This computer animation is also available in broadcast quality to the media (please contact Herbert Zodet). One of these asteroids was 87 Sylvia, which was known to be double since 2001, from observations made by Mike Brown and Jean-Luc Margot with the Keck telescope. The astronomers used NACO to observe Sylvia on 27 occasions, over a two-month period. On each of the images, the known small companion was seen, allowing Marchis and his colleagues to precisely compute its orbit. But on 12 of the images, the astronomers also found a closer and smaller companion. 87 Sylvia is thus not double but triple! Because 87 Sylvia was named after Rhea Sylvia, the mythical mother of the founders of Rome [3], Marchis proposed naming the twin moons after those founders: Romulus and Remus. The International Astronomical Union approved the names. Sylvia's moons are considerably smaller, orbiting in nearly circular orbits and in the same plane and direction. The closest and newly discovered moonlet, orbiting about 710 km from Sylvia, is Remus, a body only 7 km across and circling Sylvia every 33 hours. The second, Romulus, orbits at about 1360 km in 87.6 hours and measures about 18 km across. The asteroid 87 Sylvia is one of the largest known from the asteroid main belt, and is located about 3.5 times further away from the Sun than the Earth, between the orbits of Mars and Jupiter. The wealth of details provided by the NACO images show that 87 Sylvia is shaped like a lumpy potato, measuring 380 x 260 x 230 km (see ESO PR Photo 25a/05). It is spinning at a rapid rate, once every 5 hours and 11 minutes. The observations of the moonlets' orbits allow the astronomers to precisely calculate the mass and density of Sylvia. With a density only 20% higher than the density of water, it is likely composed of water ice and rubble from a primordial asteroid. "It could be up to 60 percent empty space," said co-discoverer Daniel Hestroffer (Observatoire de Paris, France). "It is most probably a "rubble-pile" asteroid", Marchis added. These asteroids are loose aggregations of rock, presumably the result of a collision. Two asteroids smacked into each other and got disrupted. The new rubble-pile asteroid formed later by accumulation of large fragments while the moonlets are probably debris left over from the collision that were captured by the newly formed asteroid and eventually settled into orbits around it. "Because of the way they form, we expect to see more multiple asteroid systems like this." Marchis and his colleagues will report their discovery in the August 11 issue of the journal Nature, simultaneously with an announcement that day at the Asteroid Comet Meteor conference in Armação dos Búzios, Rio de Janeiro state, Brazil.

HATS-43b, HATS-44b, HATS-45b, and HATS-46b: Four Short-period Transiting Giant Planets in the Neptune–Jupiter Mass Range

NASA Astrophysics Data System (ADS)

Brahm, R.; Hartman, J. D.; Jordán, A.; Bakos, G. Á.; Espinoza, N.; Rabus, M.; Bhatti, W.; Penev, K.; Sarkis, P.; Suc, V.; Csubry, Z.; Bayliss, D.; Bento, J.; Zhou, G.; Mancini, L.; Henning, T.; Ciceri, S.; de Val-Borro, M.; Shectman, S.; Crane, J. D.; Arriagada, P.; Butler, P.; Teske, J.; Thompson, I.; Osip, D.; Díaz, M.; Schmidt, B.; Lázár, J.; Papp, I.; Sári, P.

2018-03-01

We report the discovery of four short-period extrasolar planets transiting moderately bright stars from photometric measurements of the HATSouth network coupled to additional spectroscopic and photometric follow-up observations. While the planet masses range from 0.26 to 0.90 {M}{{J}}, the radii are all approximately a Jupiter radii, resulting in a wide range of bulk densities. The orbital period of the planets ranges from 2.7 days to 4.7 days, with HATS-43b having an orbit that appears to be marginally non-circular (e = 0.173 ± 0.089). HATS-44 is notable for having a high metallicity ([{Fe}/{{H}}] = 0.320 ± 0.071). The host stars spectral types range from late F to early K, and all of them are moderately bright (13.3 < V < 14.4), allowing the execution of future detailed follow-up observations. HATS-43b and HATS-46b, with expected transmission signals of 2350 ppm and 1500 ppm, respectively, are particularly well suited targets for atmospheric characterization via transmission spectroscopy. The HATSouth network is operated by a collaboration consisting of Princeton University (PU), the Max Planck Institute für Astronomie (MPIA), the Australian National University (ANU), and the Pontificia Universidad Católica de Chile (PUC). The station at Las Campanas Observatory (LCO) of the Carnegie Institute is operated by PU in conjunction with PUC, the station at the High Energy Spectroscopic Survey (H.E.S.S.) site is operated in conjunction with MPIA, and the station at Siding Spring Observatory (SSO) is operated jointly with ANU. This paper includes data gathered with the MPG 2.2 m and ESO 3.6 m telescopes at the ESO Observatory in La Silla. This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile.

Complete identification of the Parkes half-Jansky sample of GHz peaked spectrum radio galaxies

NASA Astrophysics Data System (ADS)

de Vries, N.; Snellen, I. A. G.; Schilizzi, R. T.; Lehnert, M. D.; Bremer, M. N.

2007-03-01

Context: Gigahertz Peaked Spectrum (GPS) radio galaxies are generally thought to be the young counterparts of classical extended radio sources. Statistically complete samples of GPS sources are vital for studying the early evolution of radio-loud AGN and the trigger of their nuclear activity. The "Parkes half-Jansky" sample of GPS radio galaxies is such a sample, representing the southern counterpart of the 1998 Stanghellini sample of bright GPS sources. Aims: As a first step of the investigation of the sample, the host galaxies need to be identified and their redshifts determined. Methods: Deep R-band VLT-FORS1 and ESO 3.6 m EFOSC II images and long slit spectra have been taken for the unidentified sources in the sample. Results: We have identified all twelve previously unknown host galaxies of the radio sources in the sample. Eleven have host galaxies in the range 21.0 < RC < 23.0, while one object, PKS J0210+0419, is identified in the near infrared with a galaxy with Ks = 18.3. The redshifts of 21 host galaxies have been determined in the range 0.474 < z < 1.539, bringing the total number of redshifts to 39 (80%). Analysis of the absolute magnitudes of the GPS host galaxies show that at z>1 they are on average a magnitude fainter than classical 3C radio galaxies, as found in earlier studies. However their restframe UV luminosities indicate that there is an extra light contribution from the AGN, or from a population of young stars. Based on observations collected at the European Southern Observatory Very Large Telescope, Paranal, Chile (ESO prog. ID No. 073.B-0289(B)) and the European Southern Observatory 3.6 m Telescope, La Silla, Chile (prog. ID No. 073.B-0289(A)). Appendices are only available in electronic form at http://www.aanda.org

IFU simulator: a powerful alignment and performance tool for MUSE instrument

NASA Astrophysics Data System (ADS)

Laurent, Florence; Boudon, Didier; Daguisé, Eric; Dubois, Jean-Pierre; Jarno, Aurélien; Kosmalski, Johan; Piqueras, Laure; Remillieux, Alban; Renault, Edgard

2014-07-01

MUSE (Multi Unit Spectroscopic Explorer) is a second generation Very Large Telescope (VLT) integral field spectrograph (1x1arcmin² Field of View) developed for the European Southern Observatory (ESO), operating in the visible wavelength range (0.465-0.93 μm). A consortium of seven institutes is currently commissioning MUSE in the Very Large Telescope for the Preliminary Acceptance in Chile, scheduled for September, 2014. MUSE is composed of several subsystems which are under the responsibility of each institute. The Fore Optics derotates and anamorphoses the image at the focal plane. A Splitting and Relay Optics feed the 24 identical Integral Field Units (IFU), that are mounted within a large monolithic instrument mechanical structure. Each IFU incorporates an image slicer, a fully refractive spectrograph with VPH-grating and a detector system connected to a global vacuum and cryogenic system. During 2012 and 2013, all MUSE subsystems were integrated, aligned and tested to the P.I. institute at Lyon. After successful PAE in September 2013, MUSE instrument was shipped to the Very Large Telescope in Chile where that was aligned and tested in ESO integration hall at Paranal. After, MUSE was directly transferred in monolithic way without dismounting onto VLT telescope where the first light was overcame. This talk describes the IFU Simulator which is the main alignment and performance tool for MUSE instrument. The IFU Simulator mimics the optomechanical interface between the MUSE pre-optic and the 24 IFUs. The optomechanical design is presented. After, the alignment method of this innovative tool for identifying the pupil and image planes is depicted. At the end, the internal test report is described. The success of the MUSE alignment using the IFU Simulator is demonstrated by the excellent results obtained onto MUSE positioning, image quality and throughput. MUSE commissioning at the VLT is planned for September, 2014.

Catherine Cesarsky elected President of the International Astronomical Union and Ian Corbett elected Assistant General Secretary

NASA Astrophysics Data System (ADS)

2006-08-01

The General Assembly of the International Astronomical Union (IAU), meeting in Prague (Czech Republic), has elected the ESO Director General, Dr. Catherine Cesarsky, as President for a three-year period (2006-2009). The IAU is a body of distinguished professional astronomers, founded in 1919 to promote and safeguard the science of astronomy in all its aspects through international cooperation. It now has almost 10 000 individual members drawn from all continents. Dr. Cesarsky is the first woman to receive this high distinction. At the same General Assembly, Dr. Ian Corbett, ESO's Deputy Director General, was elected Assistant General Secretary for 2006-2009, with the expectation of becoming General Secretary in 2009-2012. ESO PR Photo 32/06 ESO PR Photo 32/06 The New IAU Officers Prof. Ron Ekers, the outgoing IAU President said: "The past few years have been highly productive for astronomy, with many discoveries giving new insights into our Universe which have excited scientists and general public alike. Catherine Cesarsky is internationally honoured as a scientist, and I am delighted that she has agreed to serve the IAU as President. She has already given invaluable service to the IAU and I am confident that she will provide outstanding leadership as President." "It is a great honour and a pleasure for me to be President of the International Astronomical Union for the next three years, especially in view of the proposed International Year of Astronomy in 2009, in which the IAU will play a leading role as a catalyst and a coordinator," said Catherine Cesarsky. "I am very much looking forward to working with my colleagues in the IAU to ensure that this is a great success." Dr. Cesarsky, ESO Director General since 1999, is known for her successful research activities in several central areas of modern astrophysics. She first worked on the theory of cosmic ray propagation and acceleration, and galactic gamma-ray emission. Later, she led the design and construction of the ISOCAM camera onboard the Infrared Space Observatory (ISO) of the European Space Agency (ESA), and the ISOCAM Central Programme that studied the infrared emission from many different galactic and extragalactic sources. This has led to new and exciting results on star formation and galactic evolution, and in the identification of the sources providing the bulk of the energy in the Cosmic Infrared Background. Dr. Cesarsky is author of more than 250 scientific papers. As ESO Director General, she has ensured that ESO is now accepted as the leading ground based observatory with its unique Very Large Telescope (VLT) and its associated interferometer (the VLTI). She has headed the European involvement in the international Atacama Large Millimeter Array (ALMA) project, due for completion in 2012. She is now leading the efforts by the European astronomy community to define the European Extremely Large Telescope (E-ELT), expected to be operational well before the end of the next decade. Dr. Cesarsky received the COSPAR (Committee on Space Research) Space Science Award in 1998 and is member of several renowned national and international Science Academies. She is married and has two children. Dr. Ian Corbett came to ESO from the UK Particle Physics and Astronomy Research Council (PPARC) in 2001. He started his research in particle physics and moved into astronomy about 25 years ago, initially with involvement in the UK telescopes on Hawaii, La Palma, and Australia, and then with Gemini and the UK space science programme. He has represented the UK on a large number of international bodies concerned with scientific collaboration. With ESO he has been particularly concerned with ALMA. At the same General Assembly, the IAU choose Dr. Robert Williams of the Space Telescope Science Institute as President-Elect and Prof. Karel A. van der Hucht of SRON, Netherlands, as General Secretary.

Australia to Build Fibre Positioner for the Very Large Telescope

NASA Astrophysics Data System (ADS)

1998-06-01

The Anglo-Australian Observatory (AAO) at Epping (New South Wales, Australia) has been awarded the contract to build a fibre positioner for the European Southern Observatory's Very Large Telescope (VLT). This new, large astronomical facility is located at the Paranal Observatory in Chile and will feature four Unit Telescopes, each with a main mirror of 8.2-m diameter. This positioner, (affectionately) known as the OzPoz , will form part of the FLAMES facility (the F ibre L arge A rea M ulti- E lement S pectrograph), to be mounted on the second Unit Telescope (UT2) of the VLT in 2001. The construction of this facility includes other institutes in Europe, e.g. Observatoire de Genève (Switzerland) and Observatoire de Meudon (France). The ESO Instrument Division will coordinate the entire project that will result in an observational capability that is unique in the world. Optical fibres at astronomical telescopes Optical fibres have come to play an increasingly important role as transmitters of information, for instance in telephone and computer networks. It may be less known that they can be used in a similar way to transmit visible and infrared light in astronomical telescopes. Over the past decade, the AAO has been refining its skills in building optical-fibre instruments for its own telescopes, the 3.9-metre Anglo-Australian Telescope and the 1.2-m UK Schmidt Telescope (a telescope dedicated to wide-field surveys). These instruments enable astronomers to study many celestial objects simultaneously, increasing the effectiveness and productivity by enormous factors. The OzPoz positioner sets up to 560 optical fibres (developed in collaboration with the Observatoire de Meudon in France) very precisely by a robotic arm to match the positions of galaxies and quasars in the telescope's focal plane. The positional accuracy is about 50 µm (0.05 mm), or 0.08 arcsec on the sky. The fibres siphon the light from these very faint and distant astronomical objects and guide it to very efficient, custom designed, spectrographs. Here the light is dispersed into its characteristic colours and analysed to determine the object's type, distance and chemical composition, etc. ESO PR Photo 18/98 ESO PR Photo 18/98 Reduced resolution 1024 x 1024 pix [JPEG, 860k] Full resolution 1500 x 1500 pix [GIF, 2.1 Mb] This image illustrates the use of the new Fibre Positioner (OzPoz). It shows an example of the 25 arcmin field-of-view of the VLT with the FLAMES facility, as recorded during the ESO Imaging Survey (EIS) with the 3.5-m New Technology Telescope (NTT) at La Silla. Within only one night, FLAMES with the OzPoz positioner will be capable of obtaining optical and infrared spectra for no less than 1/3 of the approx. 9000 objects (many of which are distant galaxies) seen in this image! They can then be used to determine their redshift, chemical composition and dynamics. This will increase enormously the observational efficiency of the VLT. In just one night, it is possible to observe and analyse thousands of objects, a task that would have taken years in the past. The contract Dr. Brian Boyle , Director of the AAO, is very pleased with the new ESO contract: "The AAO has been recognised many times in the past as being a world-leader in astronomy, but this contract marks a new era. Up until now, we have built instruments for our own telescopes to ensure we stay ahead. Now we have expanded into instrument making for other telescopes. Our engineers, computer programmers and scientists have formed a productive and innovative team which is the envy of many observatories around the world." The Director General of ESO, Professor Riccardo Giacconi , is also happy: "The Anglo-Australian Observatory has excellent credentials in instrument making, and we have no doubt about their ability to build the critical optical fibre positioner for the VLT. The spectacular success of the AAO 2dF instrument (see below) reinforced our decision." The contract will take about 3 years to build and will involve the work of at least 10 AAO engineers and technicians over this period. The AAO 2dF optical fibre positioner The 2dF (two-degree field) optical fibre positioner has taken more than seven years to perfect, and is now fully operational at the 3.9 m Anglo-Australian Telescope. With it, two very ambitious survey projects are now well underway. The 2dF Galaxy Redshift Survey and the 2dF Quasar Redshift Survey aim at analysing more than 250 000 galaxies and 3000 quasars over the next few years to give a three-dimensional picture of the Universe on a large scale. A few nights of early observations yielded spectra from 4000 galaxies and 1000 quasars; a massive data set which, through expert, dedicated software, was analysed on-line and distributed to the international science team by email within minutes of the completion of the observations. Note: [1] This Press Release is issued jointly by ESO and the Anglo-Australian Observatory (AAO). This Press Release is accompanied by ESO PR Photo 18/98 . It is available in two versions: Reduced resolution 1024 x 1024 pix [JPEG, 860k] and Full resolution 1500 x 1500 pix [GIF, 2.1 Mb]. It may be reproduced, if credit is given to the European Southern Observatory. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

Charting the Giants

NASA Astrophysics Data System (ADS)

2004-06-01

Largest Census Of X-Ray Galaxy Clusters Provides New Constraints on Dark Matter [1] Clusters of galaxies Clusters of galaxies are very large building blocks of the Universe. These gigantic structures contain hundreds to thousands of galaxies and, less visible but equally interesting, an additional amount of "dark matter" whose origin still defies the astronomers, with a total mass of thousands of millions of millions times the mass of our Sun. The comparatively nearby Coma cluster, for example, contains thousands of galaxies and measures more than 20 million light-years across. Another well-known example is the Virgo cluster at a distance of about 50 million light-years, and still stretching over an angle of more than 10 degrees in the sky! Clusters of galaxies form in the densest regions of the Universe. As such, they perfectly trace the backbone of the large-scale structures in the Universe, in the same way that lighthouses trace a coastline. Studies of clusters of galaxies therefore tell us about the structure of the enormous space in which we live. The REFLEX survey ESO PR Photo 18a/04 ESO PR Photo 18a/04 Galaxy Cluster RXCJ 1206.2-0848 (Visible and X-ray) [Preview - JPEG: 400 x 478 pix - 70k] [Normal - JPEG: 800 x 956 pix - 1.2Mk] Caption: PR Photo 18a shows the very massive distant cluster of galaxies RXCJ1206.2-0848, newly discovered during the REFLEX project, and located at a redshift of z = 0.44 [3]. The contours indicate the X-ray surface brightness distribution. Most of the yellowish galaxies are cluster members. A gravitationally lensed galaxy with a distorted, very elongated image is seen, just right of the centre. The image was obtained with the EFOSC multi-mode instrument on the ESO 3.6-m telescope at the La Silla Observatory (Chile). ESO PR Photo 18b/04 ESO PR Photo 18b/04 Galaxy cluster RXCJ1131.9-1955 [Preview - JPEG: 400 x 477 pix - 40k] [Normal - JPEG: 800 x 953 pix - 912k] [FullRes - JPEG: 2251 x 2681 pix - 7.7Mk] Caption: PR Photo 18b displays the very massive galaxy cluster RXCJ1131.9-1955 at redshift z = 0.306 [3] in a very rich galaxy field with two major concentrations. It was originally found by George Abell and designated "Abell 1300". The image was obtained with the ESO/MPG 2.2-m telescope and the WFI camera at La Silla. ESO PR Photo 18c/04 ESO PR Photo 18c/04 Galaxy Cluster RXCJ0937.9-2020 [Preview - JPEG: 400 x 746 pix - 60k] [Normal - JPEG: 800 x 1491 pix - 1.3M] [HiRes - JPEG: 2380 x 4437 pix - 14.2M] Caption: PR Photo 18c/04 shows the much smaller, more nearby galaxy group RXCJ0937.9-2020 at a redshift of z = 0.034 [3]. It is dominated by the massive elliptical galaxy seen at the top of the image. The photo covers only the southern part of this group. Such galaxy groups with typical masses of a few 1013 solar masses constitute the smallest objects included in the REFLEX catalogue. This image was obtained with the FORS1 multi-mode instrument on the ESO 8.2-m VLT Antu telescope. ESO PR Video Clip 05/04 ESO PR Video Clip 05/04 Galaxy Clusters in the REFLEX Catalogue (3D-visualization) [MPG - 11.7Mb] Caption: ESO PR Video Clip 05/04 illustrates the three-dimensional distribution of the galaxy clusters identfied in the ROSAT All-Sky survey in the northern and southern sky. In addition to the galaxy clusters in the REFLEX catalogue this movie also contains those identified during the ongoing, deeper search for X-ray clusters: the extension of the southern REFLEX Survey and the northern complementary survey that is conducted by the MPE team at the Calar Alto observatory and at US observatories in collaboration with John Huchra and coworkers at the Harvard-Smithonian Center for Astrophysics. In total, more than 1400 X-ray bright galaxy cluster have been found to date. (Prepared by Ferdinand Jamitzky.) Following this idea, a European team of astronomers [2], under the leadership of Hans Böhringer (MPE, Garching, Germany), Luigi Guzzo (INAF, Milano, Italy), Chris A. Collins (JMU, Liverpool), and Peter Schuecker (MPE, Garching) has embarked on a decade-long study of these gargantuan structures, trying to locate the most massive of clusters of galaxies. Since about one-fifth of the optically invisible mass of a cluster is in the form of a diffuse very hot gas with a temperature of the order of several tens of millions of degrees, clusters of galaxies produce powerful X-ray emission. They are therefore best discovered by means of X-ray satellites. For this fundamental study, the astronomers thus started by selecting candidate objects using data from the X-ray Sky Atlas compiled by the German ROSAT satellite survey mission. This was the beginning only - then followed a lot of tedious work: making the final identification of these objects in visible light and measuring the distance (i.e., redshift [3]) of the cluster candidates. The determination of the redshift was done by means of observations with several telescopes at the ESO La Silla Observatory in Chile, from 1992 to 1999. The brighter objects were observed with the ESO 1.5-m and the ESO/MPG 2.2-m telescopes, while for the more distant and fainter objects, the ESO 3.6-m telescope was used. Carried out at these telescopes, the 12 year-long programme is known to astronomers as the REFLEX (ROSAT-ESO Flux Limited X-ray) Cluster Survey. It has now been concluded with the publication of a unique catalogue with the characteristics of the 447 brightest X-ray clusters of galaxies in the southern sky. Among these, more than half the clusters were discovered during this survey. Constraining the dark matter content ESO PR Photo 18d/04 ESO PR Photo 18d/04 Constraints on Cosmological Parameters [Preview - JPEG: 400 pix x 572 - 37k] [Normal - JPEG: 800 x 1143 pix - 265k] Caption: PR Photo 18d demonstrates the current observational constraints on the cosmic density of all matter including dark matter (Ωm) and the dark energy (ΩΛ) relative to the density of a critical-density Universe (i.e., an expanding Universe which approaches zero expansion asymptotically after an infinite time and has a flat geometry). All three observational tests by means of supernovae (green), the cosmic microwave background (blue) and galaxy clusters converge at a Universe around Ωm ~ 0.3 and ΩΛ ~ 0.7. The dark red region for the galaxy cluster determination corresponds to 95% certainty (2-sigma statistical deviation) when assuming good knowledge of all other cosmological parameters, and the light red region assumes a minimum knowledge. For the supernovae and WMAP results, the inner and outer regions corespond to 68% (1-sigma) and 95% certainty, respectively. References: Schuecker et al. 2003, A&A, 398, 867 (REFLEX); Tonry et al. 2003, ApJ, 594, 1 (supernovae); Riess et al. 2004, ApJ, 607, 665 (supernovae) Galaxy clusters are far from being evenly distributed in the Universe. Instead, they tend to conglomerate into even larger structures, "super-clusters". Thus, from stars which gather in galaxies, galaxies which congregate in clusters and clusters tying together in super-clusters, the Universe shows structuring on all scales, from the smallest to the largest ones. This is a relict of the very early (formation) epoch of the Universe, the so-called "inflationary" period. At that time, only a minuscule fraction of one second after the Big Bang, the tiny density fluctuations were amplified and over the eons, they gave birth to the much larger structures. Because of the link between the first fluctuations and the giant structures now observed, the unique REFLEX catalogue - the largest of its kind - allows astronomers to put considerable constraints on the content of the Universe, and in particular on the amount of dark matter that is believed to pervade it. Rather interestingly, these constraints are totally independent from all other methods so far used to assert the existence of dark matter, such as the study of very distant supernovae (see e.g. ESO PR 21/98) or the analysis of the Cosmic Microwave background (e.g. the WMAP satellite). In fact, the new REFLEX study is very complementary to the above-mentioned methods. The REFLEX team concludes that the mean density of the Universe is in the range 0.27 to 0.43 times the "critical density", providing the strongest constraint on this value up to now. When combined with the latest supernovae study, the REFLEX result implies that, whatever the nature of the dark energy is, it closely mimics a Universe with Einstein's cosmological constant. A giant puzzle The REFLEX catalogue will also serve many other useful purposes. With it, astronomers will be able to better understand the detailed processes that contribute to the heating of the gas in these clusters. It will also be possible to study the effect of the environment of the cluster on each individual galaxy. Moreover, the catalogue is a good starting point to look for giant gravitational lenses, in which a cluster acts as a giant magnifying lens, effectively allowing observations of the faintest and remotest objects that would otherwise escape detection with present-day telescopes. But, as Hans Böhringer says: "Perhaps the most important advantage of this catalogue is that the properties of each single cluster can be compared to the entire sample. This is the main goal of surveys: assembling the pieces of a gigantic puzzle to build the grander view, where every single piece then gains a new, more comprehensive meaning." More information The results presented in this Press Release will appear in the research journal Astronomy and Astrophysics ("The ROSAT-ESO Flux Limited X-ray (REFLEX) Galaxy Cluster Survey. V. The cluster catalogue" by H. Böhringer et al.; astro-ph/0405546). See also the REFLEX website.

Planet Formation in Action? - Astronomers may have found the first object clearing its path in the natal disc surrounding a young star

NASA Astrophysics Data System (ADS)

2011-02-01

Using ESO's Very Large Telescope an international team of astronomers has been able to study the short-lived disc of material around a young star that is in the early stages of making a planetary system. For the first time a smaller companion could be detected that may be the cause of the large gap found in the disc. Future observations will determine whether this companion is a planet or a brown dwarf. Planets form from the discs of material around young stars, but the transition from dust disc to planetary system is rapid and few objects are caught during this phase [1]. One such object is T Chamaeleontis (T Cha), a faint star in the small southern constellation of Chamaeleon that is comparable to the Sun, but very near the beginning of its life [2]. T Cha lies about 350 light-years from the Earth and is only about seven million years old. Up to now no forming planets have been found in these transitional discs, although planets in more mature discs have been seen before (eso0842, heic0821). "Earlier studies had shown that T Cha was an excellent target for studying how planetary systems form," notes Johan Olofsson (Max Planck Institute for Astronomy, Heidelberg, Germany), one of the lead authors of two papers in the journal Astronomy & Astrophysics that describe the new work. "But this star is quite distant and the full power of the Very Large Telescope Interferometer (VLTI) was needed to resolve very fine details and see what is going on in the dust disc." The astronomers first observed T Cha using the AMBER instrument and the VLT Interferometer (VLTI) [3]. They found that some of the disc material formed a narrow dusty ring only about 20 million kilometres from the star. Beyond this inner disc, they found a region devoid of dust with the outer part of the disc stretching out into regions beyond about 1.1 billion kilometres from the star. Nuria Huélamo (Centro de Astrobiología, ESAC, Spain), the lead author of the second paper takes up the story: "For us the gap in the dust disc around T Cha was a smoking gun, and we asked ourselves: could we be witnessing a companion digging a gap inside its protoplanetary disc?" However, finding a faint companion so close to a bright star is a huge challenge and the team had to use the VLT instrument NACO in a novel and powerful way, called sparse aperture masking, to reach their goal [4]. After careful analysis they found the clear signature of an object located within the gap in the dust disc, about one billion kilometres from the star - slightly further out than Jupiter is within our Solar System and close to the outer edge of the gap. This is the first detection of an object much smaller than a star within a gap in the planet-forming dust disc around a young star. The evidence suggests that the companion object cannot be a normal star [5] but it could be either a brown dwarf [6] surrounded by dust or, most excitingly, a recently formed planet. Huélamo concludes: "This is a remarkable joint study that combines two different state-of-the-art instruments at ESO's Paranal Observatory. Future observations will allow us to find out more about the companion and the disc, and also understand what fuels the inner dusty disc." Notes [1] The transitional discs can be spotted because they give off less radiation at mid-infrared wavelengths. The clearing of the dust close to the star and the creation of gaps and holes can explain this missing radiation. Recently formed planets may have created these gaps, although there are also other possibilities. [2] T Cha is a T Tauri star, a very young star that is still contracting towards the main sequence. [3] The astronomers used the AMBER instrument (Astronomical Multi-BEam combineR) and the VLTI to combine the light from all four of the 8.2-metre VLT Unit Telescopes and create a "virtual telescope" 130 metres across. [4] NACO (or NAOS-CONICA in full) is an adaptive optics instrument attached to ESO's Very Large Telescope. Thanks to adaptive optics, astronomers can remove most of the blurring effect of the atmosphere and obtain very sharp images. The team used NACO in a novel way, called sparse aperture masking (SAM) to search for the companion. This is a type of interferometry that, rather than combining the light from multiple telescopes as the VLTI does, uses different parts of the mirror of a single telescope (in this case, the mirror of the VLT Unit Telescope 4). This new technique is particularly good for finding faint objects very close to bright ones. VLTI/AMBER is better suited to studying the structure of the inner disc and is less sensitive to the presence of a distant companion. [5] The astronomers searched for the companion using NACO in two different spectral bands - at around 2.2 microns and at 3.8 microns. The companion is only seen at the longer wavelength, which means that the object is either cool, like a planet, or a dust-shrouded brown dwarf. [6] Brown dwarfs are objects between stars and planets in size. They are not massive enough to fuse hydrogen in their cores but are larger than giant planets such as Jupiter. More information This research was presented in two papers: Olofsson et al. 2011, "Warm dust resolved in the cold disk around TCha with VLTI/AMBER", and Huélamo et al. 2011, "A companion candidate in the gap of the T Cha transitional disk", to appear in the journal Astronomy & Astrophysics. The team is composed of J. Olofsson (Max-Planck-Institut für Astronomie [MPIA], Heidelberg, Germany), M. Benisty (MPIA), J.-C. Augereau (Institut de Planétologie et d'Astrophysique de Grenoble [IPAG], France) C. Pinte (IPAG), F. Ménard (IPAG), E. Tatulli (IPAG), J.-P. Berger (ESO, Santiago, Chile), F. Malbet (IPAG), B. Merín (Herschel Science Centre, Madrid, Spain), E. F. van Dishoeck (Leiden University, Holland), S. Lacour (Observatoire de Paris, France), K. M. Pontoppidan (California Institute of Technology, USA), J.-L. Monin (IPAG), J. M. Brown (Max-Planck-Institut für extraterrestrische Physik, Garching, Germany), G. A. Blake (California Institute of Technology), N. Huélamo (Centro de Astrobiología, ESAC, Spain), P. Tuthill (University of Sydney, Australia), M. Ireland (University of Sydney), A. Kraus (University of Hawaii) and G. Chauvin (Université Joseph Fourier, Grenoble, France). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

ESO PR Highlights in 2005

NASA Astrophysics Data System (ADS)

2006-01-01

2005 was the year of Physics. It was thus also in part the year of astronomy and this is clearly illustrated by the numerous breakthroughs that were achieved, in particular using ESO's telescopes. One of the highlights was without any doubt the confirmation of the first image of an exoplanet , around the star 2M1207 (see ESO PR 12/05). ESO's telescopes also found a Neptune-mass exoplanet around a small star ( PR 30/05) - a discovery that proves crucial in the census of other planetary systems, and imaged a tiny companion in the close vicinity of the star GQ Lupi, a very young object still surrounded by a disc, with an age between 100,000 and 2 million years ( PR 09/05). Moreover, using a new high-contrast adaptive optics camera on the VLT, the NACO Simultaneous Differential Imager, or NACO SDI, astronomers were able for the first time to image a companion 120 times fainter than its star , very near the star AB Doradus A. This companion appears to be almost twice as heavy as theory predicts it to be ( PR 02/05). ESO's telescopes proved very useful in helping to solve a 30-year old puzzle . Astronomers have for the first time observed the visible light from a short gamma-ray burst (GRB). Using the 1.5m Danish telescope at La Silla (Chile), they showed that these short, intense bursts of gamma-ray emission most likely originate from the violent collision of two merging neutron stars ( PR 26/05). Additional evidence came from witnessing another event with the VLT ( PR 32/05). Also in this field, astronomers found the farthest known gamma-ray burst with ESO's VLT, observing an object with a redshift 6.3, i.e. that is seen when the Universe was less than 900 million years old ( PR 22/05). On July 4, NASA's Deep Impact spacecraft plunged onto Comet 9P/Tempel 1 with the aim to create a crater and expose pristine material from beneath the surface. For two days before and six days after, all major ESO telescopes have been observing the comet, in a coordinated fashion and in very close collaboration with the space mission' scientific team, in what was perhaps the most comprehensive ground-observing campaign of a celestial object. On this occasion, a dedicated Deep Impact at ESO web site was created, reporting on all the developments. This was not the sole contribution of ESO to the study of the solar system . The NACO SDI instrument was used to obtain outstanding images of Titan, the satellite of Saturn ( PHOT 04/05) and NACO also allowed astronomers to discover the first triple asteroid - two small asteroids orbiting a larger one known since 1866 as 87 Sylvia ( PR 21/05). 2005 was also a very important year for sub-millimetric astronomy at ESO. In July, APEX , the 12-m Atacama Pathfinder Experiment's telescope had first light ( PR 18/05) and since then, has been performing regular science observations ( PR 25/05). Moreover, two major contracts have been signed for ALMA , the Atacama Large Millimeter Array project, among which the largest-ever European industrial contract for a ground-based astronomy project ( PR 31/05 and 34/05). ESO's Very Large Telescope (VLT) proves to be a very efficient science machine that reached in April 2005, the count of more than 1000 scientific papers (see ESO PR 11/05) and the trend does not seem to change, as about 350 papers were published in 2005 based on data collected with the VLT. This efficiency was also recognised worldwide as ESO received the ComputerWorld Honors Program 21st Century Achievement Award in the Science Category ( PR 16/05). The interferometric mode of the VLT (VLTI) was able to observe with unprecedented detail the environment of two stars ( PR 29/05). The VLTI has also seen another extension of its already impressive capabilities by combining interferometrically the light from two relocatable 1.8-m Auxiliary Telescopes ( PR 06/05). ESO PR Highlights 2005 In 2005 again, many nice, amazing astronomical images have been obtained with ESO's telescopes: the super star cluster Westerlund 1 ( PR 08/05), the blob in the LMC ( PHOT 12/05), dream galaxies ( PHOT 24/05), a colossal cosmic eye ( PHOT 31/05), a monster being fed (PHOT 33/05), a perturbed family ( PHOT 34/05), and a cosmic Christmas ghost ( PHOT 42/05). All this, in addition to some images of the observatories ( PR 33/05 and PHOT 43/05). These developments are described in ESO's Press Releases, most with Press Photos, cf. the 2005 PR Index. Some of last year's ESO PR highlights may be accessed directly via the first clickable image above while some of the Press Photos are available via the second clickable image.

Two Galaxies for a Unique Event

NASA Astrophysics Data System (ADS)

2009-04-01

To celebrate the 100 Hours of Astronomy, ESO is sharing two stunning images of unusual galaxies, both belonging to the Sculptor group of galaxies. The images, obtained at two of ESO's observatories at La Silla and Paranal in Chile, illustrate the beauty of astronomy. ESO PR Photo 14a/09 Irregular Galaxy NGC 55 ESO PR Photo 14b/09 Spiral Galaxy NGC 7793 As part of the International Year of Astronomy 2009 Cornerstone project, 100 Hours of Astronomy, the ambitious "Around the World in 80 Telescopes" event is a unique live webcast over 24 hours, following night and day around the globe to some of the most advanced observatories on and off the planet. To provide a long-lasting memory of this amazing world tour, observatories worldwide are revealing wonderful, and previously unseen, astronomical images. For its part, ESO is releasing outstanding pictures of two galaxies, observed with telescopes at the La Silla and Paranal observatories. The first of these depicts the irregular galaxy NGC 55, a member of the prominent Sculptor group of galaxies in the southern constellation of Sculptor. The galaxy is about 70 000 light-years across, that is, a little bit smaller than our own Milky Way. NGC 55 actually resembles more our galactic neighbour, the Large Magellanic Cloud (LMC), although the LMC is seen face-on, whilst NGC 55 is edge-on. By studying about 20 planetary nebulae in this image, a team of astronomers found that NGC 55 is located about 7.5 million light-years away. They also found that the galaxy might be forming a bound pair with the gorgeous spiral galaxy NGC 300 . Planetary nebulae are the final blooming of Sun-like stars before their retirement as white dwarfs. This striking image of NGC 55, obtained with the Wide Field Imager on the 2.2-metre MPG/ESO telescope at La Silla, is dusted with a flurry of reddish nebulae, created by young, hot massive stars. Some of the more extended ones are not unlike those seen in the LMC, such as the Tarantula Nebula. The quality of the image is clearly demonstrated by the remarkable number of background galaxies seen, as well as the huge numbers of individual stars that can be counted within NGC 55. The second image shows another galaxy belonging to the Sculptor group. This is NGC 7793, which has a chaotic spiral structure, unlike the class of grand-design spiral galaxies to which our Milky Way belongs. The image shows how difficult it is to identify any particular spiral arm in these chaotic structures, although it is possible to guess at a general rotating pattern. NGC 7793 is located slightly further away than NGC 55, about 12.5 million light-years from us, and is about half the size of NGC 55. NGC 7793 was observed with one of the workhorses of the ESO Paranal Observatory, the FORS instrument, attached to the Very Large Telescope.

Strong Winds over the Keel

NASA Astrophysics Data System (ADS)

2009-02-01

The latest ESO image reveals amazing detail in the intricate structures of one of the largest and brightest nebulae in the sky, the Carina Nebula (NGC 3372), where strong winds and powerful radiation from an armada of massive stars are creating havoc in the large cloud of dust and gas from which the stars were born. ESO PR Photo 05a/09 The Carina Nebula ESO PR Video 05a/09 Pan over the Carina Nebula ESO PR Video 05b/09 Carina Nebula Zoom-in The large and beautiful image displays the full variety of this impressive skyscape, spattered with clusters of young stars, large nebulae of dust and gas, dust pillars, globules, and adorned by one of the Universe's most impressive binary stars. It was produced by combining exposures through six different filters from the Wide Field Imager (WFI), attached to the 2.2 m ESO/MPG telescope at ESO's La Silla Observatory, in Chile. The Carina Nebula is located about 7500 light-years away in the constellation of the same name (Carina; the Keel). Spanning about 100 light-years, it is four times larger than the famous Orion Nebula and far brighter. It is an intensive star-forming region with dark lanes of cool dust splitting up the glowing nebula gas that surrounds its many clusters of stars. The glow of the Carina Nebula comes mainly from hot hydrogen basking in the strong radiation of monster baby stars. The interaction between the hydrogen and the ultraviolet light results in its characteristic red and purple colour. The immense nebula contains over a dozen stars with at least 50 to 100 times the mass of our Sun. Such stars have a very short lifespan, a few million years at most, the blink of an eye compared with the Sun's expected lifetime of ten billion years. One of the Universe's most impressive stars, Eta Carinae, is found in the nebula. It is one of the most massive stars in our Milky Way, over 100 times the mass of the Sun and about four million times brighter, making it the most luminous star known. Eta Carinae is highly unstable, and prone to violent outbursts, most notably the false supernova event in 1842. For just a few years, Eta Carinae became the second brightest star in the night sky and produced almost as much visible light as a supernova explosion (the usual death throes of a massive star), but it survived. Eta Carinae is also thought to have a hot companion that orbits around it in 5.54 years, in an elliptical orbit. Both stars have strong winds, which collide, leading to interesting phenomena. In mid-January 2009, the companion was at its closest distance to Eta Carinae. This event, which may provide a unique insight into the wind structure of the massive stars, has been followed by a flotilla of instruments on several of ESO's telescopes.

Deep Sky Diving with the ESO New Technology Telescope

NASA Astrophysics Data System (ADS)

1998-01-01

Preparations for future cosmological observations with the VLT Within a few months, the first 8.2-meter Unit Telescope of the ESO Very Large Telescope (VLT) array will open its eye towards the sky above the Atacama desert. As documented by recent Press Photos from ESO, the construction work at the Paranal VLT Observatory is proceeding rapidly. Virtually all of the telescope components, including the giant Zerodur mirror (cf. ESO PR Photos 35a-l/97 ), are now on the mountain. While the integration of the telescope and its many optical, mechanical and electronic components continues, astronomers in the ESO member countries and at ESO are now busy defining the observing programmes that will be carried out with the new telescope, soon after it enters into operation. In this context, new and exciting observations have recently been obtained with the 3.5-m New Technology Telescope at the ESO La Silla Observatory, 600 km to the south of Paranal. How to record the faintest and most remote astronomical objects With its very large mirror surface (and correspondingly great light collecting power), as well as an unsurpassed optical quality, the VLT will be able to look exceedingly far out into the Universe, well beyond current horizons. The best technique to record the faintest possible light and thus the most remote celestial objects, is to combine large numbers of exposures of the same field with slightly different telescope pointing. This increases the total number of photons recorded and by imaging the stars and galaxies on different areas (pixels) of the detector, the signal-to-noise ratio and hence the visibility of the faintest objects is improved. The famous Hubble Deep Field Images were obtained in this way by combining over 300 single exposures and they show myriads of faint galaxies in the distant realms of the Universe. The NTT as test bench for the VLT ESO is in the fortunate situation of possessing a `prototype' model of the Very Large Telescope, the 3.5-m New Technology Telescope. Many of the advanced technological concepts now incorporated into the VLT were first tested in the NTT. When this new facility entered into operation at La Silla in 1990, it represented a break-through in telescope technology and it has since then made many valuable contributions to front-line astronomical projects. Last year, the control and data flow system at the NTT was thoroughly refurbished to the high VLT standards and current observations with the NTT closely simulate the future operation of the VLT. The successful, early tests with the new operations system have been described in ESO Press Release 03/97. The NTT SUSI Deep Field With the possibility to test already now observing procedures which will become standard for the operation of the VLT, a group of astronomers [1] was granted NTT time for observations of Faint Galaxies in an Ultra-Deep Multicolour SUSI field . This is a programme aimed at the study of the distribution of faint galaxies in the field and of gravitational lensing effects (cosmic mirages and deformation of images of distant galaxies caused by the gravitational field of intervening matter). SUSI (SUperb Seeing Imager) is a high-resolution CCD-camera at the NTT that is particularly efficient under excellent sky conditions. The observations were fully defined in advance and were carried out in service mode from February to April 1997 with flexible scheduling by a team of dedicated ESO astronomers (the NTT team). Only in this way was it possible to obtain the exposures under optimal atmospheric conditions, i.e. `photometric' sky and little atmospheric turbulence (seeing better than 1 arcsec). A total of 122 CCD frames were obtained in four colours (blue, green-yellow, red and near-infrared) with a total exposure time of no less than 31.5 hours. The frames cover a 2.3 x 2.3 arcmin `empty' sky field centered south of the high-redshift quasar QSO BR 1202-0725 (z=4.7), located just south of the celestial equator. ESO PR Photo 01a/98 Caption to ESO PR Photo 01/98 and access to two versions of the photo The frames were computer processed and combined to yield a colour view of the corresponding sky field ( ESO Press Photo 01/98 ). This is indeed a very deep look into the southern sky. The astronomers have found that the limiting magnitude (at a signal-to-noise ratio of 3) is beyond 27 in the blue and red frames and only slightly brighter in the two others. Magnitude 27 corresponds to a brightness that is 250 million times fainter than what can be perceived with the unaided eye. Although not as deep as the Hubble Deep Field due to the shorter exposure time and brighter sky background (caused by light emission in the upper layers of the terrestrial atmosphere), this new set of data is among the best ground-based observations of this type ever obtained. Galaxies down to a magnitude of roughly 25 will soon be targets of detailed spectroscopic observations with the VLT. They will provide a measure of their basic physical parameters like redshift, luminosity and mass. How to access the new data This scientific program aims at the study of the photometric redshift distribution of the faint galaxies [2] and of gravitational lensing effects (cosmic mirages). It has been decided to make the complete data set available to the wide scientific community and it is expected that many astronomers all over the world will want to perform their own investigations by means of this unique observational material. A full description of the project is available on the ESO Web at http://www.eso.org/ndf/. Here you will find a comprehensive explanation of the scientific background, details about the observations and the data reduction, as well as easy access to the corresponding data files. Notes: [1] The group consists of Sandro D'Odorico (Principal Investigator, ESO) and Jacqueline Bergeron (ESO), Hans-Martin Adorf (ESO), Stephane Charlot (IAP, Paris, France), David Clements (IAS, Orsay, France), Stefano Cristiani (Univ. of Padova, Italy), Luiz da Costa (ESO), Eiichi Egami (MPI Extraterrestrial Physics, Garching, Germany), Adriano Fontana (Rome Observatory, Italy), Bernard Fort (Paris Observatory, France), Laurent Gautret (Paris Observatory, France), Emanuele Giallongo (Rome Observatory, Italy), Roberto Gilmozzi, Richard N.Hook and Bruno Leibundgut (ESO), Yannick Mellier and Patrick Petitjean (IAP, Paris, France), Alvio Renzini, Sandra Savaglio and Peter Shaver (ESO), Stella Seitz (Munich Observatory, Germany) and Lin Yan (ESO). [2]. The photometric redshift method allows to determine an approximate distance of a distant galaxy by measuring its colour, i.e., its relative brightness (magnitude) in different wavebands. It is based on the proportionality between the distance of a galaxy and its recession velocity (the Hubble law). The higher the velocity, the more its emission will be shifted towards longer wavelengths and the redder is the colour. Recent investigations of galaxies seen in the Hubble Deep Field have shown that the redshifts (and thus distances) found by this method are quite accurate in most cases. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

A Look into the Hellish Cradles of Suns and Solar Systems

NASA Astrophysics Data System (ADS)

2009-09-01

New images released today by ESO delve into the heart of a cosmic cloud, called RCW 38, crowded with budding stars and planetary systems. There, young stars bombard fledgling suns and planets with powerful winds and blazing light, helped in their task by short-lived, massive stars that explode as supernovae. In some cases, this onslaught cooks away the matter that may eventually form new solar systems. Scientists think that our own Solar System emerged from such an environment. The dense star cluster RCW 38 glistens about 5500 light years away in the direction of the constellation Vela (the Sails). Like the Orion Nebula Cluster, RCW 38 is an "embedded cluster", in that the nascent cloud of dust and gas still envelops its stars. Astronomers have determined that most stars, including the low mass, reddish ones that outnumber all others in the Universe, originate in these matter-rich locations. Accordingly, embedded clusters provide scientists with a living laboratory in which to explore the mechanisms of star and planetary formation. "By looking at star clusters like RCW 38, we can learn a great deal about the origins of our Solar System and others, as well as those stars and planets that have yet to come", says Kim DeRose, first author of the new study that appears in the Astronomical Journal. DeRose did her work on RCW 38 as an undergraduate student at the Harvard-Smithsonian Center for Astrophysics, USA. Using the NACO adaptive optics instrument on ESO's Very Large Telescope [1], astronomers have obtained the sharpest image yet of RCW 38. They focused on a small area in the centre of the cluster that surrounds the massive star IRS2, which glows in the searing, white-blue range, the hottest surface colour and temperatures possible for stars. These dramatic observations revealed that IRS2 is actually not one, but two stars - a binary system consisting of twin scorching stars, separated by about 500 times the Earth-Sun distance. In the NACO image, the astronomers found a handful of protostars - the faintly luminous precursors to fully realised stars - and dozens of other candidate stars that have eked out an existence here despite the powerful ultraviolet light radiated by IRS2. Some of these gestating stars may, however, not get past the protostar stage. IRS2's strong radiation energises and disperses the material that might otherwise collapse into new stars, or that has settled into so-called protoplanetary discs around developing stars. In the course of several million years, the surviving discs may give rise to the planets, moons and comets that make up planetary systems like our own. As if intense ultraviolet rays were not enough, crowded stellar nurseries like RCW 38 also subject their brood to frequent supernovae when giant stars explode at the ends of their lives. These explosions scatter material throughout nearby space, including rare isotopes - exotic forms of chemical elements that are created in these dying stars. This ejected material ends up in the next generation of stars that form nearby. Because these isotopes have been detected in our Sun, scientists have concluded that the Sun formed in a cluster like RCW 38, rather than in a more rural portion of the Milky Way. "Overall, the details of astronomical objects that adaptive optics reveals are critical in understanding how new stars and planets form in complex, chaotic regions like RCW 38", says co-author Dieter Nürnberger. Notes [1] The name "NACO" is a combination of the Nasmyth Adaptive Optics System (NAOS) and the Near-Infrared Imager and Spectrograph (CONICA). Adaptive optics cancels out most of the image-distorting turbulence in Earth's atmosphere caused by temperature variations and wind. More information This research was presented in a paper that appeared in the Astronomical Journal: A Very Large Telescope / NACO study of star formation in the massive embedded cluster RCW 38, by DeRose et al. (2009, AJ, 138, 33-45). The team is composed of K.L. DeRose, T.L. Bourke, R.A. Gutermuth and S.J. Wolk (Harvard-Smithsonian Center for Astrophysics, Cambridge, USA), S.T. Megeath (Department of Physics and Astronomy, The University of Toledo, USA), J. Alves (Centro Astronómico Hispano Alemán, Almeria, Spain), and D. Nürnberger (ESO). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

VizieR Online Data Catalog: HeI 5876 & 10830Å EWs of solar-type stars (Andretta+, 2017)

NASA Astrophysics Data System (ADS)

Andretta, V.; Giampapa, M. S.; Covino, E.; Reiners, A.; Beeck, B.

2017-11-01

A total of 134 FEROS spectra (R=48000) of our targets (including telluric standards) were acquired on the night of UT 2011 December 6-7; spectral coverage from 3500 to 9200Å. The Fiber Extended-range Optical Spectrograph (FEROS) was mounted at the 2.2m Max-Planck Gesellschaft/European Southern Observatory (MPG/ESO) telescope at La Silla (Chile). The HeIλ10830 spectroscopic observations were carried out on the same night as the FEROS D3 observations, using the CRyogenic high-resolution InfraRed Echelle Spectrograph (CRIRES), mounted at Unit Telescope 1 (Antu) of the VLT array at Cerro Paranal. The details of the observations is given in table 1. (3 data files).

uvby photometry of theta Tucanae

NASA Astrophysics Data System (ADS)

Sterken, C.; Spoon, H.

2017-12-01

theta Tucanae (HR 139, V=6.11, A7 IV) is a binary with a delta Scuti primary that was the subject of several photometric monitoring campaigns during the 1970s and again in the 1990s. The data presented in this paper were collected during an observing campaign from mid-September to the end of October 1993 at ESO La Silla, Chile, using the simultaneous Stroemgren uvby photometer at the SAT telescope during 25 partial nights. We present a time series of 1432 four-colour extinction-corrected magnitudes in the SAT instrumental system. This collection of data forms a homogeneous and contiguous dataset, obtained in one single instrumental setup, at one single observing site using one single observing protocol, and with centralized data reduction.

Growth of Astronomy Education in Chile: a late but successful story

NASA Astrophysics Data System (ADS)

Quintana, Hernán

2017-06-01

The first present international observatories were stablished in Chile by 1963, at a time when local astronomy was devoted to traditional Fundamental Astronomy research, as in most other Latin-american countries. For over 35 years little was achieved in the way of effectively developing a healthy university teaching in the field, in spite of initiatives started and helped in the mid-sixties by some astronomers at CTIO or ESO. Up to 1998, when a second try to start a university degree, this time at U. Católica, was unexpectedly successful, the number of Chileans astronomers had remained constant or slightly decreased. The number started to grow significantly when the new degree attracted the keen interest of students, reaching the potential widely recognized since a long time. Today some 13 universities have astronomy courses or degrees and the number of students and post-docs are in the hundreds.The series of events and university policies originally prevailing in the country, and the changes that allowed the new state of affairs, will be reviewed and described. This will include the barriers and difficulties encountered, and the ways devised to overcome these.

A 3000 TNOs Survey Project at ESO La Silla

NASA Astrophysics Data System (ADS)

Boehnhardt, H.; Hainaut, O.

We propose a wide-shallow TNO search to be done with the Wide Field Imager (WFI) instrument at the 2.2m MPG/ESO telescope in La Silla/Chile. The WFI is a half-deg camera equipped with an 8kx8k CCD (0.24 arcsec/pixel). The telescope can support excellent seeing quality down to 0.5arcsec FWHM. A TNO search pilot project was run with the 2.2m+WFI in 1999: images with just 1.6sdeg sky coverage and typically 24mag limiting brightness revealed 6 new TNOs when processed with our new automatic detection program MOVIE. The project is now continued on a somewhat larger scale in order to find more TNOs and to fine-tune the operational environment for a full automatic on-line detection, astrometry and photometry of the objects at the telescope. The future goal is to perform - with the 2.2m+WFI and in an international colaboration - an even larger TNO survey over a major part of the sky (typically 2000sdeg in and out of Ecliptic) down to 24mag. Follow-up astrometry and photometry of the expected more than 3000 discovered objects will secure their orbital and physical characterisation for synoptic dynamical and taxonomic studies of the Transneptunian population.

The environment of the fast rotating star Achernar. III. Photospheric parameters revealed by the VLTI

NASA Astrophysics Data System (ADS)

Domiciano de Souza, A.; Kervella, P.; Moser Faes, D.; Dalla Vedova, G.; Mérand, A.; Le Bouquin, J.-B.; Espinosa Lara, F.; Rieutord, M.; Bendjoya, P.; Carciofi, A. C.; Hadjara, M.; Millour, F.; Vakili, F.

2014-09-01

Context. Rotation significantly impacts on the structure and life of stars. In phases of high rotation velocity (close to critical), the photospheric structure can be highly modified, and present in particular geometrical deformation (rotation flattening) and latitudinal-dependent flux (gravity darkening). The fastest known rotators among the nondegenerate stars close to the main sequence, Be stars, are key targets for studying the effects of fast rotation on stellar photospheres. Aims: We seek to determine the purely photospheric parameters of Achernar based on observations recorded during an emission-free phase (normal B phase). Methods: Several recent works proved that optical/IR long-baseline interferometry is the only technique able to sufficiently spatially resolve and measure photospheric parameters of fast rotating stars. We thus analyzed ESO-VLTI (PIONIER and AMBER) interferometric observations of Achernar to measure its photospheric parameters by fitting our physical model CHARRON using a Markov chain Monte Carlo method. This analysis was also complemented by spectroscopic, polarimetric, and photometric observations to investigate the status of the circumstellar environment of Achernar during the VLTI observations and to cross-check our model-fitting results. Results: Based on VLTI observations that partially resolve Achernar, we simultaneously measured five photospheric parameters of a Be star for the first time: equatorial radius (equatorial angular diameter), equatorial rotation velocity, polar inclination, position angle of the rotation axis projected on the sky, and the gravity darkening β coefficient (effective temperature distribution). The close circumstellar environment of Achernar was also investigated based on contemporaneous polarimetry, spectroscopy, and interferometry, including image reconstruction. This analysis did not reveal any important circumstellar contribution, so that Achernar was essentially in a normal B phase at least from mid-2009 to end-2012, and the model parameters derived in this work provide a fair description of its photosphere. Finally, because Achernar is the flattest interferometrically resolved fast rotator to-date, the measured β and flattening, combined with values from previous works, provide a crucial test for a recently proposed gravity darkening model. This model offers a promising explanation to the fact that the measured β parameter decreases with flattening and shows significantly lower values than the classical prediction of von Zeipel. Based on observations performed at ESO, Chile under VLTI PIONIER and AMBER programme IDs 087.D-0150 and 084.D-0456.

Bulge RR Lyrae stars in the VVV tile b201

NASA Astrophysics Data System (ADS)

Gran, F.; Minniti, D.; Saito, R. K.; Navarrete, C.; Dékány, I.; McDonald, I.; Contreras Ramos, R.; Catelan, M.

2015-03-01

Context. The VISTA Variables in the Vía Láctea (VVV) Survey is one of the six ESO public surveys currently ongoing at the VISTA telescope on Cerro Paranal, Chile. VVV uses near-IR (ZYJHKs) filters that at present provide photometry to a depth of Ks ~ 17.0 mag in up to 36 epochs spanning over four years, and aim at discovering more than 106 variable sources as well as trace the structure of the Galactic bulge and part of the southern disk. Aims: A variability search was performed to find RR Lyrae variable stars. The low stellar density of the VVV tile b201, which is centered at (ℓ,b) ~ (-9°, -9°), makes it suitable to search for variable stars. Previous studies have identified some RR Lyrae stars using optical bands that served to test our search procedure. The main goal is to measure the reddening, interstellar extinction, and distances of the RR Lyrae stars and to study their distribution on the Milky Way bulge. Methods: For each star in the tile with more than 25 epochs (~90% of the objects down to Ks ~ 17.0 mag), the standard deviation and χ2 test were calculated to identify variable candidates. Periods were determined using the analysis of variance. Objects with periods in the RR Lyrae range of 0.2 ≤ P ≤ 1.2 days were selected as candidate RR Lyrae. They were individually examined to exclude false positives. Results: A total of 1.5 sq deg were analyzed, and we found 39 RR Lyr stars, 27 of which belong to the ab-type and 12 to the c-type. Our analysis recovers all the previously identified RR Lyrae variables in the field and discovers 29 new RR Lyr stars. The reddening and extinction toward all the RRab stars in this tile were derived, and distance estimations were obtained through the period-luminosity relation. Despite the limited amount of RR Lyrae stars studied, our results are consistent with a spheroidal or central distribution around ~8.1 and ~8.5 kpc. for either the Cardelli or Nishiyama extinction law. Our analysis does not reveal a stream-like structure. Nevertheless, a larger area must be analyzed to definitively rule out streams. Based on observations taken within the ESO VISTA Public Survey VVV, Programme ID 179.B-2002.

Impact of a school-based intervention on nutritional education and physical activity in primary public schools in Chile (KIND) programme study protocol: cluster randomised controlled trial.

PubMed

Bustos, Nelly; Olivares, Sonia; Leyton, Bárbara; Cano, Marcelo; Albala, Cecilia

2016-12-03

Chile has suffered a fast increase in childhood obesity in the last 10 years. As a result, several school programmes have been implemented, however the effectiveness of these needs to be evaluated to identify and prioritize strategies to curve this trend. Cluster randomized controlled trial. Twelve primary public schools chosen at random over three regions of the country will take part in this study. The sample size consisted of a total of 1,655 children. For each region one school will be selected for each of the three nutritional intervention modes and one school will be selected as the control group. The intervention modes consist of the following: Healthy Kiosk and nutritional education (KSEAN); Optimized physical activity (AFSO); Healthy Kiosk and nutritional education (KSEAN) + optimized physical activity (AFSO); Control group. The effectiveness of each intervention will be evaluated by determining the nutritional condition of each child by measuring percentage of body fat, BMI and the z-score of the BMI. This study will also identify the eating behaviours, nutritional knowledge and fitness of each child, along with the effective time of moderate activity during physical education classes. A protocol to evaluate the effectiveness of a school based intervention to control and/or reduce the rates of childhood obesity for children between 6 and 10 years of age was developed. The protocol was developed in line with the Declaration of Helsinski, the Nüremberg Code and the University of Chile Guidelines for ethical committees, and was approved by the INTA, Universidad de Chile ethical committee on Wednesday 12 March 2014. There is consensus among researchers and health and education personnel that schools are a favourable environment for actions to prevent and/or control childhood obesity. However a lack of evidence on the effectiveness of interventions to date has led some to question the wisdom of allocating resources to programmes. This is the first study of this kind in Chile and could be an important first step to provide guidance to political authorities in relation to which food and nutrition strategies to prioritize to curve this alarming trend. ISRCTN32136790 , registered retrospectively on 05 September 2014.

Detection of magnetic field in the B2 star ρ Ophiuchi A with ESO FORS2

NASA Astrophysics Data System (ADS)

Pillitteri, I.; Fossati, L.; Castro Rodriguez, N.; Oskinova, L.; Wolk, S. J.

2018-02-01

Circumstantial evidence suggests that magnetism and enhanced X-ray emission are likely correlated in early B-type stars: similar fractions of them ( 10%) are strong and hard X-ray sources and possess strong magnetic fields. It is also known that some B-type stars have spots on their surface. Yet up to now no X-ray activity associated with spots on early-type stars was detected. In this Letter we report the detection of a magnetic field on the B2V star ρ Oph A. Previously, we assessed that the X-ray activity of this star is associated with a surface spot, herewith we establish its magnetic origin. We analyze spectra of ρ Oph A obtained with the FORS2 spectrograph at ESO Very Large Telescope (VLT) at two epochs, and detect a longitudinal component of the magnetic field of the order of 500 G in one of the datasets. The detection of the magnetic field only at one epoch can be explained by stellar rotation which is also invoked to explain observed periodic X-ray activity. From archival HARPS ESO VLT high resolution spectra we derived the fundamental stellar parameters of ρ Oph A and further constrained its age. We conclude that ρ Oph A provides strong evidence for the presence of active X-ray emitting regions on young magnetized early type stars. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 099.D-0067(A) and 078.C-0403(A).

Europe Agrees on Common Strategy to Initiate Study of LSA/MMA

NASA Astrophysics Data System (ADS)

1998-09-01

Council Specifies ESO's Role in Planning In an extraordinary meeting at the ESO Headquarters, the ESO Council today endorsed ESO's involvement in the planning of a major new astronomical facility in the southern hemisphere. Some years from now, the Large Southern Array/Millimetre Array (LSA/MMA) may become the world's prime sub-mm/mm radio observatory [1] at a pristine site at 5000 m altitude in the Chilean Andes, not very far from the VLT Paranal Observatory. Background One of the highest-priority items in astronomy today is a large millimetre-wavelength array. This would be a millimetre counterpart to the ESO VLT and the NASA/ESA Hubble Space Telescope (HST), with similar scientific objectives and comparable high angular resolution and sensitivity. An antenna array with about 10,000 m 2 area would provide very high sensitivity and angular resolution, compatible with that of the VLT and HST. Such a large collecting area implies an array with many antennas and baselines, which give the added advantage of fast, high-quality images. The site must be high, dry, large, and flat - a high plateau in the Atacama desert is ideal, and has the great advantage of being in the southern hemisphere, important for compatibility with the VLT. Thus, discussions in Europe have focussed on a "Large Southern Array" (LSA) . The scientific case for such a telescope is overwhelming. It would be able to study the origins of galaxies and stars: the epoch of first galaxy formation and the evolution of galaxies at later stages, including the dust-obscured star-forming galaxies that the HST and VLT cannot see, and all phases of star formation hidden away in dusty molecular clouds. But the LSA will go far beyond these main science drivers - it will have a major impact on virtually all areas of astronomy, and make millimetre astronomy accessible to all astronomers. It may well have as big a user community as the VLT itself. European involvement in millimetre astronomy Europe already has a strong involvement in millimetre astronomy: the 5 x 15-m IRAM array on Plateau de Bure (France), the 30-m IRAM antenna (Spain), the 20-m at Onsala (Sweden), the 15-m Swedish-ESO Submillimetre Telescope (SEST, La Silla), the 15-m JCMT (Mauna Kea, Hawaii), the 10-m HHT (Arizona), and others. Over 60 research institutes around Europe use these facilities. Many of them have developed technical expertise and leadership in this area together with European industry, so it is natural that a European collaboration should be looking to the future. The idea of a large European southern millimetre array has been discussed since 1991. In 1995, an LSA Project collaboration was established between ESO, the Institut de Radio Astronomie Millimetrique (IRAM), the Onsala Space Observatory, and the Netherlands Foundation for Research in Astronomy (NFRA). This consortium of observatories agreed to pool resources to study critical technical areas and conduct site surveys in Chile. Details are available in a Messenger article (March 98). Possibilities of intercontinental collaboration An important step was taken in June 1997. A similar project is under study in the United States of America (the "Millimeter Array", MMA ). An agreement was entered into between ESO and the U.S. National Radio Astronomy Observatory (NRAO) to explore the possibility of merging the two projects into one. Until then the emphasis in Europe had been on the large collecting area provided by 16-m antennas operating at purely millimetre wavelengths, while in the U.S. the concept was a smaller array of 8-m antennas with good submillimetre performance. However, as there is also considerable interest in Europe in submillimetre observations, and in the U.S. in a larger collecting area, a compromise seemed feasible. Several joint working groups formed under the ESO-NRAO agreement were set up to explore the possibility of a collaborative project. It was concluded that a homogeneous array of 64 x 12-m antennas, providing submillimetre performance with a total collecting area of 7,000 m 2 , could be built at the high (5000 m) Chajnantor site , an hour from the array control center at the town of San Pedro de Atacama. It is this collaborative facility that is presently referred to as the Large Southern Array/Millimetre Array (LSA/MMA) . The decision by the ESO Council The ESO Council today passed a resolution that emphasizes the great potential of this proposed astronomical facility for scientific discoveries. It will operate in a relatively unexplored waveband region and with imaging and spectral resolution vastly better than anything now available. The ESO Council requests the ESO Executive to develop a proposal for ESO's role in the design and development phase of the new facility to be submitted to Council in its December 1998 meeting. This phase (Phase I) will cover the technical, financial, human resources, scheduling and organizational aspects for the development, construction, commissioning and operation of the LSA/MMA. The ESO Council supports the intention to create a European Coordinating Committee with participation of ESO that will discuss related policy and technical matters. A European Negotiating Team will then be established that will discuss with the U.S. and other interested nations the conditions of the union of the LSA and MMA as a single common enterprise. Note: [1] The corresponding wavelength interval is about 0.3 to 10 mm. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

What Counts is not Falling … but Landing1

PubMed Central

BROUSSELLE, ASTRID

2012-01-01

Implementation evaluations, also called process evaluations, involve studying the development of programmes, and identifying and understanding their strengths and weaknesses. Undertaking an implementation evaluation offers insights into evaluation objectives, but does not help the researcher develop a research strategy. During the implementation analysis of the UNAIDS drug access initiative in Chile, the strategic analysis model developed by Crozier and Friedberg was used. However, a major incompatibility was noted between the procedure put forward by Crozier and Friedberg and the specific characteristics of the programme being evaluated. In this article, an adapted strategic analysis model for programme evaluation is proposed. PMID:23526306

Catherine Cesarsky - President Elect of the International Astronomical Union (IAU)

NASA Astrophysics Data System (ADS)

2003-07-01

The General Assembly of the International Astronomical Union (IAU), meeting in Sydney (Australia), has appointed the ESO Director General, Dr. Catherine Cesarsky, as President Elect for a three-year period (2003-2006). The IAU is the world's foremost organisation for astronomy, uniting almost 9000 professional scientists on all continents. The IAU General Assembly also elected Prof. Ron Ekers (Australia) as President (2003 - 2006). Dr. Cesarsky will then become President of the IAU in 2006, when the General Assembly next meets in Prague (The Czech Republic). Dr. Cesarsky is the first woman scientist to receive this high distinction. "The election of Catherine Cesarsky as President-Elect of the IAU is an important recognition for a scientist who has made impressive contributions to various areas of modern astrophysics, from cosmic rays to the interstellar medium and cosmology" , commented the outgoing IAU President, Prof. Franco Pacini. "It is also an honour and an important accolade for the European astronomical community in general and ESO in particular." Dr. Cesarsky, who assumed the function as ESO Director General in 1999, was born in France. She received a degree in Physical Sciences at the University of Buenos Aires and graduated with a PhD in Astronomy in 1971 from Harvard University (Cambridge, Mass., USA). Afterwards she worked at the California Institute of Technology (CALTECH). In 1974, she became a staff member of the Service d'Astrophysique (SAp), Direction des Sciences de la Matière (DSM), Commissariat à l'Energie Atomique (CEA) (France). As Director of DSM (1994 - 1999), she was leading about 3000 scientists, engineers and technicians active within a broad spectrum of basic research programmes in physics, chemistry, astrophysics and earth sciences. Dr. Cesarsky is known for her successful research activities in several central areas of modern astrophysics. She first worked on the theory of cosmic ray propagation and acceleration, and galactic gamma-ray emission. Later, she led the design and construction of the ISOCAM camera onboard the Infrared Space Observatory (ISO) of the European Space Agency (ESA), and the ISOCAM Central Programme which studied the infrared emission from many different galactic and extragalactic sources. This has led to new and exciting results on star formation and galactic evolution, and in the identification of the sources providing the bulk of the energy in the Cosmic Infrared Background. As ESO Director General, she has been a driving force towards the realisation of the full potential of ESO's unique Very Large Telescope (VLT) and its associated interferometer ( VLTI), and also towards the recent European-North American agreement on the powerful Atacama Large Millimeter Array (ALMA). Dr. Cesarsky received the COSPAR (Committee on Space Research) Space Science Award in 1998. She is married and has two children.

VLT Detects First Superstorm on Exoplanet

NASA Astrophysics Data System (ADS)

2010-06-01

Astronomers have measured a superstorm for the first time in the atmosphere of an exoplanet, the well-studied "hot Jupiter" HD209458b. The very high-precision observations of carbon monoxide gas show that it is streaming at enormous speed from the extremely hot day side to the cooler night side of the planet. The observations also allow another exciting "first" - measuring the orbital speed of the exoplanet itself, providing a direct determination of its mass. The results appear this week in the journal Nature. "HD209458b is definitely not a place for the faint-hearted. By studying the poisonous carbon monoxide gas with great accuracy we found evidence for a super wind, blowing at a speed of 5000 to 10 000 km per hour" says Ignas Snellen, who led the team of astronomers. HD209458b is an exoplanet of about 60% the mass of Jupiter orbiting a solar-like star located 150 light-years from Earth towards the constellation of Pegasus (the Winged Horse). Circling at a distance of only one twentieth the Sun-Earth distance, the planet is heated intensely by its parent star, and has a surface temperature of about 1000 degrees Celsius on the hot side. But as the planet always has the same side to its star, one side is very hot, while the other is much cooler. "On Earth, big temperature differences inevitably lead to fierce winds, and as our new measurements reveal, the situation is no different on HD209458b," says team member Simon Albrecht. HD209458b was the first exoplanet to be found transiting: every 3.5 days the planet moves in front of its host star, blocking a small portion of the starlight during a three-hour period. During such an event a tiny fraction of the starlight filters through the planet's atmosphere, leaving an imprint. A team of astronomers from the Leiden University, the Netherlands Institute for Space Research (SRON), and MIT in the United States, have used ESO's Very Large Telescope and its powerful CRIRES spectrograph to detect and analyse these faint fingerprints, observing the planet for about five hours, as it passed in front of its star. "CRIRES is the only instrument in the world that can deliver spectra that are sharp enough to determine the position of the carbon monoxide lines at a precision of 1 part in 100 000," says another team member Remco de Kok. "This high precision allows us to measure the velocity of the carbon monoxide gas for the first time using the Doppler effect." The astronomers achieved several other firsts. They directly measured the velocity of the exoplanet as it orbits its home star. "In general, the mass of an exoplanet is determined by measuring the wobble of the star and assuming a mass for the star, according to theory. Here, we have been able to measure the motion of the planet as well, and thus determine both the mass of the star and of the planet," says co-author Ernst de Mooij. Also for the first time, the astronomers measured how much carbon is present in the atmosphere of this planet. "It seems that H209458b is actually as carbon-rich as Jupiter and Saturn. This could indicate that it was formed in the same way," says Snellen. "In the future, astronomers may be able to use this type of observation to study the atmospheres of Earth-like planets, to determine whether life also exists elsewhere in the Universe." More information This research was presented in a paper that appears this week in the journal Nature: "The orbital motion, absolute mass, and high-altitude winds of exoplanet HD209458b", by I. Snellen et al. The team is composed of Ignas A. G. Snellen and Ernst J. W. de Mooij, (Leiden Observatory, The Netherlands), Remco J. de Kok (SRON, Utrecht, The Netherlands), and Simon Albrecht (Massachusetts Institute of Technology, USA). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Monitoring a high-amplitude δ Scuti star for 152 days: discovery of 12 additional modes and modulation effects in the light curve of CoRoT 101155310

NASA Astrophysics Data System (ADS)

Poretti, E.; Rainer, M.; Weiss, W. W.; Bognár, Zs.; Moya, A.; Niemczura, E.; Suárez, J. C.; Auvergne, M.; Baglin, A.; Baudin, F.; Benkő, J. M.; Debosscher, J.; Garrido, R.; Mantegazza, L.; Paparó, M.

2011-04-01

Aims: The detection of small-amplitude nonradial modes in high-amplitude δ Sct (HADS) variables has been very elusive until at least five of them were detected in the light curve of V974 Oph obtained from ground-based observations. The combination of radial and nonradial modes has a high asteroseismic potential, thanks to the strong constraints we can put in the modelling. The continuous monitoring of ASAS 192647-0030.0 ≡ CoRoT 101155310 (P = 0.1258 d, V = 13.4) ensured from space by the CoRoT (COnvection, ROtation and planetary Transits) mission constitutes a unique opportunity to exploit such potential. Methods: The 22270 CoRoT measurements were performed in the chromatic mode. They span 152 d and cover 1208 consecutive cycles. After the correction for one jump and the long-term drift, the level of the noise turned out to be 29 μmag. The phase shifts and amplitude ratios of the coloured CoRoT data, the HARPS spectra, and the period-luminosity relation were used to determine a self-consistent physical model. In turn, it allowed us to model the oscillation spectrum, also giving feedback on the internal structure of the star. Results: In addition to the fundamental radial mode f1 = 7.949 d-1 with harmonics up to 10f1, we detected 12 independent terms. Linear combinations were also found and the light curve was solved by means of 61 frequencies (smallest amplitude 0.10 mmag). The newest result is the detection of a periodic modulation of the f1 mode (triplets at ± 0.193 d-1 centred on f1 and 2f1), discussed as a rotational effect or as an extension of the Blazhko effect to HADS stars. The physical model suggests that CoRoT 101155310 is an evolved star, with a slight subsolar metallic abundance, close to the terminal age main sequence. All the 12 additional terms are identified with mixed modes in the predicted overstable region. The CoRoT space mission was developed and is operated by the French space agency CNES, with the participation of ESA's RSSD and Science Programmes, Austria, Belgium, Brazil, Germany, and Spain. This work uses ground-based spectroscopic observations made with the HARPS instrument at the 3.6 m-ESO telescope (La Silla, Chile) under the ESO Large Programme LP182.D-0356 and complementary photometric measurements made at the Piszkéstető Mountain Station of Konkoly Observatory (Hungary).Table 1 is also, and Table 2 only, available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/528/A147

Stellar Family Portrait Takes Imaging Technique to New Extremes

NASA Astrophysics Data System (ADS)

2009-12-01

The young star cluster Trumpler 14 is revealed in another stunning ESO image. The amount of exquisite detail seen in this portrait, which beautifully reveals the life of a large family of stars, is due to the Multi-conjugate Adaptive optics Demonstrator (MAD) on ESO's Very Large Telescope. Never before has such a large patch of sky been imaged using adaptive optics [1], a technique by which astronomers are able to remove most of the atmosphere's blurring effects. Noted for harbouring Eta Carinae - one of the wildest and most massive stars in our galaxy - the impressive Carina Nebula also houses a handful of massive clusters of young stars. The youngest of these stellar families is the Trumpler 14 star cluster, which is less than one million years old - a blink of an eye in the Universe's history. This large open cluster is located some 8000 light-years away towards the constellation of Carina (the Keel). A team of astronomers, led by Hugues Sana, acquired astounding images of the central part of Trumpler 14 using the Multi-conjugate Adaptive optics Demonstrator (MAD, [2]) mounted on ESO's Very Large Telescope (VLT). Thanks to MAD, astronomers were able to remove most of the blurring effects of the atmosphere and thus obtain very sharp images. MAD performs this correction over a much larger patch of the sky than any other current adaptive optics instrument, allowing astronomers to make wider, crystal-clear images. Thanks to the high quality of the MAD images, the team of astronomers could obtain a very nice family portrait. They found that Trumpler 14 is not only the youngest - with a refined, newly estimated age of just 500 000 years - but also one of the most populous star clusters within the nebula. The astronomers counted about 2000 stars in their image, spanning the whole range from less than one tenth up to a factor of several tens of times the mass of our own Sun. And this in a region which is only about six light-years across, that is, less than twice the distance between the Sun and its closest stellar neighbour! The most prominent star is the supergiant HD 93129A, one of the most luminous stars in the Galaxy. This titan has an estimated mass of about 80 times that of the Sun and is approximately two and a half million times brighter! It makes a stellar couple - a binary star - with another bright, massive star. The astronomers found that massive stars tend to pair up more often than less massive stars, and preferably with other more massive stars. The Trumpler 14 cluster is undoubtedly a remarkable sight to observe: this dazzling patch of sky contains several white-blue, hot, massive stars, whose fierce ultraviolet light and stellar winds are blazing and heating up the surrounding dust and gas. Such massive stars rapidly burn their vast hydrogen supplies - the more massive the star, the shorter its lifespan. These giants will end their brief lives dramatically in convulsive explosions called supernovae, just a few million years from now. A few orange stars are apparently scattered through Trumpler 14, in charming contrast to their bluish neighbours. These orange stars are in fact stars located behind Trumpler 14. Their reddened colour is due to absorption of blue light in the vast veils of dust and gas in the cloud. The technology used in MAD to correct for the effect of the Earth's atmosphere over large areas of sky will play a crucial role in the success of the next generation European Extremely Large Telescope (E-ELT). Notes [1] Telescopes on the ground suffer from a blurring effect introduced by atmospheric turbulence. This turbulence causes the stars to twinkle in a way that delights poets but frustrates astronomers, since it smears out the fine details of the images. However, with adaptive optics techniques, this major drawback can be overcome so that the telescope produces images that are as sharp as theoretically possible, i.e. approaching conditions in space. Adaptive optics systems work by means of a computer-controlled deformable mirror that counteracts the image distortion introduced by atmospheric turbulence. It is based on real-time optical corrections computed at very high speed (several hundreds of times each second) from image data obtained by a wavefront sensor (a special camera) that monitors light from a reference star. [2] Present adaptive optics systems can only correct the effect of atmospheric turbulence in a very small region of the sky - typically 15 arcseconds or less - the correction degrading very quickly when moving away from the reference star. Engineers have therefore developed new techniques to overcome this limitation, one of which is multi-conjugate adaptive optics. MAD uses up to three stars instead of one as references to remove the blur caused by atmospheric turbulence over a field of view thirty times larger than that available to existing techniques (eso0719). More information This research has been presented in a paper submitted to Astronomy and Astrophysics ("A MAD view of Trumpler 14", by H. Sana et al.). The team is composed of H. Sana, Y. Momany, M. Gieles, G. Carraro, Y. Beletsky, V. Ivanov, G. De Silva and G. James (ESO). H. Sana is now working at the Amsterdam University, The Netherlands. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

GIRAFFE Reaches towards the Stars

NASA Astrophysics Data System (ADS)

2002-07-01

"First Light" of New Powerful Spectrograph at the VLT Summary The first observations of stellar spectra have just been performed with the new GIRAFFE multi-object spectrograph on the ESO Very Large Telescope (VLT) at the Paranal Observatory in Chile. This milestone event was achieved in the early morning of July 3, 2002. It signifies another important step towards the full implementation of the extremely powerful Fibre Large Array Multi-Element Spectrograph (FLAMES) , one of the main instruments for the ESO VLT. This project is co-ordinated by ESO and incorporates many complex components that have been constructed at various research institutions in Europe and Australia. The GIRAFFE spectrograph provides unique possibilities for detailed observations of the properties of individual stars located in our Milky Way galaxy ( PR 16b/02 ) as well as in other galaxies of the Local Group. PR Photo 16a/02 : A series of stellar spectra recorded by GIRAFFE during "First Light" . PR Photo 16b/02 : Details of some of these stellar spectra . FLAMES and GIRAFFE ESO PR Photo 16a/02 ESO PR Photo 16a/02 [Preview - JPEG: 756 x 400 pix - 363k] [Normal - JPEG: 1511 x 800 pix - 1.2M] ESO PR Photo 16b/02 ESO PR Photo 16b/02 [Preview - JPEG: 461 x 400 pix - 196k] [Normal - JPEG: 921 x 800 pix - 606k] Caption : PR Photo 16a/02 : "First Light" test observation with the GIRAFFE spectrograph of about 50 high-quality spectra (10 min exposure at spectral resolution 7,000) of stars in the Milky Way disk, in the early morning of July 3, 2002. The stars have magnitudes of 12 - 16 and are all of solar type. The photo shows part of the image recorded with a 2000 x 4000 pixel CCD detector at the focal plane of the spectrograph. Each stellar spectrum is seen as one vertical line - some of the absorption lines can be seen as dark horizontal features. PR Photo 16b/02 shows a small part of this image. The three strong absorption lines that are visible as horizontal, dark lines in the lower part of the photo are due to the common element Magnesium in the atmospheres of these stars (the Mg b triplet at wavelength 517 nm). The different intensity of the spectra is due to the different brightness of the stars. The multi-object GIRAFFE spectrograph , now installed on the 8.2-m KUEYEN Unit Telescope of ESO's Very Large Telescope (VLT) at the Paranal Observatory (Chile), achieved "First Light" in the early morning hours of July 3, 2002. This complex instrument allows to obtain high-quality spectra of a large variety of celestial objects, from individual stars in the Milky Way and other nearby galaxies, to very distant galaxies. It functions by means of multiple optical fibres that guide the light from the telescope's focal plane into the entry slit of the spectrograph. Here the light is dispersed into its different colours. Anticipating already at this early moment the future, highly effective operation of the new facility, the first data were immediately prepared for astronomical interpretation ("reduced") by means of a dedicated software package ("pipeline"). GIRAFFE and these fibres are an integral part of the advanced Fibre Large Array Multi-Element Spectrograph (FLAMES) facility which also includes the OzPoz positioner and an optical field corrector . It is the outcome of a collaboration between ESO, Observatoire de Paris-Meudon Observatoire de Genève-Lausanne and the Anglo Australian Observatory (AAO) . More details are available in ESO PR 01/02. The principle of this instrument involves the positioning in the telescope's focal plane of a large number of optical fibres. This is done in such a way that each of them guides the light from one particular celestial object towards the spectrograph that records the spectra of all these objects simultaneously. The size of the available field-of-view is no less than about 25 arcmin across, i.e. almost as large as the full moon. The individual fibres are moved and positioned "on the objects" in the field by means of the OzPoz positioner. Different observational modes FLAMES has several different modes of operation. Two of these are of the simple "multi-object" type: each fibre collects the light from one star or galaxy - up to 132 objects can be observed simultaneously, cf. PR 16a/02 . In this respect, GIRAFFE provides absolutely unique possibilities for detailed observations of the properties (age, chemical composition, rotation and space velocity) of individual stars located in the main disk, central bulge or halo of our Milky Way galaxy ( PR 16b/02 ), and also of stars in other galaxies of the Local Group. Another observational mode is known as "3-D spectroscopy" or "integrated field". This consists of obtaining simultaneous spectra of smaller areas of extended objects like galaxies or nebulae. For this, 15 deployable fibre bundles, the so-called Integral Field Units (IFUs) , cf. ESO PR 01/02 , are used. Each IFU is a microscopic, state-of-the-art two-dimensional lens array with an aperture of 3 x 2 arcsec 2 on the sky. It is like an insect's eye, with twenty micro-lenses coupled with optical fibres leading the light recorded at each point in the field to the entry slit of the spectrograph. Unique research opportunities opening The FLAMES facility, once in full operation after further testing and fine-tuning later this year, will enormously increase the possibilities to study stellar physics and the evolution of galaxies , two of the cornerstones in our understanding of the structure and evolution of the Universe. With the great light-gathering capacity of the VLT, FLAMES will be able to gather very comprehensive information about even rather faint objects, enabling the astronomers to study them in a degree of detail so far reserved for brighter, nearby stars. The quality of the first spectra from GIRAFFE, although far from exploiting the ultimate potential of the new facility, fully confirm these expectations. Note [1]: This is a joint Press Release of ESO and the Observatoire de Paris.

Riccardo Giacconi to Receive National Medal of Science

NASA Astrophysics Data System (ADS)

2005-02-01

Riccardo Giacconi, very recently retired President of Associated Universities, Inc. (AUI), will be awarded the National Medal of Science by President George W. Bush on March 14, according to the White House. Giacconi, who received the Nobel Prize in Physics in 2002, will be honored for his pioneering research in X-ray astronomy and for his visionary leadership of major astronomy facilities. Established by Congress in 1959, the National Medal of Science is the Nation's highest honor for American scientists and is awarded annually by the President of the United States to individuals "deserving of special recognition for their outstanding contributions to knowledge." "We are extremely proud that Riccardo Giacconi has been selected to receive the nation's highest award for scientific achievement," said current AUI President Ethan J. Schreier, a long-term colleague of Dr. Giacconi. "It is another fitting recognition for an outstanding scientific career that has enhanced our basic understanding of the universe," Schreier added. Giacconi, known as the father of X-ray astronomy, used X-ray detectors launched on rockets to discover the first cosmic X-ray source in 1962. Because X-ray radiation is absorbed in Earth's atmosphere, space-based instruments are necessary to study it. Giacconi outlined a methodical program to investigate this new X-ray universe and, working with his research group at American Science and Engineering, Inc. in Cambridge, Massachusetts, developed the first space satellite dedicated to the new field of X-ray astronomy. Named Uhuru, this X-ray satellite observatory was launched in 1970 and subsequently discovered hundreds of X-ray sources. The ground-breaking work of Giacconi and his group led to the discovery of black holes, which to that point had been hypothesized but never seen. Giacconi was also the first to prove that the universe contains background radiation of X-ray light. Riccardo Giacconi has played a key role in many other landmark astronomy programs. He was the Principal Investigator for the Einstein Observatory, the first imaging X-ray observatory, and led the team that proposed the current Chandra X-ray Observatory. He became the first director of the Space Telescope Science Institute, responsible for conducting the science program of the Hubble Space Telescope. He later moved to Germany to become Director-General of the European Southern Observatory (ESO), building the Very Large Telescope, an array of four 8-meter telescopes in Chile. While Director-General of ESO, Giacconi initiated a new cooperative program between the United States, ESO, and Canada to develop and build a large array of antennas for radio astronomy, the Atacama Large Millimeter Array (ALMA), in northern Chile. Giacconi was President of AUI from 1999 to 2004, managing the world-class National Radio Astronomy Observatory (NRAO), an astronomical research facility of the National Science Foundation. During his tenure, Giacconi's scientific vision dramatically advanced the observatory's capabilities. NRAO began the construction of ALMA in Chile and also the Expansion of the Very Large Array (EVLA) in New Mexico, opening new scientific frontiers across the entire radio spectrum. "I am delighted that Riccardo Giacconi has received this recognition," said NRAO Director Fred K.Y. Lo. "The value and impact of the multi-wavelength astronomy which he enabled has been nothing short of revolutionary. This honor recognizes Giacconi's contributions to astronomy and the broader scientific community." Dr. Giacconi is currently a University Professor at Johns Hopkins University in Baltimore, and remains a Distinguished Advisor to the Trustees of Associated Universities, Inc.

a Passage to the Universe

NASA Astrophysics Data System (ADS)

1995-11-01

Exciting Week Ahead for Winners of Unique Astronomy Contest Following the very successful events of 1993 and 1994 [1], ESO again opens its doors for an `educational adventure' next week. It takes place within the framework of the `Third European Week for Scientific and Technological Culture', initiated and supported by the European Commission. On Tuesday, November 14, 1995, about forty 16-18 year old students and their teachers will converge towards Munich from all corners of Europe. They are the happy winners of a Europe-wide astronomy contest (`Europe Towards the Stars') that took place during the summer and early autumn. Their prize is a free, week-long stay at the Headquarters of the European Southern Observatory. During this time they will work with professional astronomers and get a hands-on experience within modern astronomy and astrophysics at one of the world's foremost international centres. In particular, the participants will be exposed to the scientific method by carrying through a research programme of their own, all the way from conception to interpretation of the data. The culmination of the stay will be the opportunity to perform remote observations via a satellite link with two major telescopes at the ESO La Silla observatory in Chile, including the very advanced 3.5-metre New Technology Telescope (NTT). The European Contest This year's EU/ESO programme was devised as a contest between joint teams of secondary school students and their teachers. The teams had to choose between four different subjects requiring either practical or theoretical work, and all with strong scientific and technological components. One subject was to devise an observational programme with an existing telescope and instrument and to discuss the resulting data in order to arrive at a scientific conclusion. This was the preferred subject by many teams. For instance, the winning German team observed the moons of Jupiter and the Danish team studied a star cluster in order to derive its age and other characteristics. The second subject, to build and test an astronomical instrument, posed a welcome challenge to teams with a particular interest in technology. Some of the instruments were quite advanced; in France, for instance, the winning team built a working solar radio interferometer. In the same direction, but with a more theoretical touch, some teams chose the third subject, to design on paper an instrument for a future space mission to the outer Solar System for the exploration of Pluto and the newly discovered Transneptunian Objects. The last subject, which secured the first prize for the Dutch winning team, concerned the study of a hypothetical, stable planetary system around another star, its properties and the technical requirements for observing this system from the Earth. With the recent discovery of a planet around the nearby star 51 Pegasi, this theme has unexpectedly gained added relevance. During the past few weeks, the work by the teams was evaluated by specially established, national juries, consisting of scientists, educators and ministerial representatives (addresses below). The establishment of the European Association for Astronomy Education (EAAE) last year contributed to the Europe-wide interest in these matters and many EAAE members have been involved in the present contest, as participants or in its organisation. The national winners have now been selected; their names are listed below. In most countries, the award ceremonies have already taken place. Media Coverage The main event, i.e. the stay of the winning teams at the ESO Headquarters in Garching (Germany) from November 14 - 20, 1995, will be covered by the various media in the appropriate ways. More information, including a detailed programme of the many (day and night) activities during this event, may be obtained at request from the ESO Education and Public Relations Department at the Headquarters. In this connection, ESO is also pleased to invite the media to a concluding Press Conference , during which the outcome of this unique event will be summarized by the participants and the organisers: Monday, November 20, 1995, 15:30 pm, at the ESO Headquarters, Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany List of National First-Prize Winners Belgium: Mr. Freddy Allemeersch (Teacher), Mr. Pieter De Ceuninck, Mr. Jeroen Staelens (Onze-Lieve-Vrouwecollege, Brugge) Denmark: Mr. Joern C. Olsen, Mr. Henrik Struckmann, Mr. Uffe A. Hansen, Mr. Mogens Winther (Teacher) (Soenderborg Amtsgymnasium) Finland: Mr. Reima Eresmaa, Ms. Laura Elina Nykyri, Ms. Reetamaija Janhonen (Cygnaeues-Lukeo, Jyvaeskylae and Jyvaeskylaen Lyseon Lukeo) France: Mr. Rene Cavaroz (Teacher), Mr. Vincent Hardy, Mr. Antoine Lesuffleur (Lycee Chartier, Bayeux) Germany: Ms. Dorothee Barth, Mr. Walter Czech (Teacher), Mr. Uwe Kranz, Ms. Karin Wieland (Immanuel-Kant-Gymnasium, Leinfelden-Echterdingen, Baden-Wuerttemberg) Greece: Ms. Agni Ioannidi, Ms. Elena Katifori, Mr. Vassilis Samiotis, Mr. Vassillos Tzotzes (Teacher) (Second Varvakelo Experimental Lyceum, Athens) Ireland: Mr. Declan Maccuarta (Teacher), Mr. Colm Mcloughlin (St. Peter's College, Wexford, Co. Wexford) Italy: Mr. Pasquale Ciarletta, Ms. Francesca D'elia, Ms. Ada Fortugna (Teacher), Mr. Alfredo Pudano (Liceo Scientifico `Leonardo da Vinci', Reggio Calabria) The Netherlands: Mr. Alex De Beer, Mr. Klaas Huijbregts, Mr. Ruud Nellen (Norbertuscollege, Rosendaal) Spain: Mr. Aritz Atela Aio, Mr. Julen Sarasola Manich (Teacher), Mr. Jon Huertas Rodriquez (Txorierri Batxilergoko Institua, Derio Bizkaia) Sweden: Mr. Rahman Amanullah, Mr. Kjell L. Bonander (Teacher), Mr. Tomas Oppelstrup, Ms. Christin Wiedemann (Saltsjoebadens Samskola, Saltsjoebaden) United Kingdom: Mr. Michael Ching, Dr. Richard Field (Teacher) (Oundle School, Peterborough) National Committees Further information about the national contests may be obtained from the National Committees: Belgium: Dr. C. Sterken, Vrije Universiteit Brussel, Campus Ofenplein, Pleinlaan 2, B-1050 Brussels, Tel. 0032-2-6293469, Fax 0032-9-3623976, E-mail csterken@is1.vub.ac.be Denmark: Mr. B. F. Joergensen, Tycho Brahe Planetariet, Gl. Kongevej 10, DK-1610 Copenhagen V, Tel. 0045-33-144888, Fax 0045-33-142888, E-mail tycho@inet.uni-c.dk Finland: Mr. M. Hotakainen, Taehtitieteellinen Yhdistys Ursa, Laivanvarustajankatu 9C 54, FIN-00140 Helsinki, Tel. 00358-0-174048, Fax 00358-0-657728 France: Mr. B. Pellequer, Geospace d'Aniane, Boite Postale 22, F-34150 Aniane, Tel. 0033-6-7034949, Fax 0033-6-7752864 Germany: Dr. K.-H. Lotze, Friedrich-Schiller-Universitaet, Max-Wien-Platz 1, D-07743 Jena, Germany, Tel. +49-3641-635904/636654, Fax +49-3641-636728 Greece: Dr. D. Simopoulos, Eugenides Foundation, Astronomy Department, 387 Sygrou Avenue, Palaio Faliro, GR-175 64 Athens, Tel. 0030-1-941-1181, Fax 0030-1-941-7372 Ireland: Dr. I. Elliot, Dunsink Observatory (Dublin Institute for Advanced Studies), Castleknock, Dublin 15, Tel. 00353-1- 838-7911/7959, Fax 00353-1-8387090, E-mail ie@dunsink.dias.ie Italy: Dr. B. Monsignori Fossi, Osservatorio Astrofisico di Arcetri, Largo Enrico Fermi 5, I-50125 Florence, Tel. 0039-55-2752246, Fax 0039-55-220039, E-mail bmonsignori@arcetri.astro.it The Netherlands: Dr. M. Drummen, Stichting `De Koepel', Zonnenburg 2, NL-3512 NL Utrecht, Tel. 0031-30-311360, Fax 0031-30-342852, E-mail dekoepel@knoware.nl Spain: Dr. A. Sanchez/Dr. T. Fernandez, Planetario de Madrid, Parque Tierno Galvan, E-28045 Madrid, Tel. 0034-1-4673578, Fax 0034-1-4681154, E-mail tfc@vilspa.esa.es Sweden: Dr. K. Loden, Stockholms Observatorium, S-133 36 Saltsjoebaden, Tel. 0046-8-164454, Fax 0046-8-7174719, E-mail lodenk@astro.su.se United Kingdom: Dr. A. M. Cohen, c/o The Association for Astronomy Education, 9 Hurst Lane, Bollington, Macclesfield, Cheshire SK10 5LN, England Notes: [1] See ESO Press Releases 08/93 of 5 November 1993 and 17/94

ESO Director General to Become President of AUI

NASA Astrophysics Data System (ADS)

1998-11-01

The appointment of Professor Riccardo Giacconi , Director General of the European Southern Observatory (ESO) since January 1, 1993, to the Presidency of Associated Universities, Inc. ( AUI ) in the USA, has been jointly announced by Professor Paul C. Martin, Chair of AUI's Board of Trustees and Mr. Henrik Grage, President of the ESO Council. Professor Giacconi will assume this new position at the end of his term at ESO as of July 1, 1999. AUI is a not-for-profit science management corporation that operates the National Radio Astronomy Observatory ( NRAO) under a Cooperative Agreement with the National Science Foundation (NSF). Corporate headquarters are located in Washington, D.C. The President is its chief executive officer. Nine northeastern universities joined in founding AUI in 1946: Columbia University, Cornell University, Harvard University, The Johns Hopkins University, Massachusetts Institute of Technology, the University of Pennsylvania, Princeton University, the University of Rochester, and Yale University. Over the years, AUI has taken on a broad national character with a diversified Board of Trustees from universities and other institutions across the United States. ESO is an intergovernmental organization, at present with the following member countries: Belgium, Denmark, France, Germany, Italy, The Netherlands, Sweden and Switzerland. Portugal has an agreement with ESO aiming at full membership. ESO was founded in 1962 to establish and operate an astronomical observatory in the southern hemisphere and to promote and organize co-operation in astronomical research in Europe. While the ESO Headquarters are situated in Europe, the observing facilities are located in Chile (South America). The organization's main administrative and technical departments are located at the ESO Headquarters, in Garching near Munich, Germany. They include a number of highly specialized facilities, e.g. the optical, infrared, detector and instrumentation laboratories, all engaged in front-line research and development. The European Coordinating Facility for the Hubble Space Telescope, jointly managed by ESO and the European Space Agency (ESA), is also situated in Garching. Mr. Grage , President of the ESO Council, expressed the gratitude of the ESO Community for the leadership provided by Prof. Giacconi during these crucial years of development of the organization and its La Silla and Paranal Observatories. In particular, the splendid achievements on the Very Large Telescope (VLT) are a tribute to the ESO staff and to his management and guidance. VLT is currently the largest single project in ground-based astronomy. It has met or exceeded all performance requirements while being built on time and within budget. When reached for comment, Professor Giacconi pointed out: "I have enjoyed enormously the time I have spent here at ESO and I consider it one of the high points of my career. I feel confident that I am leaving ESO in very good condition. The fine performance of the entire staff has succeeded in bringing the organization to an outstanding position in ground-based astronomy in the world. The prospects for the future are equally brilliant. I will be happy and proud to assume the Presidency of Associated Universities, Inc. starting next summer. For more than fifty years, AUI has, in collaboration with universities and the national and international scientific community, overseen and managed national facilities which have made possible a wealth of important discoveries in physics, astronomy, and many other areas of science and technology. In the 21st Century, new challenges and opportunities to serve the community await AUI." Asked about the recent developments in astronomy, Professor Giacconi added that "Advances in this fundamental field of research have come to depend more and more on the execution of complex and large projects. Many of these necessitate international cooperation on the broadest scale. The VLT is an outstanding example and will be the prime ground-based optical observatory of the coming Century. The expertise of AUI and NRAO in providing effective support to the radio astronomy community will prove an invaluable asset in carrying out, under NSF sponsorship, the new and ambitious international cooperative project in submillimeter wave astronomy. I look forward to the opportunity to help AUI in the realization of this undertaking, so important for future advances in the field. Scientific research in different disciplines is ever more closely interwoven today in methodology and management approaches. The expertise of AUI and of the university community it represents qualifies the organization to manage scientific endeavors in many fields. Guiding AUI in responding to the many challenges and opportunities it faces will be interesting and exciting." "We are thrilled that Professor Giacconi has decided to take this position," said Professor Paul Martin , Chairman of the Board of AUI. "It is hard to imagine anyone better qualified to lead an organization committed to managing facilities performing frontier science. His vision and foresight have been at the heart of pioneering projects including the Einstein Observatory, the Space Telescope, and the VLT. He is an extraordinary scientist and an outstanding manager whose accomplishments and values have earned him worldwide respect and admiration." Prior to this assignment at ESO, Prof. Giacconi had served as Director of the Hubble Space Telescope Science Institute in Baltimore, Maryland. He is best known in scientific circles for his pioneering contributions to X-ray astronomy. His seminal work in this field, which started at American Science and Engineering, Inc., culminated in the realization, while on the faculty of Harvard University, of the orbital Einstein Observatory in the 1970's. He is currently on leave as Research Professor of Johns Hopkins University and Astronomer Emeritus at STScI. He is the recipient of numerous prestigious scientific awards for his work. Prof. Giacconi is a member of the U.S. National Academy of Sciences and the American Academy of Arts and Sciences. He is the author of books as well as more than 200 scientific publications. Note: [1] This is a joint Press Release of ESO and AUI (URL: http://www.aui.edu/ ). How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

New ultracool subdwarfs identified in large-scale surveys using Virtual Observatory tools (Corrigendum). I. UKIDSS LAS DR5 vs. SDSS DR7

NASA Astrophysics Data System (ADS)

Lodieu, N.; Espinoza Contreras, M.; Zapatero Osorio, M. R.; Solano, E.; Aberasturi, M.; Martín, E. L.

2017-01-01

Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 084.C-0928A.Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway, and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias.

Anatomy of a Bird

NASA Astrophysics Data System (ADS)

2007-12-01

Using ESO's Very Large Telescope, an international team of astronomers [1] has discovered a stunning rare case of a triple merger of galaxies. This system, which astronomers have dubbed 'The Bird' - albeit it also bears resemblance with a cosmic Tinker Bell - is composed of two massive spiral galaxies and a third irregular galaxy. ESO PR Photo 55a/07 ESO PR Photo 55a/07 The Tinker Bell Triplet The galaxy ESO 593-IG 008, or IRAS 19115-2124, was previously merely known as an interacting pair of galaxies at a distance of 650 million light-years. But surprises were revealed by observations made with the NACO instrument attached to ESO's VLT, which peered through the all-pervasive dust clouds, using adaptive optics to resolve the finest details [2]. Underneath the chaotic appearance of the optical Hubble images - retrieved from the Hubble Space Telescope archive - the NACO images show two unmistakable galaxies, one a barred spiral while the other is more irregular. The surprise lay in the clear identification of a third, clearly separate component, an irregular, yet fairly massive galaxy that seems to be forming stars at a frantic rate. "Examples of mergers of three galaxies of roughly similar sizes are rare," says Petri Väisänen, lead author of the paper reporting the results. "Only the near-infrared VLT observations made it possible to identify the triple merger nature of the system in this case." Because of the resemblance of the system to a bird, the object was dubbed as such, with the 'head' being the third component, and the 'heart' and 'body' making the two major galaxy nuclei in-between of tidal tails, the 'wings'. The latter extend more than 100,000 light-years, or the size of our own Milky Way. ESO PR Photo 55b/07 ESO PR Photo 55b/07 Anatomy of a Bird Subsequent optical spectroscopy with the new Southern African Large Telescope, and archive mid-infrared data from the NASA Spitzer space observatory, confirmed the separate nature of the 'head', but also added further surprises. The 'head' and major parts of the 'Bird' are moving apart at more than 400 km/s (1.4 million km/h!). Observing such high velocities is very rare in merging galaxies. Also, the 'head' appears to be the major source of infrared luminosity in the system, though it is the smallest of the three galaxies. "It seems that NACO has caught the action right at the time of the first high-speed fly-by of the 'head' galaxy through the system consisting of the other two galaxies," says Seppo Mattila, member of the discovery team. "These two galaxies must have met earlier, probably a couple of hundred million years ago." The 'head' is forming stars violently, at a rate of nearly 200 solar masses per year, while the other two galaxies appear to be at a more quiescent epoch of their interaction-induced star formation history. The 'Bird' belongs to the prestigious family of luminous infrared galaxies, with an infrared luminosity nearly one thousand billion times that of the Sun. This family of galaxies has long been thought to signpost important events in galaxy evolution, such as mergers of galaxies, which in turn trigger bursts of star formation, and may eventually lead to the formation of a single elliptical galaxy. The findings presented here are reported in a paper to appear in a future issue of the journal Monthly Notices of the Royal Astronomical Society ("Adaptive optics imaging and optical spectroscopy of a multiple merger in a luminous infrared galaxy", by P. Väisänen" et al.). Note [1]: The team is composed of P. Väisänen, A. Kniazev, D. A. H. Buckley, L. Crause, Y. Hashimoto, N. Loaring, E. Romero-Colmenero, and M. Still (SAAO, South Africa), S. Mattila (Tuorla Observatory, Finland), A. Adamo and G. Östlin (Stockholm University, Sweden), A. Efstathiou (Cyprus College, Nicosia, Cyprus), D. Farrah (Cornell University, USA), P. H. Johansson (Universitäts-Sternwarte München, Germany), E. B. Burgh and K. Nordsieck (University of Wisconsin, USA), P. Lira (Universidad de Chile, Santiago, Chile), A. Zijlstra (University of Manchester, UK ), and S. Ryder (AAO, Australia). [2]: The final resolution was better than a tenth of an arcsecond, that is, the angle sustained by a 2-cm coin seen from a distance of 40 km. This is roughly a factor 600 better than what a keen human eye can distinguish.

Stellar students win fantastic prizes

NASA Astrophysics Data System (ADS)

2008-05-01

School students and teachers across Europe and around the world are discovering today who has won fantastic prizes in "Catch a Star", the international astronomical competition run by ESO and the European Association for Astronomy Education (EAAE). CAS2008 artwork ESO PR Photo 14/08 One of the winning artworks "We were extremely impressed by the high quality of the entries, and the number of participants was even higher than last year. We wish to congratulate everybody who took part," said Douglas Pierce-Price, Education Officer at ESO. "'Catch a Star' clearly shows astronomy's power to inspire and excite students of all ages," added Fernand Wagner, President of the EAAE. The top prize, of a week-long trip to Chile to visit the ESO Very Large Telescope (VLT) on Paranal, was won by students Roeland Heerema, Liesbeth Schenkels, and Gerben Van Ranst from the Instituut Spijker in Hoogstraten, Belgium, together with their teacher Ann Verstralen. With their "story of aged binary stars... Live and Let Die", they take us on a vivid tour of the amazing zoo of binary stars, and the life and death of stars like our Sun. The students show how state-of-the-art telescopes, particularly those at ESO's sites of La Silla and Paranal, help us understand these stars. They take as an illustrative example the binary star system V390 Velorum. In the last phases of its life, V390 Velorum will shed its outer shell of gas and dust, turning from a celestial chrysalis into a beautiful cosmic butterfly. The students also involved other pupils from their school, showing them how to test their eyesight by observing the binary star system of Alcor and Mizar. But perhaps the most important discovery they made is that, as they write in their report, "Astronomy lives! Discoveries are being made each day and there is still very much to be found and learned by astronomers!" The team will travel to Chile and visit the ESO VLT - the world's most advanced optical/infrared telescope. At Paranal, they will meet astronomers and be present during a night of observations. Learning that they won, the team was enthusiastic: "We are very pleased to hear this fantastic news and are looking forward to the trip!" Another winner was Marta Kotarba, with her teacher Grzegorz Sęk, from the school IV Liceum Ogólnokształcące im. Tadeusza Kościuszki, Poland. Her prize is a trip to the Hispano-German Astronomical Observatory of Calar Alto in Almeria, Spain, kindly donated by the Spanish Council for Scientific Research. Marta's project "Galaxy Zoo and I" tells how she joined the website "Galaxy Zoo" to study galaxies and help astronomical researchers understand the structure of the Universe. Galaxy Zoo volunteers classify galaxies into different types, such as spiral or elliptical - a task much more easily done by humans than computers. Marta explains that the project "is like an adventure to me. Galaxy Zoo gives me abilities to enlarge my knowledge about the Universe and to gain new skills." Her winning entry also shows how anyone can get involved in the world of real astronomical research, simply by using the Internet. A third winner, of a trip to Königsleiten Observatory in Austria, is Andreia Nascimento with her teacher Leonor Cabral, from Escola Secundária da Cidadela in Portugal. Her project, on "Hunting for Open Star Clusters" near young stars, used data from the robotic Faulkes Telescope in Hawaii, which is used for research-based science education. "Catch a Star" also includes an artwork competition, for which students created artwork with an astronomical theme. This competition, through which students can get involved with astronomy even outside of science classes, has become increasingly popular, with over one thousand entries this year from around the world. Not only were prizes awarded by public votes in a web gallery, but special prizes were awarded by Garry Harwood, a Fellow and life member of the International Association of Astronomy Artists. Harwood said: "It was a real pleasure to discover such a varied and impressive collection of art from so many young people representing almost every corner of the globe. I was extremely impressed with the quality of art on display which made judging all the competition entries a difficult but thoroughly enjoyable task." Other prizes in "Catch a Star" include astronomical software, posters of breathtaking astronomical images from ESO telescopes, and exclusive "Catch a Star" T-shirts. The full list of winners is available on the competition website.

ESO-Hα 574 and Par-Lup 3-4 jets: Exploring the spectral, kinematical, and physical properties

NASA Astrophysics Data System (ADS)

Whelan, E. T.; Bonito, R.; Antoniucci, S.; Alcalá, J. M.; Giannini, T.; Nisini, B.; Bacciotti, F.; Podio, L.; Stelzer, B.; Comerón, F.

2014-05-01

In this paper a comprehensive analysis of VLT/X-Shooter observations of two jet systems, namely ESO-Hα 574 a K8 classical T Tauri star and Par-Lup 3-4 a very low mass (0.13 M⊙) M5 star, is presented. Both stars are known to have near-edge on accretion disks. A summary of these first X-shooter observations of jets was given in a 2011 letter. The new results outlined here include flux tables of identified emission lines, information on the morphology, kinematics and physical conditions of both jets and, updated estimates of Ṁout/Ṁacc. Asymmetries in the ESO-Hα 574 flow are investigated while the Par-Lup 3-4 jet is much more symmetric. The density, temperature, and therefore origin of the gas traced by the Balmer lines are investigated from the Balmer decrements and results suggest an origin in a jet for ESO-Hα 574 while for Par-Lup 3-4 the temperature and density are consistent with an accretion flow. Ṁacc is estimated from the luminosity of various accretion tracers. For both targets, new luminosity relationships and a re-evaluation of the effect of reddening and grey extinction (due to the edge-on disks) allows for substantial improvements on previous estimates of Ṁacc. It is found that log(Ṁacc) = -9.15 ± 0.45M⊙ yr-1 and -9.30 ± 0.27M⊙ yr-1 for ESO-Hα 574 and Par-Lup 3-4 respectively. Additionally, the physical conditions in the jets (electron density, electron temperature, and ionisation) are probed using various line ratios and compared with previous determinations from iron lines. The results are combined with the luminosity of the [SII]λ6731 line to derive Ṁout through a calculation of the gas emissivity based on a 5-level atom model. As this method for deriving Ṁout comes from an exact calculation based on the jet parameters (measured directly from the spectra) rather than as was done previously from an approximate formula based on the value of the critical density at an assumed unknown temperature, values of Ṁout are far more accurate. Overall the accuracy of earlier measurements of Ṁout/Ṁacc is refined and Ṁout/Ṁacc = 0.5 (+1.0)(- 0.2) and 0.3 (+0.6)(- 0.1) for the ESO-Hα 574 red and blue jets, respectively, and 0.05 (+0.10)(- 0.02) for both the Par-Lup 3-4 red and blue jets. While the value for the total (two-sided) Ṁout/Ṁacc in ESO-Hα 574 lies outside the range predicted by magneto-centrifugal jet launching models, the errors are large and the effects of veiling and scattering on extinction measurements, and therefore the estimate of Ṁacc, should also be considered. ESO-Hα 574 is an excellent case study for understanding the impact of an edge-on accretion disk on the observed stellar emission. The improvements in the derivation of Ṁout/Ṁacc means that this ratio for Par-Lup 3-4 now lies within the range predicted by leading models, as compared to earlier measurements for very low mass stars. Par-Lup 3-4 is one of a small number of brown dwarfs and very low mass stars which launch jets. Therefore, this result is important in the context of understanding how Ṁout/Ṁacc and, thus, jet launching mechanisms for the lowest mass jet drivingsources, compare to the case of the well-studied low mass stars. Based on Observations collected with X-Shooter and UVES at the Very Large Telescope on Cerro Paranal (Chile), operated by the European Southern Observatory (ESO). Program ID's: 085.C-0238(A) and 078.C-0429(A).Appendix A is available in electronic form at http://www.aanda.org

Guiding the Giant

NASA Astrophysics Data System (ADS)

1998-08-01

New ESO Survey Provides Targets for the VLT Giant astronomical telescopes like the ESO Very Large Telescope (VLT) must be used efficiently. Observing time is expensive and there are long waiting lines of excellent research programmes. Thus the work at the telescope must be very well prepared and optimized as much as possible - mistakes should be avoided and no time lost! Astronomers working with the new 8-m class optical/infrared telescopes must base their observations on detailed lists of suitable target objects if they want to perform cutting-edge science. This is particularly true for research programmes that depend on observations of large samples of comparatively rare, distant objects. This type of work requires that extensive catalogues of such objects must be prepared in advance. One such major catalogue - that will serve as a very useful basis for future VLT observations - has just become available from the new ESO Imaging Survey (EIS). The Need for Sky Surveys Astronomers have since long recognized the need to carry out preparatory observations with other telescopes in order to "guide" large telescopes. To this end, surveys of smaller or larger parts of the sky have been performed by wide-field telescopes, paving the way for subsequent work at the limits of the largest available ground-based telescopes. For instance, a complete photographic survey of the sourthern sky (declination < -17.5°) was carried out in the 1970's with the ESO 1-metre Schmidt Telescope in support of the work at the 3.6-m telescope at the ESO La Silla observatory. However, while until recently most observational programmes could rely on samples of objects found on photographic plates, this is no longer possible. New image surveys must match the fainter limiting magnitudes reached by the new and larger telescopes. Modern digital, multi-colour, deep imaging surveys have thus become an indispensable complement to the 8-m telescopes. The new generation of imaging surveys will, without doubt, be the backbone of future research and are likely to be as long-lived as their earlier counterparts, which have served the astronomical community so well over the past decades. The new surveys are now becoming possible, thanks to the new, extremely light-sensitive CCD-mosaics mounted on wide-field telescopes. The ESO Imaging Survey (EIS) A very successful, major step in this direction has recently been taken at ESO. It concerns an imaging survey with the 3.5-m New Technology Telescope (NTT) at La Silla, aimed at defining targets for the first year of operation of the VLT. In addition to serving the future observers, this survey is also public , i.e., the resulting data are made available to all interested parties. The project is known as the ESO Imaging Survey (EIS). It is supervised by a Working Group with members from the European astronomical community ( [1]) that has been responsible for defining the survey strategy and for monitoring the progress. It has been a major challenge to carry out such a public survey in the very short time available. The work by the EIS Team has involved the survey observations at the NTT, development of a pipeline to process the raw data, advanced data reduction, identification of large samples of astronomically "interesting" targets and, not least, the distribution of images and other survey products before the start of operation of the VLT. To cope with the ambitious one-year timetable, a novel type of collaboration between ESO and the astronomical communities in the ESO Member States was set up. It has allowed to combine efficiently the scientific and technical expertise of the community with ESO in-house know-how and infrastructure. This model has been very successful and may well set the example for future surveys. Science Goals of EIS EIS is in many aspects a novel approach for large-scale, ground-based optical observations, in support of large-telescope science. The speed with which raw EIS data have been converted to deliverable products is quite unprecedented, given the nature and scope of this project. This is a key ingredient for imaging surveys, the main goal of which is to provide target lists for 8-m class telescopes. EIS consists of two parts: a wide-angle survey ( "EIS-wide" ) and a deep, multi-colour survey in four optical and two infrared bands ( "EIS-deep" ). EIS-wide covers four pre-selected patches of sky (spanning the R.A. range from 22 h to 9 h ). The main science goals of EIS-wide include the search for distant clusters of galaxies and quasars. In addition, there are important spin-offs in terms of bright and distant galaxies, as well as new information about galactic structure and stellar populations. The observations were conducted in 10 runs in the period July 1997 - March 1998. A total of 36 nights were used for this part of the project. The images obtained cover a total area of 17 square degrees in the near-infrared I-band, reaching limiting magnitude of I ~ 23 and, furthermore, an area of 1.7 square degrees in the B- (blue), V- (green-yellow) and I-bands to a comparable depth. Altogether, the EIS data set consists of about 6000 science and calibration frames, totaling 96 Gbytes of raw data and over 200 Gbytes of reduced images and derived products. Some results from EIS ESO PR Photo 29/98 ESO PR Photo 29/98 [Preview - JPEG: 800 x 417 pix - 160k] [High-Res - JPEG: 3000 x 1562 pix - 1.2Mb] This photo shows three views of a small field in the so-called EIS Patch-B . They were obtained during this survey in different colours: B - blue; V - green-yellow; I - near-infrared. At the centre is located a (candidate) cluster of galaxies at very large distance. This conclusion is based upon the different appearance of this cluster in the three frames: it is not seen in B; it is hardly visible in V and it is most obvious in I. This indicates that the galaxies in the cluster have very red colours. The effect is most likely due to high redshift (and therefore large distance) that has shifted the bulk of their emission from the visual to the near-infrared region of the spectrum. The other objects in the field - which are nearer - can be seen in all three frames. On these images, over one million galaxies were detected and about 250 distant clusters of galaxies were identified, with estimated redshifts in the range 0.2 < z < 1.3 [2]. This is by far the largest sample of distant clusters of galaxies currently available. In addition, white dwarfs, very-low mass stars/brown dwarfs and high-redshift quasar candidates were identified in the field that lies in the direction of the South Galactic Pole. All the calibrated images and derived catalogs are now publicly available. They can be examined and/or retrieved through an interface in the EIS release WWW-page built in collaboration with the ESO Science Archive, a prototype for future distribution of data to the ESO community. A photo of a 25 arcmin wide field from EIS is available on the web as ESO PR Photo 18/98 ; the two versions may be accessed via ESO PR 07/98. Future surveys at ESO The EIS project has been conceived as a pilot project for more ambitious, future wide-field imaging surveys to be conducted by ESO. Together, they will provide the basic framework and infrastructure for the gradual development of the required capabilities for pipeline processing, archiving and data mining. By January 1999, the ESO/MPIA 2.2-m telescope at La Silla will start regular observations with a wide-field camera capable of imaging in one shot an area of the sky that is larger than the full moon. This telescope will be fully dedicated to wide-field imaging and will be approximately 6 times more efficient than is the NTT for imaging surveys such as EIS. An even more powerful survey telescope is now planned for the Paranal Observatory , next to the VLT. A Memorandum of Understanding has recently been signed by the Director General of ESO, Professor Riccardo Giaconni and the Director of the Capodimonte Observatory (Naples, Italy), Professor Massimo Capaccioli . According to this, the Capodimonte Observatory will deliver to ESO a wide-field 2.6-m telescope, referred to as the VLT Survey Telescope (VST). The VST will be over 12 times more efficient than the 2.2-m telescope for survey work. When it goes into operation some years from now, ESO will consolidate its front-line position in wide-field imaging capabilities. Another survey, the DEep Near Infrared Southern Sky Survey (DENIS) , is now being carried out at La Silla. It is a joint European project that is conducted at the 1-m ESO telescope by a consortium of 20 astronomical institutes. More information Further information about EIS is available at http://www.eso.org/eis. From this site, it is possible to visit the EIS release page and to browse through pictures of the distant Universe and of individual objects, some of which will be observed with the VLT in the future. Notes [1] The home institutes of the astronomers involved in EIS include the European Southern Observatory, Osservatorio Astronomico di Trieste (Italy), Leiden Observatory (The Netherlands), Institut d'Astrophysique de Paris (France), Max-Planck Institut für Astrophysik (Germany), Astronomisk Observatorium (Copenhagen, Denmark), Istituto di Radioastronomia del CNR (Bologna, Italy), Landensternwarte Heidelberg-Königstuhl (Heidelberg, Germany), DAEC, Observatoire de Paris-Meudon (France), ESA/ESO Space Telescope-European Coordinating Facility (Garching, Germany), Osservatorio Astronomico di Pino Torinese, Torino (Italy) and Osservatorio Astronomico di Capodimonte (Napoli, Italy). [2] In astronomy, the redshift (z) denotes the fraction by which the lines in the spectrum of an object are shifted towards longer wavelengths. The observed redshift of a distant galaxy or quasar gives a direct estimate of the universal expansion (i.e. the `recession velocity'). Since this expansion rate increases with the distance, the velocity (and thus the redshift) is itself a function (the Hubble relation) of the distance to the object. The indicated redshift interval (0.2 < z < 1.3) corresponds to a distance interval of approx. 3,000 to 7,000 million light-years. This Press Release is accompanied by ESO PR Photo 29/98 , available in two versions. It may be reproduced, if credit is given to the European Southern Observatory. © ESO Education & Public Relations Department Karl-Schwarzschild-Strasse 2, D-85748 Garching, Germany ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org ).

Watching a Cannibal Galaxy Dine

NASA Astrophysics Data System (ADS)

2009-11-01

A new technique using near-infrared images, obtained with ESO's 3.58-metre New Technology Telescope (NTT), allows astronomers to see through the opaque dust lanes of the giant cannibal galaxy Centaurus A, unveiling its "last meal" in unprecedented detail - a smaller spiral galaxy, currently twisted and warped. This amazing image also shows thousands of star clusters, strewn like glittering gems, churning inside Centaurus A. Centaurus A (NGC 5128) is the nearest giant, elliptical galaxy, at a distance of about 11 million light-years. One of the most studied objects in the southern sky, by 1847 the unique appearance of this galaxy had already caught the attention of the famous British astronomer John Herschel, who catalogued the southern skies and made a comprehensive list of nebulae. Herschel could not know, however, that this beautiful and spectacular appearance is due to an opaque dust lane that covers the central part of the galaxy. This dust is thought to be the remains of a cosmic merger between a giant elliptical galaxy and a smaller spiral galaxy full of dust. Between 200 and 700 million years ago, this galaxy is indeed believed to have consumed a smaller spiral, gas-rich galaxy - the contents of which appear to be churning inside Centaurus A's core, likely triggering new generations of stars. First glimpses of the "leftovers" of this meal were obtained thanks to observations with the ESA Infrared Space Observatory , which revealed a 16 500 light-year-wide structure, very similar to that of a small barred galaxy. More recently, NASA's Spitzer Space Telescope resolved this structure into a parallelogram, which can be explained as the remnant of a gas-rich spiral galaxy falling into an elliptical galaxy and becoming twisted and warped in the process. Galaxy merging is the most common mechanism to explain the formation of such giant elliptical galaxies. The new SOFI images, obtained with the 3.58-metre New Technology Telescope at ESO's La Silla Observatory, allow astronomers to get an even sharper view of the structure of this galaxy, completely free of obscuring dust. The original images, obtained by observing in the near-infrared through three different filters (J, H, K) were combined using a new technique that removes the dark, screening effect of the dust, providing a clear view of the centre of this galaxy. What the astronomers found was surprising: "There is a clear ring of stars and clusters hidden behind the dust lanes, and our images provide an unprecedentedly detailed view toward it," says Jouni Kainulainen, lead author of the paper reporting these results. "Further analysis of this structure will provide important clues on how the merging process occurred and what has been the role of star formation during it." The research team is excited about the possibilities this new technique opens: "These are the first steps in the development of a new technique that has the potential to trace giant clouds of gas in other galaxies at high resolution and in a cost-effective way," explains co-author João Alves. "Knowing how these giant clouds form and evolve is to understand how stars form in galaxies." Looking forward to the new, planned telescopes, both on the ground and in space, "this technique is very complementary to the radio data ALMA will collect on nearby galaxies, and at the same time it poses interesting avenues of research for extragalactic stellar populations with the future European Extremely Large Telescope and the James Webb Space Telescope, as dust is omnipresent in galaxies," says co-author Yuri Beletsky. Previous observations done with ISAAC on the VLT have revealed that a supermassive black hole lurks inside Centaurus A. Its mass is about 200 million times the mass of our Sun, or 50 times more massive than the one that lies at the centre of our Milky Way. In contrast to our own galaxy, the supermassive black hole in Centaurus A is continuously fed by material falling onto into it, making the giant galaxy a very active one. Centaurus A is in fact one of the brightest radio sources in the sky (hence the "A" in its name). Jets of high energy particles from the centre are also observed in radio and X-ray images. The new image of Centaurus A is a wonderful example of how frontier science can be combined with aesthetic aspects. Fine images of Centaurus A have been obtained in the past with ESO's Very Large Telescope and with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at La Silla. More information This research was presented in a paper in Astronomy and Astrophysics (vol. 502): "Uncovering the kiloparsec-scale stellar ring of NGC5128", by J.T. Kainulainen et al. The team is composed of J. T. Kainulainen (University of Helsinki, Finland, and MPIA, Germany), J. F. Alves (Calar Alto Observatory, Spain and University of Vienna, Austria), Y. Beletsky (ESO), J. Ascenso (Harvard-Smithsonian Center for Astrophysics, USA), J. M. Kainulainen (TKK/Department of Radio Science and Engineering, Finland), A. Amorim, J. Lima, F. D. Santos, and A. Moitinho (SIM-IDL, University of Lisbon, Portugal), R. Marques and J. Pinhão (University of Coimbra, Portugal), and J. Rebordão (INETI, Amadora, Portugal). SOFI (Son of ISAAC) is an infrared spectro-imager attached to ESO's 3.58-metre New Technology Telescope (NTT) and a simplified version of the Short Wavelength arm of ISAAC on the Very Large Telescope. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

The high-redshift gamma-ray burst GRB 140515A. A comprehensive X-ray and optical study

NASA Astrophysics Data System (ADS)

Melandri, A.; Bernardini, M. G.; D'Avanzo, P.; Sánchez-Ramírez, R.; Nappo, F.; Nava, L.; Japelj, J.; de Ugarte Postigo, A.; Oates, S.; Campana, S.; Covino, S.; D'Elia, V.; Ghirlanda, G.; Gafton, E.; Ghisellini, G.; Gnedin, N.; Goldoni, P.; Gorosabel, J.; Libbrecht, T.; Malesani, D.; Salvaterra, R.; Thöne, C. C.; Vergani, S. D.; Xu, D.; Tagliaferri, G.

2015-09-01

High-redshift gamma-ray bursts (GRBs) offer several advantages when studying the distant Universe, providing unique information about the structure and properties of the galaxies in which they exploded. Spectroscopic identification with large ground-based telescopes has improved our knowledge of this kind of distant events. We present the multi-wavelength analysis of the high-zSwift GRB GRB 140515A (z = 6.327). The best estimate of the neutral hydrogen fraction of the intergalactic medium towards the burst is xHI ≤ 0.002. The spectral absorption lines detected for this event are the weakest lines ever observed in GRB afterglows, suggesting that GRB 140515A exploded in a very low-density environment. Its circum-burst medium is characterised by an average extinction (AV ~ 0.1) that seems to be typical of z ≥ 6 events. The observed multi-band light curves are explained either with a very hard injected spectrum (p = 1.7) or with a multi-component emission (p = 2.1). In the second case a long-lasting central engine activity is needed in order to explain the late time X-ray emission. The possible origin of GRB 140515A in a Pop III (or in a Pop II star with a local environment enriched by Pop III) massive star is unlikely. Based on observations collected at the European Southern Observatory, ESO, the VLT/Kueyen telescope, Paranal, Chile (proposal code: 093.A-0069), on observations made with the Nordic Optical Telescope, operated by the Nordic Optical Telescope Scientific Association at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofísica de Canarias (programme 49-008), and on observations made with the Italian 3.6-m Telescopio Nazionale Galileo (TNG), operated by the Fundación Galileo Galilei of the INAF (Instituto Nazionale di Astrofisica) at the Spanish Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofísica de Canarias (programme A26TAC_63).Appendix A is available in electronic form at http://www.aanda.org

Ionization processes in a local analogue of distant clumpy galaxies: VLT MUSE IFU spectroscopy and FORS deep images of the TDG NGC 5291N

NASA Astrophysics Data System (ADS)

Fensch, J.; Duc, P.-A.; Weilbacher, P. M.; Boquien, M.; Zackrisson, E.

2016-01-01

Context. We present Integral Field Unit (IFU) observations with MUSE and deep imaging with FORS of a dwarf galaxy recently formed within the giant collisional HI ring surrounding NGC 5291. This Tidal Dwarf Galaxy (TDG) -like object has the characteristics of typical z = 1-2 gas-rich spiral galaxies: a high gas fraction, a rather turbulent clumpy interstellar medium, the absence of an old stellar population, and a moderate metallicity and star formation efficiency. Aims: The MUSE spectra allow us to determine the physical conditions within the various complex substructures revealed by the deep optical images and to scrutinize the ionization processes at play in this specific medium at unprecedented spatial resolution. Methods: Starburst age, extinction, and metallicity maps of the TDG and the surrounding regions were determined using the strong emission lines Hβ, [OIII], [OI], [NII], Hα, and [SII] combined with empirical diagnostics. Different ionization mechanisms were distinguished using BPT-like diagrams and shock plus photoionization models. Results: In general, the physical conditions within the star-forming regions are homogeneous, in particular with a uniform half-solar oxygen abundance. On small scales, the derived extinction map shows narrow dust lanes. Regions with atypically strong [OI] emission line immediately surround the TDG. The [OI]/ Hα ratio cannot be easily accounted for by the photoionization by young stars or shock models. At greater distances from the main star-foming clumps, a faint diffuse blue continuum emission is observed, both with the deep FORS images and the MUSE data. It does not have a clear counterpart in the UV regime probed by GALEX. A stacked spectrum towards this region does not exhibit any emission line, excluding faint levels of star formation, or stellar absorption lines that might have revealed the presence of old stars. Several hypotheses are discussed for the origin of these intriguing features. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile: ESO MUSE programme 60.A-9320(A) and FORS programme 382.B-0213(A).

Ghosts of Milky Way's past: the globular cluster ESO 37-1 (E 3)

NASA Astrophysics Data System (ADS)

de la Fuente Marcos, R.; de la Fuente Marcos, C.; Moni Bidin, C.; Ortolani, S.; Carraro, G.

2015-09-01

Context. In the Milky Way, most globular clusters are highly conspicuous objects that were found centuries ago. However, a few dozen of them are faint, sparsely populated systems that were identified largely during the second half of the past century. One of the faintest is ESO 37-1 (E 3) and as such it remains poorly studied, with no spectroscopic observations published so far although it was discovered in 1976. Aims: We investigate the globular cluster E 3 in an attempt to better constrain its fundamental parameters. Spectroscopy of stars in the field of E 3 is shown here for the first time. Methods: Deep, precise VI CCD photometry of E 3 down to V ~ 26 mag is presented and analysed. Low-resolution, medium signal-to-noise ratio spectra of nine candidate members are studied to derive radial velocity and metallicity. Proper motions from the UCAC4 catalogue are used to explore the kinematics of the bright members of E 3. Results: Isochrone fitting indicates that E 3 is probably very old, with an age of about 13 Gyr; its distance from the Sun is nearly 10 kpc. It is also somewhat metal rich with [Fe/H] = -0.7. Regarding its kinematics, our tentative estimate for the proper motions is (μα cosδ,μδ) = (-7.0 ± 0.8, 3.5 ± 0.3) mas yr-1 (or a tangential velocity of 382 ± 79 km s-1) and for the radial velocity 45 ± 5 km s-1 in the solar rest frame. Conclusions: E 3 is one of the most intriguing globular clusters in the Galaxy. Having an old age and being metal rich is clearly a peculiar combination, only seen in a handful of objects like the far more conspicuous NGC 104 (47 Tucanae). In addition, its low luminosity and sparse population make it a unique template for the study of the final evolutionary phases in the life of a star cluster. Unfortunately, E 3 is among the most elusive and challenging known globular clusters because field contamination severely hampers spectroscopic studies. This research note is based on observations made with the ESO VLT at the Paranal Observatory, under the program 078.D-0186 and includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile (program ID CHILE-2015A-029).Figure 6 and Appendix A are available in electronic form at http://www.aanda.orgTables of the individual photometric measurements are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/581/A13

What Counts is not Falling … but Landing: Strategic Analysis: An Adapted Model for Implementation Evaluation.

PubMed

Brousselle, Astrid

2004-04-01

Implementation evaluations, also called process evaluations, involve studying the development of programmes, and identifying and understanding their strengths and weaknesses. Undertaking an implementation evaluation offers insights into evaluation objectives, but does not help the researcher develop a research strategy. During the implementation analysis of the UNAIDS drug access initiative in Chile, the strategic analysis model developed by Crozier and Friedberg was used. However, a major incompatibility was noted between the procedure put forward by Crozier and Friedberg and the specific characteristics of the programme being evaluated. In this article, an adapted strategic analysis model for programme evaluation is proposed.

The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo

NASA Astrophysics Data System (ADS)

Lind, K.; Koposov, S. E.; Battistini, C.; Marino, A. F.; Ruchti, G.; Serenelli, A.; Worley, C. C.; Alves-Brito, A.; Asplund, M.; Barklem, P. S.; Bensby, T.; Bergemann, M.; Blanco-Cuaresma, S.; Bragaglia, A.; Edvardsson, B.; Feltzing, S.; Gruyters, P.; Heiter, U.; Jofre, P.; Korn, A. J.; Nordlander, T.; Ryde, N.; Soubiran, C.; Gilmore, G.; Randich, S.; Ferguson, A. M. N.; Jeffries, R. D.; Vallenari, A.; Allende Prieto, C.; Pancino, E.; Recio-Blanco, A.; Romano, D.; Smiljanic, R.; Bellazzini, M.; Damiani, F.; Hill, V.; de Laverny, P.; Jackson, R. J.; Lardo, C.; Zaggia, S.

2015-03-01

A small fraction of the halo field is made up of stars that share the light element (Z ≤ 13) anomalies characteristic of second generation globular cluster (GC) stars. The ejected stars shed light on the formation of the Galactic halo by tracing the dynamical history of the clusters, which are believed to have once been more massive. Some of these ejected stars are expected to show strong Al enhancement at the expense of shortage of Mg, but until now no such star has been found. We search for outliers in the Mg and Al abundances of the few hundreds of halo field stars observed in the first eighteen months of the Gaia-ESO public spectroscopic survey. One halo star at the base of the red giant branch, here referred to as 22593757-4648029 is found to have [ Mg/Fe ] = -0.36 ± 0.04 and [ Al/Fe ] = 0.99 ± 0.08, which is compatible with the most extreme ratios detected in GCs so far. We compare the orbit of 22593757-4648029 to GCs of similar metallicity andfind it unlikely that this star has been tidally stripped with low ejection velocity from any of the clusters. However, both chemical and kinematic arguments render it plausible that the star has been ejected at high velocity from the anomalous GC ω Centauri within the last few billion years. We cannot rule out other progenitor GCs, because some may have disrupted fully, and the abundance and orbital data are inadequate for many of those that are still intact. Based on data acquired by the Gaia-ESO Survey, programme ID 188.B-3002. Observations were made with ESO Telescopes at the La Silla Paranal Observatory.Appendix A is available in electronic form at http://www.aanda.org

ESO's Two Observatories Merge

NASA Astrophysics Data System (ADS)

2005-02-01

On February 1, 2005, the European Southern Observatory (ESO) has merged its two observatories, La Silla and Paranal, into one. This move will help Europe's prime organisation for astronomy to better manage its many and diverse projects by deploying available resources more efficiently where and when they are needed. The merged observatory will be known as the La Silla Paranal Observatory. Catherine Cesarsky, ESO's Director General, comments the new development: "The merging, which was planned during the past year with the deep involvement of all the staff, has created unified maintenance and engineering (including software, mechanics, electronics and optics) departments across the two sites, further increasing the already very high efficiency of our telescopes. It is my great pleasure to commend the excellent work of Jorge Melnick, former director of the La Silla Observatory, and of Roberto Gilmozzi, the director of Paranal." ESO's headquarters are located in Garching, in the vicinity of Munich (Bavaria, Germany), and this intergovernmental organisation has established itself as a world-leader in astronomy. Created in 1962, ESO is now supported by eleven member states (Belgium, Denmark, Finland, France, Germany, Italy, The Netherlands, Portugal, Sweden, Switzerland, and the United Kingdom). It operates major telescopes on two remote sites, all located in Chile: La Silla, about 600 km north of Santiago and at an altitude of 2400m; Paranal, a 2600m high mountain in the Atacama Desert 120 km south of the coastal city of Antofagasta. Most recently, ESO has started the construction of an observatory at Chajnantor, a 5000m high site, also in the Atacama Desert. La Silla, north of the town of La Serena, has been the bastion of the organization's facilities since 1964. It is the site of two of the most productive 4-m class telescopes in the world, the New Technology Telescope (NTT) - the first major telescope equipped with active optics - and the 3.6-m, which hosts HARPS, a unique instrument capable of measuring stellar radial velocities with an unsurpassed accuracy better than 1 m/s, making it a very powerful tool for the discovery of extra-solar planets. In addition, astronomers have also access to the 2.2-m ESO/MPG telescope with its Wide Field Imager camera. A new control room, the RITZ (Remote Integrated Telescope Zentrum), allows operating all three ESO telescopes at La Silla from a single place. The La Silla Observatory is also the first world-class observatory to have been granted certification for the International Organization for Standardization (ISO) 9001 Quality Management System. Moreover, the infrastructure of La Silla is still used by many of the ESO member states for targeted projects such as the Swiss 1.2-m Euler telescope and the robotic telescope specialized in the follow-up of gamma-ray bursts detected by satellites, the Italian REM (Rapid Eye Mount). In addition, La Silla is in charge of the APEX (Atacama Pathfinder Experiment) 12-m sub-millimetre telescope which will soon start routine observations at Chajnantor, the site of the future Atacama Large Millimeter Array (ALMA). The APEX project is a collaboration between the Max Planck Society in Germany, Onsala Observatory in Sweden and ESO. ESO also operates Paranal, home of the Very Large Telescope (VLT) and the VLT Interferometer (VLTI). Antu, the first 8.2-m Unit Telescope of the VLT, saw First Light in May 1998, starting what has become a revolution in European astronomy. Since then, the three other Unit Telescopes - Kueyen, Melipal and Yepun - have been successfully put into operation with an impressive suite of the most advanced astronomical instruments. The interferometric mode of the VLT (VLTI) is also operational and fully integrated in the VLT data flow system. In the VLTI mode, one state-of-the-art instrument is already available and another will follow soon. With its remarkable resolution and unsurpassed surface area, the VLT is at the forefront of astronomical technology and is one of the premier facilities in the world for optical and near-infrared observations. In addition to the state-of-the-art Very Large Telescope and the four Auxiliary Telescopes of 1.8-m diameter which can move to relocate in up to 30 different locations feeding the interferometer, Paranal will also be home to the 2.6-m VLT Survey telescope (VST) and the 4.2-m VISTA IR survey telescope. Both Paranal and La Silla have a proven record of their unique ability to address most current issues in observational astronomy. In 2004 alone, each observatory provided data for the publication of about 350 peer-reviewed journal articles, more than any other ground-based observatory. With the present merging of these top-ranking astronomical observatories, fostering synergies and harmonizing the many diverse activities, ESO and the entire community of European astronomers will profit even more from these highly efficient research facilities. Images of ESO's observatories and telescopes are available in the ESO gallery.

Direct detection of scattered light gaps in the transitional disk around HD 97048 with VLT/SPHERE

NASA Astrophysics Data System (ADS)

Ginski, C.; Stolker, T.; Pinilla, P.; Dominik, C.; Boccaletti, A.; de Boer, J.; Benisty, M.; Biller, B.; Feldt, M.; Garufi, A.; Keller, C. U.; Kenworthy, M.; Maire, A. L.; Ménard, F.; Mesa, D.; Milli, J.; Min, M.; Pinte, C.; Quanz, S. P.; van Boekel, R.; Bonnefoy, M.; Chauvin, G.; Desidera, S.; Gratton, R.; Girard, J. H. V.; Keppler, M.; Kopytova, T.; Lagrange, A.-M.; Langlois, M.; Rouan, D.; Vigan, A.

2016-11-01

Aims: We studied the well-known circumstellar disk around the Herbig Ae/Be star HD 97048 with high angular resolution to reveal undetected structures in the disk which may be indicative of disk evolutionary processes such as planet formation. Methods: We used the IRDIS near-IR subsystem of the extreme adaptive optics imager SPHERE at the ESO/VLT to study the scattered light from the circumstellar disk via high resolution polarimetry and angular differential imaging. Results: We imaged the disk in unprecedented detail and revealed four ring-like brightness enhancements and corresponding gaps in the scattered light from the disk surface with radii between 39 au and 341 au. We derived the inclination and position angle as well as the height of the scattering surface of the disk from our observational data. We found that the surface height profile can be described by a single power law up to a separation 270 au. Using the surface height profile we measured the scattering phase function of the disk and found that it is consistent with theoretical models of compact dust aggregates. We discuss the origin of the detected features and find that low mass (≤1 MJup) nascent planets are a possible explanation. Based on data collected at the European Southern Observatory, Chile (ESO Programs 096.C-0248, 096.C-0241, 077.C-0106).

Chemical Abundance Analysis of Three α-poor, Metal-poor Stars in the Ultrafaint Dwarf Galaxy Horologium I

NASA Astrophysics Data System (ADS)

Nagasawa, D. Q.; Marshall, J. L.; Li, T. S.; Hansen, T. T.; Simon, J. D.; Bernstein, R. A.; Balbinot, E.; Drlica-Wagner, A.; Pace, A. B.; Strigari, L. E.; Pellegrino, C. M.; DePoy, D. L.; Suntzeff, N. B.; Bechtol, K.; Walker, A. R.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Annis, J.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Cunha, C. E.; D’Andrea, C. B.; da Costa, L. N.; Davis, C.; Desai, S.; Doel, P.; Eifler, T. F.; Flaugher, B.; Fosalba, P.; Frieman, J.; García-Bellido, J.; Gaztanaga, E.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Gschwend, J.; Gutierrez, G.; Hartley, W. G.; Honscheid, K.; James, D. J.; Jeltema, T.; Krause, E.; Kuehn, K.; Kuhlmann, S.; Kuropatkin, N.; March, M.; Miquel, R.; Nord, B.; Roodman, A.; Sanchez, E.; Santiago, B.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, M.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Suchyta, E.; Tarle, G.; Thomas, D.; Tucker, D. L.; Wechsler, R. H.; Wolf, R. C.; Yanny, B.

2018-01-01

We present chemical abundance measurements of three stars in the ultrafaint dwarf galaxy Horologium I, a Milky Way satellite discovered by the Dark Energy Survey. Using high-resolution spectroscopic observations, we measure the metallicity of the three stars, as well as abundance ratios of several α-elements, iron-peak elements, and neutron-capture elements. The abundance pattern is relatively consistent among all three stars, which have a low average metallicity of [Fe/H] ∼ ‑2.6 and are not α-enhanced ([α/Fe] ∼ 0.0). This result is unexpected when compared to other low-metallicity stars in the Galactic halo and other ultrafaint dwarfs and suggests the possibility of a different mechanism for the enrichment of Hor I compared to other satellites. We discuss possible scenarios that could lead to this observed nucleosynthetic signature, including extended star formation, enrichment by a Population III supernova, and or an association with the Large Magellanic Cloud. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. This paper also includes data based on observations made with the ESO Very Large Telescope at Paranal Observatory, Chile (ID 096.D-0967(B); PI: E. Balbinot).

MUSE alignment onto VLT

NASA Astrophysics Data System (ADS)

Laurent, Florence; Renault, Edgard; Boudon, Didier; Caillier, Patrick; Daguisé, Eric; Dupuy, Christophe; Jarno, Aurélien; Lizon, Jean-Louis; Migniau, Jean-Emmanuel; Nicklas, Harald; Piqueras, Laure

2014-07-01

MUSE (Multi Unit Spectroscopic Explorer) is a second generation Very Large Telescope (VLT) integral field spectrograph developed for the European Southern Observatory (ESO). It combines a 1' x 1' field of view sampled at 0.2 arcsec for its Wide Field Mode (WFM) and a 7.5"x7.5" field of view for its Narrow Field Mode (NFM). Both modes will operate with the improved spatial resolution provided by GALACSI (Ground Atmospheric Layer Adaptive Optics for Spectroscopic Imaging), that will use the VLT deformable secondary mirror and 4 Laser Guide Stars (LGS) foreseen in 2015. MUSE operates in the visible wavelength range (0.465-0.93 μm). A consortium of seven institutes is currently commissioning MUSE in the Very Large Telescope for the Preliminary Acceptance in Chile, scheduled for September, 2014. MUSE is composed of several subsystems which are under the responsibility of each institute. The Fore Optics derotates and anamorphoses the image at the focal plane. A Splitting and Relay Optics feed the 24 identical Integral Field Units (IFU), that are mounted within a large monolithic structure. Each IFU incorporates an image slicer, a fully refractive spectrograph with VPH-grating and a detector system connected to a global vacuum and cryogenic system. During 2012 and 2013, all MUSE subsystems were integrated, aligned and tested to the P.I. institute at Lyon. After successful PAE in September 2013, MUSE instrument was shipped to the Very Large Telescope in Chile where that was aligned and tested in ESO integration hall at Paranal. After, MUSE was directly transported, fully aligned and without any optomechanical dismounting, onto VLT telescope where the first light was overcame the 7th of February, 2014. This paper describes the alignment procedure of the whole MUSE instrument with respect to the Very Large Telescope (VLT). It describes how 6 tons could be move with accuracy better than 0.025mm and less than 0.25 arcmin in order to reach alignment requirements. The success of the MUSE alignment is demonstrated by the excellent results obtained onto MUSE image quality and throughput directly onto the sky.

MUSE field splitter unit: fan-shaped separator for 24 integral field units

NASA Astrophysics Data System (ADS)

Laurent, Florence; Renault, Edgard; Anwand, Heiko; Boudon, Didier; Caillier, Patrick; Kosmalski, Johan; Loupias, Magali; Nicklas, Harald; Seifert, Walter; Salaun, Yves; Xu, Wenli

2014-07-01

MUSE (Multi Unit Spectroscopic Explorer) is a second generation Very Large Telescope (VLT) integral field spectrograph developed for the European Southern Observatory (ESO). It combines a 1' x 1' field of view sampled at 0.2 arcsec for its Wide Field Mode (WFM) and a 7.5"x7.5" field of view for its Narrow Field Mode (NFM). Both modes will operate with the improved spatial resolution provided by GALACSI (Ground Atmospheric Layer Adaptive Optics for Spectroscopic Imaging), that will use the VLT deformable secondary mirror and 4 Laser Guide Stars (LGS) foreseen in 2015. MUSE operates in the visible wavelength range (0.465-0.93 μm). A consortium of seven institutes is currently commissioning MUSE in the Very Large Telescope for the Preliminary Acceptance in Chile, scheduled for September, 2014. MUSE is composed of several subsystems which are under the responsibility of each institute. The Fore Optics derotates and anamorphoses the image at the focal plane. A Splitting and Relay Optics feed the 24 identical Integral Field Units (IFU), that are mounted within a large monolithic instrument mechanical structure. Each IFU incorporates an image slicer, a fully refractive spectrograph with VPH-grating and a detector system connected to a global vacuum and cryogenic system. During 2012 and 2013, all MUSE subsystems were integrated, aligned and tested to the P.I. institute at Lyon. After successful PAE in September 2013, MUSE instrument was shipped to the Very Large Telescope in Chile where it was aligned and tested in ESO integration hall at Paranal. After, MUSE was directly transferred in monolithic way onto VLT telescope where the first light was achieved. This paper describes the MUSE main optical component: the Field Splitter Unit. It splits the VLT image into 24 subfields and provides the first separation of the beam for the 24 Integral Field Units. This talk depicts its manufacturing at Winlight Optics and its alignment into MUSE instrument. The success of the MUSE alignment is demonstrated by the excellent results obtained onto MUSE positioning, image quality and throughput onto the sky. MUSE commissioning at the VLT is planned for September, 2014.

Around 1500 near-Earth-asteroid orbits improved via EURONEAR

NASA Astrophysics Data System (ADS)

Vaduvescu, O.; Hudin, L.; Birlan, M.; Popescu, M.; Tudorica, A.; Toma, R.

2014-07-01

Born in 2006 in Paris, the European Near Earth Asteroids Research project (EURONEAR, euronear.imcce.fr) aims ''to study NEAs and PHAs using existing telescopes available to its network and hopefully in the future some automated dedicated 1--2 m facilities''. Although we believe the first aim is fulfilled, the second was not achieved yet, requiring serious commitment from the European NEA researchers and funding agencies. Mainly using free labor by about 30 students and amateur astronomers (from Romania, Chile, UK, France, etc), the PI backed up by his associates M. Birlan (IMCCE Paris) and J. Licandro (IAC Tenerife) and a few other astronomers of the EURONEAR network having access to a few telescopes are approaching around 1,500 observed NEAs whose orbits were improved based on our astrometric contributions. To achive this milestone, we used two main resources and a total of 15 facilities: i) Observing time obtained at 11 professional 1--4 m class telescopes (Chile, La Palma, France, Germany) plus 3 smaller 30--50 cm educational/public outreach telescopes (Romania and Germany) adding about 1,000 observed NEAs; and ii) astrometry obtained from data mining of 4 major image archives (ESO/MPG WFI, INT WFC, CFHTLS Megacam and Subaru SuprimeCam) adding about 500 NEAs recovered in archival images. Among the highlights, about 100 NEAs, PHAs and VIs were observed, recovered or precovered in archives at their second opposition (up to about 15 years away from discovery) or have their orbital arc much extended, and a few VIs and PHAs were eliminated. Incidentally, about 15,000 positions of almost 2,000 known MBAs were reported (mostly in the INT, ESO/MPG and Blanco large fields). About 40 new (one night) NEO candidates and more than 2,000 (one night) unknown MBAs were reported, including about 150 MBAs credited as EURONEAR discoveries. Based on the INT and Blanco data we derived some statistics about the MBA and NEA population observable with 2m and 4m telescopes, proposing a model to rate the NEO candidates observed close to opposition. Based on this work, 10 papers and around 100 MPC circulars were published since 2006.

New Sub-Millimetre Light in the Desert

NASA Astrophysics Data System (ADS)

2005-07-01

The Atacama Pathfinder Experiment (APEX) project has just passed another major milestone by successfully commissioning its new technology 12-m telescope, located on the 5100m high Chajnantor plateau in the Atacama Desert (Chile). The APEX telescope, designed to work at sub-millimetre wavelengths, in the 0.2 to 1.5 mm range, has just performed its first scientific observations. This new front-line facility will provide access to the "Cold Universe" with unprecedented sensitivity and image quality. Karl Menten, Director of the group for Millimeter and Sub-Millimeter Astronomy at the Max-Planck-Institute for Radio Astronomy (MPIfR) and Principal Investigator of the APEX project is excited: " Among the first observations, we have obtained wonderful spectra, which took only minutes to take but offer a fascinating view of the highly complex organic chemistry in star-forming regions. In addition, we have also obtained exquisite images from the Magellanic Clouds and observed molecules in the active nuclei of several external galaxies. Traditionally, telescopes turn to weak extragalactic sources only after they are well in operation. With APEX, we could pick them amongst our first targets!" Because sub-millimetre radiation from space is heavily absorbed by water vapour in the Earth's atmosphere, APEX is located at an altitude of 5100 metres in the high Chilean Atacama desert on the Chajnantor plains, 50 km east of San Pedro de Atacama in northern Chile. The Atacama desert is one of the driest places on Earth, thus providing unsurpassed observing opportunities - at the costs of the demanding logistics required to operate a frontier science observatory at this remote place. Along with the Japanese 10-m ASTE telescope, which is operating at a neighbouring, lower altitude location, APEX is the first and largest sub-millimetre facility under southern skies. With its precise antenna and large collecting area, it will provide, at this exceptional location, unprecedented access to a whole new domain in astronomical observations. Indeed, millimetre and sub-millimetre astronomy opens exciting new possibilities in the study of the first galaxies to have formed in the Universe and of the formation processes of stars and planets. APEX will, among other things, allow astronomers to study the chemistry and physical conditions of molecular clouds, that is, dense regions of gas and dust in which new stars are forming. APEX follows in the footsteps of the 15m Swedish-ESO Submillimetre Telescope (SEST) which was operated at ESO La Silla from 1987 until 2003 in a collaboration between ESO and the Onsala Space Observatory. SEST operated in the wavelength range from 0.8 to 3 mm. Says Catherine Cesarsky, ESO's Director General: "SEST was for a long time the only instrument of its kind in the southern hemisphere. With it, ESO and our collaborators have gained valuable operational experience with regard to ground-based observations in the non-optical spectral domain. With APEX, we offer the ESO community a most exciting new facility that will pave the way for ALMA." As its name implies, APEX is the pathfinder to the ALMA project. It is indeed a modified ALMA prototype antenna and is located at the future site of the ALMA observatory. ALMA is planned to consist of a giant array of 12-m antennas separated by baselines of up to 14 km and is expected to start operation by the end of the decade. It will bring to sub-millimetre astronomy the aperture synthesis techniques of radio astronomy, enabling precision imaging to be done on sub-arcsecond angular scales, and will so nicely complement the ESO VLT/VLTI observatory. In order to operate at the shorter sub-millimetre wavelengths, APEX presents a surface of exceedingly high quality: after a series of high precision adjustments, the APEX project team was able to adjust the surface of the mirror with remarkable precision: over the 12m diameter of the antenna, the deviation from the perfect parabola is now less than 17 thousandths of a millimetre. This is smaller than one fifth of the average thickness of a human hair! "From the engineering point of view, APEX is already a big success and its performance surpasses our expectations", says APEX Project Manager Rolf Güsten. "This could only be achieved thanks to the highly committed teams from the constructor, from the MPIfR and from the APEX project whose endless hours of work, often at high altitudes, made this project become reality." In parallel to the construction and commissioning of the APEX telescope, a demanding cutting-edge technology program has been launched to provide the best possible detectors for this outstanding facility. For its first observations, APEX was equipped with state-of-the-art sub-millimetre spectrometers developed by MPIfR's Division for Sub-Millimetre Technology and, more recently, with the first facility receiver built at Chalmers University (OSO). APEX is a collaboration between the Max-Planck-Institute for Radio Astronomy (MPIfR), Onsala Space Observatory (OSO), and the European Organisation for Astronomical Research in the Southern Hemisphere (ESO). The telescope was designed and constructed by VERTEX Antennentechnik GmbH (Germany), under contract by MPIfR, and is based on a prototype antenna constructed for the ALMA project. Operation of APEX in Chajnantor is entrusted to ESO. Background information on sub-millimetre astronomy and on the first APEX results can be found as PDF files on the APEX Fact Sheets page. A press release in German was also issued by the Max-Planck Society.

MUSE crowded field 3D spectroscopy of over 12 000 stars in the globular cluster NGC 6397. I. The first comprehensive HRD of a globular cluster

NASA Astrophysics Data System (ADS)

Husser, Tim-Oliver; Kamann, Sebastian; Dreizler, Stefan; Wendt, Martin; Wulff, Nina; Bacon, Roland; Wisotzki, Lutz; Brinchmann, Jarle; Weilbacher, Peter M.; Roth, Martin M.; Monreal-Ibero, Ana

2016-04-01

Aims: We demonstrate the high multiplex advantage of crowded field 3D spectroscopy with the new integral field spectrograph MUSE by means of a spectroscopic analysis of more than 12 000 individual stars in the globular cluster NGC 6397. Methods: The stars are deblended with a point spread function fitting technique, using a photometric reference catalogue from HST as prior, including relative positions and brightnesses. This catalogue is also used for a first analysis of the extracted spectra, followed by an automatic in-depth analysis via a full-spectrum fitting method based on a large grid of PHOENIX spectra. Results: We analysed the largest sample so far available for a single globular cluster of 18 932 spectra from 12 307 stars in NGC 6397. We derived a mean radial velocity of vrad = 17.84 ± 0.07 km s-1 and a mean metallicity of [Fe/H] = -2.120 ± 0.002, with the latter seemingly varying with temperature for stars on the red giant branch (RGB). We determine Teff and [Fe/H] from the spectra, and log g from HST photometry. This is the first very comprehensive Hertzsprung-Russell diagram (HRD) for a globular cluster based on the analysis of several thousands of stellar spectra, ranging from the main sequence to the tip of the RGB. Furthermore, two interesting objects were identified; one is a post-AGB star and the other is a possible millisecond-pulsar companion. Data products are available at http://muse-vlt.eu/scienceBased on observations obtained at the Very Large Telescope (VLT) of the European Southern Observatory, Paranal, Chile (ESO Programme ID 60.A-9100(C)).

VLT/SINFONI time-resolved spectroscopy of the central, luminous, H-rich WN stars of R136

NASA Astrophysics Data System (ADS)

Schnurr, O.; Chené, A.-N.; Casoli, J.; Moffat, A. F. J.; St-Louis, N.

2009-08-01

Using the Very Large Telescope's Spectrograph for INtegral Field Observation in the Near-Infrared, we have obtained repeated adaptive-optics-assisted, near-infrared spectroscopy of the six central luminous, Wolf-Rayet (WR) stars in the core of the very young (~1 Myr), massive and dense cluster R136, in the Large Magellanic Cloud (LMC). We also de-archived available images that were obtained with the Hubble Space Telescope's Space Telescope Imaging Spectrograph, and extracted high-quality, differential photometry of our target stars to check for any variability related to binary motion. Previous studies, relying on spatially unresolved, integrated, optical spectroscopy, had reported that one of these stars was likely to be a 4.377-d binary. Our study set out to identify the culprit and any other short-period system among our targets. However, none displays significant photometric variability, and only one star, BAT99-112 (R136c), located on the outer fringe of R136, displays a marginal variability in its radial velocities; we tentatively report an 8.2-d period. The binary status of BAT99-112 is supported by the fact that it is one of the brightest X-ray sources among all known WR stars in the LMC, consistent with it being a colliding wind system. Followup observations have been proposed to confirm the orbital period of this potentially very massive system. Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile, under programme ID 076.D-0563, and on observations made with the Hubble Space Telescope (HST) obtained from the European Southern Observatory (ESO)/Space Telescope-European Coordinating Facility (ST-ECF) Science Archive. E-mail: o.schnurr@sheffield.ac.uk

A direct imaging search for close stellar and sub-stellar companions to young nearby stars

NASA Astrophysics Data System (ADS)

Vogt, N.; Mugrauer, M.; Neuhäuser, R.; Schmidt, T. O. B.; Contreras-Quijada, A.; Schmidt, J. G.

2015-01-01

A total of 28 young nearby stars (ages {≤ 60} Myr) have been observed in the K_s-band with the adaptive optics imager Naos-Conica of the Very Large Telescope at the Paranal Observatory in Chile. Among the targets are ten visual binaries and one triple system at distances between 10 and 130 pc, all previously known. During a first observing epoch a total of 20 faint stellar or sub-stellar companion-candidates were detected around seven of the targets. These fields, as well as most of the stellar binaries, were re-observed with the same instrument during a second epoch, about one year later. We present the astrometric observations of all binaries. Their analysis revealed that all stellar binaries are co-moving. In two cases (HD 119022 AB and FG Aqr B/C) indications for significant orbital motions were found. However, all sub-stellar companion candidates turned out to be non-moving background objects except PZ Tel which is part of this project but whose results were published elsewhere. Detection limits were determined for all targets, and limiting masses were derived adopting three different age values; they turn out to be less than 10 Jupiter masses in most cases, well below the brown dwarf mass range. The fraction of stellar multiplicity and of the sub-stellar companion occurrence in the star forming regions in Chamaeleon are compared to the statistics of our search, and possible reasons for the observed differences are discussed. Based on observations made with ESO telescopes at Paranal Observatory under programme IDs 083.C-0150(B), 084.C-0364(A), 084.C-0364(B), 084.C-0364(C), 086.C-0600(A) and 086.C-0600(B).

The HELLAS2XMM survey. XI. Unveiling the nature of X-ray bright optically normal galaxies

NASA Astrophysics Data System (ADS)

Civano, F.; Mignoli, M.; Comastri, A.; Vignali, C.; Fiore, F.; Pozzetti, L.; Brusa, M.; La Franca, F.; Matt, G.; Puccetti, S.; Cocchia, F.

2007-12-01

Aims:X-ray bright optically normal galaxies (XBONGs) constitute a small but significant fraction of hard X-ray selected sources in recent Chandra and XMM-Newton surveys. Even though several possibilities were proposed to explain why a relatively luminous hard X-ray source does not leave any significant signature of its presence in terms of optical emission lines, the nature of XBONGs is still subject of debate. We aim to better understand their nature by means of a multiwavelength and morphological analysis of a small sample of these sources. Methods: Good-quality photometric near-infrared data (ISAAC/VLT) of four low-redshift (z = 0.1{-}0.3) XBONGs, selected from the HELLAS2XMM survey, have been used to search for the presence of the putative nucleus, applying the surface-brightness decomposition technique through the least-squares fitting program GALFIT. Results: The surface brightness decomposition allows us to reveal a nuclear point-like source, likely to be responsible for the X-ray emission, in two out of the four sources. The results indicate that moderate amounts of gas and dust, covering a large solid angle (possibly 4π) at the nuclear source, combined with the low nuclear activity, may explain the lack of optical emission lines. The third XBONG is associated with an X-ray extended source and no nuclear excess is detected in the near infrared at the limits of our observations. The last source is associated to a close (d≤ 1 arcsec) double system and the fitting procedure cannot achieve a firm conclusion. Based on observations made at the European Southern Observatory, Paranal, Chile (ESO Programme ID 69.A-0554).

The "+" for CRIRES: enabling better science at infrared wavelength and high spectral resolution at the ESO VLT

NASA Astrophysics Data System (ADS)

Dorn, Reinhold J.; Follert, Roman; Bristow, Paul; Cumani, Claudio; Eschbaumer, Siegfried; Grunhut, Jason; Haimerl, Andreas; Hatzes, Artie; Heiter, Ulrike; Hinterschuster, Renate; Ives, Derek J.; Jung, Yves; Kerber, Florian; Klein, Barbara; Lavaila, Alexis; Lizon, Jean Louis; Löwinger, Tom; Molina-Conde, Ignacio; Nicholson, Belinda; Marquart, Thomas; Oliva, Ernesto; Origlia, Livia; Pasquini, Luca; Paufique, Jérôme; Piskunov, Nikolai; Reiners, Ansgar; Seemann, Ulf; Stegmeier, Jörg; Stempels, Eric; Tordo, Sebastien

2016-08-01

The adaptive optics (AO) assisted CRIRES instrument is an IR (0.92 - 5.2 μm) high-resolution spectrograph was in operation from 2006 to 2014 at the Very Large Telescope (VLT) observatory. CRIRES was a unique instrument, accessing a parameter space (wavelength range and spectral resolution) up to now largely uncharted. It consisted of a single-order spectrograph providing long-slit (40 arcsecond) spectroscopy with a resolving power up to R=100 000. However the setup was limited to a narrow, single-shot, spectral range of about 1/70 of the central wavelength, resulting in low observing efficiency for many scientific programmes requiring a broad spectral coverage. The CRIRES upgrade project, CRIRES+, transforms this VLT instrument into a cross-dispersed spectrograph to increase the simultaneously covered wavelength range by a factor of ten. A new and larger detector focal plane array of three Hawaii 2RG detectors with 5.3 μm cut-off wavelength will replace the existing detectors. For advanced wavelength calibration, custom-made absorption gas cells and an etalon system will be added. A spectro-polarimetric unit will allow the recording of circular and linear polarized spectra. This upgrade will be supported by dedicated data reduction software allowing the community to take full advantage of the new capabilities offered by CRIRES+. CRIRES+ has now entered its assembly and integration phase and will return with all new capabilities by the beginning of 2018 to the Very Large Telescope in Chile. This article will provide the reader with an update of the current status of the instrument as well as the remaining steps until final installation at the Paranal Observatory.

Pulsating stars in the VMC survey

NASA Astrophysics Data System (ADS)

Cioni, Maria-Rosa L.; Ripepi, Vincenzo; Clementini, Gisella; Groenewegen, Martin A. T.; Moretti, Maria I.; Muraveva, Tatiana; Subramanian, Smitha

2017-09-01

The VISTA survey of the Magellanic Clouds system (VMC) began observations in 2009 and since then, it has collected multi-epoch data at Ks and in addition multi-band data in Y and J for a wide range of stellar populations across the Magellanic system. Among them are pulsating variable stars: Cepheids, RR Lyrae, and asymptotic giant branch stars that represent useful tracers of the host system geometry. Based on observations made with VISTA at ESO under programme ID 179.B-2003.

Orthoptic status before and immediately after heroin detoxification

PubMed Central

Firth, A Y; Pulling, S; Carr, M P; Beaini, A Y

2004-01-01

Aim: To determine whether changes in orthoptic status take place during withdrawal from heroin and/or methadone. Method: A prospective study of patients, using a repeated measures design, attending a 5 day naltrexone compressed opiate detoxification programme. Results: 83 patients were seen before detoxification (mean age 27.1 (SD 4.6) years) and 69 after detoxification. The horizontal angle of deviation became less exo/more eso at distance (p<0.001) but no significant change was found at near (p = 0.069). Stereoacuity, visual acuity, and convergence were found to be reduced in the immediate post-detoxification period. Prism fusion range, refractive error, subjective accommodation, and objective accommodation at 33 cm did not reduce but a small decrease was found in objective accommodation at 20 cm. Conclusions: The eso trend found in these patients may be responsible for the development of acute concomitant esotropia in some patients undergoing heroin detoxification. However, the mechanism for this trend does not appear to be caused by divergence insufficiency or sixth nerve palsy. PMID:15317713

Turning Planetary Theory Upside Down

NASA Astrophysics Data System (ADS)

2010-04-01

The discovery of nine new transiting exoplanets is announced today at the RAS National Astronomy Meeting (NAM2010). When these new results were combined with earlier observations of transiting exoplanets astronomers were surprised to find that six out of a larger sample of 27 were found to be orbiting in the opposite direction to the rotation of their host star - the exact reverse of what is seen in our own Solar System. The new discoveries provide an unexpected and serious challenge to current theories of planet formation. They also suggest that systems with exoplanets of the type known as hot Jupiters are unlikely to contain Earth-like planets. "This is a real bomb we are dropping into the field of exoplanets," says Amaury Triaud, a PhD student at the Geneva Observatory who, with Andrew Cameron and Didier Queloz, leads a major part of the observational campaign. Planets are thought to form in the disc of gas and dust encircling a young star. This proto-planetary disc rotates in the same direction as the star itself, and up to now it was expected that planets that form from the disc would all orbit in more or less the same plane, and that they would move along their orbits in the same direction as the star's rotation. This is the case for the planets in the Solar System. After the initial detection of the nine new exoplanets [1] with the Wide Angle Search for Planets (WASP, [2]), the team of astronomers used the HARPS spectrograph on the 3.6-metre ESO telescope at the La Silla observatory in Chile, along with data from the Swiss Euler telescope, also at La Silla, and data from other telescopes to confirm the discoveries and characterise the transiting exoplanets [3] found in both the new and older surveys. Surprisingly, when the team combined the new data with older observations they found that more than half of all the hot Jupiters [4] studied have orbits that are misaligned with the rotation axis of their parent stars. They even found that six exoplanets in this extended study (of which two are new discoveries) have retrograde motion: they orbit their star in the "wrong" direction. "The new results really challenge the conventional wisdom that planets should always orbit in the same direction as their stars spin," says Andrew Cameron of the University of St Andrews, who presented the new results at the RAS National Astronomy Meeting (NAM2010) in Glasgow this week. In the 15 years since the first hot Jupiters were discovered, their origin has been a puzzle. These are planets with masses similar to or greater than that of Jupiter, but that orbit very close to their suns. The cores of giant planets are thought to form from a mix of rock and ice particles found only in the cold outer reaches of planetary systems. Hot Jupiters must therefore form far from their star and subsequently migrate inwards to orbits much closer to the parent star. Many astronomers believed this was due to gravitational interactions with the disc of dust from which they formed. This scenario takes place over a few million years and results in an orbit aligned with the rotation axis of the parent star. It would also allow Earth-like rocky planets to form subsequently, but unfortunately it cannot account for the new observations. To account for the new retrograde exoplanets an alternative migration theory suggests that the proximity of hot Jupiters to their stars is not due to interactions with the dust disc at all, but to a slower evolution process involving a gravitational tug-of-war with more distant planetary or stellar companions over hundreds of millions of years. After these disturbances have bounced a giant exoplanet into a tilted and elongated orbit it would suffer tidal friction, losing energy every time it swung close to the star. It would eventually become parked in a near circular, but randomly tilted, orbit close to the star. "A dramatic side-effect of this process is that it would wipe out any other smaller Earth-like planet in these systems," says Didier Queloz of Geneva Observatory. Two of the newly discovered retrograde planets have already been found to have more distant, massive companions that could potentially be the cause of the upset. These new results will trigger an intensive search for additional bodies in other planetary systems. This research was presented at the Royal Astronomical Society National Astronomy Meeting (NAM2010) that is taking place this week in Glasgow, Scotland. Nine publications submitted to international journals will be released on this occasion, four of them using data from ESO facilities. On the same occasion, the WASP consortium was awarded the 2010 Royal Astronomical Society Group Achievement Award. Notes [1] The current count of known exoplanets is 454. [2] The nine newly found exoplanets were discovered by the Wide Angle Search for Planets (WASP). WASP comprises two robotic observatories, each consisting of eight wide-angle cameras that simultaneously monitor the sky continuously for planetary transit events. A transit occurs when a planet passes in front of its parent star, temporarily blocking some of the light from it. The eight wide-angle cameras allow millions of stars to be monitored simultaneously to detect these rare transit events. The WASP cameras are operated by a consortium including Queen's University Belfast, the Universities of Keele, Leicester and St Andrews, the Open University, the Isaac Newton Group on La Palma and the Instituto Astrofisica Canarias. [3] To confirm the discovery and characterise a new transiting planet, it is necessary to do radial velocity follow-up to detect the wobble of the host star around its common centre of mass with the planet. This is done with a worldwide network of telescopes equipped with sensitive spectrometers. In the northern hemisphere, the Nordic Optical Telescope in the Canary Islands and the SOPHIE instrument on the 1.93-metre telescope at Haute-Provence in France lead the search. In the south, the HARPS exoplanet hunter attached to the 3.6-metre ESO telescope and the CORALIE spectrometer on the Euler Swiss telescope, both at La Silla, were used to confirm the new planets and measure the angle through which each planet's orbit is tilted relative to its star's equator. The robotic Faulkes Telescopes of the Las Cumbres Observatory, located in Hawaii and Australia, provided the brightness measurements that determined the sizes of the planets. Follow-up observations of WASP exoplanet candidates are obtained at the Swiss Euler Telescope at La Silla, Chile (in collaboration with colleagues at Geneva Observatory), at the Nordic Optical Telescope on La Palma, and at the 1.93-metre telescope of the Observatoire de Haute-Provence in France (in collaboration with colleagues at the Institut d'Astrophysique de Paris and the Laboratoire d'Astrophysique de Marseille). The studies of the orbital tilt angles of the WASP planets were made with the HARPS instrument on the ESO 3.6-metre telescope and with the CORALIE instrument on the Euler Swiss telescope, both at La Silla in the southern hemisphere, and at Tautenburg Observatory, McDonald Observatory and the Nordic Optical Telescope in the northern hemisphere. [4] Hot Jupiters are planets orbiting other stars that have masses similar to, or greater than, that of Jupiter, but that orbit their parent stars much more closely than any of the planets in our own Solar System. Because they are both large and close they are easier to detect from their gravitational effect on their stars and also more likely to transit the disc of the star. Most of the first exoplanets to be found were of this class. More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Milky Way Past Was More Turbulent Than Previously Known

NASA Astrophysics Data System (ADS)

2004-04-01

Results of 1001 observing nights shed new light on our Galaxy [1] Summary A team of astronomers from Denmark, Switzerland and Sweden [2] has achieved a major breakthrough in our understanding of the Milky Way, the galaxy in which we live. After more than 1,000 nights of observations spread over 15 years, they have determined the spatial motions of more than 14,000 solar-like stars residing in the neighbourhood of the Sun. For the first time, the changing dynamics of the Milky Way since its birth can now be studied in detail and with a stellar sample sufficiently large to allow a sound analysis. The astronomers find that our home galaxy has led a much more turbulent and chaotic life than previously assumed. PR Photo 10a/04: Distribution on the sky of the observed stars. PR Photo 10b/04: Stars in the solar neigbourhood and the Milky Way galaxy (artist's view). PR Video Clip 04/04: The motions of the observed stars during the past 250 million years. Unknown history Home is the place we know best. But not so in the Milky Way - the galaxy in which we live. Our knowledge of our nearest stellar neighbours has long been seriously incomplete and - worse - skewed by prejudice concerning their behaviour. Stars were generally selected for observation because they were thought to be "interesting" in some sense, not because they were typical. This has resulted in a biased view of the evolution of our Galaxy. The Milky Way started out just after the Big Bang as one or more diffuse blobs of gas of almost pure hydrogen and helium. With time, it assembled into the flattened spiral galaxy which we inhabit today. Meanwhile, generation after generation of stars were formed, including our Sun some 4,700 million years ago. But how did all this really happen? Was it a rapid process? Was it violent or calm? When were all the heavier elements formed? How did the Milky Way change its composition and shape with time? Answers to these and many other questions are 'hot' topics for the astronomers who study the birth and evolution of the Milky Way and other galaxies. Now the rich results of a 15 year-long marathon survey by a Danish-Swiss-Swedish research team [2] are providing some of the answers. 1,001 nights at the telescopes ESO PR Photo 10a/04 ESO PR Photo 10a/04 Sky distribution of the observed stars [Preview - JPEG: 518 x 400 pix - 96k] [Normal - JPEG: 1035 x 800 pix - 897k] Caption: ESO PR Photo 10a/04 shows the distribution on the sky of the approx. 14,000 observed stars. The region on the left that is denser than its surroundings is the nearby Hyades star cluster. The team spent more than 1,000 observing nights over 15 years at the Danish 1.5-m telescope of the European Southern Observatory at La Silla (Chile) and at the Swiss 1-m telescope of the Observatoire de Haute-Provence (France). Additional observations were made at the Harvard-Smithsonian Center for Astrophysics in the USA. A total of more than 14,000 solar-like stars (so-called F- and G-type stars) were observed at an average of four times each - a total of no less than 63,000 individual spectroscopic observations! This now complete census of neighbourhood stars provides distances, ages, chemical analysis, space velocities and orbits in the general rotation of the Milky Way. It also identifies those stars (about 1/3 of them all) which the astronomers found to be double or multiple. This very complete data set for the stars in the solar neighbourhood will provide food for thought by astronomers for years to come. A dream come true ESO PR Photo 10b/04 ESO PR Photo 10b/04 Stars in the solar neighbourhood [Preview - JPEG: 459 x 400 pix - 29k] [Normal - JPEG: 918 x 800 pix - 441k] [FullRes - JPEG: 3000 x 2613 pix - 4.4Mb] Caption: ESO PR Photo 10b/04 provides an artist's view of the observed group of stars orbiting the Milky Way together with the Sun, as seen by an imaginary observer outside the Galaxy. The orbit of the Sun is shown. For clarity, the stars surrounding the local volume have been removed here. These observations provide the long-sought missing pieces of the puzzle to get a clear overview of the solar neighbourhood. They effectively mark the conclusion of a project started more than twenty years ago.. In fact, this work marks the fulfilment of an old dream by Danish astronomer Bengt Strömgren (1908-1987), who pioneered the study of the history of the Milky Way through systematic studies of its stars. Already in the 1950's he designed a special system of colour measurements to determine the chemical composition and ages of many stars very efficiently. And the Danish 50-cm and 1.5-m telescopes at the ESO La Silla Observatory (Chile) were constructed to make such projects possible. Another Danish astronomer, Erik Heyn Olsen made the first step in the 1980's by measuring the flux (light intensity) in several wavebands (in the "Strömgren photometric system") of 30,000 A, F and G stars over the whole sky to a fixed brightness limit. Next, ESA's Hipparcos satellite determined precise distances and velocities in the plane of the sky for these and many other stars. The missing link was the motions along the line of sight (the so-called radial velocities). They were then measured by the present team from the Doppler shift of spectral lines of the stars (the same technique that is used to detect planets around other stars), using the specialized CORAVEL instrument. Stellar orbits in the Milky Way ESO PR Video Clip 04/04 ESO Video Clip 04/04 Motions of the observed stars in the Milky Way [MPG - 1.3Mb] [Quick Time Video - 248k] [Animated GIF - 128k] Caption: ESO PR Video Clip 04/04 shows the stars studied during the present programme making their most recent orbital revolution around the Galactic centre before converging into the small volume where they were observed by the team. The duration of the video corresponds to about 250 million years. The yellow dot and white curve show how the Sun moved during this last of its about 20 laps around our Galaxy. With the velocity information completed, the astronomers can now compute how the stars have wandered around in the Galaxy in the past, and where they will go in the future, cf. PR Video Clip 04/04. Birgitta Nordström, leader of the team, explains: "For the first time we have a complete set of observed stars that is a fair representation of the stellar population in the Milky Way disc in general. It is large enough for a proper statistical analysis and also has complete velocity and binary star information. We have just started the analysis of this dataset ourselves, but we know that our colleagues worldwide will rush to join in the interpretation of this treasure trove of information." The team's initial analysis indicates that objects like molecular clouds, spiral arms, black holes, or maybe a central bar in the Galaxy, have stirred up the motion of the stars throughout the entire history of the Milky Way disc. This in turn reveals that the evolution of the Milky Way was far more complex and chaotic than traditional, simplified models have long so far assumed. Supernova explosions, galaxy collisions, and infall of huge gas clouds have made the Milky Way a very lively place indeed!

ALMA Partners Break Ground on World's Largest Millimeter Wavelength Telescope

NASA Astrophysics Data System (ADS)

2003-11-01

Scientists and dignitaries from North America, Europe, and Chile broke ground today (Thursday, November 6, 2003) on what will be the world's largest, most sensitive radio telescope operating at millimeter wavelengths. ALMA - the Atacama Large Millimeter Array - will be a single instrument composed of 64 high-precision antennas located on the Chajnantor plain of the Chilean Andes in the District of San Pedro de Atacama, 16,500 feet (5,000 meters) above sea level. ALMA's primary function will be to observe and image with unprecedented clarity the enigmatic cold regions of the Universe, which are optically dark, yet shine brightly in the millimeter portion of the electromagnetic spectrum. ALMA Array Artist's Conception of ALMA Array in Compact Configuration (Click on Image for Larger Version) Other Images Available: Artist's conception of the antennas for the Atacama Large Millimeter Array Moonrise over ALMA test equipment near Cerro Chajnantor, Chile VertexRSI antenna at the VLA test site The Atacama Large Millimeter Array is an international astronomy facility. ALMA is an equal partnership between Europe and North America, in cooperation with the Republic of Chile, and is funded in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC), and in Europe by the European Southern Observatory (ESO) and Spain. ALMA construction and operations are led on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI), and on behalf of Europe by ESO. "The U.S. National Science Foundation joins today with our North American partner, Canada, and with the European Southern Observatory, Spain, and Chile to prepare for a spectacular new instrument," said Dr. Rita Colwell, director of the U.S. National Science Foundation. "The Atacama Large Millimeter Array will expand our vision of the Universe with "eyes" that pierce the shrouded mantles of space through which light cannot penetrate." Wayne Van Citters, Division Director for the NSF's Division of Astronomical Sciences represented Dr. Colwell at this ceremony. "ALMA will be a giant leap forward for our studies of this relatively little explored spectral window towards the Universe," said Dr. Catherine Cesarsky, Director General of ESO. "With ESO leading the European part of this ambitious and forward-looking project, the impact of ALMA will be felt in wide circles on our continent. Together with our partners in North America and Chile, we are all looking forward to the truly outstanding opportunities that will be offered by ALMA, also to young scientists and engineers." SCIENCE WITH ALMA ALMA will receive millimeter and sub-millimeter wavelength electromagnetic radiation from space. This portion of the spectrum, which is more energetic than most radio waves yet less energetic than visible and infrared light, holds the key to understanding a great variety of fundamental processes, including planet and star formation, and the formation and evolution of galaxies and galaxy clusters in the early Universe. The possibility to detect emission from organic and other molecules in space is of particularly high interest. "ALMA will push the limits of engineering to provide a telescope array at a fantastic site for astronomers to peer at the beginnings of the Universe, galaxies, stars and planets, and perhaps even life," said Dr. Fred K.Y. Lo, director of the National Radio Astronomy Observatory (NRAO). The millimeter and sub-millimeter radiation that ALMA will study is able to penetrate the vast clouds of dust and gas that populate interstellar and intergalactic space, revealing previously hidden details about astronomical objects. This energy, however, is blocked by atmospheric moisture here on Earth. To conduct research in this critical portion of the spectrum, astronomers need a site that is very dry, and preferably at a very high altitude where the atmosphere is thinner. Extensive tests showed that the sky above the high-altitude Chajnantor plain in the Atacama Desert has the unsurpassed clarity and stability needed to perform efficient observations with ALMA. ALMA OPERATION ALMA will be the highest altitude, full-time ground-based observatory in the world. Work at this altitude, however, is very challenging. To help ensure the safety of the scientists and engineers at ALMA, operations will be conducted from the Operations Support Facility, a compound located close to the cities of Toconao and San Pedro de Atacama, which is at a more comfortable 2,900 meters (9,500 feet) above sea level. Phase 1 of the ALMA Project, which included the design and development, was completed in 2002. The beginning of Phase 2 of this project happened on February 25, 2003, when the NSF and ESO signed an agreement to construct and operate ALMA. Construction will continue until 2012; however, initial scientific observations are planned in 2007, with a partial array of the first antennas. ALMA's operation will progressively increase until 2012 with the installation of the remaining antennas. The entire project will cost approximately $552 million U.S. (in FY 2000 dollars). Earlier this year, the ALMA Board selected Professor Massimo Tarenghi, formerly manager of ESO's VLT (Very Large Telescope) Project, to become ALMA Director. He is confident that he and his team will succeed. "We may have a lot of hard work in front of us," he said, "but all of us in the team are excited about this unique project. We are ready to work for the international astronomical community and to provide them in due time with a unique instrument allowing trailblazing research projects in many different fields of modern astrophysics." HOW IT WILL WORK ALMA will be composed of 64 high-precision antennas, each 12 meters in diameter. The ALMA antennas can be repositioned, allowing the telescope to function much like the zoom lens on a camera. At its largest, ALMA will be 14 kilometers (8.7 miles) across. This will allow the telescope to observe the fine-scale details of astronomical objects. At its smallest, approximately 150 meters (492 feet) across, ALMA will be able to study the large-scale structures of these same objects. ALMA will function as an interferometer, meaning it will combine the signals from all its antennas (two at a time) to simulate a telescope the size of the distance between the antennas. With 64 antennas, ALMA will generate 2016 individual antenna pairs (baselines) during its observations. To handle this much data, ALMA will rely on a very powerful, specialized computer called a correlator, which will perform 16,000 million-million operations per second. Currently, the two prototype ALMA antennas are undergoing rigorous testing at the NRAO's Very Large Array site, near Socorro, New Mexico. INTERNATIONAL COLLABORATION For this ambitious project, ALMA has become a joint effort among several nations and scientific institutions. This will be the first truly global project of ground-based astronomy, an essential development in view of the increasing technological sophistication and the high costs of the front line astronomy installations. "Today marks the official start of construction," said Dr. Colwell. "But the ALMA partnership also breaks ground with a novel collaboration that ensures equal access by astronomers on at least three continents. International partnerships are quickly becoming the norm of the millennium, enabling organizations and nations to combine funds to achieve greater scientific capability. NSF is proud to participate in the creation of an instrument that will provide unprecedented power for science and immeasurable knowledge for all." At the groundbreaking in Chile, the ALMA partners unveiled the ALMA logo.

Successful "First Light" for VLT High-Resolution Spectrograph

NASA Astrophysics Data System (ADS)

1999-10-01

Great Research Prospects with UVES at KUEYEN A major new astronomical instrument for the ESO Very Large Telescope at Paranal (Chile), the UVES high-resolution spectrograph, has just made its first observations of astronomical objects. The astronomers are delighted with the quality of the spectra obtained at this moment of "First Light". Although much fine-tuning still has to be done, this early success promises well for new and exciting science projects with this large European research facility. Astronomical instruments at VLT KUEYEN The second VLT 8.2-m Unit Telescope, KUEYEN ("The Moon" in the Mapuche language), is in the process of being tuned to perfection before it will be "handed" over to the astronomers on April 1, 2000. The testing of the new giant telescope has been successfully completed. The latest pointing tests were very positive and, from real performance measurements covering the entire operating range of the telescope, the overall accuracy on the sky was found to be 0.85 arcsec (the RMS-value). This is an excellent result for any telescope and implies that KUEYEN (as is already the case for ANTU) will be able to acquire its future target objects securely and efficiently, thus saving precious observing time. This work has paved the way for the installation of large astronomical instruments at its three focal positions, all prototype facilities that are capable of catching the light from even very faint and distant celestial objects. The three instruments at KUEYEN are referred to by their acronyms UVES , FORS2 and FLAMES. They are all dedicated to the investigation of the spectroscopic properties of faint stars and galaxies in the Universe. The UVES instrument The first to be installed is the Ultraviolet Visual Echelle Spectrograph (UVES) that was built by ESO, with the collaboration of the Trieste Observatory (Italy) for the control software. Complete tests of its optical and mechanical components, as well as of its CCD detectors and of the complex control system, cf. ESO PR Photos 44/98 , were made in the laboratories of the ESO Headquarters in Garching (Germany) before it was fully dismounted and shipped (some parts by air, others by ship) to the ESO Paranal Observatory, 130 km south of Antofagasta (Chile). Here, the different pieces of UVES (with a total weight of 8 tons) were carefully reassembled on the Nasmyth platform of KUEYEN and made ready for real observations (see ESO PR Photos 36p-t/99 ). UVES is a complex two-channel spectrograph that has been built around two giant optical (echelle diffraction) gratings, each ruled on a 84 cm x 21 cm x 12 cm block of the ceramic material Zerodur (the same that is used for the VLT 8.2-m main mirrors) and weighing more than 60 kg. These echelle gratings finely disperse the light from celestial objects collected by the telescope into its constituent wavelengths (colours). UVES' resolving power (an optical term that indicates the ratio between a given wavelength and the smallest wavelength difference between two spectral lines that are clearly separated by the spectrograph) may reach 110,000, a very high value for an astronomical instrument of such a large size. This means for instance that even comparatively small changes in radial velocity (a few km/sec only) can be accurately measured and also that it is possible to detect the faint spectral signatures of very rare elements in celestial objects. One UVES channel is optimized for the ultraviolet and blue, the other for visual and red light. The spectra are digitally recorded by two highly efficient CCD detectors for subsequent analysis and astrophysical interpretation. By optimizing the transmission of the various optical components in its two channels, UVES has a very high efficiency all the way from the UV (wavelength about 300 nm) to the near-infrared (1000 nm or 1 µm). This guarantees that only a minimum of the precious light that is collected by KUEYEN is lost and that detailed spectra can be obtained of even quite faint objects, down to about magnitude 20 (corresponding to nearly one million times fainter than what can be perceived with the unaided eye). The possibility of doing simultaneous observations in the two channels (with a dichroic mirror) ensures a further gain in data gathering efficiency. First Observations with UVES In the evening of September 27, 1999, the ESO astronomers turned the KUEYEN telescope and - for the first time - focussed the light of stars and galaxies on the entrance aperture of the UVES instrument. This is the crucial moment of "First Light" for a new astronomical facility. The following test period will last about three weeks. Much of the time during the first observing nights was spent by functional tests of the various observation modes and by targeting "standard stars" with well-known properties in order to measure the performance of the new instrument. They showed that it is behaving very well. This marks the beginning of a period of progressive fine-tuning that will ultimately bring UVES to peak performance. The astronomers also did a few "scientific" observations during these nights, aimed at exploring the capabilities of their new spectrograph. They were eager to do so, also because UVES is the first spectrograph of this type installed at a telescope of large diameter in the southern hemisphere . Many exciting research possibilities are now opening with UVES . They include a study of the chemical history of many galaxies in the Local Group, e.g. by observing the most metal-poor (oldest) stars in the Milky Way Galaxy and by obtaining the first, extremely detailed spectra of their brightest stars in the Magellanic Clouds. Quasars and distant compact galaxies will also be among the most favoured targets of the first UVES observers, not least because their spectra carry crucial information about the density, physical state and chemical composition of the early Universe. UVES First Light: SN 1987A One of the first spectral test exposures with UVES at KUEYEN was of SN 1987A , the famous supernova that exploded in the Large Magellanic Cloud (LMC) in February 1987, and the brightest supernova of the last 400 years. ESO PR Photo 37a/99 ESO PR Photo 37a/99 [Preview - JPEG: 400 x 455 pix - 87k] [Normal - JPEG: 645 x 733 pix - 166k] Caption to ESO PR Photo 37a/99 : This is a direct image of SN1987A, flanked by two nearby stars. The distance between these two is 4.5 arcsec. The slit (2.0 arcsec wide) through which the echelle spectrum shown in PR Photo 37b/99 was obtained, is outlined. This reproduction is from a 2-min exposure through a R(ed) filter with the FORS1 multi-mode instrument at VLT ANTU, obtained in 0.55 arcsec seeing on September 20, 1998. North is up and East is left. ESO PR Photo 37b/99 ESO PR Photo 37b/99 [Preview - JPEG: 400 x 459 pix - 130k] [Normal - JPEG: 800 x 917 pix - 470k] [High-Res - JPEG: 3000 x 3439 pix - 6.5M] Caption to ESO PR Photo 37b/99 : This shows the raw image, as read from the CCD, with the recorded echelle spectrum of SN1987A. With this technique, the supernova spectrum is divided into many individual parts ( spectral orders , each of which appears as a narrow horizontal line) that together cover the wavelength interval from 479 to 682 nm (from the bottom to the top), i.e. from blue to red light. Many bright emission lines from different elements are visible, e.g. the strong H-alpha line from hydrogen near the centre of the fourth order from the top. Emission lines from the terrestrial atmosphere are seen as vertical bright lines that cover the full width of the individual horizontal bands. Since this exposure was done with the nearly Full Moon above the horizon, an underlying, faint absorption-line spectrum of reflected sunlight is also visible. The exposure time was 30 min and the seeing conditions were excellent (0.5 arcsec). ESO PR Photo 37c/99 ESO PR Photo 37c/99 [Preview - JPEG: 400 x 355 pix - 156k] [Normal - JPEG: 800 x 709 pix - 498k] [High-Res - JPEG: 1074 x 952 pix - 766k] Caption to ESO PR Photo 37c/99 : This false-colour image has been extracted from another UVES echelle spectrum of SN 1987A, similar to the one shown in PR Photo 37b/99 , but with a slit width of 1 arcsec only. The upper part shows the emission lines of nitrogen, sulfur and hydrogen, as recorded in some of the spectral orders. The pixel coordinates (X,Y) in the original frame are indicated; the red colour indicates the highest intensities. Below is a more detailed view of the complex H-alpha emission line, with the corresponding velocities and the position along the spectrograph slit indicated. Several components of this line can be distinguished. The bulk of the emission (here shown in red colour) comes from the ring surrounding the supernova; the elongated shape here is due to the differential velocity exhibited by the near (to us) and far sides of the ring. The two bright spots on either side are emission from two outer rings (not immediately visible in PR Photo 37a/99 ). The extended emission in the velocity direction originates from material inside the ring upon which the fastest moving ejecta from the supernova have impacted (As seen in VLT data obtained previously with the ANTU/ISAAC combination (cf. PR Photo 11/99 ), exciting times now lie ahead for SN 1987A. The ejecta moving at 30,000 km/s (1/10th the speed of light) have now, 12 years after the explosion, reached the ring of material and the predicted "fireworks" are about to be ignited.) Finally, there is a broad emission extending all along the spectrograph slit (here mostly yellow) upon which the ring emission is superimposed. This is not associated with the supernova itself, but is H-alpha emission by diffuse gas in the Large Magellanic Cloud (LMC) in which SN 1987A is located. UVES First Light: QSO HE2217-2818 The power of UVES is demonstrated by this two-hour test exposure of the southern quasar QSO HE2217-2818 with U-magnitude = 16.5 and a redshift of z = 2.4. It was discovered a few years ago during the Hamburg-ESO Quasar Survey , by means of photographic plates taken with the 1-m ESO Schmidt Telescope at La Silla, the other ESO astronomical site in Chile. ESO PR Photo 37d/99 ESO PR Photo 37d/99 [Preview - JPEG: 400 x 309 pix - 92k] [Normal - JPEG: 800x 618 pix - 311k] [High-Res - JPEG: 3000 x 2316 pix - 5.0M] ESO PR Photo 37e/99 ESO PR Photo 37e/99 [Preview - JPEG: 400 x 310 pix - 43k] [Normal - JPEG: 800 x 619 pix - 100k] [High-Res - JPEG: 3003 x 2324 pix - 436k] Caption to ESO PR Photo 37d/99 : This UVES echelle spectrum QSO HE2217-2818 (U-magnitude = 16.5) is recorded in different orders (the individual horizontal lines) and altogether covers the wavelength interval between 330 - 450 nm (from the bottom to the top). It illustrates the excellent capability of UVES to work in the UV-band on even faint targets. Simultaneously with this observation, UVES also recorded the adjacent spectral region 465 - 660 nm in its other channel. The broad Lyman-alpha emission from ionized hydrogen associated with the powerful energy source of the QSO is seen in the upper half of the spectrum at wavelength 413 nm. At shorter wavelengths, the dark regions in the spectrum are Lyman-alpha absorption lines from intervening, neutral hydrogen gas located along the line-of-sight at different redshifts (the so-called Lyman-alpha forest ) in the redshift interval z = 1.7 - 2.4. Note that since this exposure was done with the nearly Full Moon above the horizon, an underlying, faint absorption-line spectrum of reflected sunlight is also visible. Caption to ESO PR Photo 37e/99 : A tracing of one spectral order, corresponding to one horizontal line in the echelle spectrum displayed in PR Photo 37d/99 . It shows part of the Lyman-alpha forest in the ultraviolet spectrum of the southern quasar QSO HE2217-2818 . The absorption lines are caused by intervening, neutral hydrogen gas located at different distances along the line-of-sight towards this quasar. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../ ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

Three Good Reasons for Celebrating at the ESO/ST-ECF Science Archive Facility

NASA Astrophysics Data System (ADS)

2000-12-01

Great Demand for Data from New "Virtual Observatory" Summary Due to a happy coincidence, the ESO/ST-ECF Science Archive Facility is celebrating three different milestones at the same time: * its 10th anniversary since the establishment in 1991 * the 10,000th request for data , and * the signing-up of active user number 2000 . This Archive contains over 8 Terabytes (1 Terabyte = 1 million million bytes) of valuable observational data from the NASA/ESA Hubble Space Telescope (HST), the ESO Very Large Telescope (VLT) and other ESO telescopes . Its success paves the way for the establishment of "Virtual Observatories" from which first-class data can be obtained by astronomers all over the world. This greatly enhances the opportunities for more (young) scientists to participate in front-line research. PR Photo 34/00 : Front-page of a new brochure, describing the ESO/ST-ECF Science Archive Facility. Just 10 years ago, on the 1st of January 1991, the ESO/ST-ECF (European Southern Observatory/Space Telescope-European Coordinating Facility) Science Archive Facility opened. It has since served the astronomical community with gigabyte after gigabyte of high-quality astronomical data from some of the world's leading telescopes. The Archive, which is located in Garching, just outside Munich (Germany), contains data from the 2.4-m NASA/ESA Hubble Space Telescope , as well as from several ESO telescopes: the four 8.2-m Unit Telescopes of the Very Large Telescope (VLT) at the Paranal Observatory , and the 3.5-m New Technology Telescope (NTT) , the 3.6-m telescope and the MPG/ESO 2.2-m telescope at La Silla. The Archive is a continuously developing project - in terms of amounts of data stored, the number of users and in particular because of the current dramatic development of innovative techniques for data handling and storage. In the year 2000 more than 2 Terabytes (2000 Gigabytes) of data were distributed to users worldwide. The archiving of VLT data has been described in ESO PR 10/99. Celebrating the 10th anniversary Due to a happy coincidence, the Archive passes two other milestones almost exactly at the time of its ten-year anniversary: the 10,000th request for data has just arrived, and active user number 2000 has just signed up to start using the Archive . Dataset number 10000 was requested by Danish astronomer Søren Larsen who works at the University of California (USA). He asked for images of galaxies taken with the Hubble Space Telescope and expressed great satisfaction with the material: "The extremely sharp images from Hubble have provided a quantum leap forward in our ability to study star clusters in external galaxies. We now know that some galaxies contain extremely bright young star clusters. These might constitute a "link" between open and globular clusters as we know them in the Milky Way galaxy in which we live. We are now trying to understand whether all these clusters really form in the same basic way." Active user number 2000 is Swiss astronomer Frédéric Pont , working at the Universidad de Chile: "We use observations from the ESO VLT Unit Telescopes to map the chemical and star-formation history of dwarf galaxies in the Local Group. The stars we are looking at are very faint and we simply need the large size and excellent quality of VLT to observe them in detail. With the new data, we can really move forward in this fundamental research field." ESO PR Photo 34/00 ESO PR Photo 34/00 [Preview - JPEG: 400 x 281 pix - 63k] [Normal - JPEG: 800 x 562 pix - 224k] [Full-Res - JPEG: 1024 x 714 pix - 336k] Caption : PR Photo 34/00 shows the frontpage of the new brochure that describes the ESO/ST-ECF Science Archive Facility (available in PDF version on the web). The collage shows the Hubble Space Telescope above the world's largest optical/infrared telescope, the Very Large Telescope (VLT). To celebrate this special occasion, a 4-page brochure has been prepared that describes the Archive and its various services. The brochure can be requested from ESO or ST-ECF and is now available in PDF format on the web. As a small token, the two astronomers will receive a commemorative version of the photo that accompanies this release. The ASTROVIRTEL initiative One of the major new initiatives undertaken by ESO and ST-ECF in connection with the ESO/ST-ECF Science Archive is ASTROVIRTEL (Accessing Astronomical Archives as Virtual Telescopes) , cf. ESO PR 09/00. It is a project aimed at helping scientists to cope efficiently with the massive amounts of data now becoming available from the world's leading telescopes and so to exploit the true potential of the Archive treasures. ASTROVIRTEL represents the European effort in an area that many astronomers considers one of the most important developments within observing astronomy in the past decade. The future The head of the ESO/ST-ECF Science Archive Facility , Benoît Pirenne , believes that the future holds exciting challenges: "Due to the many improvements of the ESO, NASA and ESA telescopes and instruments expected in the coming years, we anticipate a tremendous increase in the amount of data to be archived and re-distributed. It will not be too long before we will have to start counting storage space in Petabytes (1 Petabyte = 1,000 Terabytes). We are now trying to figure out how to best prepare for this new era." But he is also concerned with maintaining and further enhancing the astronomical value of the data that are made available to the users: "Apart from improving the data storage, we need to invest much effort in building automatic software that will help users with the tedious pre-processing and 'cleaning' of the data, thereby allowing them to focus more on scientific than technical problems."

Man-made Star Shines in the Southern Sky

NASA Astrophysics Data System (ADS)

2006-02-01

Scientists celebrate another major milestone at Cerro Paranal in Chile, home of ESO's Very Large Telescope array. Thanks to their dedicated efforts, they were able to create the first artificial star in the Southern Hemisphere, allowing astronomers to study the Universe in the finest detail. This artificial laser guide star makes it possible to apply adaptive optics systems, that counteract the blurring effect of the atmosphere, almost anywhere in the sky. ESO PR Photo 07a/06 ESO PR Photo 07a/06 First Light of the VLT Laser Guide Star On 28 January 2006, at 23:07 local time, a laser beam of several watts was launched from Yepun, the fourth 8.2m Unit Telescope of the Very Large Telescope, producing an artificial star, 90 km up in the atmosphere. Despite this star being about 20 times fainter than the faintest star that can be seen with the unaided eye, it is bright enough for the adaptive optics to measure and correct the atmosphere's blurring effect. The event was greeted with much enthusiasm and happiness by the people in the control room of one of the most advanced astronomical facilities in the world. It was the culmination of five years of collaborative work by a team of scientists and engineers from ESO and the Max Planck Institutes for Extraterrestrial Physics in Garching and for Astronomy in Heidelberg, Germany. After more than one month of integration on site with the invaluable support of the Paranal Observatory staff, the VLT Laser Guide Star Facility saw First Light and propagated into the sky a 50cm wide, vivid, beautifully yellow beam. ESO PR Photo 07b/06 ESO PR Photo 07b/06 An Artificial Star Above Paranal "This event tonight marks the beginning of the Laser Guide Star Adaptive Optics era for ESO's present and future telescopes", said Domenico Bonaccini Calia, Head of the Laser Guide Star group at ESO and LGSF Project Manager. Normally, the achievable image sharpness of a ground-based telescope is limited by the effect of atmospheric turbulence. This drawback can be surmounted with adaptive optics, allowing the telescope to produce images that are as sharp as if taken from space. This means that finer details in astronomical objects can be studied, and also that fainter objects can be observed. In order to work, adaptive optics needs a nearby reference star that has to be relatively bright, thereby limiting the area of the sky that can be surveyed. To overcome this limitation, astronomers use a powerful laser that creates an artificial star, where and when they need it. ESO PR Photo 07c/06 ESO PR Photo 07c/06 The Laser Guide Star Laboratory The laser beam, shining at a well-defined wavelength, makes the layer of sodium atoms that is present in Earth's atmosphere at an altitude of 90 kilometres glow. The laser is hosted in a dedicated laboratory under the platform of Yepun. A custom-made fibre carries the high power laser to the launch telescope situated on top of the large Unit Telescope. An intense and exhilarating twelve days of tests followed the First Light of the Laser Guide Star (LGS), during which the LGS was used to improve the resolution of astronomical images obtained with the two adaptive optics instruments in use on Yepun: the NAOS-CONICA imager and the SINFONI spectrograph. In the early hours of 9 February, the LGS could be used together with the SINFONI instrument, while in the early morning of 10 February, it was with the NAOS-CONICA system. ESO PR Video 07/06 ESO PR Video 07/06 Learn more with the video! "To have succeeded in such a short time is an outstanding feat and is a tribute to all those who have together worked so hard over the last few years," said Richard Davies, project manager for the laser source development at the Max Planck Institute for Extraterrestrial Physics. A second phase of commissioning will take place in the spring with the aim of optimizing the operations and refining the performances before the instrument is made available to the astronomers, later this year. The experience gained with this Laser Guide Star is also a key milestone in the design of the next generation of Extremely Large Telescope in the 30 to 60 metre range that is now being studied by ESO together with the European astronomical community. High resolution images and their captions are available on this page. This press release is also accompanied by Broadcast quality material. Notes The Laser Guide Star Facility is a collaborative project between ESO, the Max Planck Institute for Extraterrestrial Physics in Garching, Germany (MPE) and the Max Planck Institut for Astronomy in Heidelberg, Germany (MPIA). The team members are D. Bonaccini Calia, W. Hackenberg, M. Cullum, M. Dimmler, I. Guidolin, C. Araujo, E. Allaert, D. Popovic, M. Comin, M. Quattri, E. Brunetto, F. Koch, A. Silber, J-L. Alvarez, M. Tapia, E. Bendek, J. Quentin, G. Fischer, M. Tarenghi, G.Monnet, and R.Gilmozzi (ESO), R. Davies, S. Rabien, T. Ott, R. Genzel, S.Kellner, S. Huber, W. Zaglauer, A. Goldbrunner, and J. Li (MPE), and S. Hippler, U. Neumann, D. Butler, R.-R. Rohloff, and B.Grimm (MPIA). Members of ESO's Adaptive Optics team also participated to First Light: M. Kasper, S. Stroebele, E. Fedrigo, R. Donaldson, S. Oberti, and C. Soenke. This press release is issued in coordination between ESO and the Max Planck Society. A German version is available at http://www.mpg.de/bilderBerichteDokumente/dokumentation/pressemitteilungen/2006/

ESO Receives Computerworld Honors Program 21st Century Achievement Award in Science Category

NASA Astrophysics Data System (ADS)

2005-06-01

In a ceremony held in Washington, D.C. (USA) on June 6, 2005, ESO, the European Organisation for Astronomical Research in the southern Hemisphere, received the coveted 21st Century Achievement Award from the Computerworld Honors Program for its visionary use of information technology in the Science category. Sybase, a main database server vendor and member of the Chairmen's Committee, nominated ESO's Data Flow System in recognition of its contributions to the global information technology revolution and its positive impact on society. The citations reads: "ESO has revolutionized the operations of ground-based astronomical observatories with a new end-to-end data flow system, designed to improve the transmission and management of astronomical observations and data over transcontinental distances." This year's awards, in 10 categories, were presented at a gala event at the National Building Museum, attended by over 250 guests, including leaders of the information technology industry, former award recipients, judges, scholars, and diplomats representing many of the 54 countries from which the 17-year-old program's laureates have come. "The Computerworld Honors Program 21st Century Achievement Awards are presented to companies from around the world whose visionary use of information technology promotes positive social, economic and educational change," said Bob Carrigan, president and CEO of Computerworld and chairman of the Chairmen's Committee of the Computerworld Honors Program. "The recipients of these awards are the true heroes of the information age and have been appropriately recognized by the leading IT industry chairmen as true revolutionaries in their fields." ESO PR Photo 18/05 ESO PR Photo 18/05 ESO Receives the Award in the Science Category [Preview - JPEG: 400 x 496 pix - 53k] [Normal - JPEG: 800 x 992 pix - 470k] [Full Res - JPEG: 1250 x 1550 pix - 1.1M] Caption: ESO PR Photo 18/05: Receiving the Computerworld 21st Century Achievement Award for Science on behalf of ESO: Drs Preben Grosbøl, Michele Péron, Peter Quinn (Head of the ESO Data Management Division) and David Silva. Traditionally, ground based astronomical observatories have been used as facilities where scientists apply for observing time, eventually travel to the remote sites where telescopes are located, carry out their observations by themselves and finally take their data back to their home institutes to do the final scientific analysis. As observatories become more complex and located in ever more remote locations (to reduce light pollution), this operational concept (coupled with the weather lottery effect [1]) becomes less and less effective. In particular, the lack of data re-use has been increasingly seen as scientifically unproductive. Such thoughts guided the design and implementation of the ESO Data Flow System (DFS). The DFS allows both traditional on-site observing as well as service observing, where data is collected by observatory staff on behalf of the ESO user community based on user submitted descriptions and requirements [2]. In either case, the data is captured by DFS and saved in the ESO science archive [3]. After a one-year proprietary period during which the original investigators have private access to their data, researchers can access the data for their own use. ESO was the first ground-based observatory to implement these operational concepts and tools within a complete system. It was also the first ground-based observatory to build and maintain such an extensive science archive that does not only contain observational data, but also auxiliary information describing the operation process. In both areas, ESO remains the world-leader in end-to-end observatory operations on the ground. "The result of our strategy has been a significant increase in the scientific productivity of the ESO user community", said Peter Quinn, Head of ESO's Data Management and Operations Division, responsible for DFS. "As measured by the number of papers in peer-reviewed journals, ESO is now one of the leading astronomical facilities in the world. Coupled with cutting edge optical telescopes and astronomical instruments at the Chile sites, the DFS has contributed to this success by providing the fundamental IT infrastructure for observation and data management." The case study about ESO, together with the case studies from the other winners and laureates of the 2005 Collection, is available on the Computerworld Honors Program Archives On-Line, www.cwheroes.org, and also distributed to more than 134 members of the Computerworld Honors Global Archives. According to Dan Morrow, a founding director and chief historian for the Honors Program, "This year's award recipients exemplify the very best in the creative use of IT in service to mankind. Their work and their stories are outstanding contributions to the history of the information technology revolution in every sense of the word, and, for the archives we serve all over the world, they are, truly, priceless." From more than 250 nominations submitted this year by the industry chairmen and CEO's who serve on the program's Chairmen's Committee, 162 were honoured as laureates at ceremonies in San Francisco, on April 3, 2005, when their case studies officially became part of the Computerworld Honors 2005 Collection. Of these, 48 finalists were chosen by an academy of distinguished judges to attend the June 6 gala in Washington, D.C., at which 10 were announced recipients of the award, one in each of the following categories: Business and Related Services; Education and Academia; Environment, Energy and Agriculture; Finance, Insurance and Real Estate; Government and Non-Profit Organizations; Manufacturing; Media, Arts and Entertainment; Medicine; Science; and Transportation. Additional information about the 2005 Collection is available at www.cwheroes.org, where the entire collection is available to scholars, researchers and the general public. The ESO Data Management and Operations Division web page is at http://www.eso.org/org/dmd/. More information About the Computerworld Honors Program: Governed by the Computerworld Information Technology Awards Foundation, a Massachusetts not-for-profit corporation founded by International Data Group (IDG) in 1988, the Computerworld Honors Program searches for and recognizes individuals and organizations who have demonstrated vision and leadership as they strive to use information technology in innovative ways across 10 categories: Business and Related Services; Education and Academia; Environment, Energy and Agriculture; Finance, Insurance and Real Estate; Government and Non-Profit Organizations; Manufacturing; Media, Arts and Entertainment; Medicine; Science; and Transportation. Each year, the Computerworld Honors Chairmen's Committee nominates organizations that are using information technology to improve society for inclusion in the Computerworld Honors Online Archive and the Collections of the Global Archives. The Global Archives represents the 100-plus institutions from more than 30 countries that include the Computerworld Honors Collection in their archives and libraries.

A 12 μm ISOCAM survey of the ESO-Sculptor field. Data reduction and analysis

NASA Astrophysics Data System (ADS)

Seymour, N.; Rocca-Volmerange, B.; de Lapparent, V.

2007-12-01

We present a detailed reduction of a mid-infrared 12 μm (LW10 filter) ISOCAM open time observation performed on the ESO-Sculptor Survey field (Arnouts et al. 1997, A&AS, 124, 163). A complete catalogue of 142 sources (120 galaxies and 22 stars), detected with high significance (equivalent to 5σ), is presented above an integrated flux density of 0.24 {mJy}. Star/galaxy separation is performed by a detailed study of colour-colour diagrams. The catalogue is complete to 1 {mJy} and, below this flux density, the incompleteness is corrected using two independent methods. The first method uses stars and the second uses optical counterparts of the ISOCAM galaxies; these methods yield consistent results. We also apply an empirical flux density calibration using stars in the field. For each star, the 12 μm flux density is derived by fitting optical colours from a multi-band χ2 to stellar templates (BaSel-2.0) and using empirical optical-IR colour-colour relations. This article is a companion analysis to our 2007 paper (Rocca-Volmerange et al. 2007, A&A, 475, 801) where the 12 μ m faint galaxy counts are presented and analysed per galaxy type with the evolutionary code PÉGASE.3. Based on observations collected at the European Southern Observatory (ESO), La Silla, Chile, and on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands, and the United Kingdom) and with the participation of ISAS and NASA. Full Table [see full textsee full textsee full textsee full textsee full textsee full text] is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/475/791

A Proper Motions Study of the Globular Cluster NGC 3201

NASA Astrophysics Data System (ADS)

Sariya, Devesh P.; Jiang, Ing-Guey; Yadav, R. K. S.

2017-03-01

With a high value of heliocentric radial velocity, a retrograde orbit, and suspected to have an extragalactic origin, NGC 3201 is an interesting globular cluster for kinematical studies. Our purpose is to calculate the relative proper motions (PMs) and membership probability for the stars in the wide region of globular cluster NGC 3201. PM based membership probabilities are used to isolate the cluster sample from the field stars. The membership catalog will help address the question of chemical inhomogeneity in the cluster. Archive CCD data taken with a wide-field imager (WFI) mounted on the ESO 2.2 m telescope are reduced using the high-precision astrometric software developed by Anderson et al. for the WFI images. The epoch gap between the two observational runs is ˜14.3 years. To standardize the BVI photometry, Stetson’s secondary standard stars are used. The CCD data with an epoch gap of ˜14.3 years enables us to decontaminate the cluster stars from field stars efficiently. The median precision of PMs is better than ˜0.8 mas yr-1 for stars having V< 18 mag that increases up to ˜1.5 mas yr-1 for stars with 18< V< 20 mag. Kinematic membership probabilities are calculated using PMs for stars brighter than V˜ 20 mag. An electronic catalog of positions, relative PMs, BVI magnitudes, and membership probabilities in the ˜19.7 × 17 arcmin2 region of NGC 3201 is presented. We use our membership catalog to identify probable cluster members among the known variables and X-ray sources in the direction of NGC 3201. Based on observations with the MPG/ESO 2.2 m and ESO/VLT telescopes, located at La Silla and Paranal Observatory, Chile, under DDT programs 164.O-0561(F), 093.A-9028(A), and the archive material.

Gaia-ESO Survey: Global properties of clusters Trumpler 14 and 16 in the Carina nebula ⋆⋆

NASA Astrophysics Data System (ADS)

Damiani, F.; Klutsch, A.; Jeffries, R. D.; Randich, S.; Prisinzano, L.; Maíz Apellániz, J.; Micela, G.; Kalari, V.; Frasca, A.; Zwitter, T.; Bonito, R.; Gilmore, G.; Flaccomio, E.; Francois, P.; Koposov, S.; Lanzafame, A. C.; Sacco, G. G.; Bayo, A.; Carraro, G.; Casey, A. R.; Alfaro, E. J.; Costado, M. T.; Donati, P.; Franciosini, E.; Hourihane, A.; Jofré, P.; Lardo, C.; Lewis, J.; Magrini, L.; Monaco, L.; Morbidelli, L.; Worley, C. C.; Vink, J. S.; Zaggia, S.

2017-07-01

Aims: We present the first extensive spectroscopic study of the global population in star clusters Trumpler 16, Trumpler 14, and Collinder 232 in the Carina nebula, using data from the Gaia-ESO Survey, down to solar-mass stars. Methods: In addition to the standard homogeneous survey data reduction, a special processing was applied here because of the bright nebulosity surrounding Carina stars. Results: We find about 400 good candidate members ranging from OB types down to slightly subsolar masses. About 100 heavily reddened early-type Carina members found here were previously unrecognized or poorly classified, including two candidate O stars and several candidate Herbig Ae/Be stars. Their large brightness makes them useful tracers of the obscured Carina population. The spectroscopically derived temperatures for nearly 300 low-mass members enables the inference of individual extinction values and the study of the relative placement of stars along the line of sight. Conclusions: We find a complex spatial structure with definite clustering of low-mass members around the most massive stars and spatially variable extinction. By combining the new data with existing X-ray data, we obtain a more complete picture of the three-dimensional spatial structure of the Carina clusters and of their connection to bright and dark nebulosity and UV sources. The identification of tens of background giants also enables us to determine the total optical depth of the Carina nebula along many sightlines. We are also able to put constraints on the star formation history of the region with Trumpler 14 stars found to be systematically younger than stars in other subclusters. We find a large percentage of fast-rotating stars among Carina solar-mass members, which provide new constraints on the rotational evolution of pre-main-sequence stars in this mass range. Based on observations collected with the FLAMES spectrograph at VLT/UT2 telescope (Paranal Observatory, ESO, Chile), for the Gaia-ESO Large Public Survey (program 188.B-3002). Full Tables 1, 2, and 7 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/603/A81

First ALMA Transporter Ready for Challenging Duty

NASA Astrophysics Data System (ADS)

2008-07-01

The first of two ALMA transporters -- unique vehicles designed to move high-tech radio-telescope antennas in the harsh, high-altitude environment of the Atacama Large Millimeter/submillimeter Array -- has been completed and passed its initial operational tests. The 130-ton machine moves on 28 wheels and will be able to transport a 115-ton antenna and set it down on a concrete pad within millimeters of a prescribed position. ALMA Transporter The ALMA Transporter on a Test Run CREDIT: ESO Click on image for high-resolution file (244 KB) The ALMA transporter rolled out of its hangar and underwent the tests at the Scheuerle Fahrzeugfabrik company site near Nuremberg, Germany. The machine is scheduled for delivery at the ALMA site in Chile by the end of 2007, and a second vehicle will follow about three months later. ALMA is a giant, international observatory under construction in the Atacama Desert of northern Chile at an elevation of 16,500 feet. Using at least 66 high-precision antennas, with the possibility of increasing the number in the future, ALMA will provide astronomers with an unprecedented ability to explore the Universe as seen at wavelengths of a few millimeters to less than a millimeter. By moving the antennas from configurations as compact as 150 meters to as wide as 15 kilometers, the system will provide a zoom-lens ability for scientists. "The ability to move antennas to reconfigure the array is vital to fulfilling ALMA's scientific mission. The operations plan calls for moving antennas on a daily basis to provide the flexibility that will be such a big part of ALMA's scientific value. That's why the transporters are so important and why this is such a significant milestone," said Adrian Russell, North American Project Manager for ALMA. "The ALMA antennas will be assembled and their functionality will be verified at a base camp, located at an altitude of 2900 meters (9500 feet) and the transporters will in a first step bring the telescopes up to the 5000-meter (16,500 feet) high observatory," explained Hans Rykaczewski, the European ALMA Project Manager. "There, the transporters will move the antennas from the compact configuration to any extended configuration which could stretch up to 15 kilometers." To do their job for ALMA, the transporters will have to climb a 17-mile, high-altitude road with an average grade of 7 percent. Carrying an antenna, they can move about 7 mph; when empty, they can travel about 12 mph. The trip from the base camp to the high observing site will take about three hours. A special brake system allows them to safely make the downhill trip. The machines also incorporate a number of redundant safety devices to protect both the personnel and the valuable antennas. "In order to operate the transporter at the ALMA site, two engines with a total of about 1400 horsepower are installed and all the components have been checked to meet the requirements at this extreme conditions," says Andreas Kohler, Vice President for Research and Development at Scheuerle Fahrzeugfabrik, the company which built the transporters under contract to ESO. "The human factor was also considered. For example, the backrests of the driver seats are shaped to allow the driver to wear his oxygen tank while driving." At the high elevation of 16,500 feet, the transporter engines will only provide about half their rated power, because of the lowered amount of available oxygen. The ALMA project is a partnership between Europe, Japan and North America in cooperation with the Republic of Chile. ALMA is funded in Europe by ESO, in Japan by the National Institutes of Natural Sciences in cooperation with the Academia Sinica in Taiwan and in North America by the U.S. National Science Foundation in cooperation with the National Research Council of Canada. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of Japan by the National Astronomical Observatory of Japan and on behalf of North America by the National Radio Astronomy Observatory, which is managed by Associated Universities, Inc.

Pillars of Creation Revealed in 3-D

NASA Image and Video Library

2015-05-01

This video clip shows a visualisation of the three-dimensional structure of the Pillars of Creation within the star formation region Messier 16 (also called the Eagle Nebula). It is based on new observations of the object using the MUSE instrument on ESO’s Very Large Telescope in Chile. The pillars actually consist of several distinct pieces on either side of the star cluster NGC 6611. Credit: ESO/M. Kornmesser Read more: www.nasa.gov/image-feature/goddard/pillars-of-creation-re... NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Possible astronomical meanings of some El Molle relics near the ESO Observatory at La Silla

NASA Astrophysics Data System (ADS)

Bernardi, Gabriella; Vecchiato, Alberto; Bucciarelli, Beatrice

2012-07-01

This paper describes a peculiar, man-made circular stone structure, associated with the ancient rock engravings that are around the site of La Silla in Chile close to the European Southern Observatory, and are attributed to the El Molle Culture. Three stones of the circle, different from all the others, were likely to pinpoint the alignment of three bright stars close to the horizon, as seen from a specific vantage point inside the structure. The El Molle was the only period in which this alignment occurred significantly close to the horizon, moreover it was only in this epoch that it could also be associated with the transition from the warm to the cold season, a period of the year which was quite important for a society that supported itself by herding and farming.

Edge-on!

NASA Astrophysics Data System (ADS)

2007-08-01

Peering at Uranus's Rings as they Swing Edge-on to Earth for the First Time Since their Discovery in 1977 As Uranus coasts through a brief window of time when its rings are edge-on to Earth - a view of the planet we get only once every 42 years - astronomers peering at the rings with ESO's Very Large Telescope and other space or ground-based telescopes are getting an unprecedented view of the fine dust in the system, free from the glare of the bright rocky rings. They may even find a new moon or two. ESO PR Photo 37/07 ESO PR Photo 37/07 The Uranus System "ESO's VLT took data at the precise moment when the rings were edge-on to Earth," said Imke de Pater, of University of California, Berkeley who coordinated the worldwide campaign. She worked with two team members observing in Chile: Daphne Stam of the Technical University Delft in the Netherlands and Markus Hartung of ESO. The observations were done with NACO, one of the adaptive optics instruments installed at the VLT. With adaptive optics, it is possible to obtain images almost free from the blurring effect of the atmosphere. It is as if the 8.2-m telescope were observing from space. Observations were also done with the Keck telescope in Hawaii, the Hubble Space Telescope, and at the Palomar Observatory. "Using different telescopes around the world allows us to observe as much of the changes during the ring-plane crossing as possible: when Uranus sets as seen from the VLT, it can still be observed by the Keck," emphasised Stam. Uranus orbits the Sun in 84 years. Twice during a Uranian year, the rings appear edge-on to Earth for a brief period. The rings were discovered in 1977, so this is the first time for a Uranus ring-crossing to be observed from Earth. The advantage of observations at a ring-plane crossing is that it becomes possible to look at the rings from the shadowed or dark side. From that vantage point, the normally bright outer rings grow fainter because their centimetre- to metre-sized rocks obscure one another, while the dim inner rings get brighter as their material merges into a thin band along the line of sight. Two little satellites called Cordelia and Ophelia straddle the brightest ring, the 'Epsilon Ring', and keep it in place, but it has always been assumed there must be more of these satellites that are confining the 9 other narrow rings. Normally the satellites are lost in the glare of the rings, but during these events the unique orientation makes the bright rings essentially invisible. Thus the ring plane crossing gives astronomers a rare chance, just once every 42 years, to image these tiny satellites. Imke de Pater and colleagues made observations of the rings with the Keck II telescope on 28 May 2007. These observations are presented in an article appearing today (Thursday 23 August) in Science Express, the online edition of Science magazine. There, the astronomers report that the rings of micron-sized dust have changed significantly since the Voyager 2 spacecraft photographed the Uranus system 21 years ago. Imke de Pater will discuss these results and the new images during a talk today at the European Planetary Science Congress 2007 meeting in Potsdam, Germany. An image of Uranus with the rings clearly visible was taken with ISAAC on ESO's VLT in 2002. It is available in ESO Press Photo 31/02.

First Results from the UT1 Science Verification Programme

NASA Astrophysics Data System (ADS)

1998-11-01

Performance verification is a step which has regularly been employed in space missions to assess and qualify the scientific capabilities of an instrument. Within this framework, it was the goal of the Science Verification program to submit the VLT Unit Telescope No. 1 (UT1) to the scrutiny that can only be achieved in an actual attempt to produce scientifically valuable results. To this end, an attractive and diversified set of observations were planned in advance to be executed at the VLT. These Science Verification observations at VLT UT1 took place as planned in the period from August 17 to September 1, 1998, cf. the September issue of the ESO Messenger ( No. 93, p. 1 ) and ESO PR 12/98 for all details. Although the meteorological conditions on Paranal were definitely below average, the telescope worked with spectacular efficiency and performance throughout the entire period, and very valuable data were gathered. After completion of all observations, the Science Verification Team started to prepare all of the datasets for the public release that took place on October 2, 1998. The data related to the Hubble Deep Field South (now extensively observed by the Hubble Space Telescope) were made public world-wide, while the release of other data was restricted to ESO member states. With this public release ESO intended to achieve two specific goals: offer to the scientific community an early opportunity to work on valuable VLT data, and in the meantime submit the VLT to the widest possible scrutiny. With the public release, many scientists started to analyse scientifically the VLT data, and the following few examples of research programmes are meant to give a sample of the work that has been carried out on the Science Verification data during the past two months. They represent typical investigations that will be carried out in the future with the VLT. Many of these will be directed towards the distant universe, in order to gather insight on the formation and evolution of galaxies, galaxy clusters, and large scale structure. Others will concentrate on more nearby objects, including stars and nebulae in the Milky Way galaxy, and some will attempt to study our own solar system. The following six research programmes were presented at the Press Conference that took place at the ESO Headquarters in Garching (Germany) today. Deep Galaxy Counts and Photometric Redshifts in the HDF-S NIC3 Field The goal of this programme was to verify the capability of the VLT by obtaining the deepest possible ground-based images and using multicolour information to derive the redshifts (and hence the distances) of the faintest galaxies. The space distribution, luminosity and colour of these extreme objects may provide crucial information on the initial phases of the evolution of the universe. The method is known as photometric redshift determination . The VLT Test Camera was used to collect CCD images for a total of 16.6 hours in five spectral filters (U, B, V, R and I) in the so-called HDF-S NIC3 field. This is a small area (about 1 arcmin square) of the southern sky where very deep observations in the infrared bands J, H and K (1.1, 1.6 and 2.2µm, respectively) have been obtained by the Hubble Space Telescope (HST). The observations were combined and analyzed by a team of astronomers at ESO and the Observatory of Rome (Italy). Galaxies were detected in the field down to magnitude ~ 27-28. In most colours, the planned limiting values of the fluxes were successfully reached. ESO PR Photo 48a/98 ESO PR Photo 48a/98 [Preview - JPEG: 800 x 856 pix - 144k] [High-Res - JPEG: 3000 x 3210 pix - 728k] PR Photo 48a/98 shows some examples of photometric redshift determination for faint galaxies in the HDF-S NIC3 field. The filled points are the fluxes measured in the five colors observed with the VLT Test Camera (U, B, V, R and I) and in the infrared H spectral band with the NICMOS instrument on the Hubble Space Telescope. The curves constitute the best fit to the points obtained from a library of more than 400,000 synthetic spectra of galaxies at various redshifts (Fontana et al., in preparation). For most of these very faint sources, it is not possible to collect enough photons to measure the recession velocity (the redshift) by spectroscopy, even with an 8-m telescope. The redshifts and the main galaxy properties are then determined by comparing the colour observations with synthetic spectra (see PR Photo 48a/98 ). This has been done for more than one hundred galaxies in the field brighter than magnitude 26.5. Around 20 are found to be at redshifts larger than 2. The brighter ones are excellent candidates for future detailed studies with the UT1 instruments FORS1 and ISAAC. The scientists involved in this study are: Sandro D'Odorico, Richard Hook, Alvio Renzini, Piero Rosati, Rodolfo Viezzer (ESO) and Adriano Fontana, Emanuele Giallongo, Francesco Poli (Rome Observatory, Italy). A Gravitational Einstein Ring Because the gravitational pull of matter bends the path of light rays, astronomical objects - stars, galaxies and galaxy clusters - can act like lenses, which magnify and severely distort the images of galaxies behind them, producing weird pictures as in a hall of mirrors. In the most extreme case, where the foreground lensing galaxy and the background galaxy are perfectly lined up, the image of the background galaxy is stretched into a ring. Such an image is known as an Einstein ring , because the correct formula for the bending of light was first described by the famous phycisist Albert Einstein . ESO PR Photo 48b/98 ESO PR Photo 48b/98 [Preview - JPEG: 800 x 1106 pix - 952k] [High-Res - JPEG: 3000 x 4148 pix - 5.4Mb] ESO PR Photo 48c/98 ESO PR Photo 48c/98 [Preview - JPEG: 800 x 977 pix - 272k] [High-Res - JPEG: 3000 x 3664 pix - 1.4Mb] PR Photo 48b/98 (left) shows a new, true colour image of an Einstein ring (upper centre of photo), first discovered at ESO in 1995. The ring, which is the stretched image of a galaxy far out in the Universe, stands out clearly in green, and the red galaxy inside the ring is the lens. The discovery image was very faint, but this new picture, taken with the VLT during the Science Verification Programme allows a much clearer view of the ring because of the great light-gathering capacity of the telescope and, not least, because of the superb image quality. In Photo 48c/98 (right), four images illustrate the deduced model of the lensing effect. In the upper left, the observed ring has been enlarged and the image of the lensing galaxy removed by image processing. Below it is a model of the gravitational field (potential) around this galaxy along with the "true" image of the background galaxy shown. At the lower right is the resulting gravitationally magnified and distorted image of the background galaxy, which to the upper right has been de-sharpened to the same image quality as the observed image. The similarity between the two is most convincing. The picture shows a new, true colour image of an Einstein ring, first discovered at ESO in 1995. The ring, which is the stretched image of a galaxy far out in the Universe, stands out clearly in green, and the red galaxy inside the ring is the lens. The discovery image was very faint, but this new picture, taken with the VLT during the Science Verification Programme allows a much clearer view of the ring because of the great light-gathering capacity the telescope and, not least, because of the superb image quality. Gravitational lensing provides a very useful tool with which to study the Universe. As "weighing scales", it provides a measure of the mass within the lensing body, and as a "magnifying glass", it allows us to see details in objects which would otherwise be beyond the reach of current telescopes. This new detailed picture has allowed a much more accurate measurement of the mass of the lensing galaxy, revealing the presence of vast quantities of "unseen" matter, five times more than if just the light from the galaxy is taken into account. This additional material represents some of the Universe's dark matter . The gravitational lens action is also magnifying the background object by a factor of ten, providing an unparalleled view of this very distant galaxy which is in a stage of active star-formation. The scientists involved in this study are : Palle Møller (ESO), Stephen J. Warren (Blackett Laboratory, Imperial College, UK), Paul C. Hewett (Institute of Astronomy, Cambridge, UK) and Geraint F. Lewis (Dept. of Physics and Astronomy, University of Victoria, Canada). An Extremely Red Galaxy One of the main goals of modern cosmology is to understand when and how the galaxies formed. In the very last years, many high-redshift (i.e. very distant) galaxies have been found, suggesting that some galaxies were already assembled, when the Universe was much younger than now. None of these high-redshift galaxies have ever been found to be a bona-fide red elliptical galaxy . The VLT, however, with its very good capabilities for infrared observations, is an ideal instrument to investigate when and how the red elliptical galaxies formed. The VLT Science Verification images have provided unique multicolour information about an extremely red galaxy that was originally (Treu et al., 1998, A&A Letters, Vol. 340, p. 10) identified on the Hubble Deep Field South (HDF-S) Test Image. This galaxy is shown in PR Photo 48d/98 that is an enlargment from ESO PR Photo 35b/98. It was detected on Near-IR images and also on images obtained in the optical part of the spectrum, at the very faint limit of magnitude B ~ 29 in the blue. However, this galaxy has not been detected in the near-ultraviolet band. ESO PR Photo 48d/98 ESO PR Photo 48d/98 [Preview - JPEG: 800 x 594 pix - 264k] [High-Res - JPEG: 3000 x 2229 pix - 1.8Mb] ESO PR Photo 48e/98 ESO PR Photo 48e/98 [Preview - JPEG: 800 x 942 pix - 96k] [High-Res - JPEG: 3000 x 3533 pix - 576k] PR Photo 48d/98 (left) shows the very red galaxy (at the arrow) in the Hubble Deep Field South , discussed here. Photo 48e/98 (right) is the spectrum of a typical elliptical galaxy, redshifted to z = 1.8 and compared with the brightness of the galaxy in different wavebands (crosses), as measured during the VLT SV programme and the Hubble Deep Field South Test Program (the cross to the right). The arrow indicates the upper limit by the VLT SV in the ultraviolet band. It can be seen that these observations are fully consistent with the object being an old, elliptical galaxy at the high redshift of z=1.8 , i.e. at an epoch, when the Universe was much younger than now. The new ISAAC instrument at VLT UT1 will be able to obtain an infrared spectrum of this galaxy and thus to affirm or refute this provisional conclusion. The colours measured at the VLT and on the HST Test Image are very well matched by those of an old elliptical galaxy at redshift z ~ 1.8 ; see Photo 48e/98 . All the available evidence is thus consistent with this object being an elliptical galaxy with the highest-known redshift for this galaxy type. A preliminary analysis of Hubble Deep Field South data, just released, seems to support this hypothesis. If these conclusions are confirmed by direct measurement of its spectrum, this galaxy must already have been "old" (i.e. significantly evolved) when the Universe had an age of only about one fifth of its present value. A spectroscopic confirmation is still outstanding, but is now possible with the ISAAC instrument at VLT UT1. A positive result would demonstrate that elliptical galaxies can form very early in the history of the Universe. The scientists involved in this study are: Massimo Stiavelli, Tommaso Treu (also Scuola Normale Superiore, Italy), Stefano Casertano, Mark Dickinson, Henry Ferguson, Andrew Fruchter, Crystal Martin (STSci, Baltimore, USA), Piero Rosati and Rodolfo Viezzer (ESO), Marcella Carollo (Johns Hopkins University, Baltimore, USA) and Henry Tieplitz (NASA, Goddard Space Flight Center, Greenbelt, USA). Lyman-alpha Companions and Extended Nebulosity around a Quasar at Redshift z=2.2 In current theories of galaxy formation, luminous galaxies we see to-day were built up through repeated merging of smaller protogalactic clumps. Quasars, prodigious sources pouring out 100 to 1000 times as much light as an entire galaxy, have been used as markers of galaxy formation activity and have guided astronomers in their hunting of primeval galaxies and large-scale structures at high redshift. A supermassive black-hole, swallowing stars, gas and dust, is thought to be the engine powering a quasar and the interaction of the galaxy hosting the black-hole with neighboring galaxies is expected to play a key role in "feeding the monster". At intermediate redshift, a large fraction of radio-loud quasars and radio galaxies inhabit rich clusters of galaxies, whereas radio-quiet quasars are rarely found in very rich environments. Furthermore, tidal interaction between quasars and their nearby companions is also the favoured explanation for the presence of large gaseous nebulosities associated with radio-loud quasars and radio galaxies. At high redshift, searches for Lyman-alpha quasar companions and emission-line nebulosities show strong similarities with those seen at lower redshift, although the detection rate is lower. ESO PR Photo 48f/98 ESO PR Photo 48f/98 [Preview - JPEG: 800 x 977 pix - 184k] [High-Res - JPEG: 3000 x 3662 pix - 1.1Mb] ESO PR Photo 48g/98 ESO PR Photo 48g/98 [Preview - JPEG: 800 x 966 pix - 328k] [High-Res - JPEG: 3000 x 3621 pix - 1.8Mb] PR Photo 48f/98 (left) is a false-colour reproduction of a B-band image of the field around the radio-weak quasar J2233-606 in the Hubble Deep Field South (HDF-S) . Photo 48g/98 (right) represents emission from the same direction at a wavelength that corresponds to Lyman-alpha emission at the redshift ( z = 2.2 ) of the quasar. Three Lyman-alpha candidate companions are indicated with arrows. Note also the extended nebulosity around the quasar. A search for Lyman-alpha companions to the radio-weak quasar J2233-606 in the Hubble Deep Field South (HDF-S) was conducted during the VLT UT1 SV programme in a small field of 1.2 x 1.3 arcmin 2 , centered on the quasar. Candidate Lyman-alpha companions were identified by subtracting a broad-band B (blue) image, that traces the galaxy stellar populations, from a narrow-band image, spectrally centered on the redshifted, narrow Lyman-alpha emission line of the quasar ( z = 2.2 ). Three Lyman-alpha candidate companions were discovered at angular distances of 15 to 23 arcsec, or 200 to 300 kpc (650,000 to 1,000,000 light-years) at the distance corresponding to the quasar redshift. The emission lines are very strong, relative to the continuum emission of the galaxies - this could be a consequence of the strong ionizing radiation field of the quasar. These companions to the quasar may trace a large-scale structure which would extend over larger distances beyond the observed, small field. Even more striking is the presence of a very extended nebulosity whose size (120 kpc x 160 kpc) and Lyman-alpha luminosity (3 x 10 44 erg/cm 2 /s) are among the largest observed around radio galaxies and radio-loud quasars, but rarely seen around a radio-weak quasar. Tidal interaction between the northern, very nearby companion and the quasar is clearly present: the companion is embedded in the quasar nebulosity, most of its gas has been stripped and lies in a tail westwards of the galaxy. The scientists involved in this study are: Jacqueline Bergeron (ESO), Stefano Cristiani, Stephane Arnouts, Gianni Fasano (Padova, Italy) and Patrick Petitjean (Institut d'Astrophysique, Paris, France). Very Distant Galaxy Clusters During the past years, it has become possible to detect and subsequently study progressively more distant clusters of galaxies. For this research programme, UT1 Science Verification data were used, in combination with data obtained with the SOFI instrument at the ESO New Technology Telescope (NTT) at La Silla, to confirm the existence of two very distant galaxy clusters at redshift z ~ 1 , that had originally been detected in the ESO Imaging Survey. This redshift corresponds to an epoch when the age of the Universe was only two-thirds of the present. ESO PR Photo 48h/98 ESO PR Photo 48h/98 [Preview - JPEG: 800 x 917 pix - 896k] [High-Res - JPEG: 3000 x 3438 pix - 6.0Mb] PR Photo 48h/98 (left) is a colour composite that shows the now confirmed cluster EIS0046-2930 . The image has been produced by combining the V (green-yellow), R (red) and I (Near-IR) exposures with the Test Camera obtained during the VLT-UT1 Science Verification. The yellow-orange galaxies are the cluster members and the bluer objects are galaxies belonging to the general field population. The cluster center is at the location of the largest (yellow-orange) cluster galaxy to the left of the center of the image. The field measures 90 x 90 arcsec. This was achieved by the detection of a spatial excess density of galaxies, with measured colour equal to that of elliptical galaxies at this redshift, as established by counts in the respective sky areas. The field of one these clusters is shown in PR Photo 48h/98 . These new data show that the VLT will most certainly play a major role in the studies of the cluster galaxy population in such distant systems. This will contribute to shed important new light on the evolution of galaxies. Furthermore, the VLT clearly has the potential to identify and confirm the reality of many more such clusters and thereby to increase considerably the number of known objects. This will be important in order to determine more accurate values of the basic cosmological constants, and thus for our understanding of the evolution of the Universe as a whole. The presentation was made by Lisbeth Fogh Olsen (Copenhagen Observatory, Denmark, and ESO) on behalf of the scientists involved in this study. Icy Planets in the Outer Solar System Observations with large optical telescopes during the past years have begun to cast more light on the still very little known, distant icy planets in the outer solar system. Until November 1998, about 70 of these have been discovered outside the orbit of Neptune (between 30 and 50 AU, or 4,500 to 7,500 million km, from the Sun). They are accordingly referred to as Trans-Neptunian Objects (TNOs) . Those found so far are believed to represent the "tip of the iceberg" of a large population of such objects belonging to the so-called Kuiper Belt . This is a roughly disk-shaped region between about 50 and 120 AU (about 7,500 to 18,000 million km) from the Sun, in which remnant bodies from the formation of the solar system are thought to be present. From their measured brightness and the distance, it is found that most known TNOs have diameters of the order of a few hundred kilometres. About half of those known move in elongated Pluto-like orbits, the others move somewhat further out in stable, circular orbits. During the two-week Science Verification programme, approximately 200 minutes were spent on a small observing programme aimed at obtaining images of some TNOs in different wavebands (B, V, R and I). Since this programme was primarily designed as a back-up to be executed during less favourable atmospheric conditions, some of the observations could not be used. However, images of three faint TNOs were recorded during an excellent series of 1-10 min exposures. From these data, it was possible to measure quite accurate magnitudes (and thus approximate sizes) and to determine their colours. One of them, 1996 TL66, was among the bluest TNOs ever observed. It is believed that this is because its surface has undergone recent transformation, possibly due to collisions with other objects or the breaking-off of small pieces from the surface, in both cases revealing "fresh" layers below. The combination of all available exposures made it possible to look for faint and tenous atmospheres around these TNOs, but none were found. These results show that it is possible, with little effort and even under quite unfavourable observing conditions, to obtain valuable information with the VLT about icy objects in the outer solar system. Of even greater interest will be future spectroscopic observations with FORS and ISAAC that will allow to study the surface composition in some detail, with the potential of providing direct information about (nearly?) pristine material from the early phases of the solar system. The scientists involved in this study are: Olivier Hainaut, Hermann Boehnhardt, Catherine Delahodde and Richard West (ESO) and Karen Meech (Institute of Astronomy, Hawaii, USA). How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

The Paranal Metamorphosis

NASA Astrophysics Data System (ADS)

2000-12-01

Some years ago, the Paranal mountain was still a remote and inhospitable site, some 12 km from the Pacific Coast in the dry Atacama desert in northern Chile. Few aircraft passengers flying along that coast would notice anything particular about this peak, except perhaps that it was one of the tallest in the steep coastal mountain range. Already in the early 1960's, pioneer astronomers crossed this desolate region in search of suitable sites for future observatories. One of them, Jürgen Stock , did notice the Paranal peak as a possible candidate. However, without any water in this extremely dry area, how could any people, even hardy scientists, ever live up there? He then went on to discover La Silla, where ESO decided to build its first observatory in 1964. ESO presence at Paranal from 1983 In the beginning of the 1980's, when the main construction phase at La Silla was over, ESO launched a thorough search for the best possible site for the next-generation telescope, already then known as the "Very Large Telescope", or VLT. During this campaign, the Paranal mountain was visited by a small search troupe from this organisation, including the ESO Director General (1975 - 1987), Lo Woltjer . The first test measurements indicated a great potential for astronomical observations, both in term of clear nights and low humidity, the latter being particularly important for infrared observations. From 1983, ESO maintained a small site testing station at the top of Paranal. The meteorological conditions were registered around the clock and the atmospheric transparency and stability were recorded each night. At that time, the mountain Vizcachas, a site near ESO's first observatory, La Silla, and some 600 km further south, was also considered a possible site for the VLT. The data from the two sites were therefore carefully compared over a period of several years. Paranal becomes the site for the VLT Following the decision in December 1987 by the ESO Council to embark upon the VLT Project (with Massimo Tarenghi as Project Manager), Paranal was chosen as the site in 1991. In the meantime, the Chilean Government had resolved to donate an area of approx. 700 km 2 around this mountain to ESO, and construction work started the same year. The left photo shows Paranal at this stage. The development of Paranal included much blasting and heavy earthwork; about 350,000 m 3 of rock had to be moved to achieve a flat platform of sufficient size to house the various components of the VLT and, in particular, the spacious VLT Interferometer. The situation, right after this work, is depicted in the middle photo from 1994. An operational observatory The construction at Paranal progressed at high speed. It is hard to believe that just four years later, "First Light" was achieved with the first 8.2-m telescope, ANTU, in May 1998. Then followed KUEYEN (March 1999), MELIPAL (January 2000) and YEPUN (September 2000). The first two telescopes have now been "taken over" by the astronomers and Paranal has become an operational observatory with Roberto Gilmozzi as Director. Large numbers of scientists in the ESO member countries, and even more within international collaborations, are busy producing exciting research results, now increasingly visible in the world's professional journals and some of which are announced in the ESO Press Releases. The other two will soon be equipped with high-quality astronomical instruments; the first will be VIMOS at MELIPAL in the beginning of 2001. Both telescopes will become fully available to the astronomical community in the course of 2001. And now the VLT Interferometer... The next decisive step will happen already in early 2001, when the VLT Interferometer is expected to see "First Fringes", the equivalent of "First Light" for this type of facility. This is when two small "siderostats" on the Paranal platform will track and capture the light from one and the same (bright) star, directing the two beams towards the underground Interferometric Laboratory via a series of intermediate mirrors. Here, the critical technical elements are the "delay lines" in the Interferometric Tunnel, cf. ESO Press Photos 26a-e/00.They have already undergone the first tests with very positive results, so the ESO staff is in a confident mood. Later in 2001, two of the 8.2-m Unit Telescopes will be coupled and interferometric test observations will be made on faint celestial objects. In the next years, the three movable 1.8-m Auxiliary Telescopes will be installed on the Paranal "railroad" and the VLT Interferometer will progressively enter into full operation. From a lonely mountain top to the world's foremost optical/infrared astronomical observatory, Paranal has indeed come a long way! This is the caption to ESO PR Photo 36/00 . It may be reproduced, if credit is given to the European Southern Observatory.

Controlled by Distant Explosions

NASA Astrophysics Data System (ADS)

2007-03-01

VLT Automatically Takes Detailed Spectra of Gamma-Ray Burst Afterglows Only Minutes After Discovery A time-series of high-resolution spectra in the optical and ultraviolet has twice been obtained just a few minutes after the detection of a gamma-ray bust explosion in a distant galaxy. The international team of astronomers responsible for these observations derived new conclusive evidence about the nature of the surroundings of these powerful explosions linked to the death of massive stars. At 11:08 pm on 17 April 2006, an alarm rang in the Control Room of ESO's Very Large Telescope on Paranal, Chile. Fortunately, it did not announce any catastrophe on the mountain, nor with one of the world's largest telescopes. Instead, it signalled the doom of a massive star, 9.3 billion light-years away, whose final scream of agony - a powerful burst of gamma rays - had been recorded by the Swift satellite only two minutes earlier. The alarm was triggered by the activation of the VLT Rapid Response Mode, a novel system that allows for robotic observations without any human intervention, except for the alignment of the spectrograph slit. ESO PR Photo 17a/07 ESO PR Photo 17a/07 Triggered by an Explosion Starting less than 10 minutes after the Swift detection, a series of spectra of increasing integration times (3, 5, 10, 20, 40 and 80 minutes) were taken with the Ultraviolet and Visual Echelle Spectrograph (UVES), mounted on Kueyen, the second Unit Telescope of the VLT. "With the Rapid Response Mode, the VLT is directly controlled by a distant explosion," said ESO astronomer Paul Vreeswijk, who requested the observations and is lead-author of the paper reporting the results. "All I really had to do, once I was informed of the gamma-ray burst detection, was to phone the staff astronomers at the Paranal Observatory, Stefano Bagnulo and Stan Stefl, to check that everything was fine." The first spectrum of this time series was the quickest ever taken of a gamma-ray burst afterglow, let alone with an instrument such as UVES, which is capable of splitting the afterglow light with uttermost precision. What is more, this amazing record was broken less than two months later by the same team. On 7 June 2006, the Rapid-Response Mode triggered UVES observations of the afterglow of an even more distant gamma-ray source a mere 7.5 minutes after its detection by the Swift satellite. Gamma-ray bursts are the most intense explosions in the Universe. They are also very brief. They randomly occur in galaxies in the distant Universe and, after the energetic gamma-ray emission has ceased, they radiate an afterglow flux at longer wavelengths (i.e. lower energies). They are classified as long and short bursts according to their duration and burst energetics, but hybrid bursts have also been discovered (see ESO PR 49/06). The scientific community agrees that gamma-ray bursts are associated with the formation of black holes, but the exact nature of the bursts remains enigmatic. ESO PR Photo 17b/07 ESO PR Photo 17b/07 Kueyen at Night Because a gamma-ray burst typically occurs at very large distances, its optical afterglow is faint. In addition, it fades very rapidly: in only a few hours the optical afterglow brightness can fade by as much as a factor of 500. This makes detailed spectral analysis possible only for a few hours after the gamma-ray detection, even with large telescopes. During the first minutes and hours after the explosion, there is also the important opportunity to observe time-dependent phenomena related to the influence of the explosion on its surroundings. The technical challenge therefore consists of obtaining high-resolution spectroscopy with 8-10 m class telescopes as quickly as possible. "The afterglow spectra provide a wealth of information about the composition of the interstellar medium of the galaxy in which the star exploded. Some of us even hoped to characterize the gas in the vicinity of the explosion," said team member Cédric Ledoux (ESO). ESO PR Photo 17c/07 ESO PR Photo 17c/07 The Kueyen Control Room The Rapid Response Mode UVES observations of 17 April 2006 allowed the astronomers to discover variable spectral features associated with a huge gas cloud in the host galaxy of the gamma-ray burst. The cloud was found to be neutral but excited by the radiation from the UV afterglow light. From detailed modelling of these observations, the astronomers were able - for the first time - to not only pinpoint the physical mechanism responsible for the excitation of the atoms, but also determine the distance of the cloud to the GRB. This distance was found to be 5,500 light-years, which is much further out than was previously thought. Either this is a special case, or the common picture that the features seen in optical spectra originate very close to the explosion has to be revised. As a comparison, this distance of 5,500 light-years is more than one fifth of that between the Sun and the centre of our Galaxy. "All the material in this region of space must have been ionised, that is, the atoms have been stripped of most if not all of their electrons," said co-author Alain Smette (ESO). "Were there any life in this region of the Universe, it would most probably have been eradicated." "With the Rapid-Response Mode of the VLT, we are really looking at gamma-ray bursts as quickly as possible," said team member Andreas Jaunsen from the University of Oslo (Norway). "This is crucial if we are to unravel the mysteries of these gigantic explosions and their links with black holes!" More Information The two gamma-ray bursts were discovered with the NASA/ASI/PPARC Swift satellite, which is dedicated to the discovery of these powerful cosmic explosions. Preliminary reports on these observations have been presented in GCN GRB Observation Reports 4974 and 5237. A paper is also in press in the journal Astronomy & Astrophysics ("Rapid-Response Mode VLT/UVES spectroscopy of GRB 060418 - Conclusive evidence for UV pumping from the time evolution of Fe II and Ni II excited- and metastable-level populations" by P. M. Vreeswijk et al.). DOI: 10.1051/0004-6361:20066780 The team is composed of Paul Vreeswijk, Cédric Ledoux, Alain Smette, Andreas Kaufer and Palle Møller (ESO), Sara Ellison (University of Victoria, Canada), Andreas Jaunsen (University of Oslo, Norway), Morten Andersen (AIP, Potsdam, Germany), Andrew Fruchter (STScI, Baltimore, USA), Johan Fynbo and Jens Hjorth (Dark Cosmology Centre, Copenhagen, Denmark), Patrick Petitjean (IAP, Paris, France), Sandra Savaglio (MPE, Garching, Germany), and Ralph Wijers (Astronomical Institute, University of Amsterdam, The Netherlands). Paul Vreeswijk was at the time of this study also associated with the Universidad de Chile, Santiago.

Black hole outflows from Centaurus A detected with APEX

NASA Astrophysics Data System (ADS)

2009-01-01

Astronomers have a new insight into the active galaxy Centaurus A (NGC 5128), as the jets and lobes emanating from the central black hole have been imaged at submillimetre wavelengths for the first time. The new data, from the Atacama Pathfinder Experiment (APEX) telescope in Chile, which is operated by ESO, have been combined with visible and X-ray wavelengths to produce this striking new image. ESO PR Photo 03a/09 Centaurus A Centaurus A is our nearest giant galaxy, at a distance of about 13 million light-years in the southern constellation of Centaurus. It is an elliptical galaxy, currently merging with a companion spiral galaxy, resulting in areas of intense star formation and making it one of the most spectacular objects in the sky. Centaurus A hosts a very active and highly luminous central region, caused by the presence of a supermassive black hole (see ESO 04/01), and is the source of strong radio and X-ray emission. In the image, we see the dust ring encircling the giant galaxy, and the fast-moving radio jets ejected from the galaxy centre, signatures of the supermassive black hole at the heart of Centaurus A. In submillimetre light, we see not only the heat glow from the central dust disc, but also the emission from the central radio source and - for the first time in the submillimetre - the inner radio lobes north and south of the disc. Measurements of this emission, which occurs when fast-moving electrons spiral around the lines of a magnetic field, reveal that the material in the jet is travelling at approximately half the speed of light. In the X-ray emission, we see the jets emerging from the centre of Centaurus A and, to the lower right of the galaxy, the glow where the expanding lobe collides with the surrounding gas, creating a shockwave. The Large APEX Bolometer Camera (LABOCA), built by the Max-Planck-Institute for Radio Astronomy (MPIfR), is mounted on APEX, a 12-metre diameter submillimetre-wavelength telescope located on the 5000 m high plateau of Chajnantor in the Chilean Atacama region. APEX is a collaboration between the MPIfR, the Onsala Space Observatory and ESO. The telescope is based on a prototype antenna constructed for the next generation Atacama Large Millimeter/submillimeter Array (ALMA) project. Operation of APEX at Chajnantor is entrusted to ESO. The APEX observations of Centaurus A are presented in the paper by Axel Weiss et al. 2008, LABOCA observations of nearby, active galaxies, A&A, 490, 77-86. A German-language page about this image, "Radiosignale aus der Richtung des Schwarzen Lochs im Zentrum von Centaurus A", is available on the MPIfR website.

Edge-on Galaxy

NASA Technical Reports Server (NTRS)

1999-01-01

NASA's Hubble Space Telescope has imaged an unusual edge-on galaxy, revealing remarkable details of its warped dusty disc and showing how colliding galaxies trigger the birth of new stars.

The image, taken by Hubble's Wide Field and Planetary Camera 2 (WFPC2), is online at http://heritage.stsci.edu and http://www.jpl.nasa.gov/images/wfpc. The camera was designed and built by NASA's Jet Propulsion Laboratory, Pasadena, Calif. During observations of the galaxy, the camera passed a milestone, taking its 100,000th image since shuttle astronauts installed it in Hubble in 1993.

The dust and spiral arms of normal spiral galaxies, like our Milky Way, look flat when seen edge- on. The new image of the galaxy ESO 510-G13 shows an unusual twisted disc structure, first seen in ground-based photographs taken at the European Southern Observatory in Chile. ESO 510-G13 lies in the southern constellation Hydra, some 150 million light-years from Earth. Details of the galaxy's structure are visible because interstellar dust clouds that trace its disc are silhouetted from behind by light from the galaxy's bright, smooth central bulge.

The strong warping of the disc indicates that ESO 510-G13 has recently collided with a nearby galaxy and is in the process of swallowing it. Gravitational forces distort galaxies as their stars, gas, and dust merge over millions of years. When the disturbances die out, ESO 510-G13 will be a single galaxy.

The galaxy's outer regions, especially on the right side of the image, show dark dust and bright clouds of blue stars. This indicates that hot, young stars are forming in the twisted disc. Astronomers believe star formation may be triggered when galaxies collide and their interstellar clouds are compressed.

The Hubble Heritage Team used WFPC2 to observe ESO 510-G13 in April 2001. Pictures obtained through blue, green, and red filters were combined to make this color-composite image, which emphasizes the contrast between the dusty spiral arms, the bright bulge, and the blue star-forming regions. Additional information about the Hubble Space Telescope is online at http://www.stsci.edu. More information about the Wide Field and Planetary Camera 2 is at http://wfpc2.jpl.nasa.gov.

The Space Telescope Science Institute, Baltimore, Md., manages space operations for Hubble for NASA's Office of Space Science, Washington, D.C. The institute is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract with the Goddard Space Flight Center, Greenbelt, Md. Hubble is a project of international cooperation between NASA and the European Space Agency. JPL is a division of the California Institute of Technology in Pasadena.

First-Ever Census of Variable Mira-Type Stars in Galaxy Outside the Local Group

NASA Astrophysics Data System (ADS)

2003-05-01

First-Ever Census of Variable Mira-Type Stars in Galaxy Outsidethe Local Group Summary An international team led by ESO astronomer Marina Rejkuba [1] has discovered more than 1000 luminous red variable stars in the nearby elliptical galaxy Centaurus A (NGC 5128) . Brightness changes and periods of these stars were measured accurately and reveal that they are mostly cool long-period variable stars of the so-called "Mira-type" . The observed variability is caused by stellar pulsation. This is the first time a detailed census of variable stars has been accomplished for a galaxy outside the Local Group of Galaxies (of which the Milky Way galaxy in which we live is a member). It also opens an entirely new window towards the detailed study of stellar content and evolution of giant elliptical galaxies . These massive objects are presumed to play a major role in the gravitational assembly of galaxy clusters in the Universe (especially during the early phases). This unprecedented research project is based on near-infrared observations obtained over more than three years with the ISAAC multi-mode instrument at the 8.2-m VLT ANTU telescope at the ESO Paranal Observatory . PR Photo 14a/03 : Colour image of the peculiar galaxy Centaurus A . PR Photo 14b/03 : Location of the fields in Centaurus A, now studied. PR Photo 14c/03 : "Field 1" in Centaurus A (visual light; FORS1). PR Photo 14d/03 : "Field 2" in Centaurus A (visual light; FORS1). PR Photo 14e/03 : "Field 1" in Centaurus A (near-infrared; ISAAC). PR Photo 14f/03 : "Field 2" in Centaurus A (near-infrared; ISAAC). PR Photo 14g/03 : Light variation of six variable stars in Centaurus A PR Photo 14h/03 : Light variation of stars in Centaurus A (Animated GIF) PR Photo 14i/03 : Light curves of four variable stars in Centaurus A. Mira-type variable stars Among the stars that are visible in the sky to the unaided eye, roughly one out of three hundred (0.3%) displays brightness variations and is referred to by astronomers as a "variable star". The percentage is much higher among large, cool stars ("red giants") - in fact, almost all luminous stars of that type are variable. Such stars are known as Mira-variables ; the name comes from the most prominent member of this class, Omicron Ceti in the constellation Cetus (The Whale), also known as "Stella Mira" (The Wonderful Star). Its brightness changes with a period of 332 days and it is about 1500 times brighter at maximum (visible magnitude 2 and one of the fifty brightest stars in the sky) than at minimum (magnitude 10 and only visible in small telescopes) [2]. Stars like Omicron Ceti are nearing the end of their life. They are very large and have sizes from a few hundred to about a thousand times that of the Sun. The brightness variation is due to pulsations during which the star's temperature and size change dramatically. In the following evolutionary phase, Mira-variables will shed their outer layers into surrounding space and become visible as planetary nebulae with a hot and compact star (a "white dwarf") at the middle of a nebula of gas and dust (cf. the "Dumbbell Nebula" - ESO PR Photo 38a-b/98 ). Several thousand Mira-type stars are currently known in the Milky Way galaxy and a few hundred have been found in other nearby galaxies, including the Magellanic Clouds. The peculiar galaxy Centaurus A ESO PR Photo 14a/03 ESO PR Photo 14a/03 [Preview - JPEG: 400 x 451 pix - 53k [Normal - JPEG: 800 x 903 pix - 528k] [Hi-Res - JPEG: 3612 x 4075 pix - 8.4M] ESO PR Photo 14b/03 ESO PR Photo 14b/03 [Preview - JPEG: 570 x 400 pix - 52k [Normal - JPEG: 1140 x 800 pix - 392k] ESO PR Photo 14c/03 ESO PR Photo 14c/03 [Preview - JPEG: 400 x 451 pix - 61k [Normal - JPEG: 800 x 903 pix - 768k] ESO PR Photo 14d/03 ESO PR Photo 14d/03 [Preview - JPEG: 400 x 451 pix - 56k [Normal - JPEG: 800 x 903 pix - 760k] Captions : PR Photo 14a/03 is a colour composite photo of the peculiar galaxy Centaurus A (NGC 5128) , obtained with the Wide-Field Imager (WFI) camera at the ESO/MPG 2.2-m telescope on La Silla. It is based on a total of nine 3-min exposures made on March 25, 1999, through different broad-band optical filters (B(lue) - total exposure time 9 min - central wavelength 456 nm - here rendered as blue; V(isual) - 540 nm - 9 min - green; I(nfrared) - 784 nm - 9 min - red); it was prepared from files in the ESO Science Data Archive by ESO-astronomer Benoît Vandame . The elliptical shape and the central dust band, the imprint of a galaxy collision, are well visible. PR Photo 14b/03 identifies the two regions of Centaurus A (the rectangles in the upper left and lower right inserts) in which a search for variable stars was made during the present research project: "Field 1" is located in an area north-east of the center in which many young stars are present. This is also the direction in which an outflow ("jet") is seen on deep optical and radio images. "Field 2" is positioned in the galaxy's halo, south of the centre. High-resolution, very deep colour photos of these two fields and their immediate surroundings are shown in PR Photos 14c-d/03 . They were produced by means of CCD-frames obtained in July 1999 through U- and V-band optical filters with the VLT FORS1 multi-mode instrument at the 8.2-m VLT ANTU telescope on Paranal. Note the great variety of object types and colours, including many background galaxies which are seen through these less dense regions of Centaurus A . The total exposure time was 30 min in each filter and the seeing was excellent, 0.5 arcsec. The original pixel size is 0.196 arcsec and the fields measure 6.7 x 6.7 arcmin 2 (2048 x 2048 pix 2 ). North is up and East is left on all photos. Centaurus A (NGC 5128) is the nearest giant galaxy, at a distance of about 13 million light-years. It is located outside the Local Group of Galaxies to which our own galaxy, the Milky Way, and its satellite galaxies, the Magellanic Clouds, belong. Centaurus A is seen in the direction of the southern constellation Centaurus. It is of elliptical shape and is currently merging with a companion galaxy, making it one of the most spectacular objects in the sky, cf. PR Photo 14a/03 . It possesses a very heavy black hole at its centre (see ESO PR 04/01 ) and is a source of strong radio and X-ray emission. During the present research programme, two regions in Centaurus A were searched for stars of variable brightness; they are located in the periphery of this peculiar galaxy, cf. PR Photos 14b-d/03 . An outer field ("Field 1") coincides with a stellar shell with many blue and luminous stars produced by the on-going galaxy merger; it lies at a distance of 57,000 light-years from the centre. The inner field ("Field 2") is more crowded and is situated at a projected distance of about 30,000 light-years from the centre.. Three years of VLT observations ESO PR Photo 14e/03 ESO PR Photo 14e/03 [Preview - JPEG: 400 x 447 pix - 120k [Normal - JPEG: 800 x 894 pix - 992k] ESO PR Photo 14f/03 ESO PR Photo 14f/03 [Preview - JPEG: 400 x 450 pix - 96k [Normal - JPEG: 800 x 899 pix - 912k] Caption : PR Photos 14e-f/03 are colour composites of two small fields ("Field 1" and "Field 2") in the peculiar galaxy Centaurus A (NGC 5128) , based on exposures through three near-infrared filters (the J-, H- and K-bands at wavelengths 1.2, 1.6 and 2.2 µm, respectively) with the ISAAC multi-mode instrument at the 8.2-m VLT ANTU telescope at the ESO Paranal observatory. The corresponding areas are outlined within the two inserts in PR Photo 14b/03 and may be compared with the visual images from FORS1 ( PR Photos 14c-d/03 ). These ISAAC photos are the deepest near-infrared images ever obtained in this galaxy and show thousands of its stars of different colours. In the present colour-coding, the redder an image, the cooler is the star. The original pixel size is 0.15 arcsec and both fields measure 2.5 x 2.5 arcmin 2. North is up and East is left. Under normal circumstances, any team of professional astronomers will have access to the largest telescopes in the world for only a very limited number of consecutive nights each year. However, extensive searches for variable stars like the present require repeated observations lasting minutes-to-hours over periods of months-to-years. It is thus not feasible to perform such observations in the classical way in which the astronomers travel to the telescope each time. Fortunately, the operational system of the VLT at the ESO Paranal Observatory (Chile) is also geared to encompass this kind of long-term programme. Between April 1999 and July 2002, the 8.2-m VLT ANTU telescope on Cerro Paranal in Chile) was operated in service mode on many occasions to obtain K-band images of the two fields in Centaurus A by means of the near-infrared ISAAC multi-mode instrument. Each field was observed over 20 times in the course of this three-year period ; some of the images were obtained during exceptional seeing conditions of 0.30 arcsec. One set of complementary optical images was obtained with the FORS1 multi-mode instrument (also on VLT ANTU) in July 1999. Each image from the ISAAC instrument covers a sky field measuring 2.5 x 2.5 arcmin 2. The combined images, encompassing a total exposure of 20 hours are indeed the deepest infrared images ever made of the halo of any galaxy as distant as Centaurus A , about 13 million light-years. Discovering one thousand Mira variables ESO PR Photo 14g/03 ESO PR Photo 14g/03 [Preview - JPEG: 400 x 480 pix - 61k [Normal - JPEG: 800 x 961 pix - 808k] ESO PR Photo 14h/03 ESO PR Photo 14h/03 [Animated GIF: 263 x 267 pix - 56k ESO PR Photo 14i/03 ESO PR Photo 14i/03 [Preview - JPEG: 480 x 400 pix - 33k [Normal - JPEG: 959 x 800 pix - 152k] Captions : PR Photo 14g/03 shows a zoomed-in area within "Field 2" in Centaurus A , from the ISAAC colour image shown in PR Photo 14e/03 . Nearly all red stars in this area are of the variable Mira-type. The brightness variation of some stars (labelled A-D) is demonstrated in the animated-GIF image PR Photo 14h/03 . The corresponding light curves (brightness over the pulsation period) are shown in PR Photo 14i/03 . Here the abscissa indicates the pulsation phase (one full period corresponds to the interval from 0 to 1) and the ordinate unit is near-infrared K s -magnitude. One magnitude corresponds to a difference in brightness of a factor 2.5. Once the lengthy observations were completed, two further steps were needed to identify the variable stars in Centaurus A . First, each ISAAC frame was individually processed to identify the thousands and thousands of faint point-like images (stars) visible in these fields. Next, all images were compared using a special software package ("DAOPHOT") to measure the brightness of all these stars in the different frames, i.e., as a function of time. While most stars in these fields as expected were found to have constant brightness, more than 1000 stars displayed variations in brightness with time; this is by far the largest number of variable stars ever discovered in a galaxy outside the Local Group of Galaxies. The detailed analysis of this enormous dataset took more than a year. Most of the variable stars were found to be of the Mira-type and their light curves (brightness over the pulsation period) were measured, cf. PR Photo 14i/03 . For each of them, values of the characterising parameters, the period (days) and brightness amplitude (magnitudes) were determined. A catalogue of the newly discovered variable stars in Centaurus A has now been made available to the astronomical community via the European research journal Astronomy & Astrophysics. Marina Rejkuba is pleased and thankful: "We are really very fortunate to have carried out this ambitious project so successfully. It all depended critically on different factors: the repeated granting of crucial observing time by the ESO Observing Programmes Committee over different observing periods in the face of rigorous international competition, the stability and reliability of the telescope and the ISAAC instrument over a period of more than three years and, not least, the excellent quality of the service mode observations, so efficiently performed by the staff at the Paranal Observatory." What have we learned about Centaurus A? The present study of variable stars in this giant elliptical galaxy is the first-ever of its kind. Although the evaluation of the very large observational data material is still not finished, it has already led to a number of very useful scientific results. Confirmation of the presence of an intermediate-age population Based on earlier research (optical and near-IR colour-magnitude diagrams of the stars in the fields), the present team of astronomers had previously detected the presence of intermediate-age and young stellar populations in the halo of this galaxy. The youngest stars appear to be aligned with the powerful jet produced by the massive black hole at the centre. Some of the very luminous red variable stars now discovered confirm the presence of a population of intermediate-age stars in the halo of this galaxy. It also contributes to our understanding of how giant elliptical galaxies form. New measurement of the distance to Centaurus A The pulsation of Mira-type variable stars obeys a period-luminosity relation. The longer its period, the more luminous is a Mira-type star. This fact makes it possible to use Mira-type stars as "standard candles" (objects of known intrinsic luminosity) for distance determinations. They have in fact often been used in this way to measure accurate distances to more nearby objects, e.g., to individual clusters of stars and to the center in our Milky Way galaxy, and also to galaxies in the Local Group, in particular the Magellanic Clouds. This method works particularly well with infrared measurements and the astronomers were now able to measure the distance to Centaurus A in this new way. They found 13.7 ± 1.9 million light-years , in general agreement with and thus confirming other methods. Study of stellar population gradients in the halo of a giant elliptical galaxy The two fields here studied contain different populations of stars. A clear dependence on the location (a "gradient") within the galaxy is observed, which can be due to differences in chemical composition or age, or to a combination of both. Understanding the cause of this gradient will provide additional clues to how Centaurus A - and indeed all giant elliptical galaxies - was formed and has since evolved. Comparison with other well-known nearby galaxies Past searches have discovered Mira-type variable stars thoughout the Milky Way, our home galaxy, and in other nearby galaxies in the Local Group. However, there are no giant elliptical galaxies like Centaurus A in the Local Group and this is the first time it has been possible to identify this kind of stars in that type of galaxy. The present investigation now opens a new window towards studies of the stellar constituents of such galaxies .

Strategies for Solidarity Education at Catholic Schools in Chile: Approximations and Descriptions from the Perspectives of School Principals

ERIC Educational Resources Information Center

Santana Lopez, Alejandra Isabel; Hernandez Mary, Natalia

2013-01-01

This research project sought to learn how solidarity education is manifested in Chilean Catholic schools, considering the perspectives of school principals, programme directors and pastoral teams. Eleven Chilean schools were studied and the information gathering techniques applied included: a questionnaire, semi-structured individual interviews…

Improving Performance: Leading from the Bottom. PISA in Focus. No. 2

ERIC Educational Resources Information Center

OECD Publishing (NJ1), 2011

2011-01-01

Since the PISA (Programme for International Student Assessment) 2000 and 2009 surveys both focused on reading, one can track in detail how student reading performance has changed over that period. Among the 26 OECD (Organisation for Economic Cooperation and Development) countries with comparable results in both assessments, Chile, Germany,…

Physical activity in the classroom to prevent childhood obesity: a pilot study in Santiago, Chile.

PubMed

Mardones, Francisco; Arnaiz, Pilar; Soto-Sánchez, Johana; Saavedra, Juana; Domínguez, Angélica; Rozowski, Jaime; Iriarte, Laura; Cantwell Wood, Jennifer

2017-01-01

This paper describes a 4-month pilot study that tested the suitability of a physical activity intervention for first graders (children aged 6 and 7 years) in a public school in Santiago, Chile. Teachers were trained to deliver the programme in the classroom during the school day. Teachers were surveyed to determine if this intervention fit within their curriculum and classroom routines and they reported in a focus group that it was suitable for them. All children actively participated in the programme and positive changes in their attitudes towards physical activity were observed by their teachers. Anthropometrics, blood pressure and hand grip strength were measured in the students. A significant reduction was observed in children with high waist circumference ≥ 90th percentile, and in mean systolic blood pressure. However, statistical power values for those comparisons were rather low. Anthropometry and hand grip strength were not modified. The latter calculations and the lack of a control group are showing the weaknesses of this pilot study and that further research with a larger sample size and an experimental design is strongly needed.

Knowledge of HIV/AIDS among adolescents in Chillán, Chile.

PubMed

Pérez V, Ruth; Barrales C, Ingrid; Jara P, Jenny; Palma R, Virla; Ceballos M, Alejandra

2008-12-01

to analyse adolescents' knowledge of preventive sexual practices related to human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) by means of a questionnaire recommended by the Joint United Nations Programme on HIV/AIDS (UNAIDS). non-experimental, cross-sectional, descriptive and analytical investigation. four schools in Chillán, Chile, 2005. a total of 480 adolescents aged between 15 and 19 years. Students completed a questionnaire recommended by UNAIDS in order to develop basic indicators. the indicator of preventive sexual practices related to HIV/AIDS was 32.5%; forms of prevention (62.5%) were better known than erroneous ideas about transmission (46%). Adolescents from the only private school in the study demonstrated greater knowledge (43.3%) than students from the public schools (25%) (p<0.01). No significant differences were found in knowledge according to age, sex or educational level. adolescents have poor knowledge of preventive sexual practices related to HIV and AIDS. It is necessary to implement an indicator of knowledge that allows for the creation and monitoring of sexual education programmes.

Cancer of the gallbladder-Chilean statistics.

PubMed

Villanueva, Luis

2016-01-01

Chile has the world's highest rate of incidence as well as death from cancer of the gallbladder and biliary ducts. The problem is most acute in the southern provinces. These areas constitute the low average income associated with low educational attainment and a high rate of obesity compared with the rest of Chile. We could also include genetic factors related to processes of lithogenesis to these elements which are more common among the Mapuche. This population sub-group could benefit from special government programmes for early diagnosis and treatment of lithiasic disease and for the management of risk factors such as obesity. In this way, we could reduce the mortality rate of gallbladder cancer.

Cancer of the gallbladder—Chilean statistics

PubMed Central

Villanueva Olivares, Luis

2016-01-01

Chile has the world’s highest rate of incidence as well as death from cancer of the gallbladder and biliary ducts. The problem is most acute in the southern provinces. These areas constitute the low average income associated with low educational attainment and a high rate of obesity compared with the rest of Chile. We could also include genetic factors related to processes of lithogenesis to these elements which are more common among the Mapuche. This population sub-group could benefit from special government programmes for early diagnosis and treatment of lithiasic disease and for the management of risk factors such as obesity. In this way, we could reduce the mortality rate of gallbladder cancer. PMID:28105075

Teenage sexuality and rights in Chile: from denial to punishment.

PubMed

Casas, Lidia; Ahumada, Claudia

2009-11-01

While Chile sees itself as a country that has fully restored human rights since its return to democratic rule in 1990, the rights of teenagers to comprehensive sexuality education are still not being met. This paper reviews the recent history of sexuality education in Chile and related legislation, policies and programmes. It also reports a 2008 review of the bylaws of 189 randomly selected Chilean schools, which found that although such bylaws are mandatory, the absence of bylaws to prevent discrimination on grounds of pregnancy, HIV and sexuality was common. In relation to how sexual behaviour and discipline were addressed, bylaws that were non-compliant with the law were very common. Opposition to sexuality education in schools in Chile is predicated on the denial of teenage sexuality, and many schools punish sexual behaviour where transgression is perceived to have taken place. While the wider Chilean society has been moving towards greater recognition of individual autonomy and sexual diversity, this cultural shift has yet to be reflected in the government's political agenda, in spite of good intentions. Given this state of affairs, the Chilean polity needs to recognise its youth as having human rights, or will continue to fail in its commitment to them.

New Fast Lane towards Discoveries of Clusters of Galaxies Inaugurated

NASA Astrophysics Data System (ADS)

2003-07-01

Space and Ground-Based Telescopes Cooperate to Gain Deep Cosmological Insights Summary Using the ESA XMM-Newton satellite, a team of European and Chilean astronomers [2] has obtained the world's deepest "wide-field" X-ray image of the cosmos to date. This penetrating view, when complemented with observations by some of the largest and most efficient ground-based optical telescopes, including the ESO Very Large Telescope (VLT), has resulted in the discovery of several large clusters of galaxies. These early results from an ambitious research programme are extremely promising and pave the way for a very comprehensive and thorough census of clusters of galaxies at various epochs. Relying on the foremost astronomical technology and with an unequalled observational efficiency, this project is set to provide new insights into the structure and evolution of the distant Universe. PR Photo 19a/03: First image from the XMM-LSS survey. PR Photo 19b/03: Zoom-in on PR Photo 19b/03. PR Photo 19c/03: XMM-Newton contour map of the probable extent of a cluster of galaxies, superimposed upon a CHFT I-band image. PR Photo 19d/03: Velocity distribution in the cluster field shown in PR Photo 19c/03. The universal web Unlike grains of sand on a beach, matter is not uniformly spread throughout the Universe. Instead, it is concentrated into galaxies which themselves congregate into clusters (and even clusters of clusters). These clusters are "strung" throughout the Universe in a web-like structure, cf. ESO PR 11/01. Our Galaxy, the Milky Way, for example, belongs to the so-called Local Group which also comprises "Messier 31", the Andromeda Galaxy. The Local Group contains about 30 galaxies and measures a few million light-years across. Other clusters are much larger. The Coma cluster contains thousands of galaxies and measures more than 20 million light-years. Another well known example is the Virgo cluster, covering no less than 10 degrees on the sky ! Clusters of galaxies are the most massive bound structures in the Universe. They have masses of the order of one thousand million million times the mass of our Sun. Their three-dimensional space distribution and number density change with cosmic time and provide information about the main cosmological parameters in a unique way. About one fifth of the optically invisible mass of a cluster is in the form of a diffuse hot gas in between the galaxies. This gas has a temperature of the order of several tens of million degrees and a density of the order of one atom per liter. At such high temperatures, it produces powerful X-ray emission. Observing this intergalactic gas and not just the individual galaxies is like seeing the buildings of a city in daytime, not just the lighted windows at night. This is why clusters of galaxies are best discovered using X-ray satellites. Using previous X-ray satellites, astronomers have performed limited studies of the large-scale structure of the nearby Universe. However, they so far lacked the instruments to extend the search to large volumes of the distant Universe. The XMM-Newton wide-field observations ESO PR Photo 19a/03 ESO PR Photo 19a/03 [Preview - JPEG: 575 x 400 pix - 52k [Normal - JPEG: 1130 x 800 pix - 420k] ESO PR Photo 19b/03 ESO PR Photo 19b/03 [Preview - JPEG: 400 x 489 pix - 52k [Normal - JPEG: 800 x 978 pix - 464k] Captions: PR Photo 19a/03 is the first image from the XMM-LSS X-Ray survey. It is actually a combination of fourteen separate "pointings" of this space observatory. It represents a region of the sky eight times larger than the full Moon and contains around 25 clusters. The circles represent the X-Ray sources previously known from the 1991 ROSAT All-Sky Survey. PR Photo 19b/03 zooms in on a particularly interesting region of the image shown in ESO PR Photo 19a/03 with a possible cluster identified (in box). Each point on this graph represents a single X-ray photon detected by XMM-Newton. Marguerite Pierre (CEA Saclay, France), with a European/Chilean team of astronomers known as the XMM-LSS consortium [2], used the large field-of-view and the high sensitivity of ESA's X-ray observatory XMM-Newton to search for remote clusters of galaxies and map out their distribution in space. They could see back about 7,000 million years to a cosmological era when the Universe was about half its present size and age, when clusters of galaxies were more tightly packed. Tracking down the clusters is a painstaking, multi-step process, requiring both space and ground-based telescopes. Indeed, from X-ray images with XMM, it was possible to select several tens of cluster candidate objects, identified as areas of enhanced X-radiation (cf PR Photo 19b/03). But having candidates is not enough ! They must be confirmed and further studied with ground-based telescopes. In tandem with XMM-Newton, Pierre uses the very-wide-field imager attached to the 4-m Canada-France-Hawaii Telescope, on Mauna Kea, Hawaii, to take an optical snapshot of the same region of space. A tailor-made computer programme then combs the XMM-Newton data looking for concentrations of X-rays that suggest large, extended structures. These are the clusters and represent only about 10% of the detected X-ray sources. The others are mostly distant active galaxies. Back to the Ground ESO PR Photo 19c/03 ESO PR Photo 19c/03 [Preview - JPEG: 400 x 481 pix - 84k [Normal - JPEG: 800 x 961 pix - 1M] ESO PR Photo 19d/03 ESO PR Photo 19d/03 [Preview - JPEG: 400 x 488 pix - 44k [Normal - JPEG: 800 x 976 pix - 520k] Captions: PR Photo 19c/03 represents the XMM-Newton X-ray contour map of the cluster's probable extent superimposed upon the CFHT I-band image. A concentration of distant galaxies is conspicuous, thus confirming the X-ray detection. The symbols indicate the galaxies which have been subject to a subsequent spectroscopic measurement and found to be cluster members (triangles flag emission line galaxies). The individual galaxies in the cluster can then be targeted for further observations with ESO's VLT, in order to measure its distance and locate the cluster in the universe. Following the X-ray discovery and the optical cluster identification, galaxies in the cluster field shown in ESO PR Photo 19c/03 have been spectroscopically observed at the ESO VLT using the FORS2 instrument in order to determine the cluster redshift [3]. Using two masks, each of them observed during one hour, allowing to take the spectra of 16 emission-line galaxies at a time, the cluster was found to have a redshift of 0.84, corresponding to a distance of 8,000 million light-years, and a velocity dispersion of 750 km/s. PR Photo 19d/03 shows the measured velocity distribution. This is one of the most distant known clusters of galaxies for which a velocity dispersion has been measured. When the programme finds a cluster, it zooms in on that region and converts the XMM-Newton data into a contour map of X-ray intensity, which is then superimposed upon the CFHT optical image (PR Photo 19c/03). The astronomers use this to check if anything is visible within the area of extented X-ray emission. If something is seen, the work then shifts to one of the world's prime optical/infrared telescopes, the European Southern Observatory's Very Large Telescope (VLT) at Paranal (Chile). By means of the FORS multi-mode instruments, the astronomers zoom-in on the individual galaxies in the field, taking spectral measurements that reveal their overall characteristics, in particular their redshift and hence, distance. Cluster galaxies have similar distances and these measurement ultimately provide, by averaging, the cluster's distance as well as the velocity dispersion in the cluster. The FORS instruments are among the most efficient and versatile for this type of work, taking on the average spectra of 30 galaxies at a time. The first spectroscopic observations dedicated to the identification and redshift measurement of the XMM-LSS galaxy clusters took place during three nights in the fall of 2002. As of March 2003, there were only 5 known clusters in the literature at such a large redshift with enough spectroscopically measured redshifts to allow an estimate of the velocity dispersion. But the VLT allowed obtaining the dispersion in a distant cluster in 2 hours only, raising great expectations for future work. 700 spectra... Marguerite Pierre is extremely content : Weather and working conditions at the VLT were optimal. In three nights only, 12 cluster fields were observed, yielding no less than 700 spectra of galaxies. The overall strategy proved very successful. The high observing efficiency of the VLT and FORS support our plan to perform follow-up studies of large numbers of distant clusters with relatively little observing time. This represents a most substantial increase in efficiency compared to former searches. The present research programme has begun well, clearly demonstrating the feasibility of this new multi-telescope approach and its very high efficiency. And Marguerite Pierre and her colleagues are already seeing the first tantalising results: it seems to confirm that the number of clusters 7,000 million years ago is little different from that of today. This particular behaviour is predicted by models of the Universe that expand forever, driving the galaxy clusters further and further apart. Equally important, this multi-wavelength, multi-telescope approach developed by the XMM-LSS consortium to locate clusters of galaxies also constitutes a decisive next step in the fertile synergy between space and ground-based observatories and is therefore a basic building block of the forthcoming Virtual Observatory. More information This work is based on two papers to be published in the professional astronomy journal, Astronomy and Astrophysics (The XMM-LSS survey : I. Scientific motivations, design and first results by Marguerite Pierre et al., astro-ph/0305191 and The XMM-LSS survey : II. First high redshift galaxy clusters: relaxed and collapsing systems by Ivan Valtchanov et al., astro-ph/0305192). Dr. M. Pierre will give an invited talk on this subject at the IAU Symposium 216 - Maps of the Cosmos - this Thursday July 17, 2003 during the IAU General Assembly 2003 in Sydney, Australia.

The big comet crash of 1994. Intensive observational campaign at ESO

NASA Astrophysics Data System (ADS)

1994-01-01

Astronomers all over the world are preparing themselves for observations of a most unique event: during a period of six days in July 1994, at least 21 fragments of comet Shoemaker-Levy 9 will collide with giant planet Jupiter. At the European Southern Observatory, an intensive observational campaign with most of the major telescopes at La Silla is being organized with the participation of a dozen international teams of astronomers. This is the first time ever that it has been possible to predict such a collision. Although it is difficult to make accurate estimates, it is likely that there will be important, observable effects in the Jovian atmosphere. WHAT IS KNOWN ABOUT THE COMET ? Comet Shoemaker-Levy 9 is the ninth short-period comet discovered by Gene and Carolyn Shoemaker and David Levy. It was first seen on a photographic plate obtained on 18 March 1993 with the 18-inch Schmidt telescope at the Mount Palomar Observatory, California. It was close in the sky to Jupiter and orbital calculations soon showed that it moves in a very unusual orbit. While other comets revolve around the Sun, this one moves in an elongated orbit around Jupiter. It is obvious that it must have been ``captured'' rather recently by the gravitational field of the planet. It was also found that Shoemaker-Levy 9 consists of several individual bodies which move like ``pearls on a string'' in a majestic procession. It was later determined that this is because the comet suffered a dramatic break-up due to the strong attraction of Jupiter at the time of an earlier close passage to this planet in July 1992. High-resolution Hubble Space Telescope images have shown the existence of up to 21 individual fragments (termed ``nuclei''), whose diameters probably range between a few kilometres and a few hundred meters. There is also much cometary dust visible around the nuclei; it is probably a mixture of grains of different sizes, from sub-millimetre sand up to metre-sized boulders. No outgassing has so far been observed from Shoemaker-Levy 9, but this is not unusual for a comet at this large distance from the Sun, about 750 million kilometres. The most recent observations obtained with telescopes at Hawaii in mid-January 1994 have shown changes in the relative brightness of the individual nuclei, and many of them have now developed individual comet ``tails''. Where and when will the collision take place ? Accurate determinations of the positions of the individual nuclei have permitted to calculate quite precise orbits and it can now be said with 99 percent certainty that all of them will indeed collide with Jupiter. The points of impact are in the Jovian southern hemisphere, at -43 +- 0.6 deg latitude. Unfortunately, these impacts will happen just behind Jupiter's limb, i.e., out of sight from the Earth. However, due to the rapid rotation of the planet, the impact sites will come into view only about 10 minutes later at the very limb where they will be seen ``from the side''. It is also fortunate that the American spacecraft Galileo, now approaching Jupiter, will then be ``only'' about 200 million km away and will have a good view of the impact sites. On the basis of the recent observations, the impact times can now be predicted to about +-40 minutes. The first, rather small nucleus (``A'') will hit the upper layers of Jupiter's atmosphere on July 16, 1994 at about 18:45 Universal Time (UT); the apparently biggest nucleus (``Q'') on July 20, also at 18:45 UT, and the last one in the train (``W''), on July 22 at 07:00 UT. WHAT IS LIKELY TO HAPPEN AT JUPITER ? The comet nuclei will hit Jupiter at a high velocity, about 60 km/sec. The correspondingly large motion energy (the ``kinetic energy'') will all be deposited in the Jovian atmosphere. For a 1 km fragment, this is about equal to 10^28 erg, or no less than about 250,000 Megatons. When one of the cometary nuclei enters the upper layers of the Jovian atmosphere, it will be heated by the friction, exactly as a meteoroid in the Earth's atmosphere, and its speed will decrease very rapidly. Depending of the size of the fragment, it may evaporate completely within a few seconds, while it is still above the dense cloud layer that forms the visible ``surface'' of Jupiter, or it may plunge right through these clouds (and therefore out of sight) into increasingly denser, lower layers, where it ultimately comes to a complete stop and disintegrates in a giant explosion. All of the kinetic energy is released during this process. One part will heat the surrounding atmosphere to very high temperatures; this will result in a flash of light that lasts a few seconds. Within the next minutes, a plume of hot gas will begin to rise over the impact site. It may reach an altitude of several hundred kilometres above the cloud layers and will quickly spread out in all horizontal directions. Another part of the energy will be transformed into shock waves that will propagate into the interior of Jupiter, much as seismic waves from an earthquake do inside the Earth. When these waves again reach the upper layers of the atmosphere, they may be seen as slight increases in the local temperature along expanding circles with the impact sites at their centres (like waves on a water surface). The shock waves may also start oscillations of the entire planet, like those of a ringing bell. During the past months, atmospheric scientists have attempted to calculate the details of these impacts, but the uncertainties are still rather large. Moreover, the magnitudes of the overall effects are entirely dependent on the energies involved, i.e., on the still not well determined sizes (masses) of the cometary nuclei. It is also expected that there will be some kind of interaction between the cometary dust and Jupiter's strong magnetic field. The fast-moving dust grains may become electrically charged. This will possibly have a significant influence on Jupiter's radio emission and therefore be directly observable with Earth-based radio telescopes, as well as from several spacecraft, including Ulysses, now en route towards its first pass below the Sun. There may also be changes in the plasma torus that girdles Jupiter near the orbit of the volcanic moon Io, and some cometary dust particles may collect in Jupiter's faint ring. All in all, this spectacular event offers a unique opportunity to study Jupiter and its atmosphere. It may also provide a first ``look'' into its hitherto unobservable inner regions. Nobody knows for sure, how dramatic the effects of the impacts will actually be, but unless we are prepared to observe them, we may lose a great chance that is unlikely to come back in many years, if ever. WHICH PREPARATIONS HAVE BEEN MADE AT ESO ? In November of last year, a group of 25 cometary and planetary specialists from Europe and the U.S.A. met at ESO to discuss possible observations from the ESO La Silla observatory in connection with the cometary impacts at Jupiter. In a resulting report, they emphazised that ESO is in a particularly advantageous situation in this respect, because the excellent site of this observatory is located in the south and Jupiter will be 12 degrees south of the celestial equator at the time of the event and therefore well observable from here; the time available from observatories in the northern hemisphere will be much more restricted. Moreover, many different observing techniques are available at La Silla; this provides optimal conditions for effective coordination of the various programmes, in particular what concerns imaging and spectral observations in the infrared and submillimetre wavebands. A joint request for a coordinated observing programme was submitted by the group to the ESO Observing Programmes Committee. During its meeting at the end of November 1993, this committee reacted very positively and a substantial number of observing nights at the major telescopes at La Silla was granted at the time of the impacts in July 1994. The total amount of observing time to this programme is just over 40 full nights, a quantity never allocated for any single astronomical event at ESO. This clearly illustrates the importance attached to this very special programme. At this moment, the more than 30 astronomers involved are in the middle of the complex and detailed preparations for this unique event, less than six months from now. Together with observational programmes at other observatories, they will provide efficient coverage of the collisions and the associated effects. WHICH OBSERVATIONS WILL BE CARRIED OUT AT ESO ? Some of the earliest observations at ESO will be carried out with the Danish 1.54 m telescope by a small team of ESO astronomers led by Olivier Hainaut. Beginning in late April 1994, images will be obtained of comet Shoemaker-Levy 9 which will allow to further improve the accuracy of the orbit and thereby to increase the precision with which the times of the individual impacts can be predicted. It is expected that such observations, when made carefully up to the last days before the first impacts, will result in a final timing accuracy of a few minutes; this will of course be of importance for all other observations, both from the ground, and especially for those being carried out from the spacecraft. A team from the Munich Observatory (Germany) under the leadership of Heinz Barwig will perform rapid brightness mesurements of Jupiter's moons at the predicted times of the impacts with their special high-speed photometer attached to the ESO 1 metre telescope. The flashes from the impacts will be reflected from the surfaces of those Jupiter moons which are in view of the impact sites. If this happens when a moon is in full sunlight, the relative increase of intensity will probably only be of the order of 1. However, if one of the moons is located in the shadow of Jupiter and is at the same time visible from the Earth, then the relative brightening may be very conspicuous. Whether this will be the case will of course depend on the exact moments of the impacts. Also at the time of the impacts, a group of French astronomers, headed by Bruno Sicardy of the Observatoire de Paris, will mount a special CCD camera at the Danish telescope, which will be used for different types of observations. They also hope to be able to detect some of the expected light flashes from the Jupiter moons. In addition, this programme will monitor changes in the cloud structure around the impact sites. It may also be possible to obtain low-resolution spectra which will show the temperature of the flashes, but in view of their very short duration, a few seconds at most, this will not be easy. The same instrument will also be used by Nick Thomas of the Max-Planck-Institut fur Aeronomie (Lindau, Germany) to image the Jupiter plasma torus in order to detect possible changes after the impacts. Spectral observations of the comet will be made with the ESO 1.5 m telescope in April by Heike Rauer, also from the Max-Planck-Institut fur Aeronomie. They are expected to lead to a better knowledge about the physical and chemical state of the impacting bodies. For instance, are they really so ``dusty'', as present observations seem to indicate, or do they contain large amounts of gas ? If so, what kind of molecules are present ? This will help to refine the predictions of the impact effects. Imaging and spectral observations of the comet for the same general purposes will also be obtained in early July with the EMMI instrument at the 3.5 m New Technology Telescope by an international team headed by Rita Schulz, formerly at the University of Maryland and now at the Max-Planck-Institut fur Aeronomie. No less than 46 observing hours have been allocated at the Swedish-ESO Submillimetre Telescope (SEST) to an international group headed by Daniel Gautier, Observatoire de Paris-Meudon. During the impacts, the cometary molecules will be mixed with those in the Jovian atmosphere, some of which may come from very deep layers. Together they will be carried upwards in the plume, described above. This may provide a rare opportunity, not only to register the submillimetre emissions from those molecules which are already known to be present in the comet and on Jupiter, but also to detect new and unknown molecules otherwise not accessible for direct observations, either from the interior of the cometary nuclei or from deep down in Jupiter's enormous atmosphere. Infrared observations will play a very important role during the ESO campaign. A new ESO-developed instrument, TIMMI (Thermal Infrared Multi-Mode Instrument) will be mounted at the ESO 3.6 m telescope and will provide detailed infrared images of the impact areas when they become visible at the limb. Two teams will be active here; one is led by Timothy A. Livengood from NASA Goddard Space Flight Center (U.S.A.) and includes several ESO staff astronomers. Thanks to the excellent imaging capabilities of TIMMI in the far-infrared spectral region, this group will be able to look far down into the atmosphere and to measure minute temperature variations. This should make it possible to register the effects of the shockwaves that arise when the cometary energy is deposited in the atmosphere. The second group at the 3.6 m telescope, led by Benoit Mosser from Institut d'Astrophysique, Paris, will be looking for short- and long-term oscillations of the entire planet during the days and nights following the impacts. It is agreed that such observations will not be easy, but they offer the best hope we presently have of learning about the internal structure of Jupiter. It may be deduced from the observed frequencies and modes of oscillation. A particularly interesting problem is whether Jupiter really possesses a core of metallic hydrogen, as postulated by some scientists. Infrared images will also be made by Klaus Jockers from the Max-Planck-Institut fur Aeronomie with the ESO infrared IRAC camera at the MPI/ESO 2.2 m telescope. Since they will be obtained at shorter wavelengths than those at TIMMI, they will show higher layers of the atmosphere and the possible changes (streaming motions, new whirls and eddies ?) which may result from the impacts. These programmes will therefore complement eachother. A total of no less than 13 half-nights have been allocated at the 3.5 m New Technology Telescope. They will be shared between two groups which will both use the IRSPEC instrument to obtain detailed infrared spectra of the impact sites. One team is headed by Rita Schulz, the other by Therese Encrenaz from Observatoire de Paris. Among many others, they hope to observe some of the molecules which may be present in the deeper layers of the Jovian atmosphere, e.g., water, ammonium and phosphine (PH3). HOW WILL THE MEDIA LEARN ABOUT THE RESULTS FROM ESO ? Together, these programmes add up to a very significant observational effort at ESO in connection with this astronomical event. Although it is difficult to predict at this moment whether all of the above mentioned phenomena will actually be observed, there is an obvious and great interest in these programmes from all sides. To support the public information about the outcome, it is the intention of the ESO Information Service to provide the media with regular and rapid updates about the observational progress at the La Silla telescopes. For this, a special ESO news service will be activated some days before the series of impacts begin - it will be accessible for all interested parties during the critical period. More details about this service will be announced in a later Press Release.

Methods for economic evaluation of a factorial-design cluster randomised controlled trial of a nutrition supplement and an exercise programme among healthy older people living in Santiago, Chile: the CENEX study

PubMed Central

Walker, Damian G; Aedo, Cristian; Albala, Cecilia; Allen, Elizabeth; Dangour, Alan D; Elbourne, Diana; Grundy, Emily; Uauy, Ricardo

2009-01-01

Background In an effort to promote healthy ageing and preserve health and function, the government of Chile has formulated a package of actions into the Programme for Complementary Food in Older People (Programa de Alimentación Complementaria para el Adulto Mayor - PACAM). The CENEX study was designed to evaluate the impact, cost and cost-effectiveness of the PACAM and a specially designed exercise programme on pneumonia incidence, walking capacity and body mass index in healthy older people living in low- to medium-socio-economic status areas of Santiago. The purpose of this paper is to describe in detail the methods that will be used to estimate the incremental costs and cost-effectiveness of the interventions. Methods and design The base-case analysis will adopt a societal perspective, including the direct medical and non-medical costs borne by the government and patients. The cost of the interventions will be calculated by the ingredients approach, in which the total quantities of goods and services actually employed in applying the interventions will be estimated, and multiplied by their respective unit prices. Relevant information on costs of interventions will be obtained mainly from administrative records. The costs borne by patients will be collected via exit and telephone interviews. An annual discount rate of 8% will be used, consistent with the rate recommended by the Government of Chile. All costs will be converted from Chilean Peso to US dollars with the 2007 average period exchange rate of US$1 = 522.37 Chilean Peso. To test the robustness of model results, we will vary the assumptions over a plausible range in sensitivity analyses. Discussion The protocol described here indicates our intent to conduct an economic evaluation alongside the CENEX study. It provides a detailed and transparent statement of planned data collection methods and analyses. Trial registration ISRCTN48153354 PMID:19473513

Methods for economic evaluation of a factorial-design cluster randomised controlled trial of a nutrition supplement and an exercise programme among healthy older people living in Santiago, Chile: the CENEX study.

PubMed

Walker, Damian G; Aedo, Cristian; Albala, Cecilia; Allen, Elizabeth; Dangour, Alan D; Elbourne, Diana; Grundy, Emily; Uauy, Ricardo

2009-05-27

In an effort to promote healthy ageing and preserve health and function, the government of Chile has formulated a package of actions into the Programme for Complementary Food in Older People (Programa de Alimentación Complementaria para el Adulto Mayor - PACAM). The CENEX study was designed to evaluate the impact, cost and cost-effectiveness of the PACAM and a specially designed exercise programme on pneumonia incidence, walking capacity and body mass index in healthy older people living in low- to medium-socio-economic status areas of Santiago. The purpose of this paper is to describe in detail the methods that will be used to estimate the incremental costs and cost-effectiveness of the interventions. The base-case analysis will adopt a societal perspective, including the direct medical and non-medical costs borne by the government and patients. The cost of the interventions will be calculated by the ingredients approach, in which the total quantities of goods and services actually employed in applying the interventions will be estimated, and multiplied by their respective unit prices. Relevant information on costs of interventions will be obtained mainly from administrative records. The costs borne by patients will be collected via exit and telephone interviews. An annual discount rate of 8% will be used, consistent with the rate recommended by the Government of Chile. All costs will be converted from Chilean Peso to US dollars with the 2007 average period exchange rate of US$1 = 522.37 Chilean Peso. To test the robustness of model results, we will vary the assumptions over a plausible range in sensitivity analyses. The protocol described here indicates our intent to conduct an economic evaluation alongside the CENEX study. It provides a detailed and transparent statement of planned data collection methods and analyses. ISRCTN48153354.

The European ALMA Regional Centre: a model of user support

NASA Astrophysics Data System (ADS)

Andreani, P.; Stoehr, F.; Zwaan, M.; Hatziminaoglou, E.; Biggs, A.; Diaz-Trigo, M.; Humphreys, E.; Petry, D.; Randall, S.; Stanke, T.; van Kampen, E.; Bárta, M.; Brand, J.; Gueth, F.; Hogerheijde, M.; Bertoldi, F.; Muxlow, T.; Richards, A.; Vlemmings, W.

2014-08-01

The ALMA Regional Centres (ARCs) form the interface between the ALMA observatory and the user community from the proposal preparation stage to the delivery of data and their subsequent analysis. The ARCs provide critical services to both the ALMA operations in Chile and to the user community. These services were split by the ALMA project into core and additional services. The core services are financed by the ALMA operations budget and are critical to the successful operation of ALMA. They are contractual obligations and must be delivered to the ALMA project. The additional services are not funded by the ALMA project and are not contractual obligations, but are critical to achieve ALMA full scientific potential. A distributed network of ARC nodes (with ESO being the central ARC) has been set up throughout Europe at the following seven locations: Bologna, Bonn-Cologne, Grenoble, Leiden, Manchester, Ondrejov, Onsala. These ARC nodes are working together with the central node at ESO and provide both core and additional services to the ALMA user community. This paper presents the European ARC, and how it operates in Europe to support the ALMA community. This model, although complex in nature, is turning into a very successful one, providing a service to the scientific community that has been so far highly appreciated. The ARC could become a reference support model in an age where very large collaborations are required to build large facilities, and support is needed for geographically and culturally diverse communities.

Results from the REFLEX Cluster Survey

NASA Astrophysics Data System (ADS)

Bohringer, H.; Guzzo, L.; Collins, C. A.; Neumann, D. M.; Schindler, S.; Schuecker, P.; Cruddace, R.; Chincarini, G.; de Grandi, S.; Edge, A. C.; MacGillivray, H. T.; Shaver, P.; Vettolani, G.; Voges, W.

Based on the ROSAT All-Sky Survey we have conducted a large redshift survey as an ESO key programme to identify and secure redshifts for the X-ray brightest clusters found in the southern hemisphere. We present first results for a highly controlled sample for a flux limit of 3cdot 10^{-12} erg s^{-1} cm^{-2} (0.1 - 2.4 keV) comprising 475 clusters (87% with redshifts). The logN-logS function of the sample shows an almost perfect Euclidian slope and a preliminary X-ray luminosity function is presented.

The VLT Opening Symposium

NASA Astrophysics Data System (ADS)

1999-02-01

Scientists Meet in Antofagasta to Discuss Front-Line Astrophysics To mark the beginning of the VLT era, the European Southern Observatory is organizing a VLT Opening Symposium which will take place in Antofagasta (Chile) on 1-4 March 1999, just before the start of regular observations with the ESO Very Large Telescope on April 1, 1999. The Symposium occupies four full days and is held on the campus of the Universidad Catolica del Norte. It consists of plenary sessions on "Science in the VLT Era and Beyond" and three parallel Workshops on "Clusters of Galaxies at High Redshift" , "Star-way to the Universe" and "From Extrasolar Planets to Brown Dwarfs" . There will be many presentations of recent work at the major astronomical facilities in the world. The meeting provides a very useful forum to discuss the latest developments and, in this sense, contributes to the planning of future research with the VLT and other large telescopes. The symposium will be opened with a talk by the ESO Director General, Prof. Riccardo Giacconi , on "Paranal - an observatory for the 21st century". It will be followed by reports about the first scientific results from the main astronomical instruments on VLT UT1, FORS1 and ISAAC. The Symposium participants will see the VLT in operation during special visits to the Paranal Observatory. Press conferences are being arranged each afternoon to inform about the highlights of the conference. After the Symposium, there will be an Official Inauguration Ceremony at Paranal on 5 March Contributions from ESO ESO scientists will make several presentations at the Symposium. They include general reviews of various research fields as well as important new data and results from the VLT that show the great potential of this new astronomical facility. Some of the recent work is described in this Press Release, together with images and spectra of a large variety of objects. Note that all of these data will soon become publicly available via the VLT Archive. The text below summarizes the individual projects. Comprehensive texts with all photos and diagrammes are available in nine separate web documents ( ESO PR Photos 08/99 to 16/99 ) that may be accessed via the links at the top of each section. The degree of detail and level of complexity of the texts depend on the subject and the available materials. 1. Dwarf Galaxies in the Local Group ESO PR Photo 10a/99 ESO PR Photo 10a/99 The Antlia Galaxy (FORS1 colour composite) . Access full text and PR Photos 10a-d/99 In addition to large spiral galaxies like the Milky Way Galaxy, the Andromeda Galaxy and Messier 33, the Local Group of Galaxies contains many dwarf galaxies. The VLT has observed two of these, Antlia and NGC 6822 . Antlia is a low-surface brightness, spheroidal dwarf galaxy that was only discovered in 1997. While it contains a large amount of atomic hydrogen at its centre, no young stars are found, and it appears that most of its stars are old. This is unlike other dwarf galaxies in the Milky Way neighbourhood, as star formation is expected to occur within dense hydrogen clouds. Further observations will be necessary to understand this unusual characteristics. The VLT also obtained images of an irregular dwarf galaxy in the Local Group, NGC 6822, as well as spectra of some of its stars. This galaxy is of the "irregular" type and is situated at a distance of about 2 million light-years. A comparison of the spectra of supergiant stars in NGC 6822 shows that many spectral lines are much weaker than in stars of similar type in the Milky Way, but of similar strength as in stars in the Small Magellanic Cloud. This confirms an earlier finding that NGC 6822 has chemical composition (a lower "metallicity") that is different from what is observed in our Galaxy. 2. The Double Stellar Cluster NGC 1850 in the LMC ESO PR Photo 15/99 ESO PR Photo 15/99 NGC 1850 (FORS1 colour composite) . Access full text and PR Photo 15/99 NGC 1850 is a double cluster in the Large Magellanic Cloud, a satellite galaxy to the Milky Way Galaxy. This cluster is representative of a class of objects, young, globular-like stellar associations , that has no counterpart in our own Galaxy. The VLT images show faint nebulosity in this area, with filaments and various sharp "shocks". This offers support to the theory of supernova-induced star birth in the younger of the two clusters. It is estimated that about 1000 stars in the older of the clusters have exploded during the past 20 million years. 3. The Barred Galaxy NGC 1365 ESO PR Photo 08a/99 ESO PR Photo 08a/99 The Barred Galaxy NGC 1365 (FORS1 colour composite) . Access full text and PR Photos 08a-e/99 NGC 1365 is one of the most prominent "barred" galaxies in the sky. It is a supergiant galaxy and is a member of the Fornax Cluster of Galaxies, at a distance of about 60 million light-years. This galaxy has an intricate structure with a massive straight bar and two pronounced spiral arms. There are many dust lanes and emission nebulae in these and also a bright nuclear region at the center that may hide a black hole. Several images of NGC 1365 have recently been obtained with all three astronomical instruments, now installed at the VLT UT1. They show the overall structure of this magnificent galaxy, and also the fine details of the innermost region, close to the centre. An infrared ISAAC image penetrates deep into the obscuring dust clouds in this area. 4. The colours of NGC 1232 ESO PR Photo 13a/99 ESO PR Photo 13a/99 Differential (UV-B) image of NGC 1232 (FORS1) . Access full text and PR Photos 13a-b/99 NGC 1232 is a large spiral galaxy in the constellation Eridanus (The River). With a diameter of nearly 200,000 light-years, it is about twice the size of the Milky Way galaxy. The distance is about 100 million light-years, but the excellent optical quality of the VLT and FORS allows us to see an incredible wealth of details. Computer processed "colour-index images" have been prepared that show the "difference" between images of the galaxy, as seen in different wavebands. Since different types of objects have different brightness in different colours, this method is very useful to locate objects of a particular type and to obtain an overview of their distribution in the galaxy. The distribution of star-forming regions and dust lanes in NGC 1232 are shown on two such photos. 5. A Selection of ISAAC Spectra ESO PR Photo 11a/99 ESO PR Photo 11a/99 He I 1038 nm line in SN1987A (ISAAC spectrum) . Access full text and PR Photos 11a-c/99 Various observations were made with the ISAAC multi-mode instrument at the Nasmyth focus of VLT UT1 during the recent commissioning periods for this infrared multi-mode instrument. They impressively demonstrate the unique capabilities of this facility. The new data include several infrared spectra of faint objects with interesting features. A spectrum was obtained in the near-infrared region of the ring nebula around SN 1987A in the Large Magellanic Cloud. It consists of material blown off the progenitor star during its evolution. Of particular interest is a jet like structure in the dispersion direction which reveals the presence of a broad, blueshifted, HeI component which presumably originates in the shock ionized ejecta. Another spectrum shows emission features in two galaxies at redshift z = 0.6 [1] that allow the determination of a rotation curve at this large distance. The 1 - 2.5 µm infrared spectrum of the radio galaxy MRC0406 at z =2.42 is also included. 6. The Cluster of Galaxies MS1008.1-1224 ESO PR Photo 09b/99 ESO PR Photo 09b/99 Centre of the Cluster of Galaxies MS1008.1-122 (FORS1 colour composite) . Access full text and PR Photos 09a-b/99 The study of "Deep Fields" is becoming a common tool in astronomy. Among the various sky fields that have been selected for detailed investigation of the faint and distant objects therein, is the FORS Deep Field that will be observed during FORS1 "guaranteed time", available to astronomers from institutes that built this instrument. In preparation of this work, an imaging programme was carried out during the FORS1 Science Verification programme. Multicolour (UBVRI) deep images were obtained of the galaxy cluster MS1008.1-1224 , to be complemented with infrared (JHK) images with ISAAC of the cluster core. The redshift is z = 0.306 and many arclets from gravitational lensing are seen within the cluster area. Such observations serve many purposes, including the study of the distribution of mass and the associated gravitational field of the cluster, of individual cluster galaxies, and also of background objects whose images are amplified and distorted by gravitational lensing caused by the cluster. 7. Quasar Spectra ESO PR Photo 14a/99 ESO PR Photo 14c/99 Spectrum of Quasar at z = 5 Access full text and PR Photos 14a-c/99 The FORS1 multi-mode instrument is able to record images as well as spectra of even very distant objects. During the past months, data have been obtained that show the properties of some of the remotest known objects in the Universe. Three spectral tracings of very distant quasars are included, for which the redshifts have been determined as z = 3.11, 3.83 and 5.0. They were taken by the FORS Commissioning Team in September and December 1998 in the long-slit spectroscopy mode of FORS1. This instrument is very efficient; even for the most distant and faintest quasar, the exposure time was only 1 hour. All spectra show a wealth of details. 8. Spectrum of a Gravitationally Lensed Galaxy ESO PR Photo 16c/99 ESO PR Photo 16c/99 Spectrum of Gravitationally Lensed Galaxy at z = 3.23 (FORS1) . Access full text and PR Photos 16a-c/99 The galaxy cluster 1ES 0657-55 is located in the southern constellation Carina (The Keel), at redshift z = 0.29. It emits strong and very hot X-ray emission and has an asymmetric galaxy distribution, indicating a large mass and recent formation. Earlier images with the ESO NTT at La Silla have revealed the presence of a gravitational arc, i.e. a background galaxy at larger distance, whose image is strongly distorted by the gravitational field of this cluster. New images of this cluster have been obtained with FORS1 under good seeing conditions. They show that this arc is very thin and long. Other arcs and arclets are also visible. It was possible to obtain a spectrum of the arc. Several absorption lines are well visible and show that the arc is the highly distorted image of a young, background galaxy at redshift z = 3.23. 9. Spectra of Faint Primordial Objects ESO PR Photo 12d/99 ESO PR Photo 12d/99 Spectrum of Distant Galaxy EIS 107 at z = 3.92 (FORS1) . Access full text and PR Photos 12a-f/99 During the recent commissioning and science verification of FORS1, spectra were taken of several objects, thought to be high-redshift galaxies. These objects are extremely faint and their spectra can only be observed with very large telescopes like the VLT and a highly efficient spectrograph. The near-infrared (I) magnitudes of the objects studied during the present test observations ranged between 23.4 and 25.5, or between 10 and 65 million times fainter than what can be seen with the unaided eye. As predicted, a large fraction of the spectra obtained turned out to be those of extremely distant galaxies, in the redshift range between z = 2.8 - 4.0. Outlook These observations provide but a small demonstration of the great capability of the ESO VLT to provide front-line astronomical data. Many others will be discussed during the Symposium and contribute to the future planning of the best possible exploitation of this great new research facility. The first 8.2-m VLT Unit Telescope (UT1) with which the observations reported in this Press Release were made will soon be joined by UT2, for which "First Light" is expected shortly, cf. PR Photos 07/99. The first instrument to be mounted on this telescope will be UVES that will provide the capability of obtaining high-dispersion spectra; the next is FORS2. During the coming years, more instruments of different types and capabilities will become available on the four 8.2-m telescopes, together providing an unrivalled potential for astronomical investigations. Note: [1]: In astronomy, the redshift (z) denotes the fraction by which the lines in the spectrum of an object are shifted towards longer wavelengths. The observed redshift of a distant galaxy or quasar gives a direct estimate of the universal expansion (i.e. the `recession velocity'). Since this expansion rate increases with the distance, the velocity (and thus the redshift) is itself a function (the Hubble relation) of the distance to the object. The larger the distance, the longer it has taken the light from the object to reach us, and the larger is the "look-back" time, i.e. the fraction of the age of the Universe that has elapsed since the light we now receive, was emitted from the object. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../ ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory . Note also the comprehensive VLT Information site.

The 4MOST facility control software

NASA Astrophysics Data System (ADS)

Pramskiy, Alexander; Mandel, Holger; Rothmaier, Florian; Stilz, Ingo; Winkler, Roland; Hahn, Thomas

2016-07-01

The 4-m Multi-Object Spectrographic Telescope (4MOST) is one high-resolution (R 18000) and two lowresolution (R fi 5000) spectrographs covering the wavelength range between 390 and 950 nm. The spectrographs will be installed on ESO VISTA telescope and will be fed by approximately 2400 fibres. The instrument is capable to simultaneously obtain spectra of about 2400 objects distributed over an hexagonal field-of-view of four square degrees. This paper aims at giving an overview of the control software design, which is based on the standard ESO VLT software architecture and customised to fit the needs of the 4MOST instrument. In particular, the facility control software is intended to arrange the precise positioning of the fibres, to schedule and observe many surveys in parallel, and to combine the output from the three spectrographs. Moreover, 4MOST's software will include user-friendly graphical user interfaces that enable users to interact with the facility control system and to monitor all data-taking and calibration tasks of the instrument. A secondary guiding system will be implemented to correct for any fibre exure and thus to improve 4MOST's guiding performance. The large amount of fibres requires the custom design of data exchange to avoid performance issues. The observation sequences are designed to use spectrographs in parallel with synchronous points for data exchange between subsystems. In order to control hardware devices, Programmable Logic Controller (PLC) components will be used, the new standard for future instruments at ESO.

Operational metrics for the ESO Very Large Telescope: lessons learned and future steps

NASA Astrophysics Data System (ADS)

Primas, F.; Marteau, S.; Tacconi-Garman, L. E.; Mainieri, V.; Mysore, S.; Rejkuba, M.; Hilker, M.; Patat, F.; Sterzik, M.; Kaufer, A.; Mieske, S.

2016-07-01

When ESO's Very Large Telescope opened its first dome in April 1999 it was the first ground-based facility to offer to the scientific community access to an 8-10m class telescope with both classical and queue observing. The latter was considered to be the most promising way to ensure the observing flexibility necessary to execute the most demanding scientific programmes under the required, usually very well defined, conditions. Since then new instruments have become operational and 1st generation ones replaced, filling the 12 VLT foci and feeding the VLT Interferometer and its four Auxiliary Telescopes. Operating efficiently such a broad range of instruments installed and available every night of the year on four 8-metre telescopes offers many challenges. Although it may appear that little has changed since 1999, the underlying VLT operational model has evolved in order to accommodate different requirements from the user community and features of new instruments. Did it fulfil its original goal and, if so, how well? How did it evolve? What are the lessons learned after more than 15 years of operations? A careful analysis and monitoring of statistics and trends in Phase 1 and Phase 2 has been deployed under the DOME (Dashboard for Operational Metrics at ESO) project. The main goal of DOME is to provide robust metrics that can be followed with time in a user-friendly manner. Here, we summarize the main findings on the handling of service mode observations and present the most recent developments.

CoRoT 101186644: A transiting low-mass dense M-dwarf on an eccentric 20.7-day period orbit around a late F-star. Discovered in the CoRoT lightcurves

NASA Astrophysics Data System (ADS)

Tal-Or, L.; Mazeh, T.; Alonso, R.; Bouchy, F.; Cabrera, J.; Deeg, H. J.; Deleuil, M.; Faigler, S.; Fridlund, M.; Hébrard, G.; Moutou, C.; Santerne, A.; Tingley, B.

2013-05-01

We present the study of the CoRoT transiting planet candidate 101186644, also named LRc01_E1_4780. Analysis of the CoRoT lightcurve and the HARPS spectroscopic follow-up observations of this faint (mV = 16) candidate revealed an eclipsing binary composed of a late F-type primary (Teff = 6090 ± 200 K) and a low-mass, dense late M-dwarf secondary on an eccentric (e = 0.4) orbit with a period of ~20.7 days. The M-dwarf has a mass of 0.096 ± 0.011 M⊙, and a radius of 0.104-0.006+0.026 R⊙, which possibly makes it the smallest and densest late M-dwarf reported so far. Unlike the claim that theoretical models predict radii that are 5-15% smaller than measured for low-mass stars, this one seems to have a radius that is consistent and might even be below the radius predicted by theoretical models. Based on observations made with the 1-m telescope at the Wise Observatory, Israel, the Swiss 1.2-m Leonhard Euler telescope at La Silla Observatory, Chile, the IAC-80 telescope at the Observatory del Teide, Canarias, Spain, and the 3.6-m telescope at La Silla Observatory (ESO), Chile (program 184.C-0639).

VizieR Online Data Catalog: L-σ relation for massive star formation (Chavez+, 2014)

NASA Astrophysics Data System (ADS)

Chavez, R.; Terlevich, R.; Terlevich, E.; Bresolin, F.; Melnick, J.; Plionis, M.; Basilakos, S.

2015-03-01

We observed 128 HIIGx selected from the SDSS DR7 spectroscopic catalogue (Abazajian et al., 2009ApJS..182..543A) for having the strongest emission lines relative to the continuum (i.e. largest equivalent widths) and in the redshift range 0.01

VizieR Online Data Catalog: Selection function of Milky Way field stars (Stonkute+, 2016)

NASA Astrophysics Data System (ADS)

Stonkute, E.; Koposov, S. E.; Howes, L. M.; Feltzing, S.; Worley, C. C.; Gilmore, G.; Ruchti, G. R.; Kordopatis, G.; Randich, S.; Zwitter, T.; Bensby, T.; Bragaglia, A.; Smiljanic, R.; Costado, M. T.; Tautvaisiene, G.; Casey, A. R.; Korn, A. J.; Lanzafame, A. C.; Pancino, E.; Franciosini, E.; Hourihane, A.; Jofre, P.; Lardo, C.; Lewis, J.; Magrini, L.; Monaco, L.; Morbidelli, L.; Sacco, G. G.; Sbordone, L.

2017-10-01

The observations are conducted with the FLAMES (Pasquini et al., 2002Msngr.110....1P) at the Very Large Telescope (VLT) array operated by the European Southern Observatory on Cerro Paranal, Chile. FLAMES is a fibre facility of the VLT and is mounted at the Nasmyth A platform of the second Unit Telescope of VLT. In this paper, we present the Gaia-ESO Survey selection function only for the Milky Way field stars observed with the GIRAFFE and UVES spectrographs at VLT, not including the bulge. All targets were selected according to their colours and magnitudes, using photometry from the VISTA Hemisphere Survey (VHS; McMahon et al. 2013Msngr.154...35M) and the Two Micron All-Sky Survey (2MASS; Skrutskie et al., 2006, Cat. VII/233). Selected potential target lists were generated at the Cambridge Astronomy Survey Unit (CASU) centre. (3 data files).

CIAO: wavefront sensors for GRAVITY

NASA Astrophysics Data System (ADS)

Scheithauer, Silvia; Brandner, Wolfgang; Deen, Casey; Adler, Tobias; Bonnet, Henri; Bourget, Pierre; Chemla, Fanny; Clenet, Yann; Delplancke, Francoise; Ebert, Monica; Eisenhauer, Frank; Esselborn, Michael; Finger, Gert; Gendron, Eric; Glauser, Adrian; Gonte, Frederic; Henning, Thomas; Hippler, Stefan; Huber, Armin; Hubert, Zoltan; Jakob, Gerd; Jochum, Lieselotte; Jocou, Laurent; Kendrew, Sarah; Klein, Ralf; Kolb, Johann; Kulas, Martin; Laun, Werner; Lenzen, Rainer; Mellein, Marcus; Müller, Eric; Moreno-Ventas, Javier; Neumann, Udo; Oberti, Sylvain; Ott, Jürgen; Pallanca, Laurent; Panduro, Johana; Ramos, Jose; Riquelme, Miguel; Rohloff, Ralf-Rainer; Rousset, Gérard; Schuhler, Nicolas; Suarez, Marcos; Zins, Gerard

2016-07-01

GRAVITY is a second generation near-infrared VLTI instrument that will combine the light of the four unit or four auxiliary telescopes of the ESO Paranal observatory in Chile. The major science goals are the observation of objects in close orbit around, or spiraling into the black hole in the Galactic center with unrivaled sensitivity and angular resolution as well as studies of young stellar objects and evolved stars. In order to cancel out the effect of atmospheric turbulence and to be able to see beyond dusty layers, it needs infrared wave-front sensors when operating with the unit telescopes. Therefore GRAVITY consists of the Beam Combiner Instrument (BCI) located in the VLTI laboratory and a wave-front sensor in each unit telescope Coudé room, thus aptly named Coudé Infrared Adaptive Optics (CIAO). This paper describes the CIAO design, assembly, integration and verification at the Paranal observatory.

Visits to La Plata Observatory

NASA Astrophysics Data System (ADS)

Feinstein, A.

1985-03-01

La Plata Observatory will welcome visitors to ESO-La Silla that are willing to make a stop at Buenos Aires on their trip to Chile or on their way back. There is a nice guesthouse at the Observatory that can be used, for a couple of days or so, by astronomers interested in visiting the Observatory and delivering talks on their research work to the Argentine colleagues. No payments can, however, be made at present. La Plata is at 60 km from Buenos Aires. In the same area lie the Instituto de Astronomia y Fisica dei Espacio (IAFE), in Buenos Aires proper, and the Instituto Argentino de Radioastronomia (IAR). about 40 km from Buenos Aires on the way to La Plata. Those interested should contacl: Sr Decano Prof. Cesar A. Mondinalli, or Dr Alejandro Feinstein, Observatorio Astron6mico, Paseo dei Bosque, 1900 La Plata, Argentina. Telex: 31216 CESLA AR.

Solar Power at Play

NASA Astrophysics Data System (ADS)

2007-03-01

For the very first time, astronomers have witnessed the speeding up of an asteroid's rotation, and have shown that it is due to a theoretical effect predicted but never seen before. The international team of scientists used an armada of telescopes to discover that the asteroid's rotation period currently decreases by 1 millisecond every year, as a consequence of the heating of the asteroid's surface by the Sun. Eventually it may spin faster than any known asteroid in the solar system and even break apart. ESO PR Photo 11a/07 ESO PR Photo 11a/07 Asteroid 2000 PH5 "The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is believed to alter the way small bodies in the Solar System rotate," said Stephen Lowry (Queens University Belfast, UK), lead-author of one of the two companion papers in which this work is reported [1, 2]. "The warming caused by sunlight hitting the surfaces of asteroids and meteoroids leads to a gentle recoil effect as the heat is released," he added. "By analogy, if one were to shine light on a propeller over a long enough period, it would start spinning." Although this is an almost immeasurably weak force, its effect over millions of years is far from negligible. Astronomers believe the YORP effect may be responsible for spinning some asteroids up so fast that they break apart, perhaps leading to the formation of double asteroids. Others may be slowed down so that they take many days to complete a full turn. The YORP effect also plays an important role in changing the orbits of asteroids between Mars and Jupiter, including their delivery to planet-crossing orbits, such as those of near-Earth asteroids. Despite its importance, the effect has never been seen acting on a solar system body, until now. Using extensive optical and radar imaging from powerful Earth-based observatories, astronomers have directly observed the YORP effect in action on a small near-Earth asteroid, known as (54509) 2000 PH5. Shortly after its discovery in 2000, it was realised that asteroid 2000 PH5 would be the ideal candidate for such a YORP detection. With a diameter of just 114 metres, it is relatively small and so more susceptible to the effect. Also, it rotates very fast, with one 'day' on the asteroid lasting just over 12 Earth minutes, implying that the YORP effect may have been acting on it for some time. With this in mind, the team of astronomers undertook a long term monitoring campaign of the asteroid with the aim of detecting any tiny changes in its rotation speed. Over a 4-year time span, Stephen Lowry, Alan Fitzsimmons and colleagues took images of the asteroid at a range of telescope sites including ESO's 8.2-m Very Large Telescope array and 3.5-m New Technology Telescope in Chile, the 3.5-m telescope at Calar Alto, Spain, along with a suite of other telescopes from the Czech Republic, the Canary Islands, Hawaii, Spain and Chile. With these facilities the astronomers measured the slight brightness variations as the asteroid rotated. ESO PR Photo 11b/07 ESO PR Photo 11b/07 Radar Images of 2000 PH5 Over the same time period, the radar team led by Patrick Taylor and Jean-Luc Margot of Cornell University employed the unique capabilities of the Arecibo Observatory in Puerto Rico and the Goldstone radar facility in California to observe the asteroid by 'bouncing' a radar pulse off the asteroid and analysing its echo. "With this technique we can reconstruct a 3-D model of the asteroid's shape, with the necessary detail to allow a comparison between the observations and theory," said Taylor. After careful analysis of the optical data, the asteroid's spin rate was seen to steadily increase with time, at a rate that can be explained by the YORP theory. Critically, the effect was observed year after year, for more than 4 years. Furthermore, this number was elegantly supported via analysis of the combined radar and optical data, as it was required that the asteroid is increasing its spin rate at exactly this rate in order for a satisfactory 3-D shape model to be determined. ESO PR Video 11/07 ESO PR Video 11c/07 Watch the Asteroid Move! To predict what will happen to the asteroid in the future, Lowry and his colleagues performed detailed computer simulations using the measured strength of the YORP effect and the detailed shape model. They found that the orbit of the asteroid about the Sun could remain stable for up to the next 35 million years, allowing the rotation period to be reduced by a factor of 36, to just 20 seconds, faster than any asteroid whose rotation has been measured until now. "This exceptionally fast spin-rate could force the asteroid to reshape itself or even split apart, leading to the birth of a new double system," said Lowry.

Triton's Summer Sky of Methane and Carbon Monoxide

NASA Astrophysics Data System (ADS)

2010-04-01

According to the first ever infrared analysis of the atmosphere of Neptune's moon Triton, summer is in full swing in its southern hemisphere. The European observing team used ESO's Very Large Telescope and discovered carbon monoxide and made the first ground-based detection of methane in Triton's thin atmosphere. These observations revealed that the thin atmosphere varies seasonally, thickening when warmed. "We have found real evidence that the Sun still makes its presence felt on Triton, even from so far away. This icy moon actually has seasons just as we do on Earth, but they change far more slowly," says Emmanuel Lellouch, the lead author of the paper reporting these results in Astronomy & Astrophysics. On Triton, where the average surface temperature is about minus 235 degrees Celsius, it is currently summer in the southern hemisphere and winter in the northern. As Triton's southern hemisphere warms up, a thin layer of frozen nitrogen, methane, and carbon monoxide on Triton's surface sublimates into gas, thickening the icy atmosphere as the season progresses during Neptune's 165-year orbit around the Sun. A season on Triton lasts a little over 40 years, and Triton passed the southern summer solstice in 2000. Based on the amount of gas measured, Lellouch and his colleagues estimate that Triton's atmospheric pressure may have risen by a factor of four compared to the measurements made by Voyager 2 in 1989, when it was still spring on the giant moon. The atmospheric pressure on Triton is now between 40 and 65 microbars - 20 000 times less than on Earth. Carbon monoxide was known to be present as ice on the surface, but Lellouch and his team discovered that Triton's upper surface layer is enriched with carbon monoxide ice by about a factor of ten compared to the deeper layers, and that it is this upper "film" that feeds the atmosphere. While the majority of Triton's atmosphere is nitrogen (much like on Earth), the methane in the atmosphere, first detected by Voyager 2, and only now confirmed in this study from Earth, plays an important role as well. "Climate and atmospheric models of Triton have to be revisited now, now that we have found carbon monoxide and re-measured the methane," says co-author Catherine de Bergh. Of Neptune's 13 moons, Triton is by far the largest, and, at 2700 kilometres in diameter (or three quarters the Earth's Moon), is the seventh largest moon in the whole Solar System. Since its discovery in 1846, Triton has fascinated astronomers thanks to its geologic activity, the many different types of surface ices, such as frozen nitrogen as well as water and dry ice (frozen carbon dioxide), and its unique retrograde motion [1]. Observing the atmosphere of Triton, which is roughly 30 times further from the Sun than Earth, is not easy. In the 1980s, astronomers theorised that the atmosphere on Neptune's moon might be as thick as that of Mars (7 millibars). It wasn't until Voyager 2 passed the planet in 1989 that the atmosphere of nitrogen and methane, at an actual pressure of 14 microbars, 70 000 times less dense than the atmosphere on Earth, was measured. Since then, ground-based observations have been limited. Observations of stellar occultations (a phenomenon that occurs when a Solar System body passes in front of a star and blocks its light) indicated that Triton's surface pressure was increasing in the 1990's. It took the development of the Cryogenic High-Resolution Infrared Echelle Spectrograph (CRIRES) at the Very Large Telescope (VLT) to provide the team the chance to perform a far more detailed study of Triton's atmosphere. "We needed the sensitivity and capability of CRIRES to take very detailed spectra to look at the very tenuous atmosphere," says co-author Ulli Käufl. The observations are part of a campaign that also includes a study of Pluto [eso0908]. Pluto, often considered a cousin of Triton and with similar conditions, is receiving renewed interest in the light of the carbon monoxide discovery, and astronomers are racing to find this chemical on the even more distant dwarf planet. This is just the first step for astronomers using CRIRES to understand the physics of distant bodies in the Solar System. "We can now start monitoring the atmosphere and learn a lot about the seasonal evolution of Triton over decades," Lellouch says. Notes [1] Triton is the only large moon in the Solar System with a retrograde motion, which is a motion in the opposite direction to its planet's rotation. This is one of the reasons why Triton is thought to have been captured from the Kuiper Belt, and thus shares many features with the dwarf planets, such as Pluto. More information This research was presented in a paper to appear in Astronomy & Astrophysics ("Detection of CO in Triton's atmosphere and the nature of surface-atmosphere interactions", by E. Lellouch et al.), reference DOI : 10.1051/0004-6361/201014339. The team is composed of E. Lellouch, C. de Bergh, B. Sicardy (LESIA, Observatoire de Paris, France), S. Ferron (ACRI-ST, Sophia-Antipolis, France), and H.-U. Käufl (ESO). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Richest Planetary System Discovered - Up to seven planets orbiting a Sun-like star

NASA Astrophysics Data System (ADS)

2010-08-01

Astronomers using ESO's world-leading HARPS instrument have discovered a planetary system containing at least five planets, orbiting the Sun-like star HD 10180. The researchers also have tantalising evidence that two other planets may be present, one of which would have the lowest mass ever found. This would make the system similar to our Solar System in terms of the number of planets (seven as compared to the Solar System's eight planets). Furthermore, the team also found evidence that the distances of the planets from their star follow a regular pattern, as also seen in our Solar System. "We have found what is most likely the system with the most planets yet discovered," says Christophe Lovis, lead author of the paper reporting the result. "This remarkable discovery also highlights the fact that we are now entering a new era in exoplanet research: the study of complex planetary systems and not just of individual planets. Studies of planetary motions in the new system reveal complex gravitational interactions between the planets and give us insights into the long-term evolution of the system." The team of astronomers used the HARPS spectrograph, attached to ESO's 3.6-metre telescope at La Silla, Chile, for a six-year-long study of the Sun-like star HD 10180, located 127 light-years away in the southern constellation of Hydrus (the Male Water Snake). HARPS is an instrument with unrivalled measurement stability and great precision and is the world's most successful exoplanet hunter. Thanks to the 190 individual HARPS measurements, the astronomers detected the tiny back and forth motions of the star caused by the complex gravitational attractions from five or more planets. The five strongest signals correspond to planets with Neptune-like masses - between 13 and 25 Earth masses [1] - which orbit the star with periods ranging from about 6 to 600 days. These planets are located between 0.06 and 1.4 times the Earth-Sun distance from their central star. "We also have good reasons to believe that two other planets are present," says Lovis. One would be a Saturn-like planet (with a minimum mass of 65 Earth masses) orbiting in 2200 days. The other would be the least massive exoplanet ever discovered [2], with a mass of about 1.4 times that of the Earth. It is very close to its host star, at just 2 percent of the Earth-Sun distance. One "year" on this planet would last only 1.18 Earth-days. "This object causes a wobble of its star of only about 3 km/hour - slower than walking speed - and this motion is very hard to measure," says team member Damien Ségransan. If confirmed, this object would be another example of a hot rocky planet, similar to Corot-7b (eso0933). The newly discovered system of planets around HD 10180 is unique in several respects. First of all, with at least five Neptune-like planets lying within a distance equivalent to the orbit of Mars, this system is more populated than our Solar System in its inner region, and has many more massive planets there [3]. Furthermore, the system probably has no Jupiter-like gas giant. In addition, all the planets seem to have almost circular orbits. So far, astronomers know of fifteen systems with at least three planets. The last record-holder was 55 Cancri, which contains five planets, two of them being giant planets. "Systems of low-mass planets like the one around HD 10180 appear to be quite common, but their formation history remains a puzzle," says Lovis. Using the new discovery as well as data for other planetary systems, the astronomers found an equivalent of the Titius-Bode law that exists in our Solar System: the distances of the planets from their star seem to follow a regular pattern [4]. "This could be a signature of the formation process of these planetary systems," says team member Michel Mayor. Another important result found by the astronomers while studying these systems is that there is a relationship between the mass of a planetary system and the mass and chemical content of its host star. All very massive planetary systems are found around massive and metal-rich stars, while the four lowest-mass systems are found around lower-mass and metal-poor stars [5]. Such properties confirm current theoretical models. The discovery is announced today at the international colloquium "Detection and dynamics of transiting exoplanets", at the Observatoire de Haute-Provence, France. Notes [1] Using the radial velocity method, astronomers can only estimate a minimum mass for a planet as the mass estimate also depends on the tilt of the orbital plane relative to the line of sight, which is unknown. From a statistical point of view, this minimum mass is however often close to the real mass of the planet. [2] (added 30 August 2010) HD 10180b would be the lowest mass exoplanet discovered orbiting a "normal" star like our Sun. However, lower mass exoplanets have been previously discovered orbiting the pulsar PSR B1257+12 (a highly magnetised rotating neutron star). [3] On average the planets in the inner region of the HD 10180 system have 20 times the mass of the Earth, whereas the inner planets in our own Solar System (Mercury, Venus, Earth and Mars) have an average mass of half that of the Earth. [4] The Titius-Bode law states that the distances of the planets from the Sun follow a simple pattern. For the outer planets, each planet is predicted to be roughly twice as far away from the Sun as the previous object. The hypothesis correctly predicted the orbits of Ceres and Uranus, but failed as a predictor of Neptune's orbit. [5] According to the definition used in astronomy, "metals" are all the elements other than hydrogen and helium. Such metals, except for a very few minor light chemical elements, have all been created by the various generations of stars. Rocky planets are made of "metals". More information This research was presented in a paper submitted to Astronomy and Astrophysics ("The HARPS search for southern extra-solar planets. XXVII. Up to seven planets orbiting HD 10180: probing the architecture of low-mass planetary systems" by C. Lovis et al.). The team is composed of C. Lovis, D. Ségransan, M. Mayor, S. Udry, F. Pepe, and D. Queloz (Observatoire de Genève, Université de Genève, Switzerland), W. Benz (Universität Bern, Switzerland), F. Bouchy (Institut d'Astrophysique de Paris, France), C. Mordasini (Max-Planck-Institut für Astronomie, Heidelberg, Germany), N. C. Santos (Universidade do Porto, Portugal), J. Laskar (Observatoire de Paris, France), A. Correia (Universidade de Aveiro, Portugal), and J.-L. Bertaux (Université Versailles Saint-Quentin, France) and G. Lo Curto (ESO). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Multimodal Identity Texts as Mediational Spaces in Researching Ph.D. Students' Critical Teacher-Researcher Selves

ERIC Educational Resources Information Center

Valencia, Marlon; Herath, Sreemali

2015-01-01

This paper analyses how two Ph.D. students used multimodal identity texts (MMITs) to document their research journeys as they engaged in their doctoral studies. Drawing on qualitative data collected from multiple pre-service teacher preparation programmes in Chile and Sri Lanka, two bi-national researchers (a Colombian-Canadian and a Sri…

Supernova rates from the Southern inTermediate Redshift ESO Supernova Search (STRESS)

NASA Astrophysics Data System (ADS)

Botticella, M. T.; Riello, M.; Cappellaro, E.; Benetti, S.; Altavilla, G.; Pastorello, A.; Turatto, M.; Greggio, L.; Patat, F.; Valenti, S.; Zampieri, L.; Harutyunyan, A.; Pignata, G.; Taubenberger, S.

2008-02-01

Aims:To measure the supernova (SN) rates at intermediate redshift we performed a search, the Southern inTermediate Redshift ESO Supernova Search (STRESS). Unlike most of the current high redshift SN searches, this survey was specifically designed to estimate the rate for both type Ia and core collapse (CC) SNe. Methods: We counted the SNe discovered in a selected galaxy sample measuring SN rate per unit blue band luminosity. Our analysis is based on a sample of 43 000 galaxies and on 25 spectroscopically confirmed SNe plus 64 selected SN candidates. Our approach is aimed at obtaining a direct comparison of the high redshift and local rates and at investigating the dependence of the rates on specific galaxy properties, most notably their colour. Results: The type Ia SN rate, at mean redshift z=0.3, is 0.22+0.10 +0.16-0.08 -0.14 h702 SNu, while the CC SN rate, at z=0.21, is 0.82+0.31 +0.30-0.24 -0.26 h702 SNu. The quoted errors are the statistical and systematic uncertainties. Conclusions: With respect to the local value, the CC SN rate at z=0.2 is higher by a factor of 2, whereas the type Ia SN rate remains almost constant. This implies that a significant fraction of SN Ia progenitors has a lifetime longer than 2{-}3 Gyr. We also measured the SN rates in the red and blue galaxies and found that the SN Ia rate seems to be constant in galaxies of different colour, whereas the CC SN rate seems to peak in blue galaxies, as in the local Universe. SN rates per unit volume were found to be consistent with other measurements showing a steeper evolution with redshift for CC SNe than SNe Ia. We have exploited the link between SFH and SN rates to predict the evolutionary behaviour of the SN rates and compare it with the path indicated by observations. We conclude that in order to constrain the mass range of CC SN progenitors and SN Ia progenitor models it is necessary to reduce the uncertainties in the cosmic SFH. In addition it is important to apply a consistent dust extinction correction both to SF and to CC SN rate and to measure the SN Ia rate in star forming and in passively evolving galaxies over a wide redshift range. Based on observations collected at the European Southern Observatory, using the 2.2 m MPG/ESO telescope on the La Silla (ESO Programmes 62.H-0833, 63.H-0322, 64.H-0390, 67.D-0422, 68.D-0273, 69.D-0453, 72.D-0670, 72.D-0745, 73.D-0670, 74.A-9008, 75.D-0662) and using Very Large Telescope on the Cerro Paranal (ESO Programme 74.D-0714). Table [see full textsee full textsee full text], Figs. [see full textsee full textsee full text]-[see full textsee full textsee full text] are only available in electronic form at http://www.aanda.org

VLBA Teams With Optical Interferometer to Study Star's Layers

NASA Astrophysics Data System (ADS)

2007-05-01

Two of the World's Largest Interferometric Facilities Team-up to Study a Red Giant Star Using ESO's VLTI on Cerro Paranal and the VLBA facility operated by NRAO, an international team of astronomers has made what is arguably the most detailed study of the environment of a pulsating red giant star. They performed, for the first time, a series of coordinated observations of three separate layers within the star's tenuous outer envelope: the molecular shell, the dust shell, and the maser shell, leading to significant progress in our understanding of the mechanism of how, before dying, evolved stars lose mass and return it to the interstellar medium. S Orionis (S Ori) belongs to the class of Mira-type variable stars. It is a solar-mass star that, as will be the fate of our Sun in 5 billion years, is nearing its gloomy end as a white dwarf. Mira stars are very large and lose huge amounts of matter. Every year, S Ori ejects as much as the equivalent of Earth's mass into the cosmos. ESO PR Photo 25a/07 ESO PR Photo 25a/07 Evolution of the Mira-type Star S Orionis "Because we are all stardust, studying the phases in the life of a star when processed matter is sent back to the interstellar medium to be used for the next generation of stars, planets... and humans, is very important," said Markus Wittkowski, lead author of the paper reporting the results. A star such as the Sun will lose between a third and half of its mass during the Mira phase. S Ori pulsates with a period of 420 days. In the course of its cycle, it changes its brightness by a factor of the order of 500, while its diameter varies by about 20%. Although such stars are enormous - they are typically larger than the current Sun by a factor of a few hundred, i.e. they encompass the orbit of the Earth around the Sun - they are also distant and to peer into their deep envelopes requires very high resolution. This can only be achieved with interferometric techniques. ESO PR Photo 25b/07 ESO PR Photo 25b/07 Structure of S Ori (Artist's Impression) "Astronomers are like medical doctors, who use various instruments to examine different parts of the human body," said co-author David Boboltz. "While the mouth can be checked with a simple light, a stethoscope is required to listen to the heart beat. Similarly the heart of the star can be observed in the optical, the molecular and dust layers can be studied in the infrared and the maser emission can be probed with radio instruments. Only the combination of the three gives us a more complete picture of the star and its envelope." The maser emission comes from silicon monoxide (SiO) molecules and can be used to image and track the motion of gas clouds in the stellar envelope roughly 10 times the size of the Sun. The astronomers observed S Ori with two of the largest interferometric facilities available: the ESO Very Large Telescope Interferometer (VLTI) at Paranal, observing in the near- and mid-infrared, and the NRAO-operated Very Long Baseline Array (VLBA), that takes measurements in the radio wave domain. Because the star's luminosity changes periodically, the astronomers observed it simultaneously with both instruments, at several different epochs. The first epoch occurred close to the stellar minimum luminosity and the last just after the maximum on the next cycle. ESO PR Photo 25c/07 ESO PR Photo 25c/07 S Ori to Scale (Artist's Impression) The astronomers found the star's diameter to vary between 7.9 milliarcseconds and 9.7 milliarcseconds. At the distance of S Ori, this corresponds to a change of the radius from about 1.9 to 2.3 times the distance between the Earth and the Sun, or between 400 and 500 solar radii! As if such sizes were not enough, the inner dust shell is found to be about twice as big. The maser spots, which also form at about twice the radius of the star, show the typical structure of partial to full rings with a clumpy distribution. Their velocities indicate that the gas is expanding radially, moving away at a speed of about 10 km/s. The multi-wavelength analysis indicates that near the minimum there is more dust production and mass ejection: in these phases indeed the amount of dust is significantly higher than in the others. After this intense matter production and ejection the star continues its pulsation and when it reaches the maximum luminosity, it displays a much more expanded dust shell. This clearly supports a strong connection between the Mira pulsation and the dust production and expulsion. Furthermore, the astronomers found that grains of aluminum oxide - also called corundum - constitute most of S Ori's dust shell: the grain size is estimated to be of the order of 10 millionths of a centimetre, that is one thousand times smaller than the diameter of a human hair. "We know one chapter of the secret life of a Mira star, but much more can be learned in the near future, when we add near-infrared interferometry with the AMBER instrument on the VLTI to our (already broad) observational approach," said Wittkowski. More Information The research presented here is reported in a paper in press in the journal Astronomy and Astrophysics ("The Mira variable S Ori: Relationships between the photosphere, molecular layer, dust shell, and SiO maser shell at 4 epochs", by M. Wittkowski et al.). It is available in PDF format from the publisher's web site. The team consists of Markus Wittkowski (ESO), David A. Boboltz (U.S. Naval Observatory, USA), Keiichi Ohnaka and Thomas Driebe (MPIfR Bonn, Germany), and Michael Scholz (University of Heidelberg, Germany and University of Sydney, Australia). Notes A maser is the microwave equivalent to a laser, which emits visible light. A maser emits powerful microwave radiation instead and its study requires radio telescopes. An astrophysical maser is a naturally occurring source of stimulated emission that may arise in molecular clouds, comets, planetary atmospheres, stellar atmospheres, or from various conditions in interstellar space. ESO operates the Very Large Telescope Interferometer at Paranal Observatory, Chile, with four fixed 8.2-m telescopes and four relocatable 1.8-m telescopes, working at optical/infrared wavelengths. NRAO operates the Very Long Baseline Array with 10 stations across the U.S. working at radio wavelengths between 3 mm and 90 cm (0.3-90 GHz). ESO, NRAO and other partners will operate the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, working at millimetre wavelengths between 0.3 and 10 mm (30-950 GHz)

No Place to Hide: Missing Primitive Stars Outside Milky Way Uncovered

NASA Astrophysics Data System (ADS)

2010-02-01

After years of successful concealment, the most primitive stars outside our Milky Way galaxy have finally been unmasked. New observations using ESO's Very Large Telescope have been used to solve an important astrophysical puzzle concerning the oldest stars in our galactic neighbourhood - which is crucial for our understanding of the earliest stars in the Universe. "We have, in effect, found a flaw in the forensic methods used until now," says Else Starkenburg, lead author of the paper reporting the study. "Our improved approach allows us to uncover the primitive stars hidden among all the other, more common stars." Primitive stars are thought to have formed from material forged shortly after the Big Bang, 13.7 billion years ago. They typically have less than one thousandth the amount of chemical elements heavier than hydrogen and helium found in the Sun and are called "extremely metal-poor stars" [1]. They belong to one of the first generations of stars in the nearby Universe. Such stars are extremely rare and mainly observed in the Milky Way. Cosmologists think that larger galaxies like the Milky Way formed from the merger of smaller galaxies. Our Milky Way's population of extremely metal-poor or "primitive" stars should already have been present in the dwarf galaxies from which it formed, and similar populations should be present in other dwarf galaxies. "So far, evidence for them has been scarce," says co-author Giuseppina Battaglia. "Large surveys conducted in the last few years kept showing that the most ancient populations of stars in the Milky Way and dwarf galaxies did not match, which was not at all expected from cosmological models." Element abundances are measured from spectra, which provide the chemical fingerprints of stars [2]. The Dwarf galaxies Abundances and Radial-velocities Team [3] used the FLAMES instrument on ESO's Very Large Telescope to measure the spectra of over 2000 individual giant stars in four of our galactic neighbours, the Fornax, Sculptor, Sextans and Carina dwarf galaxies. Since the dwarf galaxies are typically 300 000 light years away - which is about three times the size of our Milky Way - only strong features in the spectrum could be measured, like a vague, smeared fingerprint. The team found that none of their large collection of spectral fingerprints actually seemed to belong to the class of stars they were after, the rare, extremely metal-poor stars found in the Milky Way. The team of astronomers around Starkenburg has now shed new light on the problem through careful comparison of spectra to computer-based models. They found that only subtle differences distinguish the chemical fingerprint of a normal metal-poor star from that of an extremely metal-poor star, explaining why previous methods did not succeed in making the identification. The astronomers also confirmed the almost pristine status of several extremely metal-poor stars thanks to much more detailed spectra obtained with the UVES instrument on ESO's Very Large Telescope. "Compared to the vague fingerprints we had before, this would be as if we looked at the fingerprint through a microscope," explains team member Vanessa Hill. "Unfortunately, just a small number of stars can be observed this way because it is very time consuming." "Among the new extremely metal-poor stars discovered in these dwarf galaxies, three have a relative amount of heavy chemical elements between only 1/3000 and 1/10 000 of what is observed in our Sun, including the current record holder of the most primitive star found outside the Milky Way," says team member Martin Tafelmeyer. "Not only has our work revealed some of the very interesting, first stars in these galaxies, but it also provides a new, powerful technique to uncover more such stars," concludes Starkenburg. "From now on there is no place left to hide!" Notes [1] According to the definition used in astronomy, "metals" are all the elements other than hydrogen and helium. Such metals, except for a very few minor light chemical elements, have all been created by the various generations of stars. [2] As every rainbow demonstrates, white light can be split up into different colours. Astronomers artificially split up the light they receive from distant objects into its different colours (or wavelengths). However, where we distinguish seven rainbow colours, astronomers map hundreds of finely nuanced colours, producing a spectrum - a record of the different amounts of light the object emits in each narrow colour band. The details of the spectrum - more light emitted at some colours, less light at others - provide tell-tale signs about the chemical composition of the matter producing the light. [3] The Dwarf galaxies Abundances and Radial-velocities Team (DART) has members from institutes in nine different countries. More information This research was presented in a paper to appear in Astronomy and Astrophysics ("The NIR Ca II triplet at low metallicity", E. Starkenburg et al.). Another paper is also in preparation (Tafelmeyer et al.) that presents the UVES measurements of several primitive stars. The team is composed of Else Starkenburg, Eline Tolstoy, Amina Helmi, and Thomas de Boer (Kapteyn Astronomical Institute, University of Groningen, the Netherlands), Vanessa Hill (Laboratoire Cassiopée, Université de Nice Sophia Antipolis, Observatoire de la Côte d'Azur, CNRS, France), Jonay I. González Hernández (Observatoire de Paris, CNRS, Meudon, France and Universidad Complutense de Madrid, Spain), Mike Irwin (University of Cambridge, UK), Giuseppina Battaglia (ESO), Pascale Jablonka and Martin Tafelmeyer (Université de Genève, Ecole Polytechnique Fédérale de Lausanne, Switzerland), Matthew Shetrone (University of Texas, McDonald Observatory, USA), and Kim Venn (University of Victoria, Canada). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Geriatric dentistry content in the curriculum of the dental schools in Chile.

PubMed

León, Soraya; Araya-Bustos, Francisca; Ettinger, Ronald L; Giacaman, Rodrigo A

2016-09-01

The purpose of this study was to identify the status of pre-doctoral geriatric dentistry education among all Chilean dental schools. Chile is one of the most rapidly ageing countries in Latin America. Consequently, specific knowledge and training on the needs of elderly populations need to be emphasised in dental schools. The current extent and methods of teaching geriatric dentistry among the dental schools in Chile are unknown. A web-based questionnaire was developed and sent to all 19 Chilean dental schools to identify which schools had a formal programme on geriatric dentistry and ask about their format, content and type of training of the faculty who taught in the programmes. Data were analysed, and a comparison was made among the schools. Sixteen (84%) of the participant schools reported teaching at least some aspects of geriatric dentistry, using various methodologies, but only 7 (37%) had specific courses. Of those schools reporting a didactic content on geriatric dentistry, 71% included clinical training, either in the school's dental clinics or in an extramural service. Contents mostly included demographics of ageing, theories of ageing and medical conditions. More than half of the faculty (57%) stated that they had formal training in geriatric dentistry, 43% were trained in prosthodontics, public health or other areas. Although most dental schools taught geriatric dentistry, only some had a specific course. Most schools with formal courses followed the international curriculum guidelines for geriatric dentistry. © 2014 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.

MHC class II/ESO tetramer-based generation of in vitro primed anti-tumor T-helper lines for adoptive cell therapy of cancer.

PubMed

Poli, Caroline; Raffin, Caroline; Dojcinovic, Danijel; Luescher, Immanuel; Ayyoub, Maha; Valmori, Danila

2013-02-01

Generation of tumor-antigen specific CD4(+) T-helper (T(H)) lines through in vitro priming is of interest for adoptive cell therapy of cancer, but the development of this approach has been limited by the lack of appropriate tools to identify and isolate low frequency tumor antigen-specific CD4(+) T cells. Here, we have used recently developed MHC class II/peptide tetramers incorporating an immunodominant peptide from NY-ESO-1 (ESO), a tumor antigen frequently expressed in different human solid and hematologic cancers, to implement an in vitro priming platform allowing the generation of ESO-specific T(H) lines. We isolated phenotypically defined CD4(+) T-cell subpopulations from circulating lymphocytes of DR52b(+) healthy donors by flow cytometry cell sorting and stimulated them in vitro with peptide ESO(119-143), autologous APC and IL-2. We assessed the frequency of ESO-specific cells in the cultures by staining with DR52b/ESO(119-143) tetramers (ESO-tetramers) and TCR repertoire of ESO-tetramer(+) cells by co-staining with TCR variable β chain (BV) specific antibodies. We isolated ESO-tetramer(+) cells by flow cytometry cell sorting and expanded them with PHA, APC and IL-2 to generate ESO-specific T(H) lines. We characterized the lines for antigen recognition, by stimulation with ESO peptide or recombinant protein, cytokine production, by intracellular staining using specific antibodies, and alloreactivity, by stimulation with allo-APC. Using this approach, we could consistently generate ESO-tetramer(+) T(H) lines from conventional CD4(+)CD25(-) naïve and central memory populations, but not from effector memory populations or CD4(+)CD25(+) Treg. In vitro primed T(H) lines recognized ESO with affinities comparable to ESO-tetramer(+) cells from patients immunized with an ESO vaccine and used a similar TCR repertoire. In this study, using MHC class II/ESO tetramers, we have implemented an in vitro priming platform allowing the generation of ESO-monospecific polyclonal T(H) lines from non-immune individuals. This is an approach that is of potential interest for adoptive cell therapy of patients bearing ESO-expressing cancers.

The Gaia-ESO Survey: dynamics of ionized and neutral gas in the Lagoon nebula (M 8)

NASA Astrophysics Data System (ADS)

Damiani, F.; Bonito, R.; Prisinzano, L.; Zwitter, T.; Bayo, A.; Kalari, V.; Jiménez-Esteban, F. M.; Costado, M. T.; Jofré, P.; Randich, S.; Flaccomio, E.; Lanzafame, A. C.; Lardo, C.; Morbidelli, L.; Zaggia, S.

2017-08-01

Aims: We present a spectroscopic study of the dynamics of the ionized and neutral gas throughout the Lagoon nebula (M 8), using VLT-FLAMES data from the Gaia-ESO Survey. The new data permit exploration of the physical connections between the nebular gas and the stellar population of the associated star cluster NGC 6530. Methods: We characterized through spectral fitting emission lines of Hα, [N II] and [S II] doublets, [O III], and absorption lines of sodium D doublet, using data from the FLAMES-Giraffe and UVES spectrographs, on more than 1000 sightlines toward the entire face of the Lagoon nebula. Gas temperatures are derived from line-width comparisons, densities from the [S II] doublet ratio, and ionization parameter from Hα/[N II] ratio. Although doubly-peaked emission profiles are rarely found, line asymmetries often imply multiple velocity components along the same line of sight. This is especially true for the sodium absorption, and for the [O III] lines. Results: Spatial maps for density and ionization are derived, and compared to other known properties of the nebula and of its massive stars 9 Sgr, Herschel 36 and HD 165052 which are confirmed to provide most of the ionizing flux. The detailed velocity fields across the nebula show several expanding shells, related to the cluster NGC 6530, the O stars 9 Sgr and Herschel 36, and the massive protostar M 8East-IR. The origins of kinematical expansion and ionization of the NGC 6530 shell appear to be different. We are able to put constrains on the line-of-sight (relative or absolute) distances between some of these objects and the molecular cloud. The data show that the large obscuring band running through the middle of the nebula is being compressed by both sides, which might explain its enhanced density. We also find an unexplained large-scale velocity gradient across the entire nebula. At larger distances, the transition from ionized to neutral gas is studied using the sodium lines. Based on observations collected with the FLAMES spectrograph at VLT/UT2 telescope (Paranal Observatory, ESO, Chile), for the Gaia-ESO Large Public Survey (program 188.B-3002).Full Tables A.1 and A.2 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/A135

Co-infection patterns of infectious salmon anaemia and sea lice in farmed Atlantic salmon, Salmo salar L., in southern Chile (2007-2009).

PubMed

Valdes-Donoso, P; Mardones, F O; Jarpa, M; Ulloa, M; Carpenter, T E; Perez, A M

2013-03-01

Infectious salmon anaemia virus (ISAV) caused a large epidemic in farmed Atlantic salmon in Chile in 2007-2009. Here, we assessed co-infection patterns of ISAV and sea lice (SL) based on surveillance data collected by the fish health authority. ISAV status and SL counts in all Atlantic salmon farms located in the 10th region of Chile were registered monthly from July 2007 through December 2009. Each farm was categorized monthly according to its ISAV and SL status. A multinomial time-space scan test using a circular window was applied to identify disease clusters, and a multivariate regression model was fitted to quantify the association between disease-clustering and farm-management factors. Most of the identified clusters (9/13) were associated with high SL burdens. There were significant associations (P < 0.05) between management factors and ISAV/SL status. Areas in which good management practices were associated with a reduced disease risk were identified. The findings of this study suggest that certain management practices can effectively reduce the risk of SL and ISAV in the face of an epidemic and will be helpful towards creating an effective disease control programme in Chile. © 2013 Blackwell Publishing Ltd.

Spectroscopy of High-Redshift Supernovae from the ESSENCE Project: The First 2 Years

NASA Astrophysics Data System (ADS)

Matheson, Thomas; Blondin, Stéphane; Foley, Ryan J.; Chornock, Ryan; Filippenko, Alexei V.; Leibundgut, Bruno; Smith, R. Chris; Sollerman, Jesper; Spyromilio, Jason; Kirshner, Robert P.; Clocchiatti, Alejandro; Aguilera, Claudio; Barris, Brian; Becker, Andrew C.; Challis, Peter; Covarrubias, Ricardo; Garnavich, Peter; Hicken, Malcolm; Jha, Saurabh; Krisciunas, Kevin; Li, Weidong; Miceli, Anthony; Miknaitis, Gajus; Prieto, Jose Luis; Rest, Armin; Riess, Adam G.; Salvo, Maria Elena; Schmidt, Brian P.; Stubbs, Christopher W.; Suntzeff, Nicholas B.; Tonry, John L.

2005-05-01

We present the results of spectroscopic observations of targets discovered during the first 2 years of the ESSENCE project. The goal of ESSENCE is to use a sample of ~200 Type Ia supernovae (SNe Ia) at moderate redshifts (0.2<~z<~0.8) to place constraints on the equation of state of the universe. Spectroscopy not only provides the redshifts of the objects but also confirms that some of the discoveries are indeed SNe Ia. This confirmation is critical to the project, as techniques developed to determine luminosity distances to SNe Ia depend on the knowledge that the objects at high redshift have the same properties as the ones at low redshift. We describe the methods of target selection and prioritization, the telescopes and detectors, and the software used to identify objects. The redshifts deduced from spectral matching of high-redshift SNe Ia with low-redshift SNe Ia are consistent with those determined from host-galaxy spectra. We show that the high-redshift SNe Ia match well with low-redshift templates. We include all spectra obtained by the ESSENCE project, including 52 SNe Ia, five core-collapse SNe, 12 active galactic nuclei, 19 galaxies, four possibly variable stars, and 16 objects with uncertain identifications. Based in part on observations obtained at the Cerro Tololo Inter-American Observatory, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under a cooperative agreement with the National Science Foundation (NSF); the European Southern Observatory, Chile (ESO Programme 170.A-0519) the Gemini Observatory, which is operated by AURA under a cooperative agreement with the NSF on behalf of the Gemini partnership (the NSF [United States], the Particle Physics and Astronomy Research Council [United Kingdom], the National Research Council [Canada], CONICYT [Chile], the Australian Research Council [Australia], CNPq [Brazil], and CONICET [Argentina] [programs GN-2002B-Q-14, GN-2003B-Q-14, and GS-2003B-Q-11]) the Magellan Telescopes at Las Campanas Observatory; the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona; and the F. L. Whipple Observatory, which is operated by the Smithsonian Astrophysical Observatory. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration; the Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

World's Biggest Astronomy Event on the World-Wide

NASA Astrophysics Data System (ADS)

1996-06-01

`Astronomy On-Line' will connect students all over Europe Astronomy On-Line is a major, all-European project that will take place in conjunction with the 4th European Week for Scientific and Technological Culture later this year. It is based on intensive use of the World-Wide-Web (WWW) and represents the first large-scale attempt in the world to bring together pupils and their teachers all over one continent to explore challenging scientific questions, using modern communication tools, both for obtaining and for communicating information. The programme will be carried out in a collaboration between the European Association for Astronomy Education (EAAE) [1] and the European Southern Observatory, and together with the European Commission (EC). The active phase of Astronomy On-Line will start on October 1 and reach a climax on November 18 - 22, 1996 . What is `Astronomy On-Line'? In this project, a large number of students and their teachers at schools all over Europe, together with professional and amateur astronomers and others interested in astronomy, will become associated in a unique experience that makes intensive use of the vast possibilities of the World-Wide-Web (WWW). Although the exact number of participants will not be known until the beginning of October, it is expected to run into thousands, possibly many more. The unusual size and scope of Astronomy On-Line will contribute to make it an important all-European media event. The central idea is that the participants, through the WWW, will `meet' in a `marketplace' where a number of different `shops' will be available, each of which will tempt them with a number of exciting and educational `events', carefully prepared to cater for different age groups, from 12 years upwards. The events will cover a wide spectrum of activities, some of which will be timed to ensure the proper progression of this very complex project through its main phases. The benefits In fact, Astronomy On-Line will be the first, internationally organised and fully structured programme which offers a large number of students the possibility to familiarize themselves with the use of this communication tool of the future, unequalled possibilities for fruitful international communication, and at the same time to learn much about the science and technology of astronomy, including the scientific methods now being practiced by the world's scientists. Within this framework, they can actively contribute to co-ordinated sub-programmes that will draw on the combined forces and ingenuity of participants from all areas of Europe. There are many other side benefits, of course, such as stimulating schools to go on-line, prompting international cooperation among the young people, etc. Another important aspect is that the programme will lead to natural involvement of business and industrial partners in local areas of the participating groups. Also its unique character and international implications will be very inviting for extensive media coverage, both in human and scientific/technological terms. The organisation An enormous programme like Astronomy On-Line obviously represents a tremendous challenge to the organisers, and careful planning is crucial to its success. This is ensured by the active participation of experienced educators, scientists and engineers in most European countries, united by the common goal to prepare a well-structured event that is exciting for everybody and which has clearly defined roles and responsibilities for all involved parties. An International Steering Committee (ISC) has been established for the programme. The ICS is responsible for the planning of the main activities, together with National Steering Committees (NSC) which will coordinate the Programme in their respective countries. The NSC's are still in the process of being formed and for the time being, most EAAE National Representatives will act as contact points for the programme in their areas. Full information about the organisational and technical aspects of the Programme is available on two central WWW nodes. They will be continuously updated as the programme is specified in increasing detail. The Astronomy On-Line WWW Homepages can be reached under: http://www.eso.org/outreach/spec-prog/aol/ and http://www.algonet.se/~sirius/eaae.htm Announcements about National WWW Homepages for the Programme, now being set up by the NCS's, will follow on the above WWW Homepages. Participation The NSCs will soon issue a call for participation to interested schools, astronomy clubs and other astronomy-interested persons in their respective areas. The deadline for registration is October 1, 1996 , the day when the first active phase of the Programme will start. Participants must register with the appropriate NSC. Participating groups may consist of at least one teacher and his/her students or of one or more astronomy enthousiasts. Each group must have access to the WWW. If access is not yet available at the school, this may be arranged by `sponsors' in the local area. These may be planetaria, science institutes, business undertakings (e.g. in the field of electronics, computers, communication, etc.), industrial firms or private benefactors. All communication via the WWW will take place in English. Only registered groups can participate actively. The main phases Astronomy On-Line will be divided into three phases, lasting from October 1 to November 22, 1996, and reflecting the gradual progression of the associated activities. Phase 1 will last about six weeks, from early October to the beginning of the 4th European Week for Scientific and Technological Culture. During this period, the participating groups will have the possibility of preparing themselves for the active participation, for instance to familiarize themselves with the hard- and software as well as to consider specific programme opportunities, now becoming available on the WWW pages. Regional or international `clusters of groups' may form at this time. Phase 2 will take place on Monday, November 18 and Tuesday, November 19, 1996. On these and the three following days ( Phase 3 : November 20--22), the `active period' will be in the six-hour interval from 15h to 21h UT [2]. Various events are planned to happen at certain times and in certain places on the WWW, keeping the programme lively and enhancing the interaction by ensuring continued attention and expectation by the participants. During Phases 2 and 3, nine or more `shops' will be available in the Astronomy On-Line WWW `marketplaces' for consultation by the participants. They will display a variety of `goods' (activities) at different levels of complexity in order to attract participants of different age groups, among others: General information; Collaborative projects which require observations by many groups all over the continent; Real astronomical observations to be submitted and executed with telescopes at participating, professional observatories; Prepared exercises which may include guided searches on the WWW; Opportunities to talk to professional astronomers, etc. More details are available at the above mentioned WWW sites. Ideas for further activities are now being actively solicited by the Steering Committees. At the end, the various results will be presented on the WWW in the form of short reports which may be commented upon, as far as possible in real time. A `final event' which will `unite' participants from all over Europe will be planned on the last day. Notes: [1] The EAAE was founded in November 1994 (cf. ESO Press Release 17/94 of 2 December 1994) and now has several hundred members located in virtually all European countries; most are secondary school physics teachers with a particular interest in astronomy. [2] This period of the day has been chosen to allow students to participate outside the the normal school hours, and by taking into account the time zones across Europe (from UT in the West to UT+2h in East). How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

ESO Council Visits First VLT Unit Telescope Structure in Milan

NASA Astrophysics Data System (ADS)

1995-12-01

As the ESO Very Large Telescope (VLT) rapidly takes on shape, Europe has just come one step closer to the realisation of its 556 million DEM astronomical showcase project. Last week, the ESO Council held its semi-annual meeting in Milan (Italy) [1]. During a break in the long agenda list, Council members had the opportunity to visit the Ansaldo factory in the outskirts of this city and to see for the first time the assembled mechanical structure of one of the four 8.2-metre VLT Unit telescopes. This Press Release is accompanied by a photo that shows the ESO Council delegates in front of the giant telescope. After a long climb up the steep staircase to the large Nasmyth platform at the side of the telescope where the astronomical instruments will later be placed, Dr. Peter Creola (Switzerland) , President of the ESO Council and a mechanics expert, grabbed the handrail and surveyed the structure with a professional eye: `I knew it was going to be big, but not that enormous!', he said. Other delegates experienced similar feelings, especially when they watched the 430 tonnes of steel in the 24-metre tall and squat structure turn smoothly and silently around the vertical axis. The Chairman of the ESO Scientific Technical Committee (STC), Dr. Johannes Andersen (Denmark) , summarized his first, close encounter with the VLT by `This is great fun!' and several of his colleague astronomers were soon seen in various corners of the vast structure, engaged in elated discussions about the first scientific investigations to be done with the VLT in two years' time. The VLT Main Structures The visit by Council took place at the invitation of Ansaldo Energia S.p.A. (Genova), EIE-European Industrial Engineering S.r.I. (Venice) and SOIMI-Societa Impianti Industriale S.p.A. (Milan), the three Italian enterprises responsible for the construction of the main structures of the VLT 8.2-metre Unit telescopes. Short speeches were given on this occasion by Drs. Ferruccio Bressani (Ansaldo), Luigi Guiffrida (SOIMI), Gianpietro Marchiori (EIE) and Prof. Massimo Tarenghi (ESO), describing the very successful implementation of this major VLT contract that was awarded by ESO in September 1991 [2]. All speakers praised the good collaboration between ESO and its industrial partners and Prof. Riccardo Giacconi , Director General of ESO, expressed his satisfaction `with the splendid performance of the ESO-Industry team which was bringing us close to the realisation of the premier telescope array in optical ground-based astronomy in the world'. The participants were also pleased to listen to several of the Italian engineers present who commented on the very positive experience of being personally involved in the world's largest telescope project. The VLT telescope structures incorporate many new technological concepts. Thanks to these and careful planning of the many components and their integration, it has been possible to achieve, among others, light weight construction, high mechanical stiffness, good thermal equilibrium with the ambient air (of importance for the seeing during the observations), low electromagnetic emissitivity (i.e. low interference with the sensitive astronomical instruments) and easy maintainability. Of particular interest is also the giant, direct drive system with a diameter of 9 metres and the sophisticated, innovative laser encoder system. In this way, there is no direct contact between the moving parts and the friction during the rotation is kept at an absolute minimum. The Next Steps The ESO VLT project is now entering into a decisive phase and the next years will see an increasing number of telescope parts and instruments from the scientific and industrial laboratories of Europe converging towards the VLT observatory at Cerro Paranal in Chile. It is gratifying that, despite its high degree of complexity and incorporation of a substantial number of new technologies, the project is within schedule and budget. There will be several important milestones in 1996. During the next two months, the mounting of the mechanical structure in Milan will be completed. Following this, a group of ESO hard- and software experts will spend about 6 months next to it, implementing and thoroughly testing all aspects of the very advanced VLT telescope control system. In the meantime, the erection of the first telescope enclosure at Paranal is rapidly proceeding and the outside panelling will soon be put in place. This work will be completed in January 1996, after which the integration of all inside mechanical components will follow. The take-over by ESO of the fully operational, first enclosure is scheduled for May 1996. The other enclosures will become ready at regular intervals thereafter. In Milan, all of the heavy parts of the second telescope structure have already been produced and the third and fourth are about 60 percent complete. While the first structure has now been pre-assembled for tests, the individual parts of the second will not be put together before they are shipped to Paranal in early 1996. Starting in June 1996, they will then be assembled inside the completed, first enclosure. Thus, the `second' structure will become the `first' VLT Unit telescope (UT1). This work will last until early 1997, after which the first 8.2-metre mirror will arrive from Europe and be installed. Finally, after another test and optimisation period, `first light' for UT1 is expected in late 1997. This procedure is very advantageous, because it allows to continue under less time pressure the extensive tests on the `first' structure in Milan until a satisfactory state of debugging and optimisation of the new VLT control system has been reached. In this way, the time necessary for the installation of this system in UT1 at Paranal in 1997 will be significantly shortened. In fact, the structure seen by the ESO Council in Milan will be the last to be shipped to Paranal where it will then become the fourth 8.2-metre Unit telescope (UT4). Mirrors and Instruments As earlier announced, ESO officially received the first 8.2-metre VLT mirror from REOSC in Paris [3] on November 21. The polishing of the second mirror has already started and, based on the experience gained with the first, it is expected that this work will be accomplished in less time. The third blank is already at REOSC and the fourth will soon be ready at Schott Glaswerke in Mainz (Germany). Following extended studies, and as yet another move towards new technology within the VLT project, it has now been decided to make the 1.2-metre secondary VLT mirrors of beryllium, a very light, exotic metal. The contracting firm is Dornier of the DASA group (Germany). This saves much weight and allows these relatively large mirrors to be efficiently used in the `chopping and tilting' mode needed for observations in the infrared wavelength region as well as for the critical, image-sharpening adaptive optics system. Significant progress has also been achieved on the first astronomical instruments which will be installed at the VLT. The integration of the first two of these, ISAAC and CONICA which will be installed on UT1 in the course of 1997, has already started in the ESO laboratories at the Headquarters in Garching. Important advances have also taken place within the FORS (managed by a consortium of Landessternwarte Heidelberg, Universitaets-Sternwarte Goettingen and Institut fuer Astronomie und Astrophysik der Ludwig Maximilians Universitaet Muenchen) and FUEGOS (Paris Observatory, Meudon Observatory, Toulouse Observatory, Geneva Observatory and Bologna Observatory) projects. More details about these and other VLT instruments will be given in later communications. Notes: [1] The Council of ESO consists of two representatives from each of the eight member states. It is the highest legislative authority of the organisation and normally meets twice a year. This time, Council was invited to Milan by the Director of the Osservatorio di Brera (Milan), Prof. Guido Chincarini, and the Italian delegation. [2] See ESO Press Release 08/91 of 24 September 1991. [3] See ESO Press Release 15/95 of 13 November 1995. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

Discovery of a stellar companion to the nearby solar-analogue HD 104304

NASA Astrophysics Data System (ADS)

Schnupp, C.; Bergfors, C.; Brandner, W.; Daemgen, S.; Fischer, D.; Marcy, G.; Henning, Th.; Hippler, S.; Janson, M.

2010-06-01

Context. Sun-like stars are promising candidates to host exoplanets and are often included in exoplanet surveys by radial velocity (RV) and direct imaging. In this paper we report on the detection of a stellar companion to the nearby solar-analogue star HD 104304, which previously was considered to host a planetary mass or brown dwarf companion. Aims: We searched for close stellar and substellar companions around extrasolar planet host stars with high angular resolution imaging to characterize planet formation environments. Methods: The detection of the stellar companion was achieved by high angular resolution measurements, using the “Lucky Imaging” technique at the ESO NTT 3.5 m with the AstraLux Sur instrument. We combined the results with VLT/NACO archive data, where the companion could also be detected. The results were compared to precise RV measurements of HD 104304, obtained at the Lick and Keck observatories from 2001-2010. Results: We confirmed common proper motion of the binary system. A spectral type of M4V of the companion and a mass of 0.21 M_⊙ was derived. Due to comparison of the data with RV measurements of the unconfirmed planet candidate listed in the Extrasolar Planets Encyclopaedia, we suggest that the discovered companion is the origin of the RV trend and that the inclination of the orbit of i≈35°explains the relatively small RV signal. Based on observations made with ESO Telescopes at the La Silla and Paranal Observatory under programme IDs 083.C-0145 and 084.C-0812, and on data obtained from the ESO Science Archive Facility.

Two VLT 8.2-m Unit Telescopes in Action

NASA Astrophysics Data System (ADS)

1999-04-01

Visitors at ANTU - Astronomical Images from KUEYEN The VLT Control Room at the Paranal Observatory is becoming a busy place indeed. From here, two specialist teams of ESO astronomers and engineers now operate two VLT 8.2-m Unit Telescopes in parallel, ANTU and KUEYEN (formerly UT1 and UT2, for more information about the naming and the pronunciation, see ESO Press Release 06/99 ). Regular science observations have just started with the first of these giant telescopes, while impressive astronomical images are being obtained with the second. The work is hard, but the mood in the control room is good. Insiders claim that there have even been occasions on which the groups have had a friendly "competition" about which telescope makes the "best" images! The ANTU-team has worked with the FORS multi-mode instrument , their colleagues at KUEYEN use the VLT Test Camera for the ongoing tests of this new telescope. While the first is a highly developed astronomical instrument with a large-field CCD imager (6.8 x 6.8 arcmin 2 in the normal mode; 3.4 x 3.4 arcmin 2 in the high-resolution mode), the other is a less complex CCD camera with a smaller field (1.5 x 1.5 arcmin 2 ), suited to verify the optical performance of the telescope. As these images demonstrate, the performance of the second VLT Unit Telescope is steadily improving and it may not be too long before its optical quality will approach that of the first. First KUEYEN photos of stars and galaxies We present here some of the first astronomical images, taken with the second telescope, KUEYEN, in late March and early April 1999. They reflect the current status of the optical, electronic and mechanical systems, still in the process of being tuned. As expected, the experience gained from ANTU last year has turned out to be invaluable and has allowed good progress during this extremely delicate process. ESO PR Photo 19a/99 ESO PR Photo 19a/99 [Preview - JPEG: 400 x 433 pix - 160k] [Normal - JPEG: 800 x 866 pix - 457k] [High-Res - JPEG: 1985 x 2148 pix - 2.0M] ESO PR Photo 19b/99 ESO PR Photo 19b/99 [Preview - JPEG: 400 x 478 pix - 165k] [Normal - JPEG: 800 x 956 pix - 594k] [High-Res - JPEG: 3000 x 3583 pix - 7.1M] Caption to PR Photo 19a/99 : This photo was obtained with VLT KUEYEN on April 4, 1999. It is reproduced from an excellent 60-second R(ed)-band exposure of the innermost region of a globular cluster, Messier 68 (NGC 4590) , in the southern constellation Hydra (The Water-Snake). The distance to this 8-mag cluster is about 35,000 light years, and the diameter is about 140 light-years. The excellent image quality is 0.38 arcsec , demonstrating a good optical and mechanical state of the telescope, already at this early stage of the commissioning phase. The field measures about 90 x 90 arcsec 2. The original scale is 0.0455 pix/arcsec and there are 2048x2048 pixels in one frame. North is up and East is left. Caption to PR Photo 19b/99 : This photo shows the central region of spiral galaxy ESO 269-57 , located in the southern constellation Centaurus at a distance of about 150 million light-years. Many galaxies are seen in this direction at about the same distance, forming a loose cluster; there are also some fainter, more distant ones in the background. The designation refers to the ESO/Uppsala Survey of the Southern Sky in the 1970's during which over 15,000 southern galaxies were catalogued. ESO 269-57 is a tightly bound object of type Sar , the "r" referring to the "ring" that surrounds the bright centre, that is overexposed here. The photo is a composite, based on three exposures (Blue - 600 sec; Yellow-Green - 300 sec; Red - 300 sec) obtained with KUEYEN on March 28, 1999. The image quality is 0.7 arcsec and the field is 90 x 90 arcsec 2. North is up and East is left. ESO PR Photo 19c/99 ESO PR Photo 19c/99 [Preview - JPEG: 400 x 478 pix - 132k] [Normal - JPEG: 800 x 956 pix - 446k] [High-Res - JPEG: 3000 x 3583 pix - 4.6M] ESO PR Photo 19d/99 ESO PR Photo 19d/99 [Preview - JPEG: 400 x 454 pix - 86k] [Normal - JPEG: 800 x 907 pix - 301k] [High-Res - JPEG: 978 x 1109 pix - 282k] Caption to PR Photo 19c/99 : Somewhat further out in space, and right on the border between the southern constellations Hydra and Centaurus lies this knotty spiral galaxy, IC 4248 ; the distance is about 210 million light-years. It was imaged with KUEYEN on March 28, 1999, with the same filters and exposure times as used for Photo 19b/99. The image quality is 0.75 arcsec and the field is 90 x 90 arcsec 2. North is up and East is left. Caption to PR Photo 19d/99 : This is a close-up view of the double galaxy NGC 5090 (right) and NGC 5091 (left), in the southern constellation Centaurus. The first is a typical S0 galaxy with a bright diffuse centre, surrounded by a fainter envelope of stars (not resolved in this picture). However, some of the starlike objects seen in this region may be globular clusters (or dwarf galaxies) in orbit around NGC 5090. The other galaxy is of type Sa (the spiral structure is more developed) and is seen at a steep angle. The three-colour composite is based on frames obtained with KUEYEN on March 29, 1999, with the same filters and exposure times as used for Photo 19b/99. The image quality is 0.7 arcsec and the field is 90 x 90 arcsec 2. North is up and East is left. ( Note inserted on April 26: The original caption text identified the second galaxy as NGC 5090B - this error has now been corrected. ESO PR Photo 19e/99 ESO PR Photo 19e/99 [Preview - JPEG: 400 x 441 pix - 282k] [Normal - JPEG: 800 x 882 pix - 966k] [High-Res - JPEG: 3000 x 3307 pix - 6,4M] Caption to PR Photo 19e/99 : Wide-angle photo of the second 8.2-m VLT Unit Telescope, KUEYEN , obtained on March 10, 1999, with the main mirror and its cell in place at the bottom of the telescope structure. The Test Camera with which the astronomical images above were made, is positioned at the Cassegrain focus, inside this mirror cell. The Paranal Inauguration on March 5, 1999, took place under this telescope that was tilted towards the horizon to accommodate nearly 300 persons on the observing floor. Astronomical observations with ANTU have started On April 1, 1999, the first 8.2-m VLT Unit Telescope, ANTU , was "handed over" to the astronomers. Last year, about 270 observing proposals competed about the first, precious observing time at Europe's largest optical telescope and more than 100 of these were accommodated within the six-month period until the end of September 1999. The complete observing schedule is available on the web. These observations will be carried out in two different modes. During the Visitor Mode , the astronomers will be present at the telescope, while in the Service Mode , ESO observers perform the observations. The latter procedure allows a greater degree of flexibility and the possibility to assign periods of particularly good observing conditions to programmes whose success is critically dependent on this. The first ten nights at ANTU were allocated to service mode observations. After some initial technical problems with the instruments, these have now started. Already in the first night, programmes at ISAAC requiring 0.4 arcsec conditions could be satisfied, and some images better than 0.3 arcsec were obtained in the near-infrared . The first astronomers to use the telescope in visitors mode will be Professors Immo Appenzeller (Heidelberg, Germany; "Photo-polarimetry of pulsars") and George Miley (Leiden, The Netherlands; "Distant radio galaxies") with their respective team colleagues. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../ ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory. Note also the dedicated webarea with VLT Information.

Confirmation of the binary status of Chamaeleon Hα 2 - a very young low-mass binary in Chamaeleon

NASA Astrophysics Data System (ADS)

Schmidt, T. O. B.; Neuhäuser, R.; Vogt, N.; Seifahrt, A.; Roell, T.; Bedalov, A.

2008-06-01

Context: Neuhäuser & Comerón (1998, Science, 282, 83; 1999, A&A, 350, 612) presented direct imaging evidence, as well as first spectra, of several young stellar and sub-stellar M6- to M8-type objects in the Cha I dark cloud. One of these objects is Cha Hα 2, classified as brown dwarf candidate in several publications and suggested as possible binary in Neuhäuser et al. (2002, A&A, 384, 999). Aims: We have searched around Cha Hα 2 for close and faint companions with adaptive optics imaging. Methods: Two epochs of direct imaging data were taken with the Very Large Telescope (VLT) Adaptive Optics instrument NACO in February 2006 and March 2007 in Ks-band together with a Hipparcos binary for astrometric calibration. Moreover, we took a J-band image in March 2007 to get color information. We retrieved an earlier image from 2005 from the European Southern Observatory (ESO) Science Archive Facility, increasing the available time coverage. After confirmation of common proper motion, we deduce physical parameters of the objects by spectroscopy, like temperature and mass. Results: We find Cha Hα 2 to be a very close binary of 0.16 arcsec separation, having a flux ratio of 0.91, thus having almost equal brightness and indistinguishable spectral types within the errors. We show that the two tentative components of Cha Hα 2 form a common proper motion pair, and that neither component is a non-moving background object. We even find evidence for orbital motion. A combined spectrum of both stars spanning optical and near-infrared parts of the spectral energy distribution yields a temperature of 3000 ± 100 K, corresponding to a spectral type of M6 ± 1 and a surface gravity of log{g} = 4.0+0.75-0.5, both from a comparison with GAIA model atmospheres. Furthermore, we obtained an optical extinction of AV ≃ 4.3 mag from this comparison. Conclusions: We derive masses of 0.110 M⊙ (≥0.070 M⊙) and 0.124 M⊙ (≥0.077 M⊙) for the two components of Cha Hα 2, i.e., probably low-mass stars, but one component could possibly be a brown dwarf. Based on observations made with ESO telescopes at the Paranal Observatory under programme IDs 076.C-0292A, 076.C-0339B, 078.C-0535A, at the La Silla Observatory under programme ID 065.L-0144B, the Hubble Space Telescope under programme ID GO-8716 and on observations made with the European Southern Observatory telescopes obtained from the ESO/ST-ECF Science Archive Facility. Color version of Fig. [see full textsee full text] is only available in electronic form at http://www.aanda.org

Proper motions and membership probabilities of stars in the region of globular cluster NGC 6366

NASA Astrophysics Data System (ADS)

Sariya, Devesh P.; Yadav, R. K. S.

2015-12-01

Context. NGC 6366 is a metal-rich globular cluster that is relatively unstudied. It is a kinematically interesting cluster, reported as belonging to the slowly rotating halo system, which is unusual given its metallicity and spatial location in the Galaxy. Aims: The purpose of this research is to determine the relative proper motion and membership probability of the stars in the region of globular cluster NGC 6366. To target cluster members reliably during spectroscopic surveys without including field stars, a good proper motion and membership probability catalogue of NGC 6366 is needed. Methods: To derive relative proper motions, the archival data from the Wide Field Imager mounted on the ESO 2.2 m telescope have been reduced using a high precision astrometric software. The images used are in the B,V, and I photometric bands with an epoch gap of ~3.2 yr. The calibrated BVI magnitudes have been determined using recent data for secondary standard stars. Results: We determined relative proper motions and cluster membership probabilities for 2530 stars in the field of globular cluster NGC 6366. The median proper motion rms errors for stars brighter than V ~ 18 mag is ~2 mas yr-1, which gradually increases to ~5 mas yr-1 for stars having magnitudes V ~ 20 mag. Based on the membership catalogue, we checked the membership status of the X-ray sources and variable stars of NGC 6366 mentioned in the literature. We also provide the astronomical community with an electronic catalogue that includes B, V, and I magnitudes; relative proper motions; and membership probabilities of the stars in the region of NGC 6366. Based on observations with the MPG/ESO 2.2 m and ESO/VLT telescopes, located at La Silla and Paranal Observatory, Chile, under DDT programs 164.O-0561(F), 71.D-0220(A) and the archive material.Full Table 4 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/584/A59

ESO Large Program on physical studies of Trans-Neptunian objects and Centaurs: Final results of the visible spectrophotometric observations

NASA Astrophysics Data System (ADS)

Fornasier, S.; Doressoundiram, A.; Tozzi, G. P.; Barucci, M. A.; Boehnhardt, H.; de Bergh, C.; Delsanti, A.; Davies, J.; Dotto, E.

2004-07-01

The Large Program on physical studies of TNOs and Centaurs, started at ESO Cerro Paranal on April 2001, has recently been concluded. This project was devoted to the investigation of the surface properties of these icy bodies through photometric and spectroscopic observations. In this paper we present the latest results on these pristine bodies obtained from the spectrophotometric investigation in the visible range. The newly obtained spectrophotometric data on 3 Centaurs and 5 TNOs, coming from 2 observing runs at the Very Large Telescope (VLT), show a large variety of spectral characteristics, comprising both gray and red objects in the two different populations. A very broad and weak absorption feature, centered around 7000 Å , has been revealed in the spectrum of the gray TNO 2003 AZ84. This absorption is very similar to a feature observed on low albedo main belt asteroids and attributed to the action of the aqueous alteration process on minerals. This process was previously also claimed as the most plausible explanation for some peculiar visible absorption bands observed on 2000 EB173 and 2000 GN171 in the framework of the Large Program (Lazzarin et al. \\cite{Lazzarin03}; de Bergh et al. \\cite{Bergh04}). This detection seems to reinforce the hypothesis that aqueous alteration might have taken place also at such large heliocentric distances. We also report the results of a spectroscopic investigation performed outside the Large Program on the very interesting TNO 2000 GN171 during part of its rotational period. This object, previously observed twice in the framework of the Large Program, had shown during the early observations a very peculiar absorption band tentatively attributed to aqueous alteration processes. As this feature was not confirmed in a successive spectrum, we recently repeated the investigations of 2000 GN171, finding out that it has an heterogeneous composition. Finally an analysis of the visible spectral slopes is reported for all the data coming from the Large Program and those available in literature. Based on observations obtained at the VLT Observatory Cerro Paranal of European Southern Observatory, ESO, Chile, in the framework of programs 167.C-0340(G), 071.C-0500.

ESO Reflex: A Graphical Workflow Engine for Data Reduction

NASA Astrophysics Data System (ADS)

Hook, R.; Romaniello, M.; Péron, M.; Ballester, P.; Gabasch, A.; Izzo, C.; Ullgrén, M.; Maisala, S.; Oittinen, T.; Solin, O.; Savolainen, V.; Järveläinen, P.; Tyynelä, J.

2008-08-01

Sampo {http://www.eso.org/sampo} (Hook et al. 2005) is a project led by ESO and conducted by a software development team from Finland as an in-kind contribution to joining ESO. The goal is to assess the needs of the ESO community in the area of data reduction environments and to create pilot software products that illustrate critical steps along the road to a new system. Those prototypes will not only be used to validate concepts and understand requirements but will also be tools of immediate value for the community. Most of the raw data produced by ESO instruments can be reduced using CPL {http://www.eso.org/cpl} recipes: compiled C programs following an ESO standard and utilizing routines provided by the Common Pipeline Library. Currently reduction recipes are run in batch mode as part of the data flow system to generate the input to the ESO VLT/VLTI quality control process and are also made public for external users. Sampo has developed a prototype application called ESO Reflex {http://www.eso.org/sampo/reflex/} that integrates a graphical user interface and existing data reduction algorithms. ESO Reflex can invoke CPL-based recipes in a flexible way through a dedicated interface. ESO Reflex is based on the graphical workflow engine Taverna {http://taverna.sourceforge.net} that was originally developed by the UK eScience community, mostly for work in the life sciences. Workflows have been created so far for three VLT/VLTI instrument modes ( VIMOS/IFU {http://www.eso.org/instruments/vimos/}, FORS spectroscopy {http://www.eso.org/instruments/fors/} and AMBER {http://www.eso.org/instruments/amber/}), and the easy-to-use GUI allows the user to make changes to these or create workflows of their own. Python scripts and IDL procedures can be easily brought into workflows and a variety of visualisation and display options, including custom product inspection and validation steps, are available.

Optical turbulence profiling with Stereo-SCIDAR for VLT and ELT

NASA Astrophysics Data System (ADS)

Osborn, J.; Wilson, R. W.; Sarazin, M.; Butterley, T.; Chacón, A.; Derie, F.; Farley, O. J. D.; Haubois, X.; Laidlaw, D.; LeLouarn, M.; Masciadri, E.; Milli, J.; Navarrete, J.; Townson, M. J.

2018-04-01

Knowledge of the Earth's atmospheric optical turbulence is critical for astronomical instrumentation. Not only does it enable performance verification and optimisation of existing systems but it is required for the design of future instruments. As a minimum this includes integrated astro-atmospheric parameters such as seeing, coherence time and isoplanatic angle, but for more sophisticated systems such as wide field adaptive optics enabled instrumentation the vertical structure of the turbulence is also required. Stereo-SCIDAR is a technique specifically designed to characterise the Earth's atmospheric turbulence with high altitude resolution and high sensitivity. Together with ESO, Durham University has commissioned a Stereo-SCIDAR instrument at Cerro Paranal, Chile, the site of the Very Large Telescope (VLT), and only 20 km from the site of the future Extremely Large Telescope (ELT). Here we provide results from the first 18 months of operation at ESO Paranal including instrument comparisons and atmospheric statistics. Based on a sample of 83 nights spread over 22 months covering all seasons, we find the median seeing to be 0.64" with 50% of the turbulence confined to an altitude below 2 km and 40% below 600 m. The median coherence time and isoplanatic angle are found as 4.18 ms and 1.75" respectively. A substantial campaign of inter-instrument comparison was also undertaken to assure the validity of the data. The Stereo-SCIDAR profiles (optical turbulence strength and velocity as a function of altitude) have been compared with the Surface-Layer SLODAR, MASS-DIMM and the ECMWF weather forecast model. The correlation coefficients are between 0.61 (isoplanatic angle) and 0.84 (seeing).

Protoplanetary disks in Taurus: Probing the role of multiplicity with ALMA observations

NASA Astrophysics Data System (ADS)

Laos, Stefan; Akeson, Rachel L.; Jensen, Eric L. N.

2017-01-01

We present results from an ALMA survey of single and multiple young systems in Taurus designed to probe how protoplanetary disk mass depends on both stellar mass and multiplicity. In observations taken in Cycles 0 and 2, we detect over 25 new disks. These detections include disks around stars in both single and multiple systems and are predominantly around lower mass stars with spectral types from M0 to M6. Combined with previous detections, these observations reveal a wide range of disk mass around both primary and companion stars, and allow us to test if the relation previously seen between disk and stellar mass continues at lower stellar masses. We find that within multiple systems the ratio of primary to secondary stellar mass is not correlated with the ratio of primary to secondary disk mass. In some cases, the secondary star hosts the more massive disk, contrary to theoretical predictions. We will discuss the implications of these results for the process of planet formation in multiple systems.This work makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00150.S. and ADS/JAO.ALMA#2013.1.00105.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

The Next Generation Transit Survey (NGTS)

NASA Astrophysics Data System (ADS)

Wheatley, Peter J.; West, Richard G.; Goad, Michael R.; Jenkins, James S.; Pollacco, Don L.; Queloz, Didier; Rauer, Heike; Udry, Stéphane; Watson, Christopher A.; Chazelas, Bruno; Eigmüller, Philipp; Lambert, Gregory; Genolet, Ludovic; McCormac, James; Walker, Simon; Armstrong, David J.; Bayliss, Daniel; Bento, Joao; Bouchy, François; Burleigh, Matthew R.; Cabrera, Juan; Casewell, Sarah L.; Chaushev, Alexander; Chote, Paul; Csizmadia, Szilárd; Erikson, Anders; Faedi, Francesca; Foxell, Emma; Gänsicke, Boris T.; Gillen, Edward; Grange, Andrew; Günther, Maximilian N.; Hodgkin, Simon T.; Jackman, James; Jordán, Andrés; Louden, Tom; Metrailler, Lionel; Moyano, Maximiliano; Nielsen, Louise D.; Osborn, Hugh P.; Poppenhaeger, Katja; Raddi, Roberto; Raynard, Liam; Smith, Alexis M. S.; Soto, Maritza; Titz-Weider, Ruth

2018-04-01

We describe the Next Generation Transit Survey (NGTS), which is a ground-based project searching for transiting exoplanets orbiting bright stars. NGTS builds on the legacy of previous surveys, most notably WASP, and is designed to achieve higher photometric precision and hence find smaller planets than have previously been detected from the ground. It also operates in red light, maximizing sensitivity to late K and early M dwarf stars. The survey specifications call for photometric precision of 0.1 per cent in red light over an instantaneous field of view of 100 deg2, enabling the detection of Neptune-sized exoplanets around Sun-like stars and super-Earths around M dwarfs. The survey is carried out with a purpose-built facility at Cerro Paranal, Chile, which is the premier site of the European Southern Observatory (ESO). An array of twelve 20 cm f/2.8 telescopes fitted with back-illuminated deep-depletion CCD cameras is used to survey fields intensively at intermediate Galactic latitudes. The instrument is also ideally suited to ground-based photometric follow-up of exoplanet candidates from space telescopes such as TESS, Gaia and PLATO. We present observations that combine precise autoguiding and the superb observing conditions at Paranal to provide routine photometric precision of 0.1 per cent in 1 h for stars with I-band magnitudes brighter than 13. We describe the instrument and data analysis methods as well as the status of the survey, which achieved first light in 2015 and began full-survey operations in 2016. NGTS data will be made publicly available through the ESO archive.

Optical turbulence forecast: ready for an operational application

NASA Astrophysics Data System (ADS)

Masciadri, E.; Lascaux, F.; Turchi, A.; Fini, L.

2017-04-01

One of the main goals of the feasibility study MOSE (MOdelling ESO Sites) is to evaluate the performances of a method conceived to forecast the optical turbulence (OT) above the European Southern Observatory (ESO) sites of the Very Large Telescope (VLT) and the European Extremely Large Telescope (E-ELT) in Chile. The method implied the use of a dedicated code conceived for the OT called ASTRO-MESO-NH. In this paper, we present results we obtained at conclusion of this project concerning the performances of this method in forecasting the most relevant parameters related to the OT (CN^2, seeing ɛ, isoplanatic angle θ0 and wavefront coherence time τ0). Numerical predictions related to a very rich statistical sample of nights uniformly distributed along a solar year and belonging to different years have been compared to observations, and different statistical operators have been analysed such as the classical bias, root-mean-squared error, σ and more sophisticated statistical operators derived by the contingency tables that are able to quantify the score of success of a predictive method such as the percentage of correct detection (PC) and the probability to detect a parameter within a specific range of values (POD). The main conclusions of the study tell us that the ASTRO-MESO-NH model provides performances that are already very good to definitely guarantee a not negligible positive impact on the service mode of top-class telescopes and ELTs. A demonstrator for an automatic and operational version of the ASTRO-MESO-NH model will be soon implemented on the sites of VLT and E-ELT.

Advances in detector technologies for visible and infrared wavefront sensing

NASA Astrophysics Data System (ADS)

Feautrier, Philippe; Gach, Jean-Luc; Downing, Mark; Jorden, Paul; Kolb, Johann; Rothman, Johan; Fusco, Thierry; Balard, Philippe; Stadler, Eric; Guillaume, Christian; Boutolleau, David; Destefanis, Gérard; Lhermet, Nicolas; Pacaud, Olivier; Vuillermet, Michel; Kerlain, Alexandre; Hubin, Norbert; Reyes, Javier; Kasper, Markus; Ivert, Olaf; Suske, Wolfgang; Walker, Andrew; Skegg, Michael; Derelle, Sophie; Deschamps, Joel; Robert, Clélia; Vedrenne, Nicolas; Chazalet, Frédéric; Tanchon, Julien; Trollier, Thierry; Ravex, Alain; Zins, Gérard; Kern, Pierre; Moulin, Thibaut; Preis, Olivier

2012-07-01

The purpose of this paper is to give an overview of the state of the art wavefront sensor detectors developments held in Europe for the last decade. The success of the next generation of instruments for 8 to 40-m class telescopes will depend on the ability of Adaptive Optics (AO) systems to provide excellent image quality and stability. This will be achieved by increasing the sampling, wavelength range and correction quality of the wave front error in both spatial and time domains. The modern generation of AO wavefront sensor detectors development started in the late nineties with the CCD50 detector fabricated by e2v technologies under ESO contract for the ESO NACO AO system. With a 128x128 pixels format, this 8 outputs CCD offered a 500 Hz frame rate with a readout noise of 7e-. A major breakthrough has been achieved with the recent development by e2v technologies of the CCD220. This 240x240 pixels 8 outputs EMCCD (CCD with internal multiplication) has been jointly funded by ESO and Europe under the FP6 programme. The CCD220 and the OCAM2 camera that operates the detector are now the most sensitive system in the world for advanced adaptive optics systems, offering less than 0.2 e readout noise at a frame rate of 1500 Hz with negligible dark current. Extremely easy to operate, OCAM2 only needs a 24 V power supply and a modest water cooling circuit. This system, commercialized by First Light Imaging, is extensively described in this paper. An upgrade of OCAM2 is foreseen to boost its frame rate to 2 kHz, opening the window of XAO wavefront sensing for the ELT using 4 synchronized cameras and pyramid wavefront sensing. Since this major success, new developments started in Europe. One is fully dedicated to Natural and Laser Guide Star AO for the E-ELT with ESO involvement. The spot elongation from a LGS Shack Hartman wavefront sensor necessitates an increase of the pixel format. Two detectors are currently developed by e2v. The NGSD will be a 880x840 pixels CMOS detector with a readout noise of 3 e (goal 1e) at 700 Hz frame rate. The LGSD is a scaling of the NGSD with 1760x1680 pixels and 3 e readout noise (goal 1e) at 700 Hz (goal 1000 Hz) frame rate. New technologies will be developed for that purpose: advanced CMOS pixel architecture, CMOS back thinned and back illuminated device for very high QE, full digital outputs with signal digital conversion on chip. In addition, the CMOS technology is extremely robust in a telescope environment. Both detectors will be used on the European ELT but also interest potentially all giant telescopes under development. Additional developments also started for wavefront sensing in the infrared based on a new technological breakthrough using ultra low noise Avalanche Photodiode (APD) arrays within the RAPID project. Developed by the SOFRADIR and CEA/LETI manufacturers, the latter will offer a 320x240 8 outputs 30 microns IR array, sensitive from 0.4 to 3.2 microns, with 2 e readout noise at 1500 Hz frame rate. The high QE response is almost flat over this wavelength range. Advanced packaging with miniature cryostat using liquid nitrogen free pulse tube cryocoolers is currently developed for this programme in order to allow use on this detector in any type of environment. First results of this project are detailed here. These programs are held with several partners, among them are the French astronomical laboratories (LAM, OHP, IPAG), the detector manufacturers (e2v technologies, Sofradir, CEA/LETI) and other partners (ESO, ONERA, IAC, GTC). Funding is: Opticon FP6 and FP7 from European Commission, ESO, CNRS and Université de Provence, Sofradir, ONERA, CEA/LETI and the French FUI (DGCIS).

Type II Supernova Spectral Diversity. II. Spectroscopic and Photometric Correlations

NASA Astrophysics Data System (ADS)

Gutiérrez, Claudia P.; Anderson, Joseph P.; Hamuy, Mario; González-Gaitan, Santiago; Galbany, Lluis; Dessart, Luc; Stritzinger, Maximilian D.; Phillips, Mark M.; Morrell, Nidia; Folatelli, Gastón

2017-11-01

We present an analysis of observed trends and correlations between a large range of spectral and photometric parameters of more than 100 type II supernovae (SNe II), during the photospheric phase. We define a common epoch for all SNe of 50 days post-explosion, where the majority of the sample is likely to be under similar physical conditions. Several correlation matrices are produced to search for interesting trends between more than 30 distinct light-curve and spectral properties that characterize the diversity of SNe II. Overall, SNe with higher expansion velocities are brighter, have more rapidly declining light curves, shorter plateau durations, and higher 56Ni masses. Using a larger sample than previous studies, we argue that “Pd”—the plateau duration from the transition of the initial to “plateau” decline rates to the end of the “plateau”—is a better indicator of the hydrogen envelope mass than the traditionally used optically thick phase duration (OPTd: explosion epoch to end of plateau). This argument is supported by the fact that Pd also correlates with s 3, the light-curve decline rate at late times: lower Pd values correlate with larger s 3 decline rates. Large s 3 decline rates are likely related to lower envelope masses, which enables gamma-ray escape. We also find a significant anticorrelation between Pd and s 2 (the plateau decline rate), confirming the long standing hypothesis that faster declining SNe II (SNe IIL) are the result of explosions with lower hydrogen envelope masses and therefore have shorter Pd values. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile; and the Gemini Observatory, Cerro Pachon, Chile (Gemini Program GS- 2008B-Q-56). Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (ESO Programs 076.A-0156, 078.D-0048, 080.A-0516, and 082.A-0526).

Type II Supernova Spectral Diversity. I. Observations, Sample Characterization, and Spectral Line Evolution

NASA Astrophysics Data System (ADS)

Gutiérrez, Claudia P.; Anderson, Joseph P.; Hamuy, Mario; Morrell, Nidia; González-Gaitan, Santiago; Stritzinger, Maximilian D.; Phillips, Mark M.; Galbany, Lluis; Folatelli, Gastón; Dessart, Luc; Contreras, Carlos; Della Valle, Massimo; Freedman, Wendy L.; Hsiao, Eric Y.; Krisciunas, Kevin; Madore, Barry F.; Maza, José; Suntzeff, Nicholas B.; Prieto, Jose Luis; González, Luis; Cappellaro, Enrico; Navarrete, Mauricio; Pizzella, Alessandro; Ruiz, Maria T.; Smith, R. Chris; Turatto, Massimo

2017-11-01

We present 888 visual-wavelength spectra of 122 nearby type II supernovae (SNe II) obtained between 1986 and 2009, and ranging between 3 and 363 days post-explosion. In this first paper, we outline our observations and data reduction techniques, together with a characterization based on the spectral diversity of SNe II. A statistical analysis of the spectral matching technique is discussed as an alternative to nondetection constraints for estimating SN explosion epochs. The time evolution of spectral lines is presented and analyzed in terms of how this differs for SNe of different photometric, spectral, and environmental properties: velocities, pseudo-equivalent widths, decline rates, magnitudes, time durations, and environment metallicity. Our sample displays a large range in ejecta expansion velocities, from ˜9600 to ˜1500 km s-1 at 50 days post-explosion with a median {{{H}}}α value of 7300 km s-1. This is most likely explained through differing explosion energies. Significant diversity is also observed in the absolute strength of spectral lines, characterized through their pseudo-equivalent widths. This implies significant diversity in both temperature evolution (linked to progenitor radius) and progenitor metallicity between different SNe II. Around 60% of our sample shows an extra absorption component on the blue side of the {{{H}}}α P-Cygni profile (“Cachito” feature) between 7 and 120 days since explosion. Studying the nature of Cachito, we conclude that these features at early times (before ˜35 days) are associated with Si II λ 6355, while past the middle of the plateau phase they are related to high velocity (HV) features of hydrogen lines. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile; and the Gemini Observatory, Cerro Pachon, Chile (Gemini Program GS-2008B-Q-56). Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (ESO Programs 076.A-0156, 078.D-0048, 080.A-0516, and 082.A-0526).

[Invasive infections caused by Haemophilus influenzae type b after the institution of the conjugated vaccine on the expanded programm on immunization in Chile].

PubMed

Cruces R, Pablo; Donoso F, Alejandro; Camacho A, Jorge; Llorente H, Marcela

2006-03-01

After almost a decade since the introduction of Haemophilus influenzae type b (Hib) conjugate vaccines in Chile (in a 2-4-6 month schedule), Hib invasive infections have dramatically decreased, albeit they remain to occasionally produce disease in pediatric patients. We report our experience with children whom developed Hib invasive disease in children since 2000 to 2004. Medical records of children with Hib were reviewed in order to describe the epidemiology, main clinical and laboratory findings, management and complications. Twenty three patients (17 male), between 1 and 71 months (median 30 months) were identified: pneumonia (7), meningitis (4), pleuropneumonia (2), empyema (2), sepsis (2), cellulitis (2), meningitis and pleuropneumonia (1), purpura fulminans (1), miositis (1) and epiglottitis (1). No deaths were observed and four patients presented severe sequelae at hospital discharge. Twenty patients were considered vaccine failures. Hib remains as a sporadic cause of severe disease in Chile and thus for physicians should still keep it in mind. Case analysis and active surveillance are necessary to monitor the current immunization regimen.

Discovery of a [WO] central star in the planetary nebula Th 2-A

NASA Astrophysics Data System (ADS)

Weidmann, W. A.; Gamen, R.; Díaz, R. J.; Niemela, V. S.

2008-09-01

Context: About 2500 planetary nebulae are known in our Galaxy but only 224 have central stars with reported spectral types in the Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (Acker et al. 1992; Acker et al. 1996). Aims: We have started an observational program aiming to increase the number of PN central stars with spectral classification. Methods: By means of spectroscopy and high resolution imaging, we identify the position and true nature of the central star. We carried out low resolution spectroscopic observations at CASLEO telescope, complemented with medium resolution spectroscopy performed at Gemini South and Magellan telescopes. Results: As a first outcome of this survey, we present for the first time the spectra of the central star of the PN Th 2-A. These spectra show emission lines of ionized C and O, typical in Wolf-Rayet stars. Conclusions: We identify the position of that central star, which is not the brightest one of the visual central pair. We classify it as of type [WO 3]pec, which is consistent with the high excitation and dynamical age of the nebula. Based on data collected at (i) the Complejo Astronómico El Leoncito (CASLEO), which is operated under agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina y Universidades Nacionales de La Plata, Córdoba y San Juan, Argentina; (ii) the 6.5 m Magellan Telescopes at Las Campanas Observatory, Chile; (iii) the 8 m Gemini South Telescope, Chile.

Development of telescope control system for the 50cm telescope of UC Observatory Santa Martina

NASA Astrophysics Data System (ADS)

Shen, Tzu-Chiang; Soto, Ruben; Reveco, Johnny; Vanzi, Leonardo; Fernández, Jose M.; Escarate, Pedro; Suc, Vincent

2012-09-01

The main telescope of the UC Observatory Santa Martina is a 50cm optical telescope donated by ESO to Pontificia Universidad Catolica de Chile. During the past years the telescope has been refurbished and used as the main facility for testing and validating new instruments under construction by the center of Astro-Engineering UC. As part of this work, the need to develop a more efficient and flexible control system arises. The new distributed control system has been developed on top of Internet Communication Engine (ICE), a framework developed by Zeroc Inc. This framework features a lightweight but powerful and flexible inter-process communication infrastructure and provides binding to classic and modern programming languages, such as, C/C++, java, c#, ruby-rail, objective c, etc. The result of this work shows ICE as a real alternative for CORBA and other de-facto distribute programming framework. Classical control software architecture has been chosen and comprises an observation control system (OCS), the orchestrator of the observation, which controls the telescope control system (TCS), and detector control system (DCS). The real-time control and monitoring system is deployed and running over ARM based single board computers. Other features such as logging and configuration services have been developed as well. Inter-operation with other main astronomical control frameworks are foreseen in order achieve a smooth integration of instruments when they will be integrated in the main observatories in the north of Chile

Eucheuma cottonii Sulfated Oligosaccharides Decrease Food Allergic Responses in Animal Models by Up-regulating Regulatory T (Treg) Cells.

PubMed

Xu, Sha-Sha; Liu, Qing-Mei; Xiao, An-Feng; Maleki, Soheila J; Alcocer, Marcos; Gao, Yuan-Yuan; Cao, Min-Jie; Liu, Guang-Ming

2017-04-19

In the present study, the anti-food allergy activity of Eucheuma cottonii sulfated oligosaccharide (ESO) was investigated. ESO was obtained by enzymatic degradation and purified by column chromatography. RBL-2H3 cells and BALB/c mouse model were used to test the anti-food allergy activity of ESO. The effects of ESO on the regulatory T (Treg) cells and bone marrow-derived mast cells (BMMCs) were investigated by flow cytometry. The results of in vivo assay showed that ESO decreased the levels of mast cell protease-1 and histamine and inhibited the levels of specific IgE by 77.7%. In addition, the production of interleukin (IL)-4 and IL-13 was diminished in the ESO groups compared to the non-ESO-treated group. Furthermore, ESO could up-regulate Treg cells by 22.2-97.1%. In conclusion, ESO decreased the allergy response in mice by reducing basophil degranulation, up-regulating Treg cells via Forkhead box protein 3 (Foxp3), and releasing IL-10. ESO may have preventive and therapeutic potential in allergic disease.

The Great Easter Egg Hunt: The Void's Incredible Richness

NASA Astrophysics Data System (ADS)

2006-04-01

An image made of about 300 million pixels is being released by ESO, based on more than 64 hours of observations with the Wide-Field Camera on the 2.2m telescope at La Silla (Chile). The image covers an 'empty' region of the sky five times the size of the full moon, opening an exceptionally clear view towards the most distant part of our universe. It reveals objects that are 100 million times fainter than what the unaided eye can see. Easter is in many countries a time of great excitement for children who are on the big hunt for chocolate eggs, hidden all about the places. Astronomers, however, do not need to wait this special day to get such an excitement: it is indeed daily that they look for faraway objects concealed in deep images of the sky. And as with chocolate eggs, deep sky objects, such as galaxies, quasars or gravitational lenses, come in the wildest variety of colours and shapes. ESO PR Photo 11/06 ESO PR Photo 14a/06 The Deep 3 'Empty' Field The image presented here is one of such very deep image of the sky. It is the combination of 714 frames for a total exposure time of 64.5 hours obtained through four different filters (B, V, R, and I)! It consists of four adjacent Wide-Field Camera pointings (each 33x34 arcmin), covering a total area larger than one square degree. Yet, if you were to look at this large portion of the firmament with the unaided eye, you would just see... nothing. The area, named Deep 3, was indeed chosen to be a random but empty, high galactic latitude field, positioned in such a way that it can be observed from the La Silla observatory all over the year. Together with two other regions, Deep 1 and Deep 2, Deep 3 is part of the Deep Public Survey (DPS), based on ideas submitted by the ESO community and covering a total sky area of 3 square degrees. Deep 1 and Deep 2 were selected because they overlapped with regions of other scientific interest. For instance, Deep 1 was chosen to complement the deep ATESP radio survey carried out with the Australia Telescope Compact Array (ATCA) covering the region surveyed by the ESO Slice Project, while Deep 2 included the CDF-S field. Each region is observed in the optical, with the WFI, and in the near-infrared, with SOFI on the 3.5-m New Technology Telescope also at La Silla. Deep 3 is located in the Crater ('The Cup'), a southern constellation with very little interest (the brightest star is of fourth magnitude, i.e. only a factor six brighter than what a keen observer can see with the unaided eye), in between the Virgo, Corvus and Hydra constellations. Such comparatively empty fields provide an unusually clear view towards the distant regions in the Universe and thus open a window towards the earliest cosmic times. The deep imaging data can for example be used to pre-select objects by colour for follow-up spectroscopy with ESO's Very Large Telescope instruments. ESO PR Photo 11/06 ESO PR Photo 14b/06 Galaxy ESO 570-19 and Variable Star UW Crateris But being empty is only a relative notion. True, on the whole image, the SIMBAD Astronomical database references less than 50 objects, clearly a tiny number compared to the myriad of anonymous stars and galaxies that can be seen in the deep image obtained by the Survey! Among the objects catalogued is the galaxy visible in the top middle right (see also PR Photo 14b/06) and named ESO 570-19. Located 60 million light-years away, this spiral galaxy is the largest in the image. It is located not so far - on the image! - from the brightest star in the field, UW Crateris. This red giant is a variable star that is about 8 times fainter than what the unaided eye can see. The second and third brightest stars in this image are visible in the lower far right and in the lower middle left. The first is a star slightly more massive than the Sun, HD 98081, while the other is another red giant, HD 98507. ESO PR Photo 11/06 ESO PR Photo 14c/06 The DPS Deep 3 Field (Detail) In the image, a vast number of stars and galaxies are to be studied and compared. They come in a variety of colours and the stars form amazing asterisms (a group of stars forming a pattern), while the galaxies, which are to be counted by the tens of thousands come in different shapes and some even interact or form part of a cluster. The image and the other associated data will certainly provide a plethora of new results in the years to come. In the meantime, why don't you explore the image with the zoom-in facility, and start your own journey into infinity? Just be careful not to get lost. And remember: don't eat too many of these chocolate eggs! High resolution images and their captions are available on this page.

Public surveys at ESO

NASA Astrophysics Data System (ADS)

Arnaboldi, Magda; Delmotte, Nausicaa; Hilker, Michael; Hussain, Gaitee; Mascetti, Laura; Micol, Alberto; Petr-Gotzens, Monika; Rejkuba, Marina; Retzlaff, Jörg; Mieske, Steffen; Szeifert, Thomas; Ivison, Rob; Leibundgut, Bruno; Romaniello, Martino

2016-07-01

ESO has a strong mandate to survey the Southern Sky. In this article, we describe the ESO telescopes and instruments that are currently used for ESO Public Surveys, and the future plans of the community with the new wide-field-spectroscopic instruments. We summarize the ESO policies governing the management of these projects on behalf of the community. The on-going ESO Public Surveys and their science goals, their status of completion, and the new projects selected during the second ESO VISTA call in 2015/2016 are discussed. We then present the impact of these projects in terms of current numbers of refereed publications and the scientific data products published through the ESO Science Archive Facility by the survey teams, including the independent access and scientific use of the published survey data products by the astronomical community.

Advances in SELEX ES infrared detectors for space and astronomy

NASA Astrophysics Data System (ADS)

Knowles, P.; Hipwood, L.; Baker, I.; Weller, H.

2017-11-01

Selex ES produces a wide range of infrared detectors from mercury cadmium telluride (MCT) and triglycine sulfate (TGS), and has supplied both materials into space programmes spanning a period of over 40 years. Current development activities that underpin potential future space missions include large format arrays for near- and short-wave infrared (NIR and SWIR) incorporating radiation-hard designs and suppression of glow. Improved heterostructures are aimed at the reduction of dark currents and avalanche photodiodes (APDs), and parallel studies have been undertaken for low-stress MCT array mounts. Much of this development work has been supported by ESA, UK Space, and ESO, and some has been performed in collaboration with the UK Astronomy Technology Centre and E2V. This paper focuses on MCT heterostructure developments and novel design elements in silicon read-out chips (ROICs). The 2048 x 2048 element, 17um pitch ROIC for ESA's SWIR array development forms the basis for the largest cooled infrared detector manufactured in Europe. Selex ES MCT is grown by metal organic vapour phase epitaxy (MOVPE), currently on 75mm diameter GaAs substrates. The MCT die size of the SWIR array is 35mm square and only a single array can be printed on the 75mm diameter wafer, utilising only 28% of the wafer area. The situation for 100mm substrates is little better, allowing only 2 arrays and 31% utilisation. However, low cost GaAs substrates are readily available in 150mm diameter and the MCT growth is scalable to this size, offering the real possibility of 6 arrays per wafer with 42% utilisation. A similar 2k x 2k ROIC is the goal of ESA's NIR programme, which is currently in phase 2 with a 1k x 1k demonstrator, and a smaller 320 x 256 ROIC (SAPHIRA) has been designed for ESO for the adaptive optics application in the VLT Gravity instrument. All 3 chips have low noise source-follower architecture and are enabled for MCT APD arrays, which have been demonstrated by ESO to be capable of single photon detection. The possibility therefore exists in the near future of demonstrating a photon counting, 2k x 2k SWIR MCT detector manufactured on an affordable wafer scale of 6 arrays per wafer.

A Very Cool Pair of Brown Dwarfs

NASA Astrophysics Data System (ADS)

2011-03-01

Observations with the European Southern Observatory's Very Large Telescope, along with two other telescopes, have shown that there is a new candidate for the coldest known star: a brown dwarf in a double system with about the same temperature as a freshly made cup of tea - hot in human terms, but extraordinarily cold for the surface of a star. This object is cool enough to begin crossing the blurred line dividing small cold stars from big hot planets. Brown dwarfs are essentially failed stars: they lack enough mass for gravity to trigger the nuclear reactions that make stars shine. The newly discovered brown dwarf, identified as CFBDSIR 1458+10B, is the dimmer member of a binary brown dwarf system located just 75 light-years from Earth [1]. The powerful X-shooter spectrograph on ESO's Very Large Telescope (VLT) was used to show that the composite object was very cool by brown dwarf standards. "We were very excited to see that this object had such a low temperature, but we couldn't have guessed that it would turn out to be a double system and have an even more interesting, even colder component," said Philippe Delorme of the Institut de planétologie et d'astrophysique de Grenoble (CNRS/Université Joseph Fourier), a co-author of the paper. CFBDSIR 1458+10 is the coolest brown dwarf binary found to date. The dimmer of the two dwarfs has now been found to have a temperature of about 100 degrees Celsius - the boiling point of water, and not much different from the temperature inside a sauna [2]. "At such temperatures we expect the brown dwarf to have properties that are different from previously known brown dwarfs and much closer to those of giant exoplanets - it could even have water clouds in its atmosphere," said Michael Liu of the University of Hawaii's Institute for Astronomy, who is lead author of the paper describing this new work. "In fact, once we start taking images of gas-giant planets around Sun-like stars in the near future, I expect that many of them will look like CFBDSIR 1458+10B." Unravelling the secrets of this unique object involved exploiting the power of three different telescopes. CFBDSIR 1458+10 was first found to be a binary using the Laser Guide Star (LGS) Adaptive Optics system on the Keck II Telescope in Hawaii [3]. Liu and his colleagues then employed the Canada-France-Hawaii Telescope, also in Hawaii, to determine the distance to the brown dwarf duo using an infrared camera [4]. Finally the ESO VLT was used to study the object's infrared spectrum and measure its temperature. The hunt for cool objects is a very active astronomical hot topic. The Spitzer Space Telescope has recently identified two other very faint objects as other possible contenders for the coolest known brown dwarfs, although their temperatures have not been measured so precisely. Future observations will better determine how these objects compare to CFBDSIR 1458+10B. Liu and his colleagues are planning to observe CFBDSIR 1458+10B again to better determine its properties and to begin mapping the binary's orbit, which, after about a decade of monitoring, should allow astronomers to determine the binary's mass. Notes [1] CFBDSIR 1458+10 is the name of the binary system. The two components are known as CFBDSIR 1458+10A and CFBDSIR 1458+10B, with the latter the fainter and cooler of the two. They seem to be orbiting each other at a separation of about three times the distance between the Earth and the Sun in a period of about thirty years. [2] By comparison the temperature of the surface of the Sun is about 5500 degrees Celsius. [3] Adaptive optics cancels out much of Earth's atmospheric interference, improving the image sharpness by a factor of ten and enabling the very small separation binary to be resolved. [4] The astronomers measured the apparent motion of the brown dwarfs against the background of more distant stars caused by Earth's changing position in its orbit around the Sun. The effect, known as parallax, allowed them to determine the distance to the brown dwarfs. More information This research was presented in a paper, "CFBDSIR J1458+1013B: A Very Cold (>T10) Brown Dwarf in a Binary System", Liu et al. to appear in the Astrophysical Journal. The team is composed of Michael C. Liu (Institute for Astronomy [IfA], University of Hawaii, USA), Philippe Delorme (Institut de planétologie et d'astrophysique de Grenoble, CNRS/Université Joseph Fourier, France [IPAG]), Trent J. Dupuy (Harvard-Smithsonian Center for Astrophysics, Cambridge, USA), Brendan P. Bowler (IfA), Loic Albert (Canada-France-Hawaii Telescope Corporation, Hawaii, USA), Etienne Artigau (Université de Montréal, Canada), Celine Reylé (Observatoire de Besançon, France), Thierry Forveille (IPAG) and Xavier Delfosse (IPAG). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Growing Galaxies Gently

NASA Astrophysics Data System (ADS)

2010-10-01

New observations from ESO's Very Large Telescope have, for the first time, provided direct evidence that young galaxies can grow by sucking in the cool gas around them and using it as fuel for the formation of many new stars. In the first few billion years after the Big Bang the mass of a typical galaxy increased dramatically and understanding why this happened is one of the hottest problems in modern astrophysics. The results appear in the 14 October issue of the journal Nature. The first galaxies formed well before the Universe was one billion years old and were much smaller than the giant systems - including the Milky Way - that we see today. So somehow the average galaxy size has increased as the Universe has evolved. Galaxies often collide and then merge to form larger systems and this process is certainly an important growth mechanism. However, an additional, gentler way has been proposed. A European team of astronomers has used ESO's Very Large Telescope to test this very different idea - that young galaxies can also grow by sucking in cool streams of the hydrogen and helium gas that filled the early Universe and forming new stars from this primitive material. Just as a commercial company can expand either by merging with other companies, or by hiring more staff, young galaxies could perhaps also grow in two different ways - by merging with other galaxies or by accreting material. The team leader, Giovanni Cresci (Osservatorio Astrofisico di Arcetri) says: "The new results from the VLT are the first direct evidence that the accretion of pristine gas really happened and was enough to fuel vigorous star formation and the growth of massive galaxies in the young Universe." The discovery will have a major impact on our understanding of the evolution of the Universe from the Big Bang to the present day. Theories of galaxy formation and evolution may have to be re-written. The group began by selecting three very distant galaxies to see if they could find evidence of the flow of pristine gas from the surrounding space and the associated formation of new stars. They were very careful to make sure that their specimen galaxies had not been disturbed by interactions with other galaxies. The selected galaxies were very regular, smoothly rotating discs, similar to the Milky Way, and they were seen about two billion years after the Big Bang (at a redshift of around three). In galaxies in the modern Universe the heavy elements [1] are more abundant close to the centre. But when Cresci's team mapped their selected distant galaxies with the SINFONI spectrograph on the VLT [2] they were excited to see that in all three cases there was a patch of the galaxy, close to the centre, with fewer heavy elements, but hosting vigorously forming stars, suggesting that the material to fuel the star formation was coming from the surrounding pristine gas that is low in heavy elements. This was the smoking gun that provided the best evidence yet of young galaxies accreting primitive gas and using it to form new generations of stars. As Cresci concludes: "This study has only been possible because of the outstanding performance of the SINFONI instrument on the VLT. It has opened a new window for studying the chemical properties of very distant galaxies. SINFONI provides information not only in two spatial dimensions, but also in a third, spectral dimension, which allows us to see the internal motions inside galaxies and study the chemical composition of the interstellar gas." Notes [1] The gas filling the early Universe was almost all hydrogen and helium. The first generations of stars processed this primitive material to create heavier elements such as oxygen, nitrogen and carbon by nuclear fusion. When this material was subsequently spewed back into space by intense particle winds from massive young stars and supernova explosions the amounts of heavy elements in the galaxy gradually increased. Astronomers refer to elements other than hydrogen and helium as "heavy elements". [2] By carefully splitting up the faint light coming from a galaxy into its component colours using powerful telescopes and spectrographs, astronomers can identify the fingerprints of different chemicals in remote galaxies, and measure the amounts of heavy elements present. With the SINFONI instrument on the VLT astronomers can go one better and get a separate spectrum for each part of an object. This allows them to make a map that shows the quantity of heavy elements present in different parts of a galaxy and also determine where in the galaxy star formation is occurring most vigorously. More information This research was presented in a paper, Gas accretion in distant galaxies as the origin of chemical abundance gradients, by Cresci et al., to appear in Nature on 14 October 2010. The team is composed of G. Cresci (Osservatorio Astrofisico di Arcetri, Italy), F. Mannucci (Osservatorio Astrofisico di Arcetri, Italy), R. Maiolino (INAF, Osservatorio Astronomico di Roma, Italy), A. Marconi (Universitá di Firenze, Italy), A. Gnerucci (Universitá di Firenze, Italy) and L. Magrini (Osservatorio Astrofisico di Arcetri, Italy). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

VLT Commissioning Data Now Publicly Available

NASA Astrophysics Data System (ADS)

1999-11-01

"First Light" was achieved in May 1998 for VLT ANTU , the first 8.2-m Unit Telescope at the Paranal Observatory ( ESO PR 06/98 ). Since then, thousands of detailed images and spectra of a great variety of celestial objects have been recorded with this major new research facility. While some of these were obtained for scientific programmes and were therefore directed towards specific research needs, others were made during the "Commissioning Phases" in 1998/99 for the two major astronomical instruments, FORS1 ( FO cal R educer and S pectrograph) and ISAAC ( I nfrared S pectrometer A nd A rray C amera). They were carried out in order to test thoroughly the performance of the telescope and its instruments before the new facility was handed over to the astronomers on April 1, 1999. The Commissioning data are accordingly of variable quality and, contrarily to the science data, normally not intensity calibrated. However, while some of these frames are short test exposures that mainly served to ascertain the image quality under various observing conditions, a substantial fraction still contains scientifically valuable data. 10 Gigabytes released As planned, and in order to facilitate the exploitation of this useful material, ESO has today released over 10 Gigabytes of ANTU Commissioning data (and some additional test data from before April 1, 1999), obtained in the various observing modes of FORS1 and ISAAC . They encompass a total of 2235 files and are now available to astronomers and other interested parties in the ESO Member States. Information about this release and on how to obtain the data on CD-ROM or in electronic form is now available via the Science Archive Facility website. A special page with the list of raw science data frames included in this release has been set up. Searches for specific data (e.g., by object, sky field, filter, time of observation; calibration files, etc.) can be made from the ESO Science Archive Data Products page. These Commissioning data are "raw" in the sense that they come directly from the instrument. The original files are recorded in standard FITS-format and in order to save space, they have been compressed by a factor of about 2. Before they can be used, they must therefore first be decompressed and subjected to image processing, e.g. with the ESO MIDAS system , available on a special MIDAS CD-ROM from ESO. The above image of a well-known spiral galaxy, Messier 83 , was prepared by superposing three CCD frames from this data release that are now available in the archive. This galaxy is located in the southern constellation Hydra (The Water-Snake) and is also known as NGC 5236 ; the distance is about 15 million light-years. The spiral structure resembles that of the Milky Way Galaxy in which we live, but Messier 83 also possesses a bar-like structure at the centre. Corresponding frames of many other interesting objects are included among the data now released. A small part of these have served to produce some of the VLT Astronomical Images that have been released at the ESO Outreach website during the past year. Current VLT observations Observations continue with the first two VLT Unit Telescopes, ANTU and KUEYEN ; the latter is still in the Commissioning Phase with the UVES and FORS2 instruments until it will be made available to the astronomers on April 1, 2000. The current VLT data production rate is about 2200 files/week, corresponding to about 10 Gigabytes or 16 CD-ROMs. Efficient data handling procedures developed by ESO ensure a rapid and secure transfer from the telescopes at the Paranal Observatory to the data archive at the Garching Headquarters, and from here to the receiving astronomers. A description of the main features of this "VLT Data Flow System" is available in PR 10/99. The amount of data will increase as more instruments enter into operation and will ultimately reach about 40,000 Gigabytes/year. The next major event will be the "First Light" for the third Unit Telescope, MELIPAL , now expected in February 2000. The preparations are proceeding well, with the 8.2-m main mirror of Zerodur about to be coated during the next days. The fourth telescope, YEPUN , will follow later next year. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../ ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

The VIMOS Public Extragalactic Redshift Survey (VIPERS). Full spectroscopic data and auxiliary information release (PDR-2)

NASA Astrophysics Data System (ADS)

Scodeggio, M.; Guzzo, L.; Garilli, B.; Granett, B. R.; Bolzonella, M.; de la Torre, S.; Abbas, U.; Adami, C.; Arnouts, S.; Bottini, D.; Cappi, A.; Coupon, J.; Cucciati, O.; Davidzon, I.; Franzetti, P.; Fritz, A.; Iovino, A.; Krywult, J.; Le Brun, V.; Le Fèvre, O.; Maccagni, D.; Małek, K.; Marchetti, A.; Marulli, F.; Polletta, M.; Pollo, A.; Tasca, L. A. M.; Tojeiro, R.; Vergani, D.; Zanichelli, A.; Bel, J.; Branchini, E.; De Lucia, G.; Ilbert, O.; McCracken, H. J.; Moutard, T.; Peacock, J. A.; Zamorani, G.; Burden, A.; Fumana, M.; Jullo, E.; Marinoni, C.; Mellier, Y.; Moscardini, L.; Percival, W. J.

2018-01-01

We present the full public data release (PDR-2) of the VIMOS Public Extragalactic Redshift Survey (VIPERS), performed at the ESO VLT. We release redshifts, spectra, CFHTLS magnitudes and ancillary information (as masks and weights) for a complete sample of 86 775 galaxies (plus 4732 other objects, including stars and serendipitous galaxies); we also include their full photometrically-selected parent catalogue. The sample is magnitude limited to iAB ≤ 22.5, with an additional colour-colour pre-selection devised as to exclude galaxies at z < 0.5. This practically doubles the effective sampling of the VIMOS spectrograph over the range 0.5 < z < 1.2 (reaching 47% on average), yielding a final median local galaxy density close to 5 × 10-3h3 Mpc-3. The total area spanned by the final data set is ≃ 23.5 deg2, corresponding to 288 VIMOS fields with marginal overlaps, split over two regions within the CFHTLS-Wide W1 and W4 equatorial fields (at RA ≃ 2 and ≃ 22 h, respectively). Spectra were observed at a resolution R = 220, covering a wavelength range 5500-9500 Å. Data reduction and redshift measurements were performed through a fully automated pipeline; all redshift determinations were then visually validated and assigned a quality flag. Measurements with a quality flag ≥ 2 are shown to have a confidence level of 96% or larger and make up 88% of all measured galaxy redshifts (76 552 out of 86 775), constituting the VIPERS prime catalogue for statistical investigations. For this sample the rms redshift error, estimated using repeated measurements of about 3000 galaxies, is found to be σz = 0.00054(1 + z). All data are available at http://vipers.inaf.it and on the ESO Archive. Based on observations collected at the European Southern Observatory, Cerro Paranal, Chile, using the Very Large Telescope under programmes 182.A-0886 and partly 070.A-9007. Also based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. The VIPERS web site is http://www.vipers.inaf.it/

It's Far, It's Small, It's Cool: It's an Icy Exoplanet!

NASA Astrophysics Data System (ADS)

2006-01-01

Using a network of telescopes scattered across the globe, including the Danish 1.54m telescope at ESO La Silla (Chile), astronomers [1] discovered a new extrasolar planet significantly more Earth-like than any other planet found so far. The planet, which is only about 5 times as massive as the Earth, circles its parent star in about 10 years. It is the least massive exoplanet around an ordinary star detected so far and also the coolest [2]. The planet most certainly has a rocky/icy surface. Its discovery marks a groundbreaking result in the search for planets that support life. ESO PR Photo 03a/06 ESO PR Photo 03a/06 Artist's Impression of the Newly Found Exoplanet The new planet, designated by the unglamorous identifier of OGLE-2005-BLG-390Lb, orbits a red star five times less massive than the Sun and located at a distance of about 20,000 light years, not far from the centre of our Milky Way galaxy. Its relatively cool parent star and large orbit implies that the likely surface temperature of the planet is 220 degrees Centigrade below zero, too cold for liquid water. It is likely to have a thin atmosphere, like the Earth, but its rocky surface is probably deeply buried beneath frozen oceans. It may therefore more closely resemble a more massive version of Pluto, rather than the rocky inner planets like Earth and Venus. "This planet is actually the first and only planet that has been discovered so far that is in agreement with the theories for how our Solar System formed ", said Uffe Gråe Jørgensen (Niels Bohr Institute, Copenhagen, Denmark), member of the team. The favoured theoretical explanation for the formation of planetary systems proposes that solid 'planetesimals' accumulate to build up planetary cores, which then accrete nebular gas - to form giant planets - if they are sufficiently massive. Around red dwarfs, the most common stars of our Galaxy, this model favours the formation of Earth- to Neptune-mass planets being between 1 and 10 times the Earth-Sun distance away from their host. "OGLE-2005-BLG-390Lb is only the third extra-solar planet discovered so far through microlensing searches ", said Jean-Philippe Beaulieu (Institut d'Astrophysique de Paris, France), the lead author. "While the other two microlensing planets have masses of a few times that of Jupiter, the discovery of a 5 Earth mass planet - though much harder to detect than more massive ones - is a strong hint that these lower-mass objects are very common. " Contrary to most exoplanets discovered, OGLE-2005-BLG-390Lb was indeed found using the 'microlensing' technique, based on an effect noted by Albert Einstein in 1912. "With this method, we let the gravity of a dim, intervening star act as a giant natural telescope for us, magnifying a more distant star, which then temporarily looks brighter ", explained team member Andrew Williams (Perth Observatory, Australia). "A small 'defect' in the brightening reveals the existence of a planet around the lens star. We don't see the planet, or even the star that it's orbiting, we just see the effect of their gravity. " Such an intervening star causes a characteristic brightening that lasts about a month. Any planets orbiting this star can produce an additional signal, lasting days for giant planets down to hours for Earth-mass planets. In order to be able to catch and characterize these planets, nearly-continuous round-the-clock high-precision monitoring of ongoing microlensing events is required. This is achieved by the PLANET network of 1m-class telescopes consisting of the ESO 1.54m Danish at La Silla (Chile), the Canopus Observatory 1.0m (Hobart, Tasmania, Australia), the Perth 0.6m (Bickley, Western Australia), the Boyden 1.5m (South Africa), and the SAAO 1.0m (Sutherland, South Africa). Since 2005, PLANET operates a common campaign with RoboNet, a UK operated network of 2m fully robotic telescopes currently comprising the Liverpool Telescope (Roque de Los Muchachos, La Palma, Spain) and the Faulkes Telescope North (Haleakala, Hawaii, USA). ESO PR Photo 03b/06 ESO PR Photo 03b/06 Light Curve of OGLE-2005-BLG-390 The OGLE (Optical Gravitational Lensing Experiment) search team (led by A. Udalski, Warsaw University Observatory, Poland) discovered the event OGLE-2005-BLG-390 on 11 July 2005, triggering the PLANET telescopes to start taking data. A light curve consistent with a single lens star peaking at an amplification of about 3 on 31 July 2005 was observed, until 10 August when PLANET member Pascal Fouqué, observing at the Danish 1.54m at ESO La Silla, noticed a planetary deviation. An OGLE point from the same night showed the same trend, while the last half of the planetary deviation, lasting about a day, had been covered by images from Perth Observatory. The MOA (Microlensing Observations in Astrophysics) collaboration was later able to identify the source star on its images and confirmed the deviation. No other interpretation than the presented sub-Neptune mass planet with its quoted parameters appeared to fit the extensive data set. This discovery brings a fresh look at the field of planetary science. In particular, astronomers now think that such frozen worlds are much more common than their larger, Jupiter-like brethren. "Indeed if Jupiter-like planets were as widespread, the microlensing method should have found dozens of them by now ", said David Bennett (University of Notre Dame, USA), another PLANET team member. The microlensing technique is most probably the only method currently capable of detecting planets similar to Earth. "The search for a second Earth is the driving force behind our research and this discovery constitutes a major leap forward since it is the most Earth-like planet we know of so far ", said co-author Daniel Kubas, from ESO. ESO PR Video 03/06 ESO PR Video 03/06 Learn more with the video! A report has been published in the 26 January 2006 edition of the leading journal Nature ("Discovery of a cool planet of 5.5 Earth masses through gravitational microlensing" by J.-P. Beaulieu, D. P. Bennett, P. Fouqué, A. Williams, M. Dominik, U. G. Jørgensen, D. Kubas et al.). High resolution images and their captions are available on this page. This press release is also accompanied by Broadcast quality material.

Sharpest views of Betelgeuse reveal how supergiant stars lose mass-Unveiling the true face of a behemoth

NASA Astrophysics Data System (ADS)

2009-07-01

Using different state-of-the-art techniques on ESO's Very Large Telescope, two independent teams of astronomers have obtained the sharpest ever views of the supergiant star Betelgeuse. They show that the star has a vast plume of gas almost as large as our Solar System and a gigantic bubble boiling on its surface. These discoveries provide important clues to help explain how these mammoths shed material at such a tremendous rate. Betelgeuse - the second brightest star in the constellation of Orion (the Hunter) - is a red supergiant, one of the biggest stars known, and almost 1000 times larger than our Sun [1]. It is also one of the most luminous stars known, emitting more light than 100000 Suns. Such extreme properties foretell the demise of a short-lived stellar king. With an age of only a few million years, Betelgeuse is already nearing the end of its life and is soon doomed to explode as a supernova. When it does, the supernova should be seen easily from Earth, even in broad daylight. Red supergiants still hold several unsolved mysteries. One of them is just how these behemoths shed such tremendous quantities of material - about the mass of the Sun - in only 10 000 years. Two teams of astronomers have used ESO's Very Large Telescope (VLT) and the most advanced technologies to take a closer look at the gigantic star. Their combined work suggests that an answer to the long-open mass-loss question may well be at hand. The first team used the adaptive optics instrument, NACO, combined with a so-called "lucky imaging" technique, to obtain the sharpest ever image of Betelgeuse, even with Earth's turbulent, image-distorting atmosphere in the way. With lucky imaging, only the very sharpest exposures are chosen and then combined to form an image much sharper than a single, longer exposure would be. The resulting NACO images almost reach the theoretical limit of sharpness attainable for an 8-metre telescope. The resolution is as fine as 37 milliarcseconds, which is roughly the size of a tennis ball on the International Space Station (ISS), as seen from the ground. "Thanks to these outstanding images, we have detected a large plume of gas extending into space from the surface of Betelgeuse," says Pierre Kervella from the Paris Observatory, who led the team. The plume extends to at least six times the diameter of the star, corresponding to the distance between the Sun and Neptune. "This is a clear indication that the whole outer shell of the star is not shedding matter evenly in all directions," adds Kervella. Two mechanisms could explain this asymmetry. One assumes that the mass loss occurs above the polar caps of the giant star, possibly because of its rotation. The other possibility is that such a plume is generated above large-scale gas motions inside the star, known as convection - similar to the circulation of water heated in a pot. To arrive at a solution, astronomers needed to probe the behemoth in still finer detail. To do this Keiichi Ohnaka from the Max Planck Institute for Radio Astronomy in Bonn, Germany, and his colleagues used interferometry. With the AMBER instrument on ESO's Very Large Telescope Interferometer, which combines the light from three 1.8-metre Auxiliary Telescopes of the VLT, the astronomers obtained observations as sharp as those of a giant, virtual 48-metre telescope. With such superb resolution, the astronomers were able to detect indirectly details four times finer still than the amazing NACO images had already allowed (in other words, the size of a marble on the ISS, as seen from the ground). "Our AMBER observations are the sharpest observations of any kind ever made of Betelgeuse. Moreover, we detected how the gas is moving in different areas of Betelgeuse's surface ― the first time this has been done for a star other than the Sun", says Ohnaka. The AMBER observations revealed that the gas in Betelgeuse's atmosphere is moving vigorously up and down, and that these bubbles are as large as the supergiant star itself. Their unrivalled observations have led the astronomers to propose that these large-scale gas motions roiling under Betelgeuse's red surface are behind the ejection of the massive plume into space. Notes 1] If Betelgeuse were at the centre of our Solar System it would extend out almost to the orbit of Jupiter, engulfing Mercury, Venus, Earth, Mars and the main asteroid belt. More information This research was presented in two papers to appear in Astronomy and Astrophysics: The close circumstellar environment of Betelgeuse: Adaptive optics spectro-imaging in the near-IR with VLT/NACO, by Pierre Kervella et al., and Spatially resolving the inhomogeneous structure of the dynamical atmosphere of Betelgeuse with VLTI/AMBER, by Keiichi Ohnaka et al. The teams are composed of P. Kervella, G. Perrin, S. Lacour, and X. Haubois (LESIA, Observatoire de Paris, France), T. Verhoelst (K. U. Leuven, Belgium), S. T. Ridgway (National Optical Astronomy Observatories, USA), and J. Cami (University of Western Ontario, Canada), and of K. Ohnaka, K.-H. Hofmann, T. Driebe, F. Millour, D. Schertl, and G. Weigelt (Max-Planck-Institute for Radio Astronomy, Bonn, Germany), M. Benisty (INAF-Osservatorio Astrofisico di Arcetri, Firenze, Italy), A. Chelli (LAOG, Grenoble, France), R. Petrov and F. Vakili (Lab. H. Fizeau, OCA, Nice, France), and Ph. Stee (Lab. H. Fizeau, OCA, Grasse, France). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Pulsation in the presence of a strong magnetic field: the roAp star HD166473

NASA Astrophysics Data System (ADS)

Mathys, G.; Kurtz, D. W.; Elkin, V. G.

2007-09-01

Phase-resolved high-resolution, high signal-to-noise ratio (S/N) observations of the strongly magnetic roAp star HD166473 are analysed. HD166473 was selected as the target of this study because it has one of the strongest magnetic fields of all the roAp stars known with resolved magnetically split lines. Indeed, we show that enhanced pulsation diagnosis can be achieved from consideration of the different pulsation behaviour of the π and σ Zeeman components of the resolved spectral lines. This study is based on a time-series of high spectral resolution observations obtained with the Ultraviolet and Visual Echelle Spectrograph of the Very Large Telescope of the European Southern Observatory. Radial velocity variations due to pulsation are observed in rare earth lines, with amplitudes up to 110ms-1. The variations occur with three frequencies, already detected in photometry, but which can in this work be determined with better precision: 1.833, 1.886 and 1.928mHz. The pulsation amplitudes and phases observed in the rare earth element lines vary with atmospheric height, as is the case in other roAp stars studied in detail. Lines of Fe and of other (mostly non-rare earth) elements do not show any variation to very high precision (1.5ms-1 in the case of Fe). The low amplitudes of the observed variations do not allow the original goal of studying differences between the behaviour of the resolved Zeeman line components to be reached; the S/N achieved in the radial velocity determinations is insufficient to establish definitely the possible existence of such differences. Yet the analysis provides a tantalizing hint at the occurrence of variations of the mean magnetic field modulus with the pulsation frequency, with an amplitude of 21 +/- 5G. Based on observations collected at the European Southern Observatory, Paranal, Chile, as part of programme 067.D-0272. E-mail: gmathys@eso.org

The ESA SSA NEO Coordination Centre contribution to NEO hazard monitoring and observational campaigns

NASA Astrophysics Data System (ADS)

Micheli, Marco; Borgia, Barbara; Drolshagen, Gerhard; Koschny, Detlef; Perozzi, Ettore

2015-08-01

The NEO Coordination Centre (NEOCC) has recently been established in Frascati, near Rome, within the framework of the ESA Space Situational Awareness (SSA) Programme. Among its tasks is the coordination of observational activities related to the NEO hazard, and the distribution of relevant and up-to-date information on NEOs to both the scientific community and general users through its web portal (http://neo.ssa.esa.int).On the observational side, the NEOCC is linked to an increasingly large worldwide network of collaborating observatories, ranging from amateurs observers to large professional telescopes. The Centre organizes observation campaigns, alerting the network to suggest urgent or high-priority observations, and providing them with observational support.The NEOCC is also directly obtaining astrometric observations of high-priority targets, especially Virtual Impactors (VIs), on challenging objects as faint as magnitude 26.5, thanks to successful collaborations with ESO VLT in Chile and the INAF-sponsored LBT in Arizona. In addition, the Centre carries out regular monthly runs dedicated to NEO follow-up, recovery and survey activities with the 1-meter ESA OGS telescope in Tenerife.From a service perspective, the NEO System hosted at the NEOCC collects data and information on NEOs produced by various European services (e.g. NEODyS, EARN) and makes them available to a variety of users, with a particular focus on objects with possible collision solutions with the Earth. Among the tools provided through the web portal are the Risk List (a table of all known NEOs with impact solutions), a table of recent and upcoming close approaches, a database of physical properties of NEOs and the so-called Priority List, which allows observers to identify NEOs in most urgent need of observations, and prioritise their observational activities accordingly.The results of our recent observation campaigns and some major recent improvements to the NEO System will presented and discussed in detail.

Three novel NY-ESO-1 epitopes bound to DRB1*0803, DQB1*0401 and DRB1*0901 recognized by CD4 T cells from CHP-NY-ESO-1-vaccinated patients.

PubMed

Mizote, Yu; Taniguchi, Taku; Tanaka, Kei; Isobe, Midori; Wada, Hisashi; Saika, Takashi; Kita, Shoichi; Koide, Yukari; Uenaka, Akiko; Nakayama, Eiichi

2010-07-19

Three novel NY-ESO-1 CD4 T cell epitopes were identified using PBMC obtained from patients who were vaccinated with a complex of cholesterol-bearing hydrophobized pullulan (CHP) and NY-ESO-1 protein (CHP-NY-ESO-1). The restriction molecules were determined by antibody blocking and using various EBV-B cells with different HLA alleles as APC to present peptides to CD4 T cells. The minimal epitope peptides were determined using various N- and C-termini truncated peptides deduced from 18-mer overlapping peptides originally identified for recognition. Those epitopes were DRB1*0901-restricted NY-ESO-1 87-100, DQB1*0401-restricted NY-ESO-1 95-107 and DRB1*0803-restricted NY-ESO-1 124-134. CD4 T cells used to determine those epitope peptides recognized EBV-B cells or DC that were treated with recombinant NY-ESO-1 protein or NY-ESO-1-expressing tumor cell lysate, suggesting that the epitope peptides are naturally processed. These CD4 T cells showed a cytokine profile with Th1 characteristics. Furthermore, NY-ESO-1 87-100 peptide/HLA-DRB1*0901 tetramer staining was observed. Multiple Th1-type CD4 T cell responses are beneficial for inducing effective anti-tumor responses after NY-ESO-1 protein vaccination. (c) 2010 Elsevier Ltd. All rights reserved.

MONA, LISA and VINCI Soon Ready to Travel to Paranal

NASA Astrophysics Data System (ADS)

2000-11-01

First Instruments for the VLT Interferometer Summary A few months from now, light from celestial objects will be directed for the first time towards ESO's Very Large Telescope Interferometer (VLTI) at the Paranal Observatory (Chile). During this "First Light" event and the subsequent test phase, the light will be recorded with a special test instrument, VINCI (VLT INterferometer Commissioning Instrument). The main components of this high-tech instrument are aptly named MONA (a system that combines the light beams from several telescopes by means of optical fibers) and LISA (the infrared camera). VINCI was designed and constructed within a fruitful collaboration between ESO and several research institutes and industrial companies in France and Germany . It is now being assembled at the ESO Headquarters in Garching (Germany) and will soon be ready for installation at the telescope on Paranal. With the VLTI and VINCI, Europe's astronomers are now entering the first, crucial phase of an exciting scientific and technology venture that will ultimately put the world's most powerful optical/IR interferometric facility in their hands . PR Photo 31/00 : VINCI during tests at the ESO Headquarters in Garching. The VLT Interferometer (VLTI) ESO Press Photo 31/00 ESO Press Photo 31/00 [Preview; JPEG: 400 x 301; 43k] [Normal; JPEG: 800 x 602;208xk] [Full-Res; JPEG: 1923 x 1448; 2.2Mb] PR Photo 31/00 shows the various components of the complex VINCI instrument for the VLT Interferometer , during the current tests at the Optical Laboratory at the ESO Headquarters in Garching (Germany). It will later be installed in "clean-room" conditions within the Interferometric Laboratory at the Paranal Observatory. This electronic photo was obtained for documentary purposes. VINCI (VLT INterferometer Commissioning Instrument) is the "First Light" instrument for the Very Large Telescope Interferometer (VLTI) at the Paranal Observatory (Chile). Early in 2001, it will be used for the first tests of this very complex system. Subsequently, it will serve to tune this key research facility to the highest possible performance. The VLTI is based on the combination of light (beams) from the telescopes at Paranal. Of these, the four 8.2-m Unit Telescopes are already in operation - they will soon be joined by three 1.8-m telescopes that can be relocated on rails, cf. PR Photo 43b/99. By means of a system of mirrors, the light from two or more of these telescopes will be guided to the central Interferometric Laboratory , at the center of the observing platform on Paranal. Information about the heart of this complex system, the Delay Lines that are located in the underground Interferometric Tunnel, is available with the recent ESO PR Photos 26a-e/00. The VLTI will later receive other front-line instruments, e.g. AMBER , MIDI and PRIMA. When fully ready some years from now, the VLTI will produce extremely sharp images. This will have a major impact on different types of exciting astronomical observations, e.g.: * the direct discovery and imaging of extra-solar planets comparable to Jupiter, * the discovery and imaging of low-mass stars such as brown dwarfs, * observations of star-forming regions and to better understand the physical processes that give birth to stars, * spectral analysis of the atmospheres of nearby stars, and * imaging the objects of the very core of our Galaxy and the detection of black holes in active nuclei of galaxies. The VINCI test instrument The new instrument, VINCI , will soon be delivered to Paranal by the Département de Recherche Spatiale (Department for Space Research), a joint unit of the Centre Nationale de la Recherche Scientifique (French National Centre for Scientific Research) and the Paris Observatory. VINCI is a functional copy of the FLUOR instrument - now at the IOTA (Infrared Optical Telescope Array) interferometer - that has been upgraded and adapted to the needs of the VLTI. FLUOR was developed by the Département de Recherche Spatiale (DESPA) of the Paris Observatory. It was used in 1991 at the Kitt Peak National Observatory (Arizona, USA), for the first (coherent) combination of the light beams from two independent telescopes by means of optical fibers of fluoride glass. It has since been in operation for five years as a focal instrument at the IOTA Interferometer (Mount Hopkins, Arizona, USA) within a collaboration with the Harvard Smithsonian Center for Astrophysics), producing a rich harvest of scientific data. The VINCI partners The VINCI instrument is constructed in a collaboration between ESO (that also finances it) and the following laboratories and institutes: * DESPA (Paris Observatory) provides the expertise, the general concept, the development and integration of the optomechanics (with the exception of the camera) and the electronics, * Observatoire Midi-Pyrénées that produces the control software * The LISA infrared camera is developed by the Max-Planck-Institut für Extraterrestrische Physik (Garching, Germany), and * ESO provides the IR camera electronics and the overall observational software and is also responsible for the final integration. DESPA delivered VINCI to ESO in Garching on September 27, 2000, and is now assembling the instrument in the ESO optical workshop. It will stay here during three months, until it has been fully integrated and thoroughly tested. It will then be shipped to Paranal at the beginning of next year. After set-up and further tests, the first observations on the sky are expected in late March 2001. Fluoride fibers guide the light The heart of VINCI - named MONA - is a fiber optics beam combine unit. It is the outcome of a fertile, 10-year research partnership between Science (DESPA) and Industry ("Le Verre Fluoré" [2]). Optical fibers will be used to combine the light from two telescopes inside VINCI . Since the instrument will be working in the near-infrared region of the spectrum (wavelength 2-2.5 µm), it is necessary to use optical fibers made of a special type of glass that is transparent at these wavelengths. By far the best best material for this is fluoride glass . It was invented by one of the co-founders of the company "Le Verre Fluoré", the only manufacturer of this kind of highly specialized material in the world. Optical fibers of fluoride glass from this company are therefore used in VINCI . They are of a special type ("monomode") with a very narrow core measuring only 6.5 µm (0.065 mm) across. Light that is collected by one of the telescopes in the VLTI array (e.g., by the 50 m 2 mirror of a VLT Unit Telescope) is guided through the VLTI system of optics and finally enters this core. The fibers guide the light and at the same time "clean" the light beam by eliminating the errors introduced by the atmospheric turbulence, hereby improving the accuracy of the measurements by a factor of 10. DESPA has shown that this is indeed possible by means of real astronomical observations with the FLUOR experiment. Following this positive demonstration, it has been decided to equip the instrumentation of all interferometers currently under construction with fibers or equivalent systems.

Austria Declares Intent To Join ESO

NASA Astrophysics Data System (ADS)

2008-04-01

At a press conference today at the University of Vienna's Observatory, the Austrian Science Minister Johannes Hahn announced the decision by the Austrian Government to seek membership of ESO from 1 July this year. ESO PR Photo 11/08 ESO PR Photo 11/08 Announcing Austria's Intent to Join ESO Said Minister Hahn: "With membership of ESO, Austria's scientists will receive direct access to the world's leading infrastructure in astronomy. This strengthens Austria as a place for research and provides an opportunity for young researchers to continue their work from here. With this move, Austria takes an important step in the reinforcement of Europe's science and research infrastructure." The decision constitutes a major breakthrough for Austrian scientists who have argued for membership of ESO for many years. Seeking membership in ESO also marks a step towards the further development of the European Research and Innovation Area, an important element of Europe's so-called Lisbon Strategy. "ESO welcomes the Austrian bid to join our organisation. I salute the Austrian Government for taking this important step and look forward to working closely with our Austrian friends and colleagues in the years to come," commented the ESO Director General, Tim de Zeeuw. For Austrian astronomers, ESO membership means not only unrestricted access to ESO's world-leading observational facilities including the world's most advanced optical telescope, the Very Large Telescope, and full participation in the quasi-global ALMA project, but also the possibility to participate on a par with their European colleagues in the future projects of ESO, including the realisation of ESO's Extremely Large Telescope project (E-ELT), which is currently in the design phase. All these projects require some of the most advanced technologies in key areas such as optics, detectors, lightweight structures, etc. Austrian participation in ESO opens the door for Austrian industry and major research institutes of the country to take part in the development of such technologies with their associated potential for industrial spin off. The main centres for astronomical research in Austria are at the Universities of Graz, Innsbruck and Vienna. Furthermore scientists in the area of mathematics, applied physics and computer sciences already expressed their interest to contribute to the development of advanced technologies required by ESO's future projects. The Austrian bid for ESO membership will be formally considered by the ESO Council at its next meeting on 3-4 June and is subject also to subsequent ratification by the Austrian Parliament.

Learning globally to enhance local practice: an international programme in primary care & family health.

PubMed

Godoy-Ruiz, Paula; Rodas, Jamie; Talbot, Yves; Rouleau, Katherine

2016-09-01

In a global context of growing health inequities, international learning experiences have become a popular strategy for equipping health professionals with skills, knowledge, and competencies required to work with the populations they serve. This study sought to analyse the Chilean Interprofessional Programme in Primary Health Care (CIPPHC), a 5 week international learning experience funded by the Ministry of Health in Chile targeted at Chilean primary care providers and delivered in Toronto by the Department of Family and Community Medicine at the University of Toronto. The study focused on three cohorts of students (2010-2012). Anonymous programme evaluations were analysed and semi-structured interviews conducted with programme alumni. Simple descriptive statistics were gathered from the evaluations and the interviews were analysed via thematic content analysis. The majority of participants reported high levels of satisfaction with the training programme, knowledge gain, particularly in the areas of the Canadian model of primary care, and found the materials delivered to be applicable to their local context. The CIPPHC has proven to be a successful educational initiative and provides valuable lessons for other academic centres in developing international interprofessional training programmes for primary care health care providers.

Oil-in-Water Emulsions Stabilized by Saponified Epoxidized Soybean Oil-Grafted Hydroxyethyl Cellulose.

PubMed

Huang, Xujuan; Li, Qiaoguang; Liu, He; Shang, Shibin; Shen, Minggui; Song, Jie

2017-05-03

An oil-in-water emulsion stabilized by saponified epoxidized soybean oil-grafted hydroxyethyl cellulose (H-ESO-HEC) was investigated. By using an ultrasonic method, oil-in-water emulsions were prepared by blending 50 wt % soybean oil and 50 wt % H-ESO-HEC aqueous suspensions. The influence of H-ESO-HEC concentrations on the properties of oil-in-water emulsions was examined. The H-ESO-HEC concentrations in the aqueous phase varied from 0.02 to 0.40 wt %. When the H-ESO-HEC concentration was 0.4 wt %, the emulsion remained stable for >80 days. The mean droplet sizes of the emulsions decreased by increasing the H-ESO-HEC concentration and extending the ultrasonic time. The adsorption amounts of H-ESO-HEC at the oil-water interface increased when the H-ESO-HEC concentrations in the aqueous phase increased. The rheological property revealed that the apparent viscosity of the H-ESO-HEC-stabilized oil-in-water emulsions increased when the H-ESO-HEC concentrations increased. Steady flow curves indicated an interfacial film formation in the emulsions. The evolution of G', G″, and tan η indicated the predominantly elastic behaviors of all the emulsions.

A phase I study of vaccination with NY-ESO-1f peptide mixed with Picibanil OK-432 and Montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

PubMed

Kakimi, Kazuhiro; Isobe, Midori; Uenaka, Akiko; Wada, Hisashi; Sato, Eiichi; Doki, Yuichiro; Nakajima, Jun; Seto, Yasuyuki; Yamatsuji, Tomoki; Naomoto, Yoshio; Shiraishi, Kenshiro; Takigawa, Nagio; Kiura, Katsuyuki; Tsuji, Kazuhide; Iwatsuki, Keiji; Oka, Mikio; Pan, Linda; Hoffman, Eric W; Old, Lloyd J; Nakayama, Eiichi

2011-12-15

We conducted a phase I clinical trial of a cancer vaccine using a 20-mer NY-ESO-1f peptide (NY-ESO-1 91-110) that includes multiple epitopes recognized by antibodies, and CD4 and CD8 T cells. Ten patients were immunized with 600 μg of NY-ESO-1f peptide mixed with 0.2 KE Picibanil OK-432 and 1.25 ml Montanide ISA-51. Primary end points of the study were safety and immune response. Subcutaneous injection of the NY-ESO-1f peptide vaccine was well tolerated. Vaccine-related adverse events observed were fever (Grade 1), injection-site reaction (Grade 1 or 2) and induration (Grade 2). Vaccination with the NY-ESO-1f peptide resulted in an increase or induction of NY-ESO-1 antibody responses in nine of ten patients. The sera reacted with recombinant NY-ESO-1 whole protein as well as the NY-ESO-1f peptide. An increase in CD4 and CD8 T cell responses was observed in nine of ten patients. Vaccine-induced CD4 and CD8 T cells responded to NY-ESO-1 91-108 in all patients with various HLA types with a less frequent response to neighboring peptides. The findings indicate that the 20-mer NY-ESO-1f peptide includes multiple epitopes recognized by CD4 and CD8 T cells with distinct specificity. Of ten patients, two with lung cancer and one with esophageal cancer showed stable disease. Our study shows that the NY-ESO-1f peptide vaccine was well tolerated and elicited humoral, CD4 and CD8 T cell responses in immunized patients. Copyright © 2011 UICC.

A Novel HLA-B18 Restricted CD8+ T Cell Epitope Is Efficiently Cross-Presented by Dendritic Cells from Soluble Tumor Antigen

PubMed Central

Chan, Kok-Fei; Oveissi, Sara; Jackson, Heather M.; Dimopoulos, Nektaria; Guillaume, Philippe; Knights, Ashley J.; Lowen, Tamara; Robson, Neil C.; Russell, Sarah E.; Scotet, Emmanuel; Davis, Ian D.; Maraskovsky, Eugene; Cebon, Jonathan; Luescher, Immanuel F.; Chen, Weisan

2012-01-01

NY-ESO-1 has been a major target of many immunotherapy trials because it is expressed by various cancers and is highly immunogenic. In this study, we have identified a novel HLA-B*1801-restricted CD8+ T cell epitope, NY-ESO-188–96 (LEFYLAMPF) and compared its direct- and cross-presentation to that of the reported NY-ESO-1157–165 epitope restricted to HLA-A*0201. Although both epitopes were readily cross-presented by DCs exposed to various forms of full-length NY-ESO-1 antigen, remarkably NY-ESO-188–96 is much more efficiently cross-presented from the soluble form, than NY-ESO-1157–165. On the other hand, NY-ESO-1157–165 is efficiently presented by NY-ESO-1-expressing tumor cells and its presentation was not enhanced by IFN-γ treatment, which induced immunoproteasome as demonstrated by Western blots and functionally a decreased presentation of Melan A26–35; whereas NY-ESO-188–96 was very inefficiently presented by the same tumor cell lines, except for one that expressed high level of immunoproteasome. It was only presented when the tumor cells were first IFN-γ treated, followed by infection with recombinant vaccinia virus encoding NY-ESO-1, which dramatically increased NY-ESO-1 expression. These data indicate that the presentation of NY-ESO-188–96 is immunoproteasome dependent. Furthermore, a survey was conducted on multiple samples collected from HLA-B18+ melanoma patients. Surprisingly, all the detectable responses to NY-ESO-188–96 from patients, including those who received NY-ESO-1 ISCOMATRIX™ vaccine were induced spontaneously. Taken together, these results imply that some epitopes can be inefficiently presented by tumor cells although the corresponding CD8+ T cell responses are efficiently primed in vivo by DCs cross-presenting these epitopes. The potential implications for cancer vaccine strategies are further discussed. PMID:22970293

ESO Highlights in 2008

NASA Astrophysics Data System (ADS)

2009-01-01

As is now the tradition, the European Southern Observatory looks back at the exciting moments of last year. 2008 was in several aspects an exceptionally good year. Over the year, ESO's telescopes provided data for more than 700 scientific publications in refereed journals, making ESO the most productive ground-based observatory in the world. ESO PR Highlights 2008 ESO PR Photo 01a/09 The image above is a clickable map. These are only some of the press releases issued by ESO in 2008. For a full listing, please go to ESO 2008 page. Austria signed the agreement to join the other 13 ESO member states (ESO 11/08 and 20/08), while the year marked the 10th anniversary of first light for ESO's "perfect science machine", the Very Large Telescope (ESO 16/08 and 17/08). The ALMA project, for which ESO is the European partner, had a major milestone in December, as the observatory was equipped with its first antenna (ESO 49/08). Also the Atacama Pathfinder Experiment (APEX) telescope impressed this year with some very impressive and publicly visible results. Highlights came in many fields: Astronomers for instance used the Very Large Telescope (VLT) to discover and image a probable giant planet long sought around the star Beta Pictoris (ESO 42/08). This is now the eighth extrasolar planet to have been imaged since the VLT imaged the first extrasolar planet in 2004 (three of eight were imaged with VLT). The VLT also enabled three students to confirm the nature of a unique planet (ESO 45/08). This extraordinary find, which turned up during their research project, is a planet about five times as massive as Jupiter. This is the first planet discovered orbiting a fast-rotating hot star. The world's foremost planet-hunting instrument, HARPS, located at ESO's La Silla observatory, scored a new first, finding a system of three super-Earths around a star (ESO 19/08). Based on the complete HARPS sample, astronomers now think that one Sun-like star out of three harbours short orbit, low-mass planets. With the VLT and another recent instrument, CRIRES, astronomers have also been able to study planet-forming discs around young Sun-like stars in unsurpassed detail, clearly revealing the motion and distribution of the gas in the inner parts of the disc, possibly implying the presence of giant planets (ESO 27/08). As the result of an impressive 16-year long study, that combines data obtained with ESO's New Technology Telescope and the VLT, a team of German astronomers has produced the most detailed view ever of the surroundings of the monster lurking at our Galaxy's heart -- a supermassive black hole (ESO 46/08). Combining data from APEX and the VLT, another team studied the violent flares coming from this region (ESO 41/08). The flares are the likely signatures of material being torn apart by the black hole. Making such science discoveries doesn't happen without the best technological tools. ESO is constantly upgrading its battery of instruments and telescopes on Cerro Paranal, home of the VLT. For example, the PRIMA instrument for the VLT Interferometer (VLTI) recently saw first light (ESO 29/08). When fully operational, PRIMA will boost the capabilities of the VLTI to see sources much fainter than any previous interferometers, and determine positions on the sky better than any other existing astronomical facility. The Multi-Conjugate Adaptive Optics Demonstrator (MAD) prototype, mounted on the VLT, provided astronomers with the sharpest image of the full disc of planet Jupiter ever taken from the Earth's surface (ESO 33/08). The future VISTA telescope on Paranal also received its record-curved 4.1-metre mirror, paving the way for unique surveys of the southern sky in the infrared (ESO 10/08). In preparation for other instruments of the future, staff at ESO joined with quantum optics specialists to develop a new calibration system for ultra-precise spectrographs (ESO 26/08). Given the presence of such state-of-the-art technology, it is perhaps no surprise that the crucial scenes from the latest James Bond sequel were filmed at Paranal (even though the director was really more interested in blowing up the Residencia, the lodge where staff and visitors can relax after working at one of the world's most advanced ground-based astronomical observatories). In March, a movie crew of 300 people, including the principal actors, were shooting at Paranal (ESO 007/08 and 38/08). On the outreach side, ESO's series of video podcasts, the ESOcast, premiered with the first three episodes. More than two thousand new and historic ESO images were put online in the ESO image archive as well as more than 300 hundred videos, mostly in High Definition. The work to digitise ESO's heritage will continue in 2009. Doubtless just as many exciting results will be presented this year too. Especially as 2009 has been officially declared the International Year of Astronomy (IYA) by the UN, UNESCO and the International Astronomical Union. The Year is coordinated from the global IYA Secretariat hosted by ESO. In addition ESO leads a number of global and regional activities.

News and Views: Diamond is new head of SKA; Did you read our `A&G' mobile issue? BBC writer wins astro journalism prize; Kavli prize recognizes work on Kuiper Belt objects

NASA Astrophysics Data System (ADS)

2012-10-01

Philip Diamond will become director general of the Square Kilometre Array this month, moving from Australia to the new SKA headquarters at Jodrell Bank Radio Observatory. Technology writer Katia Moskvitch has won the first European Astronomy Journalism Prize for her series of articles on the Very Large Telescope at Paranal, Chile. Moskvitch will be the guest of the ESO at the inauguration of the Atacama Large Millimeter/submillimeter Array (ALMA) in the Atacama desert in March 2013. The 2012 Kavli Prize in Astrophysics is shared between David C Jewitt (University of California, USA), Jane X Luu (Massachusetts Institute of Technology, Lincoln Laboratory, USA), and Michael E Brown (California Institute of Technology, USA) “for discovering and characterizing the Kuiper Belt and its largest members, work that led to a major advance in the understanding of the history of our planetary system”.

VizieR Online Data Catalog: Radial velocity follow-up of the HD 3167 system (Gandolfi+, 2017)

NASA Astrophysics Data System (ADS)

Gandolfi, D.; Barragan, O.; Hatzes, A. P.; Fridlund, M.; Fossati, L.; Donati, P.; Johnson, M. C.; Nowak, G.; Prieto-Arranz, J.; Albrecht, S.; Dai, F.; Deeg, H.; Endl, M.; Grziwa, S.; Hjorth, M.; Korth, J.; Nespral, D.; Saario, J.; Smith, A. M. S.; Antoniciello, G.; Alarcon, J.; Bedell, M.; Blay, P.; Brems, S. S.; Cabrera, J.; Csizmadia, S.; Cusano, F.; Cochran, W. D.; Eigmuller, P.; Erikson, A.; Gonzalez Hernandez, J. I.; Guenther, E. W.; Hirano, T.; Suarez Mascareno, A.; Narita, N.; Palle, E.; Parviainen, H.; Patzold, M.; Persson, C. M.; Rauer, H.; Saviane, I.; Schmidtobreick, L.; van Eylen, V.; Winn, J. N.; Zakhozhay, O. V.

2018-06-01

We used the FIbre-fed Echelle Spectrograph (FIES; Frandsen & Lindberg 1999anot.conf...71F; Telting et al. 2014AN....335...41T) mounted at the 2.56 m Nordic Optical Telescope (NOT) of Roque de los Muchachos Observatory (La Palma, Spain) to acquire 37 high-resolution spectra (R~67000) in 12 different nights between July and September 2016. We also acquired 50 spectra with the HARPS spectrograph (R~115000; Mayor et al. 2003Msngr.114...20M) and 32 spectra with the HARPS-N spectrograph (R~115000; Cosentino et al. 2012SPIE.8446E..1VC). HARPS and HARPS-N are fiber-fed cross-dispersed echelle spectrographs specifically designed to achieve very high-precision long-term RV stabilities (<1 m/s). They are mounted at the ESO-3.6 m telescope of La Silla observatory (Chile) and at the 3.58 m Telescopio Nazionale Galileo (TNG) of Roque de los Muchachos Observatory (La Palma, Spain). (1 data file).

The Gaia-ESO Survey. Mg-Al anti-correlation in iDR4 globular clusters

NASA Astrophysics Data System (ADS)

Pancino, E.; Romano, D.; Tang, B.; Tautvaišienė, G.; Casey, A. R.; Gruyters, P.; Geisler, D.; San Roman, I.; Randich, S.; Alfaro, E. J.; Bragaglia, A.; Flaccomio, E.; Korn, A. J.; Recio-Blanco, A.; Smiljanic, R.; Carraro, G.; Bayo, A.; Costado, M. T.; Damiani, F.; Jofré, P.; Lardo, C.; de Laverny, P.; Monaco, L.; Morbidelli, L.; Sbordone, L.; Sousa, S. G.; Villanova, S.

2017-05-01

We use Gaia-ESO (GES) Survey iDR4 data to explore the Mg-Al anti-correlation in globular clusters that were observed as calibrators, as a demonstration of the quality of Gaia-ESO Survey data and analysis. The results compare well with the available literature, within 0.1 dex or less, after a small (compared to the internal spreads) offset between the UVES and GIRAFFE data of 0.10-0.15 dex was taken into account. In particular, for the first time we present data for NGC 5927, which is one of the most metal-rich globular clusters studied in the literature so far with [ Fe / H ] = - 0.39 ± 0.04 dex; this cluster was included to connect with the open cluster regime in the Gaia-ESO Survey internal calibration. The extent and shape of the Mg-Al anti-correlation provide strong constraints on the multiple population phenomenon in globular clusters. In particular, we studied the dependency of the Mg-Al anti-correlation extension with metallicity, present-day mass,and age of the clusters, using GES data in combination with a large set of homogenized literature measurements.We find a dependency with both metallicity and mass, which is evident when fitting for the two parameters simultaneously, but we do not find significant dependency with age. We confirm that the Mg-Al anti-correlation is not seen in all clusters, but disappears for the less massive or most metal-rich clusters. We also use our data set to see whether a normal anti-correlation would explain the low [Mg/α] observed in some extragalactic globular clusters, but find that none of the clusters in our sample can reproduce it; a more extreme chemical composition, such as that of NGC 2419, would be required. We conclude that GES iDR4 data already meet the requirements set by the main survey goals and can be used to study globular clusters in detail, even if the analysis procedures were not specifically designed for them. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 188.B-3002.Full Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/601/A112

ESO Demonstration Project with the NRAO 12-m Antenna

NASA Astrophysics Data System (ADS)

Heald, R.; Karban, R.

2000-03-01

During the months of September through November 1999, an ALMA joint demonstration project between the European Southern Observatory (ESO) and the National Radio Astronomy Observatory (NRAO) was carried out in Socorro/New Mexico. During this period, Robert Karban (ESO) and Ron Heald (NRAO) worked together on the ESO Demonstration Project. The project integrated ESO software and existing NRAO software (a prototype for the future ALMA control software) to control the motion of the Kitt Peak 12-m antenna. ESO software from the VLT provided the operator interface and coordinate transformation software, while Pat Wallace's TPOINT provided the pointing- model software.

Strategy for monitoring T cell responses to NY-ESO-1 in patients with any HLA class I allele

PubMed Central

Gnjatic, Sacha; Nagata, Yasuhiro; Jäger, Elke; Stockert, Elisabeth; Shankara, Srinivas; Roberts, Bruce L.; Mazzara, Gail P.; Lee, Sang Yull; Dunbar, P. Rod; Dupont, Bo; Cerundolo, Vincenzo; Ritter, Gerd; Chen, Yao-Tseng; Knuth, Alexander; Old, Lloyd J.

2000-01-01

NY-ESO-1 elicits frequent antibody responses in cancer patients, accompanied by strong CD8+ T cell responses against HLA-A2-restricted epitopes. To broaden the range of cancer patients who can be assessed for immunity to NY-ESO-1, a general method was devised to detect T cell reactivity independent of prior characterization of epitopes. A recombinant adenoviral vector encoding the full cDNA sequence of NY-ESO-1 was used to transduce CD8-depleted peripheral blood lymphocytes as antigen-presenting cells. These modified antigen-presenting cells were then used to restimulate memory effector cells against NY-ESO-1 from the peripheral blood of cancer patients. Specific CD8+ T cells thus sensitized were assayed on autologous B cell targets infected with a recombinant vaccinia virus encoding NY-ESO-1. Strong polyclonal responses were observed against NY-ESO-1 in antibody-positive patients, regardless of their HLA profile. Because the vectors do not cross-react immunologically, only responses to NY-ESO-1 were detected. The approach described here allows monitoring of CD8+ T cell responses to NY-ESO-1 in the context of various HLA alleles and has led to the definition of NY-ESO-1 peptides presented by HLA-Cw3 and HLA-Cw6 molecules. PMID:11005863

Spain to Join ESO

NASA Astrophysics Data System (ADS)

2006-02-01

Today, during a ceremony in Madrid, an agreement was signed by the Spanish Minister of Education and Science, Mrs. María Jesús San Segundo, and the ESO Director General, Dr. Catherine Cesarsky, affirming their commitment to securing Spanish membership of ESO. ESO PR Photo 05a/06 ESO PR Photo 05a/06 Signature Event in Madrid Following approval by the Spanish Council of Ministers and the ratification by the Spanish Parliament of the ESO Convention and the associated protocols, Spain intends to become ESO's 12th member state on 1 July 2006. "Since long Spain was aware that entering ESO was a logical decision and it was even necessary for a country like Spain because Spain is ranked 8th in astrophysical research", said Mrs. María Jesús San Segundo. "The large scientific installations are not only necessary for research in different fields but are also partners and customers for hi-tech companies, helping to increase the funding of R&D." "Spanish Astronomy has made tremendous strides forward and we are delighted to welcome Spain as a new member of ESO. We very much look forward to working together with our excellent Spanish colleagues," said Dr. Cesarsky. "For ESO, the Spanish accession means that we can draw on the scientific and technological competences, some of them unique in Europe, that have been developed in Spain and, of course, for Europe the Spanish membership of ESO is an important milestone in the construction of the European Research Area." ESO PR Photo 05b/06 ESO PR Photo 05b/06 Signature Event in Madrid Indeed, Spain is an important member of the European astronomical community and has developed impressively over the last three decades, reaching maturity with major contributions in virtually all subjects of astronomy. In addition, Spain hosts, operates or owns a number of competitive facilities dedicated to foster astronomical research, among which the Observatorio del Roque de los Muchachos at La Palma, certainly the premier optical/infrared astronomical observing site in Europe and site of the Spanish 10m GranTeCan telescope now nearing completion. With the high quality of Spanish astronomical research as well as the technological competence of Spanish industry, it is only fitting that Spain should join ESO, world-leader in ground-based astronomy. Through ESO Spain will enjoy full access both to all of ESO's current facilities and to unrestricted participation in the great projects that ESO is planning for the future. Spain is already an active partner of the Atacama Large Millimeter Array (ALMA), whose construction and operations are led on behalf of Europe by ESO. ESO's Council approved the admission of Spain at its 107th meeting held in Garching on 7 and 8 December 2005. High resolution images and their captions are available on this page.

Ticking Stellar Time Bomb Identified - Astronomers find prime suspect for a Type Ia supernova

NASA Astrophysics Data System (ADS)

2009-11-01

Using ESO's Very Large Telescope and its ability to obtain images as sharp as if taken from space, astronomers have made the first time-lapse movie of a rather unusual shell ejected by a "vampire star", which in November 2000 underwent an outburst after gulping down part of its companion's matter. This enabled astronomers to determine the distance and intrinsic brightness of the outbursting object. It appears that this double star system is a prime candidate to be one of the long-sought progenitors of the exploding stars known as Type Ia supernovae, critical for studies of dark energy. "One of the major problems in modern astrophysics is the fact that we still do not know exactly what kinds of stellar system explode as a Type Ia supernova," says Patrick Woudt, from the University of Cape Town and lead author of the paper reporting the results. "As these supernovae play a crucial role in showing that the Universe's expansion is currently accelerating, pushed by a mysterious dark energy, it is rather embarrassing." The astronomers studied the object known as V445 in the constellation of Puppis ("the Stern") in great detail. V445 Puppis is the first, and so far only, nova showing no evidence at all for hydrogen. It provides the first evidence for an outburst on the surface of a white dwarf [1] dominated by helium. "This is critical, as we know that Type Ia supernovae lack hydrogen," says co-author Danny Steeghs, from the University of Warwick, UK, "and the companion star in V445 Pup fits this nicely by also lacking hydrogen, instead dumping mainly helium gas onto the white dwarf." In November 2000, this system underwent a nova outburst, becoming 250 times brighter than before and ejecting a large quantity of matter into space. The team of astronomers used the NACO adaptive optics instrument [2] on ESO's Very Large Telescope (VLT) to obtain very sharp images of V445 Puppis over a time span of two years. The images show a bipolar shell, initially with a very narrow waist, with lobes on each side. Two knots are also seen at both the extreme ends of the shell, which appear to move at about 30 million kilometres per hour. The shell - unlike any previously observed for a nova - is itself moving at about 24 million kilometres per hour. A thick disc of dust, which must have been produced during the last outburst, obscures the two central stars. "The incredible detail that we can see on such small scales - about hundred milliarcseconds, which is the apparent size of a one euro coin seen from about forty kilometres - is only possible thanks to the adaptive optics technology available on large ground-based telescopes such as ESO's VLT," says Steeghs. A supernova is one way that a star can end its life, exploding in a display of grandiose fireworks. One family of supernovae, called Type Ia supernovae, are of particular interest in cosmology as they can be used as "standard candles" to measure distances in the Universe [3] and so can be used to calibrate the accelerating expansion that is driven by dark energy. One defining characteristic of Type Ia supernovae is the lack of hydrogen in their spectrum. Yet hydrogen is the most common chemical element in the Universe. Such supernovae most likely arise in systems composed of two stars, one of them being the end product of the life of sun-like stars, or white dwarfs. When such white dwarfs, acting as stellar vampires that suck matter from their companion, become heavier than a given limit, they become unstable and explode [4]. The build-up is not a simple process. As the white dwarf cannibalises its prey, matter accumulates on its surface. If this layer becomes too dense, it becomes unstable and erupts as a nova. These controlled, mini-explosions eject part of the accumulated matter back into space. The crucial question is thus to know whether the white dwarf can manage to gain weight despite the outburst, that is, if some of the matter taken from the companion stays on the white dwarf, so that it will eventually become heavy enough to explode as a supernova. Combining the NACO images with data obtained with several other telescopes [5] the astronomers could determine the distance of the system - about 25 000 light-years from the Sun - and its intrinsic brightness - over 10 000 times brighter than the Sun. This implies that the vampire white dwarf in this system has a high mass that is near its fatal limit and is still simultaneously being fed by its companion at a high rate. "Whether V445 Puppis will eventually explode as a supernova, or if the current nova outburst has pre-empted that pathway by ejecting too much matter back into space is still unclear," says Woudt. "But we have here a pretty good suspect for a future Type Ia supernova!" Notes [1] White dwarfs represent the evolutionary end product of stars with initial masses up to a few solar masses. A white dwarf is the burnt-out stellar core that is left behind when a star like the Sun sheds its outer layers towards the end of its active life. It is composed essentially of carbon and oxygen. This process normally also leads to the formation of a surrounding planetary nebula. [2] Adaptive optics is a technique that allows astronomers to obtain an image of an object free from the blurring effect of the atmosphere. See the adaptive optics page at ESO: http://www.eso.org/public/astronomy/technology/adaptive_optics.html [3] See for example http://www.eso.org/~bleibund/papers/EPN/epn.html [4] This Chandrasekhar limit, named after the Indian physicist Subrahmanyan Chandrasekhar, is nearly 1.4 times the mass of the Sun. When a white dwarf reaches a mass above this limit, either by sucking matter from a companion or merging with another white dwarf, it will turn itself into a thermonuclear bomb that will burn carbon and oxygen explosively. [5] The team also used the SOFI instrument on ESO's New Technology Telescope, the IMACS spectrograph on the 6.5-metre Magellan Baade telescope, and the Infrared Survey Facility and the SIRIUS camera at the Sutherland station of the South African Astronomical Observatory. More information This research was presented in a paper to appear in the 20 November 2009 issue of the Astrophysical Journal, vol. 706, p. 738 ("The expanding bipolar shell of the helium nova V445 Puppis", by P. A. Woudt et al.). The team is composed of P. A. Woudt and B. Warner (University of Cape Town, South Africa), D. Steeghs and T. R. Marsh (University of Warwick, UK), M. Karovska and G. H. A. Roelofs (Harvard-Smithsonian Center for Astrophysics, Cambridge MA, USA), P. J. Groot and G. Nelemans (Radboud University Nijmegen, the Netherlands), T. Nagayama (Kyoto University, Japan), D. P. Smits (University of South Africa, South Africa), and T. O'Brien (University of Manchester, UK). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Vaccination with NY-ESO-1 overlapping peptides mixed with Picibanil OK-432 and montanide ISA-51 in patients with cancers expressing the NY-ESO-1 antigen.

PubMed

Wada, Hisashi; Isobe, Midori; Kakimi, Kazuhiro; Mizote, Yu; Eikawa, Shingo; Sato, Eiichi; Takigawa, Nagio; Kiura, Katsuyuki; Tsuji, Kazuhide; Iwatsuki, Keiji; Yamasaki, Makoto; Miyata, Hiroshi; Matsushita, Hirokazu; Udono, Heiichiro; Seto, Yasuyuki; Yamada, Kazuhiro; Nishikawa, Hiroyoshi; Pan, Linda; Venhaus, Ralph; Oka, Mikio; Doki, Yuichiro; Nakayama, Eiichi

2014-01-01

We conducted a clinical trial of an NY-ESO-1 cancer vaccine using 4 synthetic overlapping long peptides (OLP; peptides #1, 79-108; #2, 100-129; #3, 121-150; and #4, 142-173) that include a highly immunogenic region of the NY-ESO-1 molecule. Nine patients were immunized with 0.25 mg each of three 30-mer and a 32-mer long NY-ESO-1 OLP mixed with 0.2 KE Picibanil OK-432 and 1.25 mL Montanide ISA-51. The primary endpoints of this study were safety and NY-ESO-1 immune responses. Five to 18 injections of the NY-ESO-1 OLP vaccine were well tolerated. Vaccine-related adverse events observed were fever and injection site reaction (grade 1 and 2). Two patients showed stable disease after vaccination. An NY-ESO-1-specific humoral immune response was observed in all patients and an antibody against peptide #3 (121-150) was detected firstly and strongly after vaccination. NY-ESO-1 CD4 and CD8 T-cell responses were elicited in these patients and their epitopes were identified. Using a multifunctional cytokine assay, the number of single or double cytokine-producing cells was increased in NY-ESO-1-specific CD4 and CD8 T cells after vaccination. Multiple cytokine-producing cells were observed in PD-1 (-) and PD-1 (+) CD4 T cells. In conclusion, our study indicated that the NY-ESO-1 OLP vaccine mixed with Picibanil OK-432 and Montanide ISA-51 was well tolerated and elicited NY-ESO-1-specific humoral and CD4 and CD8 T-cell responses in immunized patients.

Measurement of serum antibodies against NY-ESO-1 by ELISA: A guide for the treatment of specific immunotherapy for patients with advanced colorectal cancer.

PubMed

Long, Yan-Yan; Wang, Yu; Huang, Qian-Rong; Zheng, Guang-Shun; Jiao, Shun-Chang

2014-10-01

NY-ESO-1 has been identified as one of the most immunogenic antigens; thus, is a highly attractive target for cancer immunotherapy. The present study analyzed the expression of serum antibodies (Abs) against NY-ESO-1 in patients with advanced colorectal cancer (CRC), with the aim of guiding the treatment of NY-ESO-1-based specific-immunotherapy for these patients. Furthermore, the present study was the first to evaluate the kinetic expression of anti-NY-ESO-1 Abs and investigate the possible influencing factors. A total of 239 serum samples from 155 pathologically confirmed patients with advanced CRC (stages III and IV) were collected. The presence of spontaneous Abs against NY-ESO-1 was analyzed using an enzyme-linked immunosorbent assay (ELISA). The results demonstrated that 24.5% (38/155) of the investigated patients were positive for NY-ESO-1-specific Abs. No statistically significant correlations were identified between the expression of anti-NY-ESO-1 Abs and clinicopathological parameters, including age and gender, location, grading, local infiltration, lymph node status, metastatic status and K-ras mutation status (P>0.05). In 59 patients, the kinetic expression of anti-NY-ESO-1 Abs was analyzed, of which 14 patients were initially positive and 45 patients were initially negative. Notably, 16/59 (27.1%) patients changed their expression status during the study period, and the initially positive patients were more likely to change compared with the initially negative patients (85.7 vs. 8.8%; P<0.001). Therefore, monitoring serum Abs against NY-ESO-1 by ELISA is an easy and feasible method. The high expression rate of NY-ESO-1-specific Abs in CRC patients indicates that measuring the levels of serum Abs against NY-ESO-1 may guide the treatment of NY-ESO-1-based specific immunotherapy for patients with advanced CRC.

Measurement of serum antibodies against NY-ESO-1 by ELISA: A guide for the treatment of specific immunotherapy for patients with advanced colorectal cancer

PubMed Central

LONG, YAN-YAN; WANG, YU; HUANG, QIAN-RONG; ZHENG, GUANG-SHUN; JIAO, SHUN-CHANG

2014-01-01

NY-ESO-1 has been identified as one of the most immunogenic antigens; thus, is a highly attractive target for cancer immunotherapy. The present study analyzed the expression of serum antibodies (Abs) against NY-ESO-1 in patients with advanced colorectal cancer (CRC), with the aim of guiding the treatment of NY-ESO-1-based specific-immunotherapy for these patients. Furthermore, the present study was the first to evaluate the kinetic expression of anti-NY-ESO-1 Abs and investigate the possible influencing factors. A total of 239 serum samples from 155 pathologically confirmed patients with advanced CRC (stages III and IV) were collected. The presence of spontaneous Abs against NY-ESO-1 was analyzed using an enzyme-linked immunosorbent assay (ELISA). The results demonstrated that 24.5% (38/155) of the investigated patients were positive for NY-ESO-1-specific Abs. No statistically significant correlations were identified between the expression of anti-NY-ESO-1 Abs and clinicopathological parameters, including age and gender, location, grading, local infiltration, lymph node status, metastatic status and K-ras mutation status (P>0.05). In 59 patients, the kinetic expression of anti-NY-ESO-1 Abs was analyzed, of which 14 patients were initially positive and 45 patients were initially negative. Notably, 16/59 (27.1%) patients changed their expression status during the study period, and the initially positive patients were more likely to change compared with the initially negative patients (85.7 vs. 8.8%; P<0.001). Therefore, monitoring serum Abs against NY-ESO-1 by ELISA is an easy and feasible method. The high expression rate of NY-ESO-1-specific Abs in CRC patients indicates that measuring the levels of serum Abs against NY-ESO-1 may guide the treatment of NY-ESO-1-based specific immunotherapy for patients with advanced CRC. PMID:25187840

ROSAT Discovers Unique, Distant Cluster of Galaxies

NASA Astrophysics Data System (ADS)

1995-06-01

Brightest X-ray Cluster Acts as Strong Gravitational Lens Based on exciting new data obtained with the ROSAT X-ray satellite and a ground-based telescope at the ESO La Silla Observatory, a team of European astronomers [2] has just discovered a very distant cluster of galaxies with unique properties. It emits the strongest X-ray emission of any cluster ever observed by ROSAT and is accompanied by two extraordinarily luminous arcs that represent the gravitationally deflected images of even more distant objects. The combination of these unusual characteristics makes this cluster, now known as RXJ1347.5-1145, a most interesting object for further cosmological studies. DISCOVERY AND FOLLOW-UP OBSERVATIONS This strange cluster of galaxies was discovered during the All Sky Survey with the ROSAT X-ray satellite as a moderately intense X-ray source in the constellation of Virgo. It could not be identified with any already known object and additional ground-based observations were therefore soon after performed with the Max-Planck-Society/ESO 2.2-metre telescope at the La Silla observatory in Chile. These observations took place within a large--scale redshift survey of X-ray clusters of galaxies detected by the ROSAT All Sky Survey, a so-called ``ESO Key Programme'' led by astronomers from the Max-Planck-Institut fur Extraterrestrische Physik and the Osservatorio Astronomico di Brera. The main aim of this programme is to identify cluster X-ray sources, to determine the distance to the X-ray emitting clusters and to investigate their overall properties. These observations permitted to measure the redshift of the RXJ1347.5-1145 cluster as z = 0.45, i.e. it moves away from us with a velocity (about 106,000 km/sec) equal to about one-third of the velocity of light. This is an effect of the general expansion of the universe and it allows to determine the distance as about 5,000 million light-years (assuming a Hubble constant of 75 km/sec/Mpc). In other words, we see these galaxies as they were 5,000 million years ago. Knowing the intensity of the X-ray emission as measured by ROSAT and also the distance, the astronomers were then able to estimate the total X-ray energy emitted by this cluster. It was found to be extremely high [3], in fact higher than that of any other cluster ever observed by ROSAT. It amounts to no less than 1.5 million million times the total energy emitted by the Sun. It is believed that this strong X-ray emission originates in a hot gas located between the galaxies in the cluster. The high temperature indicates that the components of the gas move very rapidly; this is related to the strong gravitational field within the cluster. THE GRAVITATIONAL ARCS To their great surprise and delight, the astronomers also discovered two bright arcs, 5 - 6 arcseconds long and symmetrically placed about 35 arcseconds to the North-East and South-West of the brightest galaxies in the cluster (see the photo). They were detected on exposures of only 3 minutes duration with the 2.2-metre telescope and are among the brightest such arcs ever found. At the indicated distance, the arcs are situated at a projected distance of about 500,000 light-years from the centre of the cluster. It is an interesting possibility that the two arcs may in fact be two images of the same, very distant galaxy, that is situated far beyond RXJ1347.5-1145 and whose light has been bent and split by this cluster's strong gravitational field. This strange phenomenon was first discovered in the late 1970's and is referred to as gravitational lensing. Quite a few examples are now known, in most cases in the form of double or multiple images of quasars. About three dozen cases involve well visible galaxy clusters and elongated arcs, but few, if any, of these arcs are as bright as those seen in the present cluster. This particular arc configuration enables a very accurate determination of the total mass of the cluster, once the distance of the background galaxy has been measured (by obtaining spectra of the arcs and measuring their redshift). The masses of galaxy clusters are important for the determination, for instance of the mean density and distribution of matter in the universe. This is because these clusters are the most massive, clearly defined objects known and as such trace these parameters in the universe on very large scales. Another possibility to derive the cluster mass is offered by X-ray observations, because the distribution of the hot, X-ray emitting gas traces the gravitational field of the cluster. Recently, in some clusters there has been a discrepancy between the mass determined in this way and that found from gravitational lensing effects. The team of astronomers now hopes that follow-up X-ray observations of RXJ1347.5-1145 will help to solve this puzzle. Moreover, the combination of extremely high X-ray brightness and the possibility to perform a rather accurate mass determination by the gravitational lensing effect makes this particular cluster a truly unique object. In view of the exceptional X-ray brightness, a very high mass is expected. The exact determination will be possible, as soon as spectra have been obtained of the two arcs. Contrary to what is the case in other clusters, this will not be so difficult, due to their unusual brightness and their ideal geometrical configuration. [1] This is a joint Press Release of ESO and the Max-Planck-Society. It is accompanied by a B/W photo. [2] The investigation described in this Press Release is the subject of a Letter to the Editor which will soon appear in the European journal Astronomy & Astrophysics, with the following authors: Sabine Schindler (Max-Planck-Institut fuer Extraterrestrische Physik and Max-Planck-Institut fuer Astrophysik, Garching, Germany), Hans Boehringer, Doris M. Neumann and Ulrich G. Briel (Max-Planck-Institut fuer Extraterrestrische Physik, Garching, Germany), Luigi Guzzo (Osservatorio Astronomico di Brera, Merate, Italy), Guido Chincarini (Osservatorio Astronomico di Brera, Merate, and Dipartimento di Fisica, Universita di Milano, Italy), Harald Ebeling (Institute of Astronomy, Cambridge, U.K.), Chris A. Collins (School of Chemical and Physical Sciences, John-Moores University, Liverpool, U.K.), Sabrina De Grandi (Dipartimento di Fisica, Universita di Milano, Italy), Peter Shaver (ESO, Garching, Germany) and Giampaolo Vettolani (Istituto di Radioastronomia del CNR, Bologna, Italy). [3] The total X-ray energy emitted by RXJ1347.5-1145 is (6.2 +-0.6) 10^45 erg s-1 in the range 0.1--2.4 keV. ESO Press Information is made available on the World-Wide Web (URL: http://www.hq.eso.org/) and on CompuServe (space science and astronomy area, GO SPACE)

Optical turbulence profiling with Stereo-SCIDAR for VLT and ELT

NASA Astrophysics Data System (ADS)

Osborn, J.; Wilson, R. W.; Sarazin, M.; Butterley, T.; Chacón, A.; Derie, F.; Farley, O. J. D.; Haubois, X.; Laidlaw, D.; LeLouarn, M.; Masciadri, E.; Milli, J.; Navarrete, J.; Townson, M. J.

2018-07-01

Knowledge of the Earth's atmospheric optical turbulence is critical for astronomical instrumentation. Not only does it enable performance verification and optimization of the existing systems, but it is required for the design of future instruments. As a minimum this includes integrated astro-atmospheric parameters such as seeing, coherence time, and isoplanatic angle, but for more sophisticated systems such as wide-field adaptive optics enabled instrumentation the vertical structure of the turbulence is also required. Stereo-SCIDAR (Scintillation Detection and Ranging) is a technique specifically designed to characterize the Earth's atmospheric turbulence with high-altitude resolution and high sensitivity. Together with ESO (European Southern Observatory), Durham University has commissioned a Stereo-SCIDAR instrument at Cerro Paranal, Chile, the site of the Very Large Telescope (VLT), and only 20 km from the site of the future Extremely Large Telescope (ELT). Here we provide results from the first 18 months of operation at ESO Paranal including instrument comparisons and atmospheric statistics. Based on a sample of 83 nights spread over 22 months covering all seasons, we find the median seeing to be 0.64″ with 50 per cent of the turbulence confined to an altitude below 2 km and 40 per cent below 600 m. The median coherence time and isoplanatic angle are found as 4.18 ms and 1.75″, respectively. A substantial campaign of inter-instrument comparison was also undertaken to assure the validity of the data. The Stereo-SCIDAR profiles (optical turbulence strength and velocity as a function of altitude) have been compared with the Surface-Layer Slope Detection And Ranging, Multi-Aperture Scintillation Sensor-Differential Image Motion Monitor, and the European Centre for Medium Range Weather Forecasts model. The correlation coefficients are between 0.61 (isoplanatic angle) and 0.84 (seeing).

On the Chemical Abundances of Miras in Clusters: V1 in the Metal-rich Globular NGC 5927

NASA Astrophysics Data System (ADS)

D’Orazi, V.; Magurno, D.; Bono, G.; Matsunaga, N.; Braga, V. F.; Elgueta, S. S.; Fukue, K.; Hamano, S.; Inno, L.; Kobayashi, N.; Kondo, S.; Monelli, M.; Nonino, M.; Przybilla, N.; Sameshima, H.; Saviane, I.; Taniguchi, D.; Thevenin, F.; Urbaneja-Perez, M.; Watase, A.; Arai, A.; Bergemann, M.; Buonanno, R.; Dall’Ora, M.; Da Silva, R.; Fabrizio, M.; Ferraro, I.; Fiorentino, G.; Francois, P.; Gilmozzi, R.; Iannicola, G.; Ikeda, Y.; Jian, M.; Kawakita, H.; Kudritzki, R. P.; Lemasle, B.; Marengo, M.; Marinoni, S.; Martínez-Vázquez, C. E.; Minniti, D.; Neeley, J.; Otsubo, S.; Prieto, J. L.; Proxauf, B.; Romaniello, M.; Sanna, N.; Sneden, C.; Takenaka, K.; Tsujimoto, T.; Valenti, E.; Yasui, C.; Yoshikawa, T.; Zoccali, M.

2018-03-01

We present the first spectroscopic abundance determination of iron, α-elements (Si, Ca, and Ti), and sodium for the Mira variable V1 in the metal-rich globular cluster NGC 5927. We use high-resolution (R ∼ 28,000), high signal-to-noise ratio (∼200) spectra collected with WINERED, a near-infrared (NIR) spectrograph covering simultaneously the wavelength range 0.91–1.35 μm. The effective temperature and the surface gravity at the pulsation phase of the spectroscopic observation were estimated using both optical (V) and NIR time-series photometric data. We found that the Mira is metal-rich ([Fe/H] = ‑0.55 ± 0.15) and moderately α-enhanced ([α/Fe] = 0.15 ± 0.01, σ = 0.2). These values agree quite well with the mean cluster abundances based on high-resolution optical spectra of several cluster red giants available in the literature ([Fe/H] = ‑ 0.47 ± 0.06, [α/Fe] = + 0.24 ± 0.05). We also found a Na abundance of +0.35 ± 0.20 that is higher than the mean cluster abundance based on optical spectra (+0.18 ± 0.13). However, the lack of similar spectra for cluster red giants and that of corrections for departures from local thermodynamical equilibrium prevents us from establishing whether the difference is intrinsic or connected with multiple populations. These findings indicate a strong similarity between optical and NIR metallicity scales in spite of the difference in the experimental equipment, data analysis, and in the adopted spectroscopic diagnostics. Based on spectra collected with the WINERED spectrograph available as a visitor instrument at the ESO New Technology Telescope (NTT), La Silla, Chile (ESO Proposal: 098.D-0878(A), PI: G. Bono).

Pox 186: An ultracompact galaxy with dominant ionized gas emission

NASA Astrophysics Data System (ADS)

Guseva, N. G.; Papaderos, P.; Izotov, Y. I.; Noeske, K. G.; Fricke, K. J.

2004-07-01

We present a ground-based optical spectroscopic and HST U, V, I photometric study of the blue compact dwarf (BCD) galaxy Pox 186. It is found that the emission of the low-surface brightness (LSB) component in Pox 186 at radii ⪉3 arcsec (⪉270 pc in linear scale) is mainly gaseous in origin. We detect Hα emission out to radii as large as 6 arcsec. At radii ⪆3 arcsec the light of the LSB component is contaminated by the emission of background galaxies complicating the study of the outermost regions. The surface brightness distribution in the LSB component can be approximated by an exponential law with a scale length α ⪉ 120 pc. This places Pox 186 among the most compact dwarf galaxies known. The derived α is likely to be an upper limit to the scale length of the LSB component because of the strong contribution of the gaseous emission. The oxygen abundance in the bright H II region derived from the 4.5 m Multiple Mirror Telescope (MMT) and 3.6 m ESO telescope spectra are 12 + log (O/H) = 7.76 ± 0.02 and 7.74 ± 0.01 (˜Z⊙/15), respectively, in accordance with previous determinations. The helium mass fractions found in this region are Y = 0.248 ± 0.009 (MMT) and Y = 0.248 ± 0.004 (3.6 m) suggesting a high primordial helium abundance. The MMT Observatory is a joint facility of the Smithsonian Institution and the University of Arizona. Based on observations collected at the European Southern Observatory, Chile, ESO program 71.B-0032(A). 12+\\log(O/H)⊙ = 8.92 (Anders & Grevesse \\cite{Anders89}).

A green observatory in the Chilean Atacama desert

NASA Astrophysics Data System (ADS)

Ramolla, Michael; Westhues, Christian; Hackstein, Moritz; Haas, Martin; Hodapp, Klaus; Lemke, Roland; Barr Domínguez, Angie; Chini, Rolf; Murphy, Miguel

2016-08-01

Since 2007, the Ruhr-Universität Bochum (RUB) in Germany and Universidad Católica del Norte (UCN) in Chile jointly operate the Universitätssternwarte der Ruhr-Universität Bochum (USB), which is located in direct neighborhood of the future E-ELT of ESO. It is the only observatory powered exclusively by solar panels and wind turbines. Excess power is stored in batteries that allow uninterrupted operation even in windless nights. The scientific equipment consists of three robotic optical telescopes with apertures ranging from 15 cm (RoBoTT) over 25 cm (BESTII) to 40 cm (BMT) and one 80 cm (IRIS) infra-red telescope. The optical telescopes are equipped with Johnson and Sloan broad band filters together with a large number of narrow and intermediate bands. In the infrared, J,H and K filters are available, accompanied by several narrow bands near the K band wavelength. The second Nasmyth focus in the 80 cm telescope feeds a high resolution echelle spectrograph similar to the FEROS instrument of ESO. This variety of instruments has evolved from different collaborations, i.e. with the University of Hawaii (IfA) in the USA, which provided the near-infrared-camera of the IRIS telescope, or with the Deutsches Zentrum für Luft- und Raumfahrt (DLR) in Germany, which provided the BESTII telescope. The highly automatized processes on all telescopes enable a single person to run the whole facility, providing the high cost efficiency required for an university observatory. The excellent site conditions allow projects that require daily observations of astronomical objects over epochs of several months or years. Here we report on such studies of young stellar objects from the Bochum Galactic Disk Survey, the multiplicity of stars, quasar variability or the hunt for exo-planets.

Some non-atlas work at ESO Sky Atlas Laboratory.

NASA Astrophysics Data System (ADS)

Madsen, C.

The ESO Sky Atlas Laboratory (SAL) was set up in 1972 with the aim of producing the ESO Quick Blue Survey and later the joint ESO/SERC Survey of the Southern Sky. With the establishment of a Scientific Group, it became apparent that ESO had additional photographic needs, the fullfilment of which was also entrusted to SAL. Thus, in the course of the years, the "Photographic Section" evolved as a subdivision of the Sky Atlas Laboratory.

VizieR Online Data Catalog: KiDS-ESO-DR3 multi-band source catalog (de Jong+, 2017)

NASA Astrophysics Data System (ADS)

de Jong, J. T. A.; Verdoes Kleijn, G. A.; Erben, T.; Hildebrandt, H.; Kuijken, K.; Sikkema, G.; Brescia, M.; Bilicki, M.; Napolitano, N. R.; Amaro, V.; Begeman, K. G.; Boxhoorn, D. R.; Buddelmeijer, H.; Cavuoti, S.; Getman, F.; Grado, A.; Helmich, E.; Huang, Z.; Irisarri, N.; La Barbera, F.; Longo, G.; McFarland, J. P.; Nakajima, R.; Paolillo, M.; Puddu, E.; Radovich, M.; Rifatto, A.; Tortora, C; Valentijn, E. A.; Vellucci, C.; Vriend, W-J.; Amon, A.; Blake, C.; Choi, A.; Fenech, Conti I.; Herbonnet, R.; Heymans, C.; Hoekstra, H.; Klaes, D.; Merten, J.; Miller, L.; Schneider, P.; Viola, M.

2017-04-01

KiDS-ESO-DR3 contains a multi-band source catalogue encompassing all publicly released tiles, a total of 440 survey tiles including the coadded images, weight maps, masks and source lists of 292 survey tiles of KiDS-ESO-DR3, adding to the 148 tiles released previously (50 in KiDS-ESO-DR1 and 98 in KiDS-ESO-DR2). (1 data file).

ESO PR Highlights in 2006

NASA Astrophysics Data System (ADS)

2007-01-01

Last year proved to be another exceptional year for the European organisation for ground-based astronomy. ESO should begin the New Year with two new member states: Spain (PR 05/06) and the Czech Republic (PR 52/06). ESO PR Highlights 2006 2006 was a year of renovation and revolution in the world of planets. A new Earth-like exoplanet has been discovered (PR 03/06) using a network of telescopes from all over the world (including the Danish 1.54-m one at ESO La Silla). It is not the only child of this fruitful year: thanks to the combined use of ESO's Very Large Telescope (VLT) and La Silla instruments, a surprising system of twin giant exoplanets was found (PR 29/06), and a trio of Neptune-like planets hosted by a nearby star were identified (PR 18/06). These results open new perspectives on the search for habitable zones and on the understanding of the mechanism of planet formation. The VISIR instrument on the VLT has been providing unique information to answer this last question, by supplying a high resolution view of a planet-forming disc (PR 36/06). There are not only new members in the planets' register: during the General Assembly of the International Astronomical Union held in Prague (Czech Republic), it was decided that Pluto is not a planet anymore but a 'dwarf planet'. Whatever its status, Pluto still has a satellite, Charon, whose radius and density have been measured more accurately by observing a rare occultation from different sites, including Cerro Paranal (PR 02/06). The scientific community dedicated 2006 to the great physicist James Clerk Maxwell (it was the 175th anniversary of the birth): without his electromagnetic theory of light, none of the astonishing discoveries of modern physics could have been achieved. Nowadays we can look at distant galaxies in great detail: the GIRAFFE spectrograph on the VLT revealed that galaxies 6 billion years ago had the same amount of dark matter relative to stars than nowadays (PR 10/06), while SINFONI gave an unprecedented detailed map of a proto-disc galaxy, showing how galaxies looked like 10 billion years ago (PR 31/06). The VLT also helped to discover a large primordial (more than 10 billion years away) 'blob', explained as the early stage formation of a galaxy (PR 23/06). Not only far away galaxies are rich of surprises: also our own Galaxy was the object of investigations during 2006 and its history is now less obscure (PR 34/06 and 41/06). ESO's Very Large Telescope unveiled that the stellar cluster Messier 12 must have lost to our Milky Way galaxy close to one million low-mass stars (PR 04/06). Stealing is not uncommon in astronomy: evidence of stellar vampires - star sucking off material from another - was unearthed in the globular cluster 47 Tucanae (PR 37/06). Still closer to home, the VLT observed Schwassmann-Wachmann 3, a comet that is breaking apart and revealed many mini-comets (PR 15/06). At Paranal, a fourth Auxiliary Telescope was installed for the Very Large Telescope Interferometer (PR 51/06), and since January 2006, not only do natural stars shine: the first artificial star twinkles in the Southern Hemisphere. It does not guide the sailors (it is too faint to be seen by the unaided eye), but it conducts the eye of the present and future telescopes (PR 07/06). And 2006 proved an important year for the future project of ESO, the Extremely Large Telescope. After approval from the ESO council, the European community can now start the final design of this telescope that will without doubt revolutionise astronomy (PR 25/06 and 46/06). ESO PR Photos 2006 2006 was without doubt an explosive year: the explosion of a supernovae of Type Ia in the enchanting Hooked Galaxy was followed from the middle of 2005 for more than a year (PR 22/06) and using observations of 17 supernovae Ia astronomers could make light on the nature of such explosions, that are likely to occur at supersonic speed (PR 44/06). Supernovae are proved to be linked to X-ray flashes (PR 33/06) and to the more energetic gamma-ray bursts. But not all the explosions are associated with supernovae, and a new kind of explosion is indeed suggested by the observation of a new mysterious category of gamma-ray bursts (PR 49/06). The Atacama Pathfinder Experiment (APEX) 12-m sub-millimetre telescope lived up to the ambitions of the scientists by providing access to the 'Cold Universe' with unprecedented sensitivity and image quality. As a demonstration, no less than 26 articles based on early science with APEX were published in a special issue of the research journal Astronomy & Astrophysics (PR 24/06). This year ESO and Chile celebrated ten years of collaboration: a cooperation that led not only to breakthrough discoveries, but also to a growth of astronomy and related sciences in the South American country (PR 21/06). ESO published many images last year as well, including two huge ones, made with the Wide Field Imager: one, made of about 300 million pixels, shows an 'empty field' (PR 14/06), while the other, a 256 million pixel mosaic, depicts in amazing detail the Tarantula Nebula (PR 50/06). These and other images can be accessed through the clickable map, including amazing images of galaxies and of a finally identified flying object (PR 48/06).

Production of Previews and Advanced Data Products for the ESO Science Archive

NASA Astrophysics Data System (ADS)

Rité, C.; Slijkhuis, R.; Rosati, P.; Delmotte, N.; Rino, B.; Chéreau, F.; Malapert, J.-C.

2008-08-01

We present a project being carried out by the Virtual Observatory Systems Department/Advanced Data Products group in order to populate the ESO Science Archive Facility with image previews and advanced data products. The main goal is to provide users of the ESO Science Archive Facility with the possibility of viewing pre-processed images associated with instruments like WFI, ISAAC and SOFI before actually retrieving the data for full processing. The image processing is done by using the ESO/MVM image reduction software developed at ESO, to produce astrometrically calibrated FITS images, ranging from simple previews of single archive images, to fully stacked mosaics. These data products can be accessed via the ESO Science Archive Query Form and also be viewed with the browser VirGO {http://archive.eso.org/cms/virgo}.

First Light with a 67-Million-Pixel WFI Camera

NASA Astrophysics Data System (ADS)

1999-01-01

The newest astronomical instrument at the La Silla observatory is a super-camera with no less than sixty-seven million image elements. It represents the outcome of a joint project between the European Southern Observatory (ESO) , the Max-Planck-Institut für Astronomie (MPI-A) in Heidelberg (Germany) and the Osservatorio Astronomico di Capodimonte (OAC) near Naples (Italy), and was installed at the 2.2-m MPG/ESO telescope in December 1998. Following careful adjustment and testing, it has now produced the first spectacular test images. With a field size larger than the Full Moon, the new digital Wide Field Imager is able to obtain detailed views of extended celestial objects to very faint magnitudes. It is the first of a new generation of survey facilities at ESO with which a variety of large-scale searches will soon be made over extended regions of the southern sky. These programmes will lead to the discovery of particularly interesting and unusual (rare) celestial objects that may then be studied with large telescopes like the VLT at Paranal. This will in turn allow astronomers to penetrate deeper and deeper into the many secrets of the Universe. More light + larger fields = more information! The larger a telescope is, the more light - and hence information about the Universe and its constituents - it can collect. This simple truth represents the main reason for building ESO's Very Large Telescope (VLT) at the Paranal Observatory. However, the information-gathering power of astronomical equipment can also be increased by using a larger detector with more image elements (pixels) , thus permitting the simultaneous recording of images of larger sky fields (or more details in the same field). It is for similar reasons that many professional photographers prefer larger-format cameras and/or wide-angle lenses to the more conventional ones. The Wide Field Imager at the 2.2-m telescope Because of technological limitations, the sizes of detectors most commonly in use in optical astronomical instruments - the "Charge-Coupled Devices (CCD's)" - are currently restricted to about 4000 x 4000 pixels. For the time being, the only possible way towards even larger detector areas is by assembling mosaics of CCD's. ESO , MPI-A and OAC have therefore undertaken a joint project to build a new and large astronomical camera with a mosaic of CCD's. This new Wide Field Imager (WFI) comprises eight CCD's with high sensitivity from the ultraviolet to the infrared spectral domain, each with 2046 x 4098 pixels. Mounted behind an advanced optical system at the Cassegrain focus of the 2.2-m telescope of the Max-Planck-Gesellschaft (MPG) at ESO's La Silla Observatory in Chile, the combined 8184 x 8196 = 67,076,064 pixels cover a square field-of-view with an edge of more than half a degree (over 30 arcmin) [1]. Compared to the viewing field of the human eye, this may still appear small, but in the domain of astronomical instrumentation, it is indeed a large step forward. For comparison, the largest field-of-view with the FORS1 instrument at the VLT is about 7 arcmin. Moreover, the level of detail detectable with the WFI (theoretical image sharpness) exceeds what is possible with the naked eye by a factor of about 10,000. The WFI project was completed in only two years in response to a recommendation to ESO by the "La Silla 2000" Working Group and the Scientific-Technical Committee (STC) to offer this type of instrument to the community. The MPI-A proposed to build such an instrument for the MPG/ESO 2.2-m telescope and a joint project was soon established. A team of astronomers from the three institutions is responsible for the initial work with the WFI at La Silla. A few other Cameras of this size are available, e.g. at Hawaii, Kitt Peak (USA) and Cerro Tololo (Chile), but this is the first time that a telescope this large has been fully dedicated to wide-field imaging with an 8kx8k CCD. The first WFI images Various exposures were obtained during the early tests with the WFI in order to arrive at the optimum adjustment of the camera at the telescope. We show here two of these that illustrate the great potential of this new facility. Spiral Galaxy NGC 253 ESO PR Photo 02a/99 ESO PR Photo 02a/99 [Preview - JPEG: 800x850 pix - 205k] [High-Res - JPEG: 4000 x 4252 pix - 3.0Mb] ESO PR Photo 02b/99 ESO PR Photo 02b/99 [Preview - JPEG: 800x870 pix - 353k] [High-Res - JPEG: 2200 x 2393 pix - 2.0Mb] Caption to PR Photos 02a/99 and 02b/99 : These photos show a sky field around the Spiral Galaxy NGC 253 (Type Sc) seen nearly edge-on. It is located in the southern constellation Sculptor at a distance of about 8 million light-years. The image is the sum of five 5-min exposures through a blue (B-band) optical filtre. They were slightly offset with respect to each other so that the small gaps between the eight CCD's of the mosaic are no longer visible. This image also shows the faint trails of 2 artificial satellites. In PR Photo 02a/99 , the full WFI field-of-view is reproduced, while the sub-field in PR Photo 02b/99 contains some fainter and smaller background galaxies. Many of the quite numerous and small, slightly fuzzy objects are undoubtedly globular clusters of NGC 253. Technical information: The image processing consisted of de-biassing, flat-fielding, and removal (by interpolation) of some bad columns. The full-width-half-maximum (FWHM) of stellar images is about 1.0 arcsec. PR Photo 02a/99 was rebinned (2x2) to 4kx4k size and sampling 0.48 arcsec/pixel. PR Photo 02b/99 is a subimage of the former, but at the full original sampling of 0.24 arcsec/pixel. It covers about 2kx2k, or about 1/16 of the full field. North is up and East is left. The observations were made on December 17, 1998. The Waning Moon ESO PR Photo 02c/99 ESO PR Photo 02c/99 [Preview - JPEG: 800 x 1245 pix - 242k] [High-Res - JPEG: 3000 x 4667 pix - 2.3Mb] ESO PR Photo 02d/99 ESO PR Photo 02d/99 [Preview - JPEG: 800 x 1003 pix - 394k] [High-Res - JPEG: 3000 x 3760 pix - 2.1Mb] ESO PR Photo 02e/99 ESO PR Photo 02e/99 [Preview - JPEG: 800 x 706 pix - 274k] [High-Res - JPEG: 3000 x 2648 pix - 1.5Mb] Caption to PR Photos 02c-e/99 : A series of short exposures through a near-infrared filtre was obtained of the waning Moon at sunrise on January 12 (at about 10 hrs UT), i.e. about 5 days before New Moon (24.3 days "old"). As can be seen in PR Photo 02c/99 , the edge of the full field-of-view is about the size of the diameter of the Moon. In addition, two impressive views were extracted from this frame and are here shown at full resolution; 1 pixel is about 470 metres on the surface of the Moon at a distance of just over 400,000 km. PR Photo 02d/99 displays the Mare Humorum area in the south-east quadrant with the crater Gassendi overlapping the northern rim. PR Photo 02d/99 is a view of the plains near the Moon's north-east rim, just eastwards of Sinus Iridum (the large crater in the shadows at the upper right), on the rim of which the crater Bianchini is located. The crater just below the centre is Mairan and the one about halfway between these two and of about the same size is Sharp . Technical information: Several 0.1 sec exposures were made through a near-infrared filtre (856 nm; FWHM 14 nm) with small offsets were recombined (to cover the gaps between the individual CCD's); otherwise, the image is raw. PR Photo 02c/99 was rebinned (2x2) to 4kx4k size and sampling 0.48 arcsec/pixel. The right-hand side of the picture was cropped in this reproduction to reduce the file size. PR Photos 02d/99 and 02e/99 are subimages of the former, but at the full original sampling of 0.24 arcsec/pixel; they covers about 1000x800 and 900x1050 pixels, or about 1/80 and 1/70 of the full field, respectively. North is up and East is left. The virtues of wide-angle imaging Wide-angle imaging is one of the most fundamental applications of observational astronomy. Only from (multi-band) observations over large areas of the sky can large-scale structures and rare objects be detected and put in a proper statistical perspective with other objects. Some typical examples of future survey work: very distant quasars and galaxies, clusters of galaxies, small bodies orbiting the Sun, brown dwarfs, low-surface brightness galaxies, peculiar stars, objects with emission-line spectra, gravitational lenses, etc. Other important applications include the search for supernovae in distant clusters of galaxies and the optical identification of the rapidly fading gamma-ray bursters which are detected by space observatories, but for which only very crude positional determinations are available. Once "promising objects" have been found and accurately located on the sky by the WFI, the enormous light collecting power of the VLT is then available to study them at much higher spectral and spatial detail and over a much wider range of wavelengths. In particular, the continuation of the ESO Imaging Survey (EIS) depends heavily on use of the WFI and will identify and classify all objects seen in a number of selected sky fields. The resulting database is made available as a special service to the community for dedicated follow-up work with the VLT. The advantage of modern digital detectors Traditionally, wide-field observations were made with Schmidt telescopes which, by means of to special optics, are able to image sharply a field with a diameter of 5-15 deg. These telescopes use photographic plates that, however, detect no more than about 3% of all incoming photons. In comparison, the photon detecting efficiency of the CCD's in the WFI exceeds 90%. Moreover, these CCD's supply digital data ready for computer analysis, whereas photographic plates must be digitized with a sophisticated scanning engine in a laborious and expensive manner which nevertheless cannot fully extract all the information. The price to be paid, until even larger CCD's become available, is the smaller field. The field, however, will not exceed 1-2 square degrees with the currently planned, new wide-field telescopes. The FIERA CCD controller The entire detector array of the WFI can be read out in only 27 seconds. Since one WFI image contains 0.14 Gbytes of data, this corresponds to the reading of a book at a rate of almost 1000 pages per second! Even for the most powerful PC's presently available, this can be a real challenge. However, much more remarkable is that FIERA , the high-tech CCD controller developed by ESO engineers, sustains this speed without adding noise or artifacts that exceed the extremely faint signal from the night-sky background on a moonless night at a completely dark site such as La Silla. In addition to the eight large CCD's of the mosaic, FIERA simultaneously commands a ninth CCD of the same type in which a small window centered on a bright star is read out continuously, up to 2 times every second. The fast-rate measurement of the instantaneous position of the star enables the telescope control system to track very accurately the apparent motion of the observed field in the sky so that the images remain perfectly sharp, even during long exposures. Future survey work at ESO In terms of bytes, it is expected that the WFI alone will acquire more observational data than all the rest of the La Silla Observatory and the UT1 of the VLT on Paranal together! This impressively illustrates the ever-accelerating pace at which astronomical facilities are developing. In the meantime, a Dutch/German/Italian consortium is preparing for the construction of the successor to WFI camera. The OmegaCam will have no less than 16,000 x 16,000 pixels and the field-of-view is four times as large, one square degree. It will be attached to the 2.6-m VLT Survey Telescope (VST) to be installed jointly by OAC and ESO on Paranal at the end of the year 2001. Note: [1]: Some technical details of the new camera: The WFI field-of-view measures 0.54 x 0.54 deg 2 (32.4 x 32.4 arcmin 2 ) and the image scale is 0.24 arcsec/pixel. An advanced optical system is indispensible to focus correctly a field of this large size - 0.8 degree diameter - on the flat CCD mosaic (12 x 12 cm 2 ). The WFI achromatic corrector consists of 6 lenses of up to 28 cm diameter and is able to concentrate 80% of the light of a point source into the area of one pixel in a flat focal plane. Up to 50 filters will be permanently mounted in the camera. A unique facility is provided by a set of 26 interference filters which cover the entire optical range from 380 - 930 nm and thus allows a rough analysis of the spectra of the typically 100,000 objects that are recorded in one field of view. The CCD's possess a very high sensitivity to ultraviolet light and the WFI is only the second UV-sensitive wide-field imager in service in the world. The camera mechanics was designed and built at the MPI-A which also provided the filters. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../ ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory.

If we build it, will they come? Curation and use of the ESO telescope bibliography

NASA Astrophysics Data System (ADS)

Grothkopf, Uta; Meakins, Silvia; Bordelon, Dominic

2015-12-01

The ESO Telescope Bibliography (telbib) is a database of refereed papers published by the ESO users community. It links data in the ESO Science Archive with the published literature, and vice versa. Developed and maintained by the ESO library, telbib also provides insights into the organization's research output and impact as measured through bibliometric studies. Curating telbib is a multi-step process that involves extensive tagging of the database records. Based on selected use cases, this talk will explain how the rich metadata provide parameters for reports and statistics in order to investigate the performance of ESO's facilities and to understand trends and developments in the publishing behaviour of the user community.

ESO

Science.gov Websites

2009 100 Hours of Astronomy The Eye 3D IMAX® 3D Film Hidden Universe Open House Day 2011 Open House and Jupiter - 1994 Comet Hale Bopp - 1994 Astronomy Communication Seminars Outreach Education Educational Material Science in School ESO Astronomy Camp 2017 ESO Astronomy Camp 2016 ESO Astronomy Camp 2015

Different definitions of esophagus influence esophageal toxicity prediction for esophageal cancer patients administered simultaneous integrated boost versus standard-dose radiation therapy.

PubMed

Huang, Bao-Tian; Huang, Rui-Hong; Zhang, Wu-Zhe; Lin, Wen; Guo, Long-Jia; Xu, Liang-Yu; Lin, Pei-Xian; Chen, Jian-Zhou; Li, De-Rui; Chen, Chuang-Zhen

2017-03-09

We aim to evaluate whether different definitions of esophagus (DEs) impact on the esophageal toxicity prediction for esophageal cancer (EC) patients administered intensity-modulated radiation therapy with simultaneous integrated boost (SIB-IMRT) vs. standard-dose IMRT (SD-IMRT). The esophagus for 21 patients diagnosed with primary EC were defined in the following four ways: the whole esophagus, including the tumor (ESO whole ); ESO whole within the treatment field (ESO infield ); ESO infield , excluding the tumor (ESO infield-tumor ) and ESO whole , excluding the tumor (ESO whole-tumor ). The difference in the dose variation, acute esophageal toxicity (AET) and late esophageal toxicity (LET) of four DEs were compared. We found that the mean esophageal dose for ESO whole , ESO infield , ESO infield-tumor and ESO whole-tumor were increased by 7.2 Gy, 10.9 Gy, 4.6 Gy and 2.0 Gy, respectively, in the SIB-IMRT plans. Radiobiological models indicated that a grade ≥ 2 AET was 2.9%, 3.1%, 2.2% and 1.6% higher on average with the Kwint model and 14.6%, 13.2%, 7.2% and 3.4% higher with the Wijsman model for the four DEs. A grade ≥ 3 AET increased by 4.3%, 7.2%, 4.2% and 1.2%, respectively. Additionally, the predicted LET increased by 0.15%, 0.39%, 1.2 × 10 -2 % and 1.5 × 10 -3 %. Our study demonstrates that different DEs influence the esophageal toxicity prediction for EC patients administered SIB-IMRT vs. SD-IMRT treatment.

Young and Exotic Stellar Zoo

NASA Astrophysics Data System (ADS)

2005-03-01

Summary Super star clusters are groups of hundreds of thousands of very young stars packed into an unbelievably small volume. They represent the most extreme environments in which stars and planets can form. Until now, super star clusters were only known to exist very far away, mostly in pairs or groups of interacting galaxies. Now, however, a team of European astronomers [1] have used ESO's telescopes to uncover such a monster object within our own Galaxy, the Milky Way, almost, but not quite, in our own backyard! The newly found massive structure is hidden behind a large cloud of dust and gas and this is why it took so long to unveil its true nature. It is known as "Westerlund 1" and is a thousand times closer than any other super star cluster known so far. It is close enough that astronomers may now probe its structure in some detail. Westerlund 1 contains hundreds of very massive stars, some shining with a brilliance of almost one million suns and some two-thousand times larger than the Sun (as large as the orbit of Saturn)! Indeed, if the Sun were located at the heart of this remarkable cluster, our sky would be full of hundreds of stars as bright as the full Moon. Westerlund 1 is a most unique natural laboratory for the study of extreme stellar physics, helping astronomers to find out how the most massive stars in our Galaxy live and die. From their observations, the astronomers conclude that this extreme cluster most probably contains no less than 100,000 times the mass of the Sun, and all of its stars are located within a region less than 6 light-years across. Westerlund 1 thus appears to be the most massive compact young cluster yet identified in the Milky Way Galaxy. PR Photo 09a/05: The Super Star Cluster Westerlund 1 (2.2m MPG/ESO + WFI) PR Photo 09b/05: Properties of Young Massive Clusters Super Star Clusters Stars are generally born in small groups, mostly in so-called "open clusters" that typically contain a few hundred stars. From a wide range of observations, astronomers infer that the Sun itself was born in one such cluster, some 4,500 million years ago. In some active ("starburst") galaxies, scientists have observed violent episodes of star formation (see, for example, ESO Press Photo 31/04), leading to the development of super star clusters, each containing several million stars. Such events were obviously common during the Milky Way's childhood, more than 12,000 million years ago: the many galactic globular clusters - which are nearly as old as our Galaxy (e.g. ESO PR 20/04) - are indeed thought to be the remnants of early super star clusters. All super star clusters so far observed in starburst galaxies are very distant. It is not possible to distinguish their individual stars, even with the most advanced technology. This dramatically complicates their study and astronomers have therefore long been eager to find such clusters in our neighbourhood in order to probe their structure in much more detail. Now, a team of European astronomers [1] has finally succeeded in doing so, using several of ESO's telescopes at the La Silla observatory (Chile). Westerlund 1 ESO PR Photo 09a/05 ESO PR Photo 09a/05 The Super Star Cluster Westerlund 1 (2.2m MPG/ESO + WFI) [Preview - JPEG: 400 x 472 pix - 58k] [Normal - JPEG: 800 x 943 pix - 986k] [Full Res - JPEG: 1261 x 1486 pix - 2.4M] Caption: ESO PR Photo 09a/05 is a composite image of the super star cluster "Westerlund 1" from 2.2-m MPG/ESO Wide-Field Imager (WFI) observations. The image covers a 5 x 5 arcmin sky region and is based on observations made in the V-band (550 nm, 2 min exposure time, associated to the blue channel), R-band (650nm, 1 min, green channel) and I-band (784nm, 18 sec, red channel). Only the central CCD of WFI was used, as the entire cluster fits comfortably inside it. The foreground stars appear blue, while the hot massive members of the cluster look orange, and the cool massive ones come out red. The open cluster Westerlund 1 is located in the Southern constellation Ara (the Altar). It was discovered in 1961 from Australia by Swedish astronomer Bengt Westerlund, who later moved from there to become ESO Director in Chile (1970 - 74). This cluster is behind a huge interstellar cloud of gas and dust, which blocks most of its visible light. The dimming factor is more than 100,000 - and this is why it has taken so long to uncover the true nature of this particular cluster. In 2001, the team of astronomers identified more than a dozen extremely hot and peculiar massive stars in the cluster, so-called "Wolf-Rayet" stars. They have since studied Westerlund 1 extensively with various ESO telescopes. They used images from the Wide Field Imager (WFI) attached to the 2.2-m ESO/MPG as well as from the SUperb Seeing Imager 2 (SuSI2) camera on the ESO 3.5-m New Technology Telescope (NTT). From these observations, they were able to identify about 200 cluster member stars. To establish the true nature of these stars, the astronomers then performed spectroscopic observations of about one quarter of them. For this, they used the Boller & Chivens spectrograph on the ESO 1.52-m telescope and the ESO Multi-Mode Instrument (EMMI) on the NTT. An Exotic Zoo These observations have revealed a large population of very bright and massive, quite extreme stars. Some would fill the solar system space within the orbit of Saturn (about 2,000 times larger than the Sun!), others are as bright as a million Suns. Westerlund 1 is obviously a fantastic stellar zoo, with a most exotic population and a true astronomical bonanza. All stars identified are evolved and very massive, spanning the full range of stellar oddities from Wolf-Rayet stars, OB supergiants, Yellow Hypergiants (nearly as bright as a million Suns) and Luminous Blue Variables (similar to the exceptional Eta Carinae object - see ESO PR 31/03). All stars so far analysed in Westerlund 1 weigh at least 30-40 times more than the Sun. Because such stars have a rather short life - astronomically speaking - Westerlund 1 must be very young. The astronomers determine an age somewhere between 3.5 and 5 million years. So, Westerlund 1 is clearly a "newborn" cluster in our Galaxy! The Most Massive Cluster ESO PR Photo 09b/05 ESO PR Photo 09b/05 Properties of Young Massive Clusters [Preview - JPEG: 400 x 511 pix - 20k] [Normal - JPEG: 800 x 1021 pix - 122k] Caption: ESO PR Photo 09b/05 shows the properties of young massive clusters in our Galaxy and in the Large Magellanic Clouds, as well as of Super Star Clusters in star-forming galaxies. The diagram shows the mass and radius of these clusters and also the position of Westerlund 1 (indicated Wd 1). Westerlund 1 is incredibly rich in monster stars - just as one example, it contains as many Yellow Hypergiants as were hitherto known in the entire Milky Way! "If the Sun were located at the heart of Westerlund 1, the sky would be full of stars, many of them brighter than the full Moon", comments Ignacio Negueruela of the Universidad de Alicante in Spain and member of the team. The large quantity of very massive stars implies that Westerlund 1 must contain a huge number of stars. "In our Galaxy, explains Simon Clark of the University College London (UK) and one of the authors of this study, "there are more than 100 solar-like stars for every star weighing 10 times as much as the Sun. The fact that we see hundreds of massive stars in Westerlund 1 means that it probably contains close to half a million stars, but most of these are not bright enough to peer through the obscuring cloud of gas and dust". This is ten times more than any other known young clusterin the Milky Way. Westerlund 1 is presumably much more massive than the dense clusters of heavy stars present in the central region of our Galaxy, like the Arches and Quintuplet clusters. Further deep infrared observations will be required to confirm this. This super star cluster now provides astronomers with a unique perspective towards one of the most extreme environments in the Universe. Westerlund 1 will certainly provide new opportunities in the long-standing quest for more and finer details about how stars, and especially massive ones, do form. ... and the Most Dense The large number of stars in Westerlund 1 was not the only surprise awaiting Clark and his colleagues. From their observations, the team members also found that all these stars are packed into an amazingly small volume of space, indeed less than 6 light-years across. In fact, this is more or less comparable to the 4 light-year distance to the star nearest to the Sun, Proxima Centauri! It is incredible: the concentration in Westerlund 1 is so high that the mean separation between stars is quite similar to the extent of the Solar System. "With so many stars in such a small volume, some of them may collide", envisages Simon Clark. "This could lead to the formation of an intermediate-mass black hole more massive than 100 solar masses. It may well be that such a monster has already formed at the core of Westerlund 1." The huge population of massive stars in Westerlund 1 suggests that it will have a very significant impact on its surroundings. The cluster contains so many massive stars that in a time span of less than 40 million years, it will be the site of more than 1,500 supernovae. A gigantic firework that may drive a fountain of galactic material! Because Westerlund 1 is at a distance of only about 10,000 light-years, high-resolution cameras such as NAOS/CONICA on ESO's Very Large Telescope can resolve its individual stars. Such observations are now starting to reveal smaller stars in Westerlund 1, including some that are less massive than the Sun. Astronomers will thus soon be able to study this exotic galactic zoo in great depth. More information The research presented in this ESO Press Release will soon appear in the leading research journal Astronomy and Astrophysics ("On the massive stellar population of the Super Star Cluster Westerlund 1" by J.S. Clark and colleagues). The PDF file is available at the A&A web site. A second paper ("Further Wolf-Rayet stars in the starburst cluster Westerlund 1", by Ignacio Negueruela and Simon Clark) will also soon be published in Astronomy and Astrophysics. It is available as astro-ph/0503303. A Spanish press release issued by Universidad de Alicante is available on the web site of Ignacio Negueruela.

Is This Speck of Light an Exoplanet?

NASA Astrophysics Data System (ADS)

2004-09-01

VLT Images and Spectra of Intriguing Object near Young Brown Dwarf [1] Summary Is this newly discovered feeble point of light the long-sought bona-fide image of an exoplanet? A research paper by an international team of astronomers [2] provides sound arguments in favour, but the definitive answer is now awaiting further observations. On several occasions during the past years, astronomical images revealed faint objects, seen near much brighter stars. Some of these have been thought to be those of orbiting exoplanets, but after further study, none of them could stand up to the real test. Some turned out to be faint stellar companions, others were entirely unrelated background stars. This one may well be different. In April of this year, the team of European and American astronomers detected a faint and very red point of light very near (at 0.8 arcsec angular distance) a brown-dwarf object, designated 2MASSWJ1207334-393254. Also known as "2M1207", this is a "failed star", i.e. a body too small for major nuclear fusion processes to have ignited in its interior and now producing energy by contraction. It is a member of the TW Hydrae stellar association located at a distance of about 230 light-years. The discovery was made with the adaptive-optics supported NACO facility [3] at the 8.2-m VLT Yepun telescope at the ESO Paranal Observatory (Chile). The feeble object is more than 100 times fainter than 2M1207 and its near-infrared spectrum was obtained with great efforts in June 2004 by NACO, at the technical limit of the powerful facility. This spectrum shows the signatures of water molecules and confirms that the object must be comparatively small and light. None of the available observations contradict that it may be an exoplanet in orbit around 2M1207. Taking into account the infrared colours and the spectral data, evolutionary model calculations point to a 5 jupiter-mass planet in orbit around 2M1207. Still, they do not yet allow a clear-cut decision about the real nature of this intriguing object. Thus, the astronomers refer to it as a "Giant Planet Candidate Companion (GPCC)" [4]. Observations will now be made to ascertain whether the motion in the sky of GPCC is compatible with that of a planet orbiting 2M1207. This should become evident within 1-2 years at the most. PR Photo 26a/04: NACO image of the brown dwarf object 2M1207 and GPCC PR Photo 26b/04: Near-infrared spectrum of the brown dwarf object 2M1207 and GPCC PR Photo 26c/04: Comparison between the possible 2M1207 system and the solar system Just a speck of light ESO PR Photo 26a/04 ESO PR Photo 26a/04 The Brown Dwarf Object 2M1207 and GPCC [Preview - JPEG: 400 x 471 pix - 65k] [Normal - JPEG: 800 x 942 pix - 158k] Caption: ESO PR Photo 26a/04 is a composite image of the brown dwarf object 2M1207 (centre) and the fainter object seen near it, at an angular distance of 778 milliarcsec. Designated "Giant Planet Candidate Companion" by the discoverers, it may represent the first image of an exoplanet. Further observations, in particular of its motion in the sky relative to 2M1207 are needed to ascertain its true nature. The photo is based on three near-infrared exposures (in the H, K and L' wavebands) with the NACO adaptive-optics facility at the 8.2-m VLT Yepun telescope at the ESO Paranal Observatory. Since 1998, a team of European and American astronomers [2] is studying the environment of young, nearby "stellar associations", i.e., large conglomerates of mostly young stars and the dust and gas clouds from which they were recently formed. The stars in these associations are ideal targets for the direct imaging of sub-stellar companions (planets or brown dwarf objects). The leader of the team, ESO astronomer Gael Chauvin notes that "whatever their nature, sub-stellar objects are much hotter and brighter when young - tens of millions of years - and therefore can be more easily detected than older objects of similar mass". The team especially focused on the study of the TW Hydrae Association. It is located in the direction of the constellation Hydra (The Water-Snake) deep down in the southern sky, at a distance of about 230 light-years. For this, they used the NACO facility [3] at the 8.2-m VLT Yepun telescope, one of the four giant telescopes at the ESO Paranal Observatory in northern Chile. The instrument's adaptive optics (AO) overcome the distortion induced by atmospheric turbulence, producing extremely sharp near-infrared images. The infrared wavefront sensor was an essential component of the AO system for the success of these observations. This unique instrument senses the deformation of the near-infrared image, i.e. in a wavelength region where objects like 2M1207 (see below) are much brighter than in the visible range. The TW Hydrae Association contains a star with an orbiting brown dwarf companion, approximately 20 times the mass of Jupiter, and four stars surrounded by dusty proto-planetary disks. Brown dwarf objects are "failed stars", i.e. bodies too small for nuclear processes to have ignited in their interior and now producing energy by contraction. They emit almost no visible light. Like the Sun and the giant planets in the solar system, they are composed mainly of hydrogen gas, perhaps with swirling cloud belts. On a series of exposures made through different optical filters, the astronomers discovered a tiny red speck of light, only 0.8 arcsec from the TW Hydrae Association brown-dwarf object 2MASSWJ1207334-393254, or just "2M1207", cf. PR Photo 26a/04. The feeble image is more than 100 times fainter than that of 2M1207. "If these images had been obtained without adaptive optics, that object would not have been seen," says Gael Chauvin. Christophe Dumas, another member of the team, is enthusiastic: "The thrill of seeing this faint source of light in real-time on the instrument display was unbelievable. Although it is surely much bigger than a terrestrial-size object, it is a strange feeling that it may indeed be the first planetary system beyond our own ever imaged." Exoplanet or Brown Dwarf? ESO PR Photo 26b/04 ESO PR Photo 26b/04 The Brown Dwarf Object 2M1207 and GPCC [Preview - JPEG: 400 x 486 pix - 102k] [Normal - JPEG: 800 x 912 pix - 234k] Caption: ESO PR Photo 26b/04 shows near-infrared H-band spectra of the brown dwarf object 2M1207 and the fainter "GPCC" object seen near it, obtained with the NACO facility at the 8.2-m VLT Yepun telescope. In the upper part, the spectrum of 2M1207 (fully drawn blue curve) is compared with that of another substellar object (T513; dashed line); in the lower, the (somewhat noisy) spectrum of GPCC (fully drawn red curve) is compared with two substellar objects of different types (2M0301 and SDSS0539). The spectrum of GPCC is clearly very similar to these, confirming the substellar nature of this body. The broad dips at the left and the right are clear signatures of water in the (atmospheres of the) objects. What is the nature of this faint object [4]? Could it be an exoplanet in orbit around that young brown dwarf object at a projected distance of about 8,250 million km (about twice the distance between the Sun and Neptune)? "If the candidate companion of 2M1207 is really a planet, this would be the first time that a gravitationally bound exoplanet has been imaged around a star or a brown dwarf" says Benjamin Zuckerman of UCLA, a member of the team and also of NASA's Astrobiology Institute. Using high-angular-resolution spectroscopy with the NACO facility, the team has confirmed the substellar status of this object - now referred to as the "Giant Planet Candidate Companion (GPCC)" - by identifying broad water-band absorptions in its atmosphere, cf. PR Photo 26b/04. The spectrum of a young and hot planet - as the GPCC may well be - will have strong similarities with an older and more massive object such as a brown dwarf. However, when it cools down after a few tens of millions of years, such an object will show the spectral signatures of a giant gaseous planet like those in our own solar system. Although the spectrum of GPCC is quite "noisy" because of its faintness, the team was able to assign to it a spectral characterization that excludes a possible contamination by extra-galactic objects or late-type cool stars with abnormal infrared excess, located beyond the brown dwarf. After a very careful study of all options, the team found that, although this is statistically very improbable, the possibility that this object could be an older and more massive, foreground or background, cool brown dwarf cannot be completely excluded. The related detailed analysis is available in the resulting research paper that has been accepted for publication in the European journal Astronomy & Astrophysics (see below). Implications The brown dwarf 2M1207 has approximately 25 times the mass of Jupiter and is thus about 42 times lighter than the Sun. As a member of the TW Hydrae Association, it is about eight million years old. Because our solar system is 4,600 million years old, there is no way to directly measure how the Earth and other planets formed during the first tens of millions of years following the formation of the Sun. But, if astronomers can study the vicinity of young stars which are now only tens of millions of years old, then by witnessing a variety of planetary systems that are now forming, they will be able to understand much more accurately our own distant origins. Anne-Marie Lagrange, a member of the team from the Grenoble Observatory (France), looks towards the future: "Our discovery represents a first step towards opening a whole new field in astrophysics: the imaging and spectroscopic study of planetary systems. Such studies will enable astronomers to characterize the physical structure and chemical composition of giant and, eventually, terrestrial-like planets." Follow-up observations ESO PR Photo 26c/04 ESO PR Photo 26c/04 Comparison between the solar and 2M1207 systems [Preview - JPEG: 400 x 190 pix - 38k] [Normal - JPEG: 800 x 397 pix - 86k] [HiRes - JPEG: 2000 x 948 pix - 326k] Caption: ESO PR Photo 26c/04 shows for illustration a comparison between the solar system and the brown dwarf object 2M1207 system with its possible planet at 55 AU distance. The sizes of the objects are drawn to the same scale, but the distances have been strongly compressed. Taking into account the infrared colours and the spectral data available for GPCC, evolutionary model calculations point to a 5 jupiter-mass planet, about 55 times more distant from 2M1207 than the Earth is from the Sun (55 AU). The surface temperature appears to be about 10 times hotter than Jupiter, about 1000 °C; this is easily explained by the amount of energy that must be liberated during the current rate of contraction of this young object (indeed, the much older giant planet Jupiter is still producing energy in its interior). The astronomers will now continue their research to confirm or deny whether they have in fact discovered an exoplanet. Over the next few years, they expect to establish beyond doubt whether the object is indeed a planet in orbit around the brown dwarf 2M1207 by watching how the two objects move through space and to learn whether or not they move together. They will also measure the brightness of the GPCC at multiple wavelengths and more spectral observations may be attempted. There is no doubt that future programmes to image exoplanets around nearby stars, either from the ground with extremely large telescopes equipped with specially designed adaptive optics, or from space with special planet-finder telescopes, will greatly profit from current technological achievements. More information The results presented in this ESO Press Release are based on a research paper ("A Giant Planet Candidate near a Young Brown Dwarf" by G. Chauvin et al.) that has been accepted for publication and will appear in the leading research journal "Astronomy and Astrophysics" on September 23, 2004 (Vol. 425, Issue 2, page L29). A preprint is available here and also as astro-ph0409323. Notes [1]: This press release is issued simultaneously by ESO and CNRS (in French). [2]: The team consists of Gael Chauvin and Christophe Dumas (ESO-Chile), Anne-Marie Lagrange and Jean-Luc Beuzit (LAOG, Grenoble, France), Benjamin Zuckerman and Inseok Song (UCLA, Los Angeles, USA), David Mouillet (LAOMP, Tarbes, France) and Patrick Lowrance (IPAC, Pasadena, USA). The American members of the team acknowledge funding in part by NASA's Astrobiology Institute. [3]: The NACO facility (from NAOS/Nasmyth Adaptive Optics System and CONICA/Near-Infrared Imager and Spectrograph) at the 8.2-m VLT Yepun telescope on Paranal offers the capability to produce diffraction-limited near-infrared images of astronomical objects. It senses the radiation in this wavelength region with the N90C10 dichroic; 90 percent of the flux is transmitted to the wavefront sensor and 10 percent to the near-infrared camera CONICA. This mode is particularly useful for sharp imaging of red and very-low-mass stellar or substellar objects. The adaptive optics corrector (NAOS) was built, under an ESO contract, by Office National d'Etudes et de Recherches Aérospatiales (ONERA), Laboratoire d'Astrophysique de Grenoble (LAOG) and the LESIA and GEPI laboratories of the Observatoire de Paris in France, in collaboration with ESO. The CONICA camera was built, under an ESO contract, by the Max-Planck-Institut für Astronomie (MPIA) (Heidelberg) and the Max-Planck Institut für extraterrestrische Physik (MPE) (Garching) in Germany, in collaboration with ESO. [4]: What is the difference between a small brown dwarf and an exoplanet ? The border line between the two is still being investigated but it appears that a brown dwarf object is formed in the same way as stars, i.e. by contraction in an interstellar cloud while planets are formed within stable circumstellar disks via collision/accretion of planetesimals or disk instabilities. This implies that brown dwarfs are formed faster (less than 1 million years) than planets (~10 million years). Another way of separating the two kinds of objects is by mass (as this is also done between brown dwarfs and stars): (giant) planets are lighter than about 13 jupiter-masses (the critical mass needed to ignite deuterium fusion), brown dwarfs are heavier. Unfortunately, the first definition cannot be used in practice, e.g., when detecting a faint companion as in the present case, since the observations do not provide information about the way the object was formed. On the contrary, the above mass criterion is useful in the sense that spectroscopy and astrometry of a faint object, together with the appropriate evolutionary models, may reveal the mass and hence the nature of the object.

First Results from the VIRIAL Survey: The Stellar Content of UVJ-selected Quiescent Galaxies at 1.5 < z < 2 from KMOS

NASA Astrophysics Data System (ADS)

Mendel, J. Trevor; Saglia, Roberto P.; Bender, Ralf; Beifiori, Alessandra; Chan, Jeffrey; Fossati, Matteo; Wilman, David J.; Bandara, Kaushala; Brammer, Gabriel B.; Förster Schreiber, Natascha M.; Galametz, Audrey; Kulkarni, Sandesh; Momcheva, Ivelina G.; Nelson, Erica J.; van Dokkum, Pieter G.; Whitaker, Katherine E.; Wuyts, Stijn

2015-05-01

We investigate the stellar populations of 25 massive galaxies (log [{{M}*}/{{M}⊙ }]≥slant 10.9) at 1.5\\lt z\\lt 2 using data obtained with the K-band Multi-Object Spectrograph (KMOS) on the ESO VLT. Targets were selected to be quiescent based on their broadband colors and redshifts using data from the 3D-HST grism survey. The mean redshift of our sample is \\bar{z}=1.75, where KMOS YJ-band data probe age- and metallicity-sensitive absorption features in the rest-frame optical, including the G-band, Fe i, and high-order Balmer lines. Fitting simple stellar population models to a stack of our KMOS spectra, we derive a mean age of 1.03-0.08+0.13 Gyr. We confirm previous results suggesting a correlation between color and age for quiescent galaxies, finding mean ages of 1.22-0.19+0.56 Gyr and 0.85-0.05+0.08 Gyr for the reddest and bluest galaxies in our sample. Combining our KMOS measurements with those obtained from previous studies at 0.2\\lt z\\lt 2 we find evidence for a 2-3 Gyr spread in the formation epoch of massive galaxies. At z\\lt 1 the measured stellar ages are consistent with passive evolution, while at 1\\lt z≲ 2 they appear to saturate at ˜1 Gyr, which likely reflects changing demographics of the (mean) progenitor population. By comparing to star formation histories inferred for “normal” star-forming galaxies, we show that the timescales required to form massive galaxies at z≳ 1.5 are consistent with the enhanced α-element abundances found in massive local early-type galaxies. Based on observations obtained at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), Paranal, Chile (ESO program IDs 092.A-0091, 093.A-0079, 093.A-0187, and 094.A-0287). This work is further based on observations taken by the 3D-HST Treasury Program (GO 12177 and 12328) with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

VLT Captures First Direct Spectrum of an Exoplanet

NASA Astrophysics Data System (ADS)

2010-01-01

By studying a triple planetary system that resembles a scaled-up version of our own Sun's family of planets, astronomers have been able to obtain the first direct spectrum - the "chemical fingerprint" [1] - of a planet orbiting a distant star [2], thus bringing new insights into the planet's formation and composition. The result represents a milestone in the search for life elsewhere in the Universe. "The spectrum of a planet is like a fingerprint. It provides key information about the chemical elements in the planet's atmosphere," says Markus Janson, lead author of a paper reporting the new findings. "With this information, we can better understand how the planet formed and, in the future, we might even be able to find tell-tale signs of the presence of life." The researchers obtained the spectrum of a giant exoplanet that orbits the bright, very young star HR 8799. The system is at about 130 light-years from Earth. The star has 1.5 times the mass of the Sun, and hosts a planetary system that resembles a scaled-up model of our own Solar System. Three giant companion planets were detected in 2008 by another team of researchers, with masses between 7 and 10 times that of Jupiter. They are between 20 and 70 times as far from their host star as the Earth is from the Sun; the system also features two belts of smaller objects, similar to our Solar System's asteroid and Kuiper belts. "Our target was the middle planet of the three, which is roughly ten times more massive than Jupiter and has a temperature of about 800 degrees Celsius," says team member Carolina Bergfors. "After more than five hours of exposure time, we were able to tease out the planet's spectrum from the host star's much brighter light." This is the first time the spectrum of an exoplanet orbiting a normal, almost Sun-like star has been obtained directly. Previously, the only spectra to be obtained required a space telescope to watch an exoplanet pass directly behind its host star in an "exoplanetary eclipse", and then the spectrum could be extracted by comparing the light of the star before and after. However, this method can only be applied if the orientation of the exoplanet's orbit is exactly right, which is true for only a small fraction of all exoplanetary systems. The present spectrum, on the other hand, was obtained from the ground, using ESO's Very Large Telescope (VLT), in direct observations that do not depend on the orbit's orientation. As the host star is several thousand times brighter than the planet, this is a remarkable achievement. "It's like trying to see what a candle is made of, by observing it from a distance of two kilometres when it's next to a blindingly bright 300 Watt lamp," says Janson. The discovery was made possible by the infrared instrument NACO, mounted on the VLT, and relied heavily on the extraordinary capabilities of the instrument's adaptive optics system [3]. Even more precise images and spectra of giant exoplanets are expected both from the next generation instrument SPHERE, to be installed on the VLT in 2011, and from the European Extremely Large Telescope. The newly collected data show that the atmosphere enclosing the planet is still poorly understood. "The features observed in the spectrum are not compatible with current theoretical models," explains co-author Wolfgang Brandner. "We need to take into account a more detailed description of the atmospheric dust clouds, or accept that the atmosphere has a different chemical composition from that previously assumed." The astronomers hope to soon get their hands on the fingerprints of the other two giant planets so they can compare, for the first time, the spectra of three planets belonging to the same system. "This will surely shed new light on the processes that lead to the formation of planetary systems like our own," concludes Janson. Notes [1] As every rainbow demonstrates, white light can be split up into different colours. Astronomers artificially split up the light they receive from distant objects into its different colours (or "wavelengths"). However, where we distinguish five or six rainbow colours, astronomers map hundreds of finely nuanced colours, producing a spectrum - a record of the different amounts of light the object emits in each narrow colour band. The details of the spectrum - more light emitted at some colours, less light at others - provide tell-tale signs about the chemical composition of the matter producing the light. This makes spectroscopy, the recording of spectra, an important investigative tool in astronomy. [2] In 2004, astronomers used NACO on the VLT to obtain an image and a spectrum of a 5 Jupiter mass object around a brown dwarf - a "failed star". It is however thought that the pair probably formed together, like a petite stellar binary, instead of the companion forming in the disc around the brown dwarf, like a star-planet system (see eso0428, eso0515 and eso0619). [3] Telescopes on the ground suffer from a blurring effect introduced by atmospheric turbulence. This turbulence causes the stars to twinkle in a way that delights poets but frustrates astronomers, since it smears out the fine details of the images. However, with adaptive optics techniques, this major drawback can be overcome so that the telescope produces images that are as sharp as theoretically possible, i.e. approaching conditions in space. Adaptive optics systems work by means of a computer-controlled deformable mirror that counteracts the image distortion introduced by atmospheric turbulence. It is based on real-time optical corrections computed at very high speed (several hundreds of times each second) from image data obtained by a wavefront sensor (a special camera) that monitors light from a reference star. More information This research was presented in a paper in press as a Letter to the Astrophysical Journal ("Spatially resolved spectroscopy of the exoplanet HR 8799 c", by M. Janson et al.). The team is composed of M. Janson (University of Toronto, Canada), C. Bergfors, M. Goto, W. Brandner (Max-Planck-Institute for Astronomy, Heidelberg, Germany) and D. Lafrenière (University of Montreal, Canada). Preparatory data were taken with the IRCS instrument at the Subaru telescope. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory, and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

APEX Snaps First Close-up of Star Factories in Distant Universe

NASA Astrophysics Data System (ADS)

2010-03-01

For the first time, astronomers have made direct measurements of the size and brightness of regions of star-birth in a very distant galaxy, thanks to a chance discovery with the APEX telescope. The galaxy is so distant, and its light has taken so long to reach us, that we see it as it was 10 billion years ago. A cosmic "gravitational lens" is magnifying the galaxy, giving us a close-up view that would otherwise be impossible. This lucky break reveals a hectic and vigorous star-forming life for galaxies in the early Universe, with stellar nurseries forming one hundred times faster than in more recent galaxies. The research is published online today in the journal Nature. Astronomers were observing a massive galaxy cluster [1] with the Atacama Pathfinder Experiment (APEX) telescope, using submillimetre wavelengths of light, when they found a new and uniquely bright galaxy, more distant than the cluster and the brightest very distant galaxy ever seen at submillimetre wavelengths. It is so bright because the cosmic dust grains in the galaxy are glowing after being heated by starlight. The new galaxy has been given the name SMM J2135-0102. "We were stunned to find a surprisingly bright object that wasn't at the expected position. We soon realised it was a previously unknown and more distant galaxy being magnified by the closer galaxy cluster," says Carlos De Breuck from ESO, a member of the team. De Breuck was making the observations at the APEX telescope on the plateau of Chajnantor at an altitude of 5000 m in the Chilean Andes. The new galaxy SMM J2135-0102 is so bright because of the massive galaxy cluster that lies in the foreground. The vast mass of this cluster bends the light of the more distant galaxy, acting as a gravitational lens [2]. As with a telescope, it magnifies and brightens our view of the distant galaxy. Thanks to a fortuitous alignment between the cluster and the distant galaxy, the latter is strongly magnified by a factor of 32. "The magnification reveals the galaxy in unprecedented detail, even though it is so distant that its light has taken about 10 billion years to reach us," explains Mark Swinbank from Durham University, lead author of the paper reporting the discovery. "In follow-up observations with the Submillimeter Array telescope, we've been able to study the clouds where stars are forming in the galaxy with great precision." The magnification means that the star-forming clouds can be picked out in the galaxy, down to a scale of only a few hundred light-years - almost down to the size of giant clouds in our own Milky Way. To see this level of detail without the help of the gravitational lens would need future telescopes such as ALMA (the Atacama Large Millimeter/submillimeter Array), which is currently under construction on the same plateau as APEX. This lucky discovery has therefore given astronomers a unique preview of the science that will be possible in a few years time. These "star factories" are similar in size to those in the Milky Way, but one hundred times more luminous, suggesting that star formation in the early life of these galaxies is a much more vigorous process than typically found in galaxies that lie nearer to us in time and space. In many ways, the clouds look more similar to the densest cores of star-forming clouds in the nearby Universe. "We estimate that SMM J2135-0102 is producing stars at a rate that is equivalent to about 250 Suns per year," says de Breuck. "The star formation in its large dust clouds is unlike that in the nearby Universe, but our observations also suggest that we should be able to use similar underlying physics from the densest stellar nurseries in nearby galaxies to understand star birth in these more distant galaxies." Notes [1] Galaxy clusters are among the most massive objects in the Universe kept together by gravity. They are composed of hundreds to thousands of galaxies, which make up to only about a tenth of their total mass. The bulk of their mass, which amounts to up to a million billion [1015] times the mass of our Sun, is composed of hot gas and dark matter. In this case, the cluster being observed has the designation MACS J2135-010217 (or MACS J213512.10-010258.5), and is at a distance of about four billion light-years. [2] Gravitational lensing is an effect forecast by Albert Einstein's theory of general relativity. Due to their gigantic mass and their intermediate position between us and very distant galaxies, galaxy clusters act as extremely efficient gravitational lenses, bending the light coming from background galaxies. Depending on the cluster mass distribution a host of interesting effects are produced, such as magnification, shape distortions, giant arcs, and multiple images of the same source. More information This research was presented in a paper, "Intense star formation within resolved compact regions in a galaxy at z=2.3" (A. M. Swinbank et al., DOI 10.1038/nature08880) to appear online in Nature today. The team is composed of A. M. Swinbank, I. Smail, J. Richard, A. C. Edge, and K. E. K. Coppin (Institute for Computational Cosmology, Durham University, UK), S. Longmore, R. Blundell, M. Gurwell, and D. Wilner (Harvard-Smithsonian Center For Astrophysics, USA), A. I. Harris and L. J. Hainline (Department of Astronomy, University of Maryland, USA), A.J. Baker (Department of Physics and Astronomy, Rutgers, University of New Jersey, USA), C. De Breuck, A. Lundgren and G. Siringo (ESO), R. J. Ivison (UKATC and Royal Observatory of Edinburgh, UK), P. Cox, M. Krips and R. Neri (Institut de Radio Astronomie Millimétrique, France), B. Siana (California Institute of Technology, USA), D. P. Stark (Institute of Astronomy, University of Cambridge, UK), and J. D. Younger (Institute for Advanced Study, USA). The Atacama Pathfinder Experiment (APEX) telescope is a 12-metre telescope, located at 5100 m altitude on the arid plateau of Chajnantor in the Chilean Andes. APEX operates at millimetre and submillimetre wavelengths. This wavelength range is a relatively unexplored frontier in astronomy, requiring advanced detectors and an extremely high and dry observatory site, such as Chajnantor. APEX, the largest submillimetre-wave telescope operating in the southern hemisphere, is a collaboration between the Max Planck Institute for Radio Astronomy, the Onsala Space Observatory and ESO. Operation of APEX at Chajnantor is entrusted to ESO. APEX is a "pathfinder" for ALMA - it is based on a prototype antenna constructed for the ALMA project, it is located on the same plateau and will find many targets that ALMA will be able to study in extreme detail. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Black Hole Caught Zapping Galaxy into Existence?

NASA Astrophysics Data System (ADS)

2009-11-01

Which come first, the supermassive black holes that frantically devour matter or the enormous galaxies where they reside? A brand new scenario has emerged from a recent set of outstanding observations of a black hole without a home: black holes may be "building" their own host galaxy. This could be the long-sought missing link to understanding why the masses of black holes are larger in galaxies that contain more stars. "The 'chicken and egg' question of whether a galaxy or its black hole comes first is one of the most debated subjects in astrophysics today," says lead author David Elbaz. "Our study suggests that supermassive black holes can trigger the formation of stars, thus 'building' their own host galaxies. This link could also explain why galaxies hosting larger black holes have more stars." To reach such an extraordinary conclusion, the team of astronomers conducted extensive observations of a peculiar object, the nearby quasar HE0450-2958 (see eso0523 for a previous study of this object), which is the only one for which a host galaxy has not yet been detected [1]. HE0450-2958 is located some 5 billion light-years away. Until now, it was speculated that the quasar's host galaxy was hidden behind large amounts of dust, and so the astronomers used a mid-infrared instrument on ESO's Very Large Telescope for the observations [2]. At such wavelengths, dust clouds shine very brightly, and are readily detected. "Observing at these wavelengths would allow us to trace dust that might hide the host galaxy," says Knud Jahnke, who led the observations performed at the VLT. "However, we did not find any. Instead we discovered that an apparently unrelated galaxy in the quasar's immediate neighbourhood is producing stars at a frantic rate." These observations have provided a surprising new take on the system. While no trace of stars is revealed around the black hole, its companion galaxy is extremely rich in bright and very young stars. It is forming stars at a rate equivalent to about 350 Suns per year, one hundred times more than rates for typical galaxies in the local Universe. Earlier observations had shown that the companion galaxy is, in fact, under fire: the quasar is spewing a jet of highly energetic particles towards its companion, accompanied by a stream of fast-moving gas. The injection of matter and energy into the galaxy indicates that the quasar itself might be inducing the formation of stars and thereby creating its own host galaxy; in such a scenario, galaxies would have evolved from clouds of gas hit by the energetic jets emerging from quasars. "The two objects are bound to merge in the future: the quasar is moving at a speed of only a few tens of thousands of km/h with respect to the companion galaxy and their separation is only about 22 000 light-years," says Elbaz. "Although the quasar is still 'naked', it will eventually be 'dressed' when it merges with its star-rich companion. It will then finally reside inside a host galaxy like all other quasars." Hence, the team have identified black hole jets as a possible driver of galaxy formation, which may also represent the long-sought missing link to understanding why the mass of black holes is larger in galaxies that contain more stars [3]. "A natural extension of our work is to search for similar objects in other systems," says Jahnke. Future instruments, such as the Atacama Large Millimeter/submillimeter Array, the European Extremely Large Telescope and the NASA/ESA/CSA James Webb Space Telescope will be able to search for such objects at even larger distances from us, probing the connection between black holes and the formation of galaxies in the more distant Universe. Notes [1] Supermassive black holes are found in the cores of most large galaxies; unlike the inactive and starving one sitting at the centre of the Milky Way, a fraction of them are said to be active, as they eat up enormous amounts of material. These frantic actions produce a copious release of energy across the whole electromagnetic spectrum; particularly spectacular is the case of quasars, where the active core is so overwhelmingly bright that it outshines the luminosity of the host galaxy. [2] This part of the study is based on observations performed at mid-infrared wavelengths, with the powerful VLT spectrometer and imager for the mid-infrared (VISIR) instrument at the VLT, combined with additional data including: spectra acquired using VLT-FORS, optical and infrared images from the NASA/ESA Hubble Space Telescope, and radio observations from the Australia Telescope National Facility. [3] Most galaxies in the local Universe contain a supermassive black hole with a mass about 1/700th the mass of the stellar bulge. The origin of this black hole mass versus stellar mass relation is one of the most debated subjects in modern astrophysics. More information This research was presented in papers published in the journal Astronomy & Astrophysics: "Quasar induced galaxy formation: a new paradigm?" by Elbaz et al., and in the Astrophysical Journal "The QSO HE0450-2958: Scantily dressed or heavily robed? A normal quasar as part of an unusual ULIRG" by Jahnke et al. The team is composed of David Elbaz (Service d'Astrophysique, CEA Saclay, France), Knud Jahnke (Max Planck Institute for Astronomy, Heidelberg, Germany), Eric Pantin (Service d'Astrophysique, CEA Saclay, France), Damien Le Borgne (Paris University 6 and CNRS, Institut d'Astrophysique de Paris, France) and Géraldine Letawe (Institut d'Astrophysique et de Géophysique, Université de Liège, Belgium). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Black Hole Hunters Set New Distance Record

NASA Astrophysics Data System (ADS)

2010-01-01

Astronomers using ESO's Very Large Telescope have detected, in another galaxy, a stellar-mass black hole much farther away than any other previously known. With a mass above fifteen times that of the Sun, this is also the second most massive stellar-mass black hole ever found. It is entwined with a star that will soon become a black hole itself. The stellar-mass black holes [1] found in the Milky Way weigh up to ten times the mass of the Sun and are certainly not be taken lightly, but, outside our own galaxy, they may just be minor-league players, since astronomers have found another black hole with a mass over fifteen times the mass of the Sun. This is one of only three such objects found so far. The newly announced black hole lies in a spiral galaxy called NGC 300, six million light-years from Earth. "This is the most distant stellar-mass black hole ever weighed, and it's the first one we've seen outside our own galactic neighbourhood, the Local Group," says Paul Crowther, Professor of Astrophysics at the University of Sheffield and lead author of the paper reporting the study. The black hole's curious partner is a Wolf-Rayet star, which also has a mass of about twenty times as much as the Sun. Wolf-Rayet stars are near the end of their lives and expel most of their outer layers into their surroundings before exploding as supernovae, with their cores imploding to form black holes. In 2007, an X-ray instrument aboard NASA's Swift observatory scrutinised the surroundings of the brightest X-ray source in NGC 300 discovered earlier with the European Space Agency's XMM-Newton X-ray observatory. "We recorded periodic, extremely intense X-ray emission, a clue that a black hole might be lurking in the area," explains team member Stefania Carpano from ESA. Thanks to new observations performed with the FORS2 instrument mounted on ESO's Very Large Telescope, astronomers have confirmed their earlier hunch. The new data show that the black hole and the Wolf-Rayet star dance around each other in a diabolic waltz, with a period of about 32 hours. The astronomers also found that the black hole is stripping matter away from the star as they orbit each other. "This is indeed a very 'intimate' couple," notes collaborator Robin Barnard. "How such a tightly bound system has been formed is still a mystery." Only one other system of this type has previously been seen, but other systems comprising a black hole and a companion star are not unknown to astronomers. Based on these systems, the astronomers see a connection between black hole mass and galactic chemistry. "We have noticed that the most massive black holes tend to be found in smaller galaxies that contain less 'heavy' chemical elements," says Crowther [2]. "Bigger galaxies that are richer in heavy elements, such as the Milky Way, only succeed in producing black holes with smaller masses." Astronomers believe that a higher concentration of heavy chemical elements influences how a massive star evolves, increasing how much matter it sheds, resulting in a smaller black hole when the remnant finally collapses. In less than a million years, it will be the Wolf-Rayet star's turn to go supernova and become a black hole. "If the system survives this second explosion, the two black holes will merge, emitting copious amounts of energy in the form of gravitational waves as they combine [3]," concludes Crowther. However, it will take some few billion years until the actual merger, far longer than human timescales. "Our study does however show that such systems might exist, and those that have already evolved into a binary black hole might be detected by probes of gravitational waves, such as LIGO or Virgo [4]." Notes [1] Stellar-mass black holes are the extremely dense, final remnants of the collapse of very massive stars. These black holes have masses up to around twenty times the mass of the Sun, as opposed to supermassive black holes, found in the centre of most galaxies, which can weigh a million to a billion times as much as the Sun. So far, around 20 stellar-mass black holes have been found. [2] In astronomy, heavy chemical elements, or "metals", are any chemical elements heavier than helium. [3] Predicted by Einstein's theory of general relativity, gravitational waves are ripples in the fabric of space and time. Significant gravitational waves are generated whenever there are extreme variations of strong gravitational fields with time, such as during the merger of two black holes. The detection of gravitational waves, never directly observed to date, is one of the major challenges for the next few decades. [4] The LIGO and Virgo experiments have the goal of detecting gravitational waves using sensitive interferometers in Italy and the United States. More information This research was presented in a letter to appear in the Monthly Notices of the Royal Astronomical Society (NGC 300 X-1 is a Wolf-Rayet/Black Hole binary, P.A. Crowther et al.). The team is composed of Paul Crowther and Vik Dhillon (University of Sheffield, UK), Robin Barnard and Simon Clark (The Open University, UK), and Stefania Carpano and Andy Pollock (ESAC, Madrid, Spain). ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory, and VISTA, the largest survey telescope in the world. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Near-infrared interferometry of η Carinae with spectral resolutions of 1 500 and 12 000 using AMBER/VLTI

NASA Astrophysics Data System (ADS)

Weigelt, G.; Kraus, S.; Driebe, T.; Petrov, R. G.; Hofmann, K.-H.; Millour, F.; Chesneau, O.; Schertl, D.; Malbet, F.; Hillier, J. D.; Gull, T.; Davidson, K.; Domiciano de Souza, A.; Antonelli, P.; Beckmann, U.; Bresson, Y.; Chelli, A.; Dugué, M.; Duvert, G.; Gennari, S.; Glück, L.; Kern, P.; Lagarde, S.; Le Coarer, E.; Lisi, F.; Perraut, K.; Puget, P.; Rantakyrö, F.; Robbe-Dubois, S.; Roussel, A.; Tatulli, E.; Zins, G.; Accardo, M.; Acke, B.; Agabi, K.; Altariba, E.; Arezki, B.; Aristidi, E.; Baffa, C.; Behrend, J.; Blöcker, T.; Bonhomme, S.; Busoni, S.; Cassaing, F.; Clausse, J.-M.; Colin, J.; Connot, C.; Delboulbé, A.; Feautrier, P.; Ferruzzi, D.; Forveille, T.; Fossat, E.; Foy, R.; Fraix-Burnet, D.; Gallardo, A.; Giani, E.; Gil, C.; Glentzlin, A.; Heiden, M.; Heininger, M.; Hernandez Utrera, O.; Kamm, D.; Kiekebusch, M.; Le Contel, D.; Le Contel, J.-M.; Lesourd, T.; Lopez, B.; Lopez, M.; Magnard, Y.; Marconi, A.; Mars, G.; Martinot-Lagarde, G.; Mathias, P.; Mège, P.; Monin, J.-L.; Mouillet, D.; Mourard, D.; Nussbaum, E.; Ohnaka, K.; Pacheco, J.; Perrier, C.; Rabbia, Y.; Rebattu, S.; Reynaud, F.; Richichi, A.; Robini, A.; Sacchettini, M.; Schöller, M.; Solscheid, W.; Spang, A.; Stee, P.; Stefanini, P.; Tallon, M.; Tallon-Bosc, I.; Tasso, D.; Testi, L.; Vakili, F.; von der Lühe, O.; Valtier, J.-C.; Vannier, M.; Ventura, N.; Weis, K.; Wittkowski, M.

2007-03-01

Aims: We present the first NIR spectro-interferometry of the LBV η Carinae. The observations were performed with the AMBER instrument of the ESO Very Large Telescope Interferometer (VLTI) using baselines from 42 to 89 m. The aim of this work is to study the wavelength dependence of η Car's optically thick wind region with a high spatial resolution of 5 mas (11 AU) and high spectral resolution. Methods: The observations were carried out with three 8.2 m Unit Telescopes in the K-band. The raw data are spectrally dispersed interferograms obtained with spectral resolutions of 1500 (MR-K mode) and 12 000 (HR-K mode). The MR-K observations were performed in the wavelength range around both the He I 2.059 μm and the Brγ 2.166 μm emission lines, the HR-K observations only in the Brγ line region. Results: The spectrally dispersed AMBER interferograms allow the investigation of the wavelength dependence of the visibility, differential phase, and closure phase of η Car. In the K-band continuum, a diameter of 4.0±0.2 mas (Gaussian FWHM, fit range 28-89 m baseline length) was measured for η Car's optically thick wind region. If we fit Hillier et al. (2001, ApJ, 553, 837) model visibilities to the observed AMBER visibilities, we obtain 50% encircled-energy diameters of 4.2, 6.5 and 9.6 mas in the 2.17 μm continuum, the He I, and the Brγ emission lines, respectively. In the continuum near the Brγ line, an elongation along a position angle of 120°±15° was found, consistent with previous VINCI/VLTI measurements by van Boekel et al. (2003, A&A, 410, L37). We compare the measured visibilities with predictions of the radiative transfer model of Hillier et al. (2001), finding good agreement. Furthermore, we discuss the detectability of the hypothetical hot binary companion. For the interpretation of the non-zero differential and closure phases measured within the Brγ line, we present a simple geometric model of an inclined, latitude-dependent wind zone. Our observations support theoretical models of anisotropic winds from fast-rotating, luminous hot stars with enhanced high-velocity mass loss near the polar regions. Based on observations collected at the European Southern Observatory, Paranal, Chile, within the AMBER guaranteed time programme 074.A-9025 and the VLTI science demonstration programme 074.A-9024.

Resolving the clumpy circumstellar environment of the B[e] supergiant LHA 120-S 35

NASA Astrophysics Data System (ADS)

Torres, A. F.; Cidale, L. S.; Kraus, M.; Arias, M. L.; Barbá, R. H.; Maravelias, G.; Borges Fernandes, M.

2018-05-01

Context. B[e] supergiants are massive post-main-sequence stars, surrounded by a complex circumstellar environment where molecules and dust can survive. The shape in which the material is distributed around these objects and its dynamics as well as the mechanisms that give rise to these structures are not well understood. Aims: The aim is to deepen our knowledge of the structure and kinematics of the circumstellar disc of the B[e] supergiant LHA 120-S 35. Methods: High-resolution optical spectra were obtained in three different years. Forbidden emission lines, that contribute to trace the disc at different distances from the star, are modelled in order to determine the kinematical properties of their line-forming regions, assuming Keplerian rotation. In addition, we used low-resolution near-infrared spectra to explore the variability of molecular emission. Results: LHA 120-S 35 displays an evident spectral variability in both optical and infrared regions. The P-Cygni line profiles of H I, as well as those of Fe II and O I, suggest the presence of a strong bipolar clumped wind. We distinguish density enhancements in the P-Cygni absorption component of the first Balmer lines, which show variations in both velocity and strength. The P-Cygni profile emission component is double-peaked, indicating the presence of a rotating circumstellar disc surrounding the star. We also observe line-profile variations in the permitted and forbidden features of Fe II and O I. In the infrared, we detect variations in the intensity of the H I emission lines as well as in the emission of the CO band-heads. Moreover, we find that the profiles of each [Ca II] and [O I] emission lines contain contributions from spatially different (complete or partial) rings. Globally, we find evidence of detached multi-ring structures, revealing density variations along the disc. We identify an inner ring, with sharp edge, where [Ca II] and [O I] lines share their forming region with the CO molecular bands. The outermost regions show a complex structure, outlined by fragmented clumps or partial-ring features of Ca II and O I. Additionally, we observe variations in the profiles of the only visible absorption features, the He I lines. Conclusions: We suggest that LHA 120-S 35 has passed through the red-supergiant (RSG) phase and evolves back bluewards in the Hertzsprung-Russell diagram. In this scenario, the formation of the complex circumstellar structure could be the result of the wind-wind interactions of the post-RSG wind with the previously ejected material from the RSG. The accumulation of material in the circumstellar environment could be attributed to enhanced mass-loss, probably triggered by stellar pulsations. However, the presence of a binary companion cannot be excluded. Finally, we find that LHA 120-S 35 is the third B[e] supergiant belonging to a young stellar cluster. Based on data acquired using (1) the du Pont Telescope at Las Campanas Observatory, Chile, under the programme CNTAC 2008-02 (PI: Barbá), (2) the MPG 2.2-m Telescope at La Silla Observatory, Chile, under the programme ID.: 094.A-9029(D) and under the agreement MPI-Observatório Nacional/MCTIC, Prog. ID.: 096.A-9030(A), (3) the J. Sahade 2.15-m Telescope at Complejo Astronómico El Leoncito, operated under agreement between the Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina and the National Universities of La Plata, Córdoba and San Juan, (4) the 8.1-m Telescope at Gemini South Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciěncia, Tecnologia e Inovacão (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina), under the programme GS-2013B-Q-6 (PI: L. Cidale), (5) the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astron. Obs. (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU) and (6) the ESO Science Archive Facility.

Finland to Join ESO

NASA Astrophysics Data System (ADS)

2004-03-01

Finland will become the eleventh member state of the European Southern Observatory. In a ceremony at the ESO Headquarters in Garching on 9 February 2004, an Agreement to this effect was signed by the Finnish Minister of Education and Science, Ms. Tuula Haatainen and the ESO Director General, Dr. Catherine Cesarsky, in the presence of other high officials from Finland and the ESO member states.

Stellar family in crowded, violent neighbourhood proves to be surprisingly normal

NASA Astrophysics Data System (ADS)

2009-06-01

Using ESO's Very Large Telescope, astronomers have obtained one of the sharpest views ever of the Arches Cluster -- an extraordinary dense cluster of young stars near the supermassive black hole at the heart of the Milky Way. Despite the extreme conditions astronomers were surprised to find the same proportions of low- and high-mass young stars in the cluster as are found in more tranquil locations in our Milky Way. ESO PR Photo 21a/09 The Arches Cluster ESO PR Photo 21b/09 The Centre of the Milky Way ESO PR Photo 21c/09 Around the Arches Cluster ESO PR Video 21a/09 A voyage to the heart of the Milky Way The massive Arches Cluster is a rather peculiar star cluster. It is located 25 000 light-years away towards the constellation of Sagittarius (the Archer), and contains about a thousand young, massive stars, less than 2.5 million years old [1]. It is an ideal laboratory to study how massive stars are born in extreme conditions as it is close to the centre of our Milky Way, where it experiences huge opposing forces from the stars, gas and the supermassive black hole that reside there. The Arches Cluster is ten times heavier than typical young star clusters scattered throughout our Milky Way and is enriched with chemical elements heavier than helium. Using the NACO adaptive optics instrument on ESO's Very Large Telescope, located in Chile, astronomers scrutinised the cluster in detail. Thanks to adaptive optics, astronomers can remove most of the blurring effect of the atmosphere, and so the new NACO images of the Arches Cluster are even crisper than those obtained with telescopes in space. Observing the Arches Cluster is very challenging because of the huge quantities of absorbing dust between Earth and the Galactic Centre, which visible light cannot penetrate. This is why NACO was used to observe the region in near-infrared light. The new study confirms the Arches Cluster to be the densest cluster of massive young stars known. It is about three light-years across with more than a thousand stars packed into each cubic light-year -- an extreme density a million times greater than in the Sun's neighbourhood. Astronomers studying clusters of stars have found that higher mass stars are rarer than their less massive brethren, and their relative numbers are the same everywhere, following a universal law. For many years, the Arches Cluster seemed to be a striking exception. "With the extreme conditions in the Arches Cluster, one might indeed imagine that stars won't form in the same way as in our quiet solar neighbourhood," says Pablo Espinoza, the lead author of the paper reporting the new results. "However, our new observations showed that the masses of stars in this cluster actually do follow the same universal law". In this image the astronomers could also study the brightest stars in the cluster. "The most massive star we found has a mass of about 120 times that of the Sun," says co-author Fernando Selman. "We conclude from this that if stars more massive than 130 solar masses exist, they must live for less than 2.5 million years and end their lives without exploding as supernovae, as massive stars usually do." The total mass of the cluster seems to be about 30 000 times that of the Sun, much more than was previously thought. "That we can see so much more is due to the exquisite NACO images," says co-author Jorge Melnick. Note [1] The name "Arches" does not come from the constellation the cluster is located in (Sagittarius, i.e., the Archer), but because it is located next to arched filaments detected in radio maps of the centre of the Milky Way.

"Infinitos"

NASA Astrophysics Data System (ADS)

1994-04-01

On Friday, 22 April 1994, a new science exhibition ``Infinitos", arranged jointly by Lisboa'94, CERN and ESO, will open at the Museu de Electricidade on the waterfront of Lisbon, the capital of Portugal. In a series of spectacular displays, it illustrates man's current understanding of how the Universe works - from the tiniest structures of matter to the most far flung galaxies. On this day, it will be inaugurated by the President of Lisboa'94, Prof. Vitor Constancio, the Portuguese Science Minister, Prof. L. Valente de Oliveira, Prof. C. Llewellyn Smith, Director General of CERN [2] and Dr. P. Creola, President of ESO Council. This exhibition is part of a rich cultural programme taking place at Lisbon during 1994 in the frame of ``Lisboa 94 - European City of Culture", after which it will travel to major cities around Europe. The frontiers of our knowledge push into inner space - the structure of the smallest components of matter - and into outer space - the dramatic phenomena of distant galaxies. Two of Europe's leading science organisations are playing a crucial role in this great human adventure. The European Laboratory for Particle Physics, CERN, operates the mighty accelerators and colliding beam machines to penetrate deep into matter and recreate the conditions which prevailed in the Universe a tiny fraction of a second after the Big Bang. The European Southern Observatory, ESO, operates the largest optical observatory in the world with a range of advanced telescopes searching the sky to study the evolution and content of our Universe. The ``Infinitos'' exhibition uses many modern exhibition techniques, including sophisticated audio-visual presentations and interactive video programmes. Visitors enter through a gallery of portraits of the most celebrated scientists from the 16th to 20th centuries and an exhibition of art inspired by scientific research. After passing a cosmic ray detector showing the streams of particles which pour down constantly from outer space, visitors continue into a central area where they are confronted with the essential questions of astro- and particle physics, f.inst. ``What is the Universe made of?'', ``How was the Universe created?'', ``What is in the sky?'', ``What is Dark Matter?'', ``Where does the stuff in our bodies come from?'', and ``Are we alone in the Universe?'' A central theme of this display is ``What we don't know''. In the second part of the exhibition visitors are shown the instruments and techniques used in today's big science research which will help to provide the answers. There are special displays on Europe's future large research projects such as the Large Hadron Collider (LHC) at CERN, which will bring protons into head-on collision at higher energies (14 TeV) than ever before to allow scientists to penetrate still further into the structure of matter and recreate the conditions prevailing in the Universe just 10-12 seconds after the "Big Bang" when the temperature was 10^16 degrees. Another highlight is a large interactive model of ESO's Very Large Telescope (VLT), the world's most ambitious optical telescope project, now under construction. The telescope's unequalled potential for exciting astronomical observations at the outer reaches of the Universe is clearly explained. Special emphasis is given to the contribution of Portuguese research institutes to the work of CERN and ESO, and particle physicists and astronomers from Portugal will be present at the exhibition to talk to visitors about their work. This exhibition will remain open until 12 June 1994 and will be a major attraction, also to the many tourists visiting this year's European City of Culture. 1. This is a joint Press Release of Lisboa'94, CERN and ESO. 2. CERN, the European Laboratory for Particle Physics, has its headquarters in Geneva. At present, its Member States are Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Netherlands, Norway, Poland, Portugal, the Slovak Republic, Spain, Sweden, Switzerland and the United Kingdom. Israel, the Russian Federation, Turkey, Yugoslavia (status suspended after UN embargo, June 1992), the European Commission and Unesco have observer status.

ESO science data product standard for 1D spectral products

NASA Astrophysics Data System (ADS)

Micol, Alberto; Arnaboldi, Magda; Delmotte, Nausicaa A. R.; Mascetti, Laura; Retzlaff, Joerg

2016-07-01

The ESO Phase 3 process allows the upload, validation, storage, and publication of reduced data through the ESO Science Archive Facility. Since its introduction, 2 million data products have been archived and published; 80% of them are one-dimensional extracted and calibrated spectra. Central to Phase3 is the ESO science data product standard that defines metadata and data format of any product. This contribution describes the ESO data standard for 1d-spectra, its adoption by the reduction pipelines of selected instrument modes for in-house generation of reduced spectra, the enhanced archive legacy value. Archive usage statistics are provided.

ESO Science Outreach Network in Poland during 2011-2013

NASA Astrophysics Data System (ADS)

Czart, Krzysztof

2014-12-01

ESON Poland works since 2010. One of the main tasks of the ESO Science Outreach Network (ESON) is translation of various materials at ESO website, as well as contacts with journalists. We support also science festivals, conferences, contests, exhibitions, astronomy camps and workshops and other educational and outreach activities. During 2011-2013 we supported events like ESO Astronomy Camp 2013, ESO Industry Days in Warsaw, Warsaw Science Festival, Torun Festival of Science and Art, international astronomy olympiad held in Poland and many others. Among big tasks there was also translation of over 60 ESOcast movies.

VizieR Online Data Catalog: Radial velocity curve of 51 Peg (Birkby+, 2017)

NASA Astrophysics Data System (ADS)

Birkby, J. L.; de Kok, R. J.; Brogi, M.; Schwarz, H.; Snellen, I. A. G.

2017-07-01

We observed the bright star 51 Peg (G2.5V, V=5.46mag, K=3.91mag) for 3.7hr during the night beginning 2010 October 21, using the CRyogenic InfraRed Echelle Spectrograph (CRIRES) mounted at Nasmyth A at the VLT (8.2 m UT1/Antu), Cerro Paranal, Chile. The observations were collected as part of the ESO large program 186.C-0289. The instrument setup consisted of a 0.2 arcsec slit centred on 3236nm (order 17), in combination with the Multi-Application Curvature Adaptive Optic system (MACAO). The CRIRES infrared detector is comprised of four Aladdin III InSb-arrays, each with 1024*512 pixels, and separated by a gap of 280 pixels. The resulting wavelength coverage of the observations was 3.1806<λ(μm)<3.2659 with a resolution of R{approx}100000 per resolution element. We observed 51 Peg continuously while its hot Jupiter companion passed through orbital phases 0.55<~{Phi}<~0.58, corresponding to an expected change in the planet's radial velocity of ΔRVP=-23km/s (15 pixels on the CRIRES detectors). In total, we obtained 42 spectra, with the first 20 spectra each consisting of two sets of 5*20s exposures, and the remainder each consisting of two sets of 5*30s exposures. The increase in the exposure time was aimed at maintaining a constant signal-to-noise ratio (S/N) in the continuum of the observed stellar spectra after a sudden and significant deterioration of the seeing (increasing from 0.75 to 1.4 arcsec between one set of frames, see Section 2.3). To enable accurate sky-background subtraction, the telescope was nodded along the slit by 10 arcsec between each set of exposures in a classic ABBA sequence, with each of the final 42 extracted spectra consisting of an AB or BA pair. A standard set of CRIRES calibration frames was taken the following morning. To ensure we had its most up-to-date orbital solution, we compiled an extensive repository of literature and archival radial velocity measurements of the star 51 Peg from multiple observatories. These data are given in Table 1 and span observing dates from 1994 September 15 to 2014 July 9, resulting in 639 radial velocity measurements over 20 years. The table includes the discovery measurements from the ELODIE spectrograph at Observatoire Haute Provence and subsequent additional monitoring. We took these radial velocity measurements from the Naef et al. 2004 (Cat. J/A+A/414/351) compilation. We also included the legacy data set from Lick Observatory observed with the Hamilton spectrograph, taking measurements from the self-consistent reprocessing of all the Lick spectra presented by Fischer et al. 2014 (Cat. J/ApJS/210/5). Finally, we included more recent additional monitoring from the High Resolution Echelle Spectrometer (HIRES) at the Keck Observatory, and extracted RVs from observations with the High Accuracy Radial velocity Planet Searcher (HARPS) at the ESO-3.6m telescope in 2013 (ESO program ID 091.C-0271, PI: Santos). The reduced HARPS spectra were obtained from the ESO Science Archive (http://archive.eso.org/wdb/wdb/adp/phase3_spectral/query). (1 data file).

The Thousand-Ruby Galaxy

NASA Astrophysics Data System (ADS)

2008-09-01

ESO's Wide Field Imager has captured the intricate swirls of the spiral galaxy Messier 83, a smaller look-alike of our own Milky Way. Shining with the light of billions of stars and the ruby red glow of hydrogen gas, it is a beautiful example of a barred spiral galaxy, whose shape has led to it being nicknamed the Southern Pinwheel. Messier 83, M83 ESO PR Photo 25/08 Spiral Galaxy Messier 83 This dramatic image of the galaxy Messier 83 was captured by the Wide Field Imager at ESO's La Silla Observatory, located high in the dry desert mountains of the Chilean Atacama Desert. Messier 83 lies roughly 15 million light-years away towards the huge southern constellation of Hydra (the sea serpent). It stretches over 40 000 light-years, making it roughly 2.5 times smaller than our own Milky Way. However, in some respects, Messier 83 is quite similar to our own galaxy. Both the Milky Way and Messier 83 possess a bar across their galactic nucleus, the dense spherical conglomeration of stars seen at the centre of the galaxies. This very detailed image shows the spiral arms of Messier 83 adorned by countless bright flourishes of ruby red light. These are in fact huge clouds of glowing hydrogen gas. Ultraviolet radiation from newly born, massive stars is ionising the gas in these clouds, causing the great regions of hydrogen to glow red. These star forming regions are contrasted dramatically in this image against the ethereal glow of older yellow stars near the galaxy's central hub. The image also shows the delicate tracery of dark and winding dust streams weaving throughout the arms of the galaxy. Messier 83 was discovered by the French astronomer Nicolas Louis de Lacaille in the mid 18th century. Decades later it was listed in the famous catalogue of deep sky objects compiled by another French astronomer and famous comet hunter, Charles Messier. Recent observations of this enigmatic galaxy in ultraviolet light and radio waves have shown that even its outer desolate regions (farther out than those seen in this image) are populated with baby stars. X-ray observations of the heart of Messier 83 have shown that its centre is a hive of vigorous star formation, held deep within a cloud of superheated gas, with temperatures of 7 million degrees Celsius. Messier 83 is also one of the most prolific producers of supernovae, that is, exploding stars: this is one of the two galaxies, which had 6 supernovae in the past 100 years. One of these, SN 1957D was observable for 30 years! The Wide Field Imager (WFI) is a specialised astronomical camera attached to the 2.2-metre Max-Planck Society/ESO telescope, sited at the La Silla observatory in Chile. Located nearly 2400 m above sea level, atop the mountains of the Atacama Desert, ESO's La Silla enjoys some of the clearest and darkest skies on the whole planet, making the site ideally suited for studying the farthest depths of the Universe. To make this image, the WFI stared at M83 for roughly 100 minutes through a series of specialist filters, allowing the faint detail of the galaxy to reveal itself. The brighter stars in the foreground are stars in our own galaxy, whilst behind M83 the darkness is peppered with the faint smudges of distant galaxies.

The Antenna Bride and Bridegroom

NASA Astrophysics Data System (ADS)

2007-03-01

ALMA Achieves Major Milestone With Antenna-Link Success The Atacama Large Millimeter/submillimeter Array (ALMA), an international telescope project, reached a major milestone on 2 March, when two 12-m ALMA prototype antennas were first linked together as an integrated system to observe an astronomical object. "This achievement results from the integration of many state-of-the-art components from Europe and North America and bodes well for the success of ALMA in Chile", said Catherine Cesarsky, ESO's Director General. ESO PR Photo 10/07 ESO PR Photo 10/07 The Prototype Antennas The milestone achievement, technically termed 'First Fringes', came at the ALMA Test Facility (ATF), located near Socorro in New Mexico. Faint radio waves emitted by the planet Saturn were collected by two ALMA prototype antennas, then processed by new, high-tech electronics to turn the two antennas into a single, high-resolution telescope system, called an interferometer. The planet's radio emissions at a frequency of 104 gigahertz were tracked by the ALMA system for more than an hour. Such pairs of antennas are the basic building blocks of the multi-antenna imaging system ALMA. In such a system, the signals recorded by each antenna are electronically combined with the signals of every other antenna to form a multitude of pairs. Each pair contributes unique information that is used to build a highly detailed image of the astronomical object under observation. When completed in the year 2012, ALMA will have 66 antennas. "Our congratulations go to the dedicated team of scientists, engineers and technicians who produced this groundbreaking achievement for ALMA. Much hard work and many long hours went into this effort, and we appreciate it all. This team should be very proud today," said NRAO Director Fred K.Y. Lo. "With this milestone behind us, we now can proceed with increased confidence toward completing ALMA," he added. ALMA, located at an elevation of 5,000m in the Atacama Desert of northern Chile, will provide astronomers with the world's most advanced tool for exploring the Universe at millimetre and submillimetre wavelengths. ALMA will detect fainter objects and be able to produce much higher-quality images at these wavelengths than any previous telescope system. Scientists are eager to use this transformational capability to study the first stars and galaxies that formed in the early Universe, to learn long-sought details about how stars are formed, and to trace the motion of gas and dust as it whirls toward the surface of newly-formed stars and planets. "The success of this test is fundamental proof that the hardware and software now under development for ALMA will work to produce a truly revolutionary astronomical tool," said Massimo Tarenghi, the ALMA Director. In addition to the leading-edge electronic and electro-optical hardware and custom software that proved itself by producing ALMA's first fringes, the system's antennas are among the most advanced in the world. The stringent requirements for the antennas included extremely precise reflecting surfaces, highly accurate ability to point at desired locations in the sky, and the ability to operate reliably in the harsh, high-altitude environment of the ALMA site. The ALMA Test Facility operates the two prototype antennas built by Alcatel Alenia Space and European Industrial Engineering in Europe, and by VertexRSI (USA). These antennas were evaluated individually at the ATF. Both prototypes were equipped with electronic equipment for receiving, digitizing and transmitting signals to a central facility, where the signals are combined to make the antennas work together as a single astronomical instrument. "The successful achievement of recording the first fringes with two ALMA antennas is certainly an important milestone in the scientific program," said Hans Rykaczewski, the European ALMA Project Manager. "It is encouraging and adds to our motivation to see that the principles of ALMA work - not only scientifically, but also from the point of view of organizing this project by partners located in four continents. This successful partnership is a good proof of principle for the future of large scientific projects in astronomy." The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership among Europe, Japan and North America, in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organisation for Astronomical Research in the Southern Hemisphere, in Japan by the National Institutes of Natural Sciences (NINS) in cooperation with the Academia Sinica in Taiwan and in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC). ALMA construction and operations are led on behalf of Europe by ESO, on behalf of Japan by the National Astronomical Observatory of Japan (NAOJ) and on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI).

VizieR Online Data Catalog: The AllWISE motion survey (AllWISE2) (Kirkpatrick+, 2016)

NASA Astrophysics Data System (ADS)

Kirkpatrick, J. D.; Kellogg, K.; Schneider, A. C.; Fajardo-Acosta, S.; Cushing, M. C.; Greco, J.; Mace, G. N.; Gelino, C. R.; Wright, E. L.; Eisenhardt, P. R. M.; Stern, D.; Faherty, J. K.; Sheppard, S. S.; Lansbury, G. B.; Logsdon, S. E.; Martin, E. C.; McLean, I. S.; Schurr, S. D.; Cutri, R. M.; Conrow, T.

2016-07-01

Observations for the spectroscopic follow-up of interesting AllWISE sources are listed in Table 4. Optical follow-up was conducted with the Palomar/Double Spectrograph on the Hale 5m telescope on Palomar Mountain, California, as our primary optical spectrograph in the northern hemisphere. It was used during the UT nights of 2014 January 26, February 23/24, April 22, June 25/26, July 21, September 27, October 24, and November 15 as well as 2015 June 08, September 07, and December 10. The Boller & Chivens Spectrograph (BCSpec) on the 2.5m Irenee duPont telescope at Las Campanas Observatory, Chile, served as our primary optical spectrograph in the southern hemisphere and was used on the UT nights of 2014 April 30, May 01-04, and November 16-20. Spectra of 10 objects were obtained on the UT nights of 2014 July 03-04 and 2015 December 07-10 at the European Southern Observatory (ESO) 3.58m New Technology Telescope (NTT) at La Silla, Chile. Spectra of seven objects were obtained on the UT nights of 2014 June 26, 2015 August 13, and 2015 December 05 with the Low Resolution Imaging Spectrometer (LRIS) at the 10m W. M. Keck Observatory on Mauna Kea, Hawaii. SpeX on the NASA 3m Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, served as our primary near-infrared spectrograph in the northern hemisphere. The UT dates of observation were 2014 November 11 and 2015 January 27, May 08-09, June 27, July 03-05, and July 20. The Folded-port Infrared Echellette (FIRE) at the 6.5m Walter Baade Telescope at Las Campanas Observatory, Chile, served as our primary near-infrared spectrograph in the southern hemisphere. The UT dates of observation were 2014 August 07-09, 2015 February 08, and 2015 May 31. Several sources were also observed with the Near-Infrared Spectrometer (NIRSPEC) at the 10m W. M. Keck Observatory on Mauna Kea, Hawaii. The observation dates were UT 2014 April 12 and December 03, and 2015 July 03 and July 11. (9 data files).

Detecting esophageal disease with second-generation capsule endoscopy: initial evaluation of the PillCam ESO 2.

PubMed

Gralnek, I M; Adler, S N; Yassin, K; Koslowsky, B; Metzger, Y; Eliakim, R

2008-04-01

Esophageal capsule endoscopy (ECE) provides an alternative, minimally invasive modality for evaluating the esophagus. This study evaluates the performance and test characteristics of a second-generation esophageal capsule endoscope, the PillCam ESO 2. Adults with known or suspected esophageal disease were included. Using the simplified ingestion procedure, each patient underwent capsule endoscopy with the PillCam ESO 2. Following ECE, esophagogastroduodenoscopy (EGD) was performed on the same day by an investigator who was blinded to the results of the ECE. In random order, capsule endoscopy videos were read and interpreted by the study investigator blinded to EGD results. 28 patients (19 men, 9 women; mean age 53.3 years) were included. In 82 % of the patients, at least 75 % of the Z line was visualized by the PillCam ESO 2. A per-lesion analysis demonstrated that the PillCam ESO 2 had definitive results in 30/43 lesions (69.8 %) and EGD in 29/43 (67.4 %), P value = 0.41. Compared with EGD for detecting suspected Barrett's esophagus and esophagitis, the PillCam ESO 2 had a sensitivity of 100 % and a specificity of 74 %, and a sensitivity of 80 % and a specificity of 87 %, respectively. The PillCam ESO 2 demonstrated 86 % agreement with EGD in describing the Z line (kappa statistic 0.68). The modified ingestion protocol provided excellent cleansing, with bubbles/saliva having no or only a minor effect on Z line images in 86 % of cases. The PillCam ESO 2 demonstrated excellent visualization of the Z line. Compared with standard EGD, the PillCam ESO 2 had good test characteristics with high rates of detection of suspected Barrett's esophagus and esophagitis. This study provides indirect validation of the simplified ingestion procedure. The PillCam ESO 2 acquires high quality esophageal images, performs safely, and should be able to replace the current PillCam ESO.

Comprehensive adipocytic and neurogenic tissue microarray analysis of NY-ESO-1 expression - a promising immunotherapy target in malignant peripheral nerve sheath tumor and liposarcoma

PubMed Central

Shurell, Elizabeth; Vergara-Lluri, Maria E.; Li, Yunfeng; Crompton, Joseph G.; Singh, Arun; Bernthal, Nicholas; Wu, Hong; Eilber, Fritz C.; Dry, Sarah M.

2016-01-01

Background Immunotherapy targeting cancer-testis antigen NY-ESO-1 shows promise for tumors with poor response to chemoradiation. Malignant peripheral nerve sheath tumors (MPNSTs) and liposarcomas (LPS) are chemoresistant and have few effective treatment options. Materials Methods Using a comprehensive tissue microarray (TMA) of both benign and malignant tumors in primary, recurrent, and metastatic samples, we examined NY-ESO-1 expression in peripheral nerve sheath tumor (PNST) and adipocytic tumors. The PNST TMA included 42 MPNSTs (spontaneous n = 26, NF1-associated n = 16), 35 neurofibromas (spontaneous n = 22, NF-1 associated n = 13), 11 schwannomas, and 18 normal nerves. The LPS TMA included 48 well-differentiated/dedifferentiated (WD/DD) LPS, 13 myxoid/round cell LPS, 3 pleomorphic LPS, 8 lipomas, 1 myelolipoma, and 3 normal adipocytic tissue samples. Stained in triplicate, NY-ESO-1 intensity and density were scored. Results NY-ESO-1 expression was exclusive to malignant tumors. 100% of myxoid/round cell LPS demonstrated NY-ESO-1 expression, while only 6% of WD/DD LPS showed protein expression, one of which was WD LPS. Of MPNST, 4/26 (15%) spontaneous and 2/16 (12%) NF1-associated MPNSTs demonstrated NY-ESO-1 expression. Strong NY-ESO-1 expression was observed in myxoid/round cell and dedifferentiated LPS, and MPNST in primary, neoadjuvant, and metastatic settings. Conclusions We found higher prevalence of NY-ESO-1 expression in MPNSTs than previously reported, highlighting a subset of MPNST patients who may benefit from immunotherapy. This study expands our understanding of NY-ESO-1 in WD/DD LPS and is the first demonstration of staining in a WD LPS and metastatic/recurrent myxoid/round cell LPS. These results suggest immunotherapy targeting NY-ESO-1 may benefit patients with aggressive tumors resistant to conventional therapy. PMID:27655679

Catching a Falling Star

NASA Astrophysics Data System (ADS)

2004-07-01

ESO's Very Large Telescope Obtains Unique Spectrum of a Meteor Summary While observing a supernova in a distant galaxy with the FORS instrument on ESO's Very Large Telescope at the Paranal Observatory (Chile), astronomers were incredibly lucky to obtain serendipitously a high quality spectrum of a very large meteor in the terrestrial atmosphere. The VLT spectrograph provided a well calibrated spectrum, making it a reference in this field of research. From this spectrum, the temperature of the meteor trail was estimated to be about 4600 degrees centigrade. The serendipitous spectrum reveals the telltale meteor emissions of oxygen and nitrogen atoms and nitrogen molecules. The VLT spectrum was the first to reveal the far red range where carbon emission lines are predicted; the absence of the lines puts constraints on the role of atmospheric chemistry when life started on earth. Because the VLT is tuned to observe objects far out in space, it focuses at infinity. The meteor, being "only" 100 km above the telescope, therefore appears out of focus in the field of view. PR Photo 22a/04: Meteor Caught in the Act (MASCOT) PR Photo 22b/04: Spectrum of a Meteor (FORS1/VLT) PR Photo 22c/04: Details of the Meteor Spectrum (FORS1/VLT) Astronomers' luck ESO PR Photo 22a/04 ESO PR Photo 22a/04 Meteor Caught in the Act (MASCOT) [Preview - JPEG: 426 x 400 pix - 85k] [Normal - JPEG: 851 x 800 pix - 187k] [Full Res - JPEG: 2567 x 2413 pix - 908k] Captions: ESO PR Photo 22a/04 shows the trail of a bright meteor, photographed by the Mini All-Sky Cloud Observation Tool (MASCOT) at the ESO Paranal Observatory. MASCOT consists of a small CCD camera behind a fish-eye objective. It typically takes 90s exposures every 3 minutes and helps astronomers inside the VLT Control Room to keep an eye on the sky. The main purpose of MASCOT is to monitor the clouds over Paranal but it also observes from time to time serendipitous events like meteor showers, atmospheric phenomena, artificial satellites, etc. This image was obtained by MASCOT on August 25, 2002 and shows a meteor caught in the act. (Note that this is not the meteor whose spectrum was recorded). The Milky Way is also clearly visible in the centre. A popular saying states that when you see a meteor, you may make a wish. While astronomers cannot promise that it will be realised, a team of astronomers [1] have indeed seen a dream come true! On May 12, 2002, they were lucky to record the spectrum of a bright meteor when it happened - by sheer chance and against all reasonable odds - to cross the narrow slit of the FORS1 instrument on the ESO Very Large Telescope. At the time of this unlikely event, the telescope was performing a series of 20-minute spectroscopic exposures of a supernova in a distant galaxy in order to establish constraints on the dark energy content of the Universe (see e.g. ESO PR 21/98). Thanks to its enormous light-collecting and magnifying power, the VLT recorded the spectrum of the meteor trail perpendicular to its path on one of these exposures. "We really hit the jackpot", says ESO astronomer Emmanuel Jehin: "Chances of capturing a meteor in the narrow slit of the FORS1 spectrograph are about as big as for me winning the national lottery." Meteor spectra have on occasion been obtained serendipitously during photographic star spectra surveys. But this is now maybe the only meteor spectrum recorded with a large telescope and a modern spectrograph. The spectrum covers the wavelength range from 637 to 1050 nm, which is dominated by emissions from air atoms and molecules in the meteor path and teach us about the collision processes in the wake of a meteoroid. The rapid motion of the meteor across the sky resulted in a very brief exposure while crossing the narrow spectrograph slit - only 1/50 of a millisecond! - and despite the relative brightness of the meteor it was only thanks to the VLT's great light-gathering power that any record was procured. The meteor was estimated at magnitude -8, or nearly as bright as the first-quarter Moon. Although it is not possible to be sure from which shower this meteor belongs, a possible candidate is the Southern May Ophiuchid shower which appears from a direction just east of the bright star Antares. The shower contributes only one or two meteors per hour but was one of the stronger showers of that night. Telltale emissions ESO PR Photo 22b/04 ESO PR Photo 22b/04 Spectrum of a Meteor (FORS1/VLT) [Preview - JPEG: 426 x 400 pix - 91k] [Normal - JPEG: 851 x 800 pix - 232k] [Full Res - JPEG: 2567 x 2413 pix - 2.1M] ESO PR Photo 22c/04 ESO PR Photo 22c/04 Details of the Meteor Spectrum (FORS1/VLT) [Preview - JPEG: 1006 x 400 pix - 122k] [Normal - JPEG: 2011 x 800 pix - 236k] [Full Res - JPEG: 3414 x 1358 pix - 957k] Captions: ESO PR Photo 22b/04 shows the spectrum of a bright meteor, as observed serendipitously by the multi-mode FORS 1 instrument on the ESO Very Large Telescope during the night of May 12-13, 2002, in front of a photo of the VLT enclosures and with a meteor trail inserted in the sky (montage). The position of the meteor trail on the narrow slit of FORS (not to scale) is also indicated. The lower panel shows the spectrum of the meteor, following removal of the supernova spectrum and before (up) and after (down) removal of the spectrum of the night sky by image processing. Several emission lines from colliding Oxygen and Nitrogen atoms (sharp emissions) and molecules (broad emissions) are visible. ESO PR Photo 22c/04 illustrates details of the extracted VLT meteor spectrum (solid line): the intensity (in arbitrary units) is shown as a function of the wavelength. The dashed line is a theoretical model of the spectrum of air heated to a temperature of 4600 degrees at an altitude of 95 km. "At first, the bright trace across the supernova spectrum was a puzzle, but then I realized that the spectroscopic signature was that of our atmosphere being bombarded," says astronomer Remi Cabanac of the Catholic University of Santiago de Chile. "We asked around to see if others in our country had witnessed the meteor, but it seems we at the VLT were the only ones, perhaps not too surprising as Paranal is located in the middle of the empty desert." And unfortunately for the astronomers, the MASCOT all-sky camera (e.g. PR Photo 22a/04) was not yet in operation at that time. The VLT spectrograph provided a well calibrated spectrum of the meteor emission, making it a reference in this field of research. The meteor emission results from collisions between air molecules, knocked to high speeds after initial collision with the meteoroid. Closer inspection of the spectrum revealed about 20 telltale meteor emissions of oxygen and nitrogen atoms and nitrogen molecules (see PR Photo 22b/04 and 22c/04). The ratio of atomic and molecular emissions could be used as a "thermometer" to measure the conditions in the meteor-induced hot gas in the wake of the meteoroid, by means of laboratory measurements and meteor models that calibrate the VLT data. From here to infinity "To our surprise, we found the meteor trail to be wider than expected and also that the meteor's heat appeared evenly distributed in the trail, with the temperature varying only from about 4,570 to 4,650 degrees across the trail," says meteor specialist, astronomer Peter Jenniskens of the SETI Intitute, who analysed the data together with Christophe Laux of the Ecole Centrale Paris (France) and Iain Boyd of the University of Michigan at Ann Arbor (USA). "We later realised that this was due to the fact that, as seen by the VLT, the meteor trail was out of focus, even though it was 100 kilometres away!" The VLT is indeed focussed at infinity, which is perfect for most astronomical objects that it routinely observes. But not for meteoroids entering the atmosphere above Paranal. A point at 100 kilometres distance will appear as a small circle of diameter 15 arcsec at the VLT focal plane. This corresponds to roughly half of the maximum apparent diameter of Mars in the evening sky! It is the same effect as when you try to photograph your children with a forest in the background. If you focus your camera on the distant forest, then (in most cases) your children will be out of focus. Or to put this in another way, the VLT is clearly not very suited to observe ships passing by on the Pacific Ocean, just 12 km from Paranal! No Trace of Carbon The meteor spectrum also provided a first view of such an object in the near-infrared window between wavelengths 900 and 1050 nm. This spectral region contains relatively strong lines of atomic carbon, but no such emissions were detected. "We calculated that these lines should have been visible if all atmospheric carbon dioxide in the meteor path was dissociated into carbon and oxygen atoms," says Jenniskens, "but they were conspicuously absent". This observation is important because it sets new constraints on the efficiency of meteor-induced atmospheric chemistry at the time when life began on our planet. Appendix: Cosmic showers Meteoroids are small grains of rocks orbiting the Sun. Far smaller than asteroids, they make their presence known to us in a dramatic and beautiful way when they enter earth's atmosphere and burn up, producing a short glowing trail in the night sky, rarely lasting more than a second or two - a meteor. Most meteoroids are completely destroyed at altitudes between 80 and 110 km, but some of the bigger ones make it to the ground. Here they may be collected as meteorites. Many meteoroids originate as fragments of asteroids and appear to be unaltered since the formation of the Solar System, some 4500 million years ago. Based on the peculiar composition of some meteorites, we know that a small fraction of meteoroids originate from the Moon, Mars or the large asteroid Vesta. They obviously result from major impacts on these bodies which blasted rock fragments into space. These fragments then orbit the Sun and may eventually collide with the Earth. Comets are another important source of meteoroids and perhaps the most spectacular. After many visits near the Sun, a comet "dirty-snowball" nucleus of ice and dust decays and fragments, leaving a trail of meteoroids along its orbit. Some "meteoroid streams" cross the earth's orbit and when our planet passes through them, some of these particles will enter the atmosphere. The outcome is a meteor shower - the most famous being the "Perseids" in the month of August [2] and the "Leonids" in November. Thus, although meteors are referred to as "shooting" or "falling stars" in many languages, they are of a very different nature. More information The research presented in this paper is published in the journal Meteoritics and Planetary Science, Vol. 39, Nr. 4, p. 1, 2004 ("Spectroscopic anatomy of a meteor trail cross section with the ESO Very Large Telescope", by P. Jenniskens et al.). Notes [1] The team is composed of Peter Jenniskens (SETI Institute, USA), Emmanuël Jehin (ESO), Remi Cabanac (Pontificia Universidad Catolica de Chile), Christophe Laux (Ecole Centrale de Paris, France), and Iain Boyd (University of Michigan, USA). [2] The maximum of the Perseids is expected on August 12 after sunset and should be easily seen.

Exoplanets: The Hunt Continues!

NASA Astrophysics Data System (ADS)

2001-04-01

Swiss Telescope at La Silla Very Successful Summary The intensive and exciting hunt for planets around other stars ( "exoplanets" ) is continuing with great success in both hemispheres. Today, an international team of astronomers from the Geneva Observatory and other research institutes [1] is announcing the discovery of no less than eleven new, planetary companions to solar-type stars, HD 8574, HD 28185, HD 50554, HD 74156, HD 80606, HD 82943, HD 106252, HD 141937, HD 178911B, HD 141937, among which two new multi-planet systems . The masses of these new objects range from slightly less than to about 10 times the mass of the planet Jupiter [2]. The new detections are based on measured velocity changes of the stars [3], performed with the CORALIE spectrometer on the Swiss 1.2-m Leonard Euler telescope at the ESO La Silla Observatory , as well as with instruments on telescopes at the Haute-Provence Observatory and on the Keck telescopes on Mauna Kea (Hawaii, USA). Some of the new planets are unusual: * a two-planet system (around the star HD 82943) in which one orbital period is nearly exactly twice as long as the other - cases like this (refered to as "orbital resonance") are well known in our own solar system; * another two-planet system (HD 74156), with a Jupiter-like planet and a more massive planet further out; * a planet with the most elongated orbit detected so far (HD 80606), moving between 5 and 127 million kilometers from the central star; * a giant planet moving in an orbit around its Sun-like central star that is very similar to the one of the Earth and whose potential satellites (in theory, at least) might be "habitable". At this moment, there are 63 know exoplanet candidates with minimum masses below 10 Jupiter masses, and 67 known objects with minimum masses below 17 Jupiter masses. The present team of astronomers has detected about half of these. PR Photo 13a/01 : Radial-velocity measurements of HD 82943, a two-planet system . PR Photo 13b/01 : Radial-velocity measurements of HD 80606, a star with a planet in a very elongated orbit . A major international effort The discovery of eleven new exoplanets has resulted from three high-precision radial-velocity surveys now searching for such objects: * The CORALIE planet-search programme on La Silla [4], conducted by astronomers of the Geneva Observatory [1] * The ELODIE high-precision radial-velocity survey of solar-type stars at the Haute-Provence Observatory (OHP/France) conducted by a Swiss-French team, including the Geneva, Grenoble and Haute-Provence Observatories [1] * The G-dwarf project , an ELODIE-HIRES/Keck planet-search programme set up by a team of astronomers from the Geneva Observatory, the Center for Astrophysics (Cambridge, Mass., USA) and the Tel Aviv University (Israel) [1] The new results are the outcome of high-precision radial-velocity measurements . This fundamental observational method is based on the detection of changes in the velocity of the central star , due to the changing direction of the gravitational pull from an (unseen) exoplanet as it orbits the star. The evaluation of the measured velocity variations allows to deduce the planet's orbit , in particular the period and the distance from the star, as well as a minimum mass [3]. Four of the new planets were detected from La Silla and three ELODIE candidates were secured with CORALIE measurements. With the eleven new discoveries, the CORALIE/ELODIE programmes have contributed to the detection of about half (32) of the known (63) planetary candidates with minimum masses below 10 Jupiter masses, or 36 out of 67 known objects with minimum masses below 17 Jupiter masses [2]. Several unusual systems Among the present detections, there are two new planetary systems (HD 82943 and HD 74156), each with two planets. They bring to six the number of known multi-planet systems, four of which owe their detection to CORALIE/ELODIE measurements. This demonstrates the outstanding role that comparatively small telescopes can still play in modern astrophysics. Detailed information about all of the new planets are available on the dedicated web page at the Geneva Observatory web site: http://obswww.unige.ch/~udry/planet/new_planet.html. Of the systems discovered at La Silla, two are quite unusual: HD 82943: a "resonant" system ESO PR Photo 13a/01 ESO PR Photo 13a/01 [Preview - JPEG: 367 x 400 pix - 53k] [Normal - JPEG: 734 x 800 pix - 248k] Caption : PR Photo 13a/01 shows the radial-velocity measurements of the central star, 82493 , in a two-planet system, as observed with the CORALIE instrument at La Silla. The best-fit curve corresponds to expected variations, caused by the planets described in the text. The abscissa shows the date; the ordinate the velocity The detection of the outer planet that orbits the star HD 82943 was announced earlier ( ESO Press Release 13/00 ), together with seven CORALIE planet candidates at other stars. The follow-up observations at La Silla soon revealed a departure from the previously determined orbit. The accumulated measurements ( PR Photo 13a/01 ) now allow the detection of a second, inner planet in this system. Its orbital period (221 days) is about half of that of the outer one (444 days). Future observations should confirm the 1:2 ratio between the periods; this indicates a "resonance" that may result from the gravitational interaction between the two planets. Similar orbital resonances are known in the solar system, especially in case of the minor planets (asteroids). HD 28185: a giant planet in the "habitable" zone With the exception of the planet iota Hor b (cf. ESO PR 12/99 ), circular orbits among exoplanets have only been found for short-period systems, contrary to what is the case for the giant planets in our own Solar System. However, the orbit of the newly found planet near the sun-like star HD 28185 is very nearly circular and with a period of 385 days (close to 1 Earth year), its distance from the star, 150.6 million km, is almost equal to the distance betwen the Sun and the Earth (149.6 million km). This new planet is therefore located in the "habitable zone" where temperatures like those on the Earth are possible. Still, it is a giant, gaseous planet (with a minimum mass of 3.5 times that of Jupiter, or about 1000 times that of the Earth) and thus an unlikely place for the development of life. Nevertheless, it may be orbited by one or more moons on which a more bio-friendly environment has evolved. The presence of natural satellites ("moons") around giant extra-solar planets is not a far-fetched idea, just look at our own Solar System. HD 80606: a giant planet in an extremely elongated orbit ESO PR Photo 13b/01 ESO PR Photo 13b/01 [Preview - JPEG: 400 x 233 pix - 21k] [Normal - JPEG: 800 x 465 pix - 41k] Caption : PR Photo 13b/01 shows the radial-velocity measurements of the star HD 80606 that hosts a planet in a very eccentric orbit. A planet in an extremely elongated orbit around the star HD 80606 was found in the frame of the ELODIE/Keck collaboration. The measured, very large eccentricity (e = 0.93; PR Photo 13b/01 ) implies of factor of no less than 26 between the smallest and largest distance to the star. When the planet is closest to the star, it is only a few stellar radii away (about 5 million kilometres). Continuation of the programme Further progress within the current programme is expected soon, when the Very Large Telescope Interferometer (VLTI) at Paranal becomes available, cf. ESO PR 06/01. This new instrument will have the observational capability of very high-accuracy positional measurements (astrometry) and thus be able to detect even very small wobbles of stellar positions in the sky that are due to the pull of orbiting planets. This will provide a crucial contribution to the determination of the true repartition of exoplanetary masses, a hotly debated question. Important advancement in our understanding of the formation of planetary systems is also expected with the advent of HARPS. This new high-resolution spectrograph, capable of reaching the extremely high radial-velocity precision of 1 m/sec, will be installed on the ESO 3.6-m telescope at La Silla at the end of 2002. HARPS will extend the domain of planets accessible with the radial-velocity technique towards significantly lower masses - down to about ten Earth masses on short-period orbits . It will also greatly improve our capability of detecting planets with longer periods and multi-planet systems. More information More information on these discoveries may be found in a Press Release from the Tel Aviv University and on the Geneva planet-search web page. Notes [1] The team consists of: Geneva Observatory (Switzerland): Michel Mayor, Dominique Naef, Francesco Pepe, Didier Queloz, Nuno C. Santos, Stephane Udry, Michel Burnet Grenoble Observatory (France): Christian Perrier, Jean-Luc Beuzit Haute-Provence Observatory (France): Jean-Pierre Sivan Center for Astrophysics (Cambridge, Mass., USA): David Latham, Guillermo Torres Tel Aviv University (Israel): Tsevi Mazeh, Shay Zucker, G. Drukier [2] The mass units for the exoplanets used in this text are 1 Jupiter mass = 318 Earth masses. [3] A fundamental limitation of the radial-velocity method, currently used by all planet-hunting research teams, is that because of the uncertainty of the inclination of the planetary orbit, it only allows to determine a lower mass limit for the planet. However, statistical considerations indicate that in most cases, the true mass will not be much higher than this value. [4] Earlier accounts of this research programme have been published as ESO Press Release 18/98 and ESO Press Release 13/00. Views of the 1.2-m Leonard Euler telescope and its dome at La Silla are available as PR Photos 13a-c/00.

The Capodimonte Deep Field

NASA Astrophysics Data System (ADS)

2001-04-01

A Window towards the Distant Universe Summary The Osservatorio Astronomico Capodimonte Deep Field (OACDF) is a multi-colour imaging survey project that is opening a new window towards the distant universe. It is conducted with the ESO Wide Field Imager (WFI) , a 67-million pixel advanced camera attached to the MPG/ESO 2.2-m telescope at the La Silla Observatory (Chile). As a pilot project at the Osservatorio Astronomico di Capodimonte (OAC) [1], the OACDF aims at providing a large photometric database for deep extragalactic studies, with important by-products for galactic and planetary research. Moreover, it also serves to gather experience in the proper and efficient handling of very large data sets, preparing for the arrival of the VLT Survey Telescope (VST) with the 1 x 1 degree 2 OmegaCam facility. PR Photo 15a/01 : Colour composite of the OACDF2 field . PR Photo 15b/01 : Interacting galaxies in the OACDF2 field. PR Photo 15c/01 : Spiral galaxy and nebulous object in the OACDF2 field. PR Photo 15d/01 : A galaxy cluster in the OACDF2 field. PR Photo 15e/01 : Another galaxy cluster in the OACDF2 field. PR Photo 15f/01 : An elliptical galaxy in the OACDF2 field. The Capodimonte Deep Field ESO PR Photo 15a/01 ESO PR Photo 15a/01 [Preview - JPEG: 400 x 426 pix - 73k] [Normal - JPEG: 800 x 851 pix - 736k] [Hi-Res - JPEG: 3000 x 3190 pix - 7.3M] Caption : This three-colour image of about 1/4 of the Capodimonte Deep Field (OACDF) was obtained with the Wide-Field Imager (WFI) on the MPG/ESO 2.2-m telescope at the la Silla Observatory. It covers "OACDF Subfield no. 2 (OACDF2)" with an area of about 35 x 32 arcmin 2 (about the size of the full moon), and it is one of the "deepest" wide-field images ever obtained. Technical information about this photo is available below. With the comparatively few large telescopes available in the world, it is not possible to study the Universe to its outmost limits in all directions. Instead, astronomers try to obtain the most detailed information possible in selected viewing directions, assuming that what they find there is representative for the Universe as a whole. This is the philosophy behind the so-called "deep-field" projects that subject small areas of the sky to intensive observations with different telescopes and methods. The astronomers determine the properties of the objects seen, as well as their distances and are then able to obtain a map of the space within the corresponding cone-of-view (the "pencil beam"). Recent, successful examples of this technique are the "Hubble Deep Field" (cf. ESO PR Photo 26/98 ) and the "Chandra Deep Field" ( ESO PR 05/01 ). In this context, the Capodimonte Deep Field (OACDF) is a pilot research project, now underway at the Osservatorio Astronomico di Capodimonte (OAC) in Napoli (Italy). It is a multi-colour imaging survey performed with the Wide Field Imager (WFI) , a 67-million pixel (8k x 8k) digital camera that is installed at the 2.2-m MPG/ESO Telescope at ESO's La Silla Observatory in Chile. The scientific goal of the OACDF is to provide an important database for subsequent extragalactic, galactic and planetary studies. It will allow the astronomers at OAC - who are involved in the VLT Survey Telescope (VST) project - to gain insight into the processing (and use) of the large data flow from a camera similar to, but four times smaller than the OmegaCam wide-field camera that will be installed at the VST. The field selection for the OACDF was based on the following criteria: * There must be no stars brighter than about 9th magnitude in the field, in order to avoid saturation of the CCD detector and effects from straylight in the telescope and camera. No Solar System planets should be near the field during the observations; * It must be located far from the Milky Way plane (at high galactic latitude) in order to reduce the number of galactic stars seen in this direction; * It must be located in the southern sky in order to optimize observing conditions (in particular, the altitude of the field above the horizon), as seen from the La Silla and Paranal sites; * There should be little interstellar material in this direction that may obscure the view towards the distant Universe; * Observations in this field should have been made with the Hubble Space Telescope (HST) that may serve for comparison and calibration purposes. Based on these criteria, the astronomers selected a field measuring about 1 x 1 deg 2 in the southern constellation of Corvus (The Raven). This is now known as the Capodimonte Deep Field (OACDF) . The above photo ( PR Photo 15a/01 ) covers one-quarter of the full field (Subfield No. 2 - OACDF2) - some of the objects seen in this area are shown below in more detail. More than 35,000 objects have been found in this area; the faintest are nearly 100 million fainter than what can be perceived with the unaided eye in the dark sky. Selected objects in the Capodimonte Deep Field ESO PR Photo 15b/01 ESO PR Photo 15b/01 [Preview - JPEG: 400 x 435 pix - 60k] [Normal - JPEG: 800 x 870 pix - 738k] [Hi-Res - JPEG: 3000 x 3261 pix - 5.1M] Caption : Enlargement of the interacting galaxies that are seen in the upper left corner of the OACDF2 field shown in PR Photo 15a/01 . The enlargement covers 1250 x 1130 WFI pixels (1 pixel = 0.24 arcsec), or about 5.0 x 4.5 arcmin 2 in the sky. The lower spiral is itself an interactive double. ESO PR Photo 15c/01 ESO PR Photo 15c/01 [Preview - JPEG: 557 x 400 pix - 93k] [Normal - JPEG: 1113 x 800 pix - 937k] [Hi-Res - JPEG: 3000 x 2156 pix - 4.0M] Caption : Enlargement of a spiral galaxy and a nebulous object in this area. The field shown covers 1250 x 750 pixels, or about 5 x 3 arcmin 2 in the sky. Note the very red objects next to the two bright stars in the lower-right corner. The colours of these objects are consistent with those of spheroidal galaxies at intermediate distances (redshifts). ESO PR Photo 15d/01 ESO PR Photo 15d/01 [Preview - JPEG: 400 x 530 pix - 68k] [Normal - JPEG: 800 x 1060 pix - 870k] [Hi-Res - JPEG: 2768 x 3668 pix - 6.2M] Caption : A further enlargement of a galaxy cluster of which most members are located in the north-east quadrant (upper left) and have a reddish colour. The nebulous object to the upper left is a dwarf galaxy of spheroidal shape. The red object, located near the centre of the field and resembling a double star, is very likely a gravitational lens [2]. Some of the very red, point-like objects in the field may be distant quasars, very-low mass stars or, possibly, relatively nearby brown dwarf stars. The field shown covers 1380 x 1630 pixels, or 5.5 x 6.5 arcmin 2. ESO PR Photo 15e/01 ESO PR Photo 15e/01 [Preview - JPEG: 400 x 418 pix - 56k] [Normal - JPEG: 800 x 835 pix - 700k] [Hi-Res - JPEG: 3000 x 3131 pix - 5.0M] Caption : Enlargement of a moderately distant galaxy cluster in the south-east quadrant (lower left) of the OACDF2 field. The field measures 1380 x 1260 pixels, or about 5.5 x 5.0 arcmin 2 in the sky. ESO PR Photo 15f/01 ESO PR Photo 15f/01 [Preview - JPEG: 449 x 400 pix - 68k] [Normal - JPEG: 897 x 800 pix - 799k] [Hi-Res - JPEG: 3000 x 2675 pix - 5.6M] Caption : Enlargement of the elliptical galaxy that is located to the west (right) in the OACDF2 field. The numerous tiny objects surrounding the galaxy may be globular clusters. The fuzzy object on the right edge of the field may be a dwarf spheroidal galaxy. The size of the field is about 6 x 5 arcmin 2. Technical Information about the OACDF Survey The observations for the OACDF project were performed in three different ESO periods (18-22 April 1999, 7-12 March 2000 and 26-30 April 2000). Some 100 Gbyte of raw data were collected during each of the three observing runs. The first OACDF run was done just after the commissioning of the ESO-WFI. The observational strategy was to perform a 1 x 1 deg 2 short-exposure ("shallow") survey and then a 0.5 x 1 deg 2 "deep" survey. The shallow survey was performed in the B, V, R and I broad-band filters. Four adjacent 30 x 30 arcmin 2 fields, together covering a 1 x 1 deg 2 field in the sky, were observed for the shallow survey. Two of these fields were chosen for the 0.5 x 1 deg 2 deep survey; OACDF2 shown above is one of these. The deep survey was performed in the B, V, R broad-bands and in other intermediate-band filters. The OACDF data are fully reduced and the catalogue extraction has started. A two-processor (500 Mhz each) DS20 machine with 100 Gbyte of hard disk, specifically acquired at the OAC for WFI data reduction, was used. The detailed guidelines of the data reduction, as well as the catalogue extraction, are reported in a research paper that will appear in the European research journal Astronomy & Astrophysics . Notes [1]: The team members are: Massimo Capaccioli, Juan M. Alcala', Roberto Silvotti, Magda Arnaboldi, Vincenzo Ripepi, Emanuella Puddu, Massimo Dall'Ora, Giuseppe Longo and Roberto Scaramella . [2]: This is a preliminary result by Juan Alcala', Massimo Capaccioli, Giuseppe Longo, Mikhail Sazhin, Roberto Silvotti and Vincenzo Testa , based on recent observations with the Telescopio Nazionale Galileo (TNG) which show that the spectra of the two objects are identical. Technical information about the photos PR Photo 15a/01 has been obtained by the combination of the B, V, and R stacked images of the OACDF2 field. The total exposure times in the three bands are 2 hours in B and V (12 ditherings of 10 min each were stacked to produce the B and V images) and 3 hours in R (13 ditherings of 15 min each). The mosaic images in the B and V bands were aligned relative to the R-band image and adjusted to a logarithmic intensity scale prior to the combination. The typical seeing was of the order of 1 arcsec in each of the three bands. Preliminary estimates of the three-sigma limiting magnitudes in B, V and R indicate 25.5, 25.0 and 25.0, respectively. More than 35,000 objects are detected above the three-sigma level. PR Photos 15b-f/01 display selected areas of the field shown in PR Photo 15a/01 at the original WFI scale, hereby also demonstrating the enormous amount of information contained in these wide-field images. In all photos, North is up and East is left.

NY-ESO-1 Protein Cancer Vaccine With Poly-ICLC and OK-432: Rapid and Strong Induction of NY-ESO-1-specific Immune Responses by Poly-ICLC.

PubMed

Takeoka, Tomohira; Nagase, Hirotsugu; Kurose, Koji; Ohue, Yoshihiro; Yamasaki, Makoto; Takiguchi, Shuji; Sato, Eiichi; Isobe, Midori; Kanazawa, Takayuki; Matsumoto, Mitsunobu; Iwahori, Kota; Kawashima, Atsunari; Morimoto-Okazawa, Akiko; Nishikawa, Hiroyoshi; Oka, Mikio; Pan, Linda; Venhaus, Ralph; Nakayama, Eiichi; Mori, Masaki; Doki, Yuichiro; Wada, Hisashi

2017-03-23

We conducted a clinical trial of a cancer vaccine using NY-ESO-1 protein with polyinosinic-polycytidylic acid-poly-L-lysine carboxymethylcellulose (poly-ICLC) and/or OK-432 against solid tumors. A total of 15 patients were sequentially enrolled in 4 cohorts. Patients in cohort 1 received NY-ESO-1 protein; cohort 2a received NY-ESO-1 protein+OK-432; cohort 2b received NY-ESO-1 protein+poly-ICLC; cohort 3 received NY-ESO-1 protein+OK-432+poly-ICLC with Montanide ISA-51. The endpoints of this trial were safety, NY-ESO-1 immune responses, and clinical response. Vaccine-related adverse events observed were fever and injection-site reaction (grade 1). Two patients showed stable disease after vaccination. NY-ESO-1 antibodies were observed in 4 patients at the baseline (sero-positive) and augmented in all patients after vaccination. Eleven patients showed a conversion of negative antibody responses at baseline to positive after vaccination (seroconversion). The seroconversions were observed in all 11 sero-negative patients by the fourth immunization; in particular, it was observed by the second immunization in patients with poly-ICLC, and these induced antibody responses were stronger than those in patients immunized without poly-ICLC. The number of NY-ESO-1-specific interferon (IFN)γ-producing T cells was increased in patients immunized with poly-ICLC and/or OK-432, and furthermore, the increase of IFNγ-producing CD8 T cells in patients immunized with poly-ICLC was significantly higher than that in patients without poly-ICLC. Nonspecific activations of T-cell or antigen presenting cells were not observed. Our present study showed that poly-ICLC is a promising adjuvant for cancer vaccines.

Pricing Employee Stock Options (ESOs) with Random Lattice

NASA Astrophysics Data System (ADS)

Chendra, E.; Chin, L.; Sukmana, A.

2018-04-01

Employee Stock Options (ESOs) are stock options granted by companies to their employees. Unlike standard options that can be traded by typical institutional or individual investors, employees cannot sell or transfer their ESOs to other investors. The sale restrictions may induce the ESO’s holder to exercise them earlier. In much cited paper, Hull and White propose a binomial lattice in valuing ESOs which assumes that employees will exercise voluntarily their ESOs if the stock price reaches a horizontal psychological barrier. Due to nonlinearity errors, the numerical pricing results oscillate significantly so they may lead to large pricing errors. In this paper, we use the random lattice method to price the Hull-White ESOs model. This method can reduce the nonlinearity error by aligning a layer of nodes of the random lattice with a psychological barrier.

The Gaia-ESO Survey: Probes of the inner disk abundance gradient

NASA Astrophysics Data System (ADS)

Jacobson, H. R.; Friel, E. D.; Jílková, L.; Magrini, L.; Bragaglia, A.; Vallenari, A.; Tosi, M.; Randich, S.; Donati, P.; Cantat-Gaudin, T.; Sordo, R.; Smiljanic, R.; Overbeek, J. C.; Carraro, G.; Tautvaišienė, G.; San Roman, I.; Villanova, S.; Geisler, D.; Muñoz, C.; Jiménez-Esteban, F.; Tang, B.; Gilmore, G.; Alfaro, E. J.; Bensby, T.; Flaccomio, E.; Koposov, S. E.; Korn, A. J.; Pancino, E.; Recio-Blanco, A.; Casey, A. R.; Costado, M. T.; Franciosini, E.; Heiter, U.; Hill, V.; Hourihane, A.; Lardo, C.; de Laverny, P.; Lewis, J.; Monaco, L.; Morbidelli, L.; Sacco, G. G.; Sousa, S. G.; Worley, C. C.; Zaggia, S.

2016-06-01

Context. The nature of the metallicity gradient inside the solar circle (RGC < 8 kpc) is poorly understood, but studies of Cepheids and a small sample of open clusters suggest that it steepens in the inner disk. Aims: We investigate the metallicity gradient of the inner disk using a sample of inner disk open clusters that is three times larger than has previously been studied in the literature to better characterize the gradient in this part of the disk. Methods: We used the Gaia-ESO Survey (GES) [Fe/H] values and stellar parameters for stars in 12 open clusters in the inner disk from GES-UVES data. Cluster mean [Fe/H] values were determined based on a membership analysis for each cluster. Where necessary, distances and ages to clusters were determined via comparison to theoretical isochrones. Results: The GES open clusters exhibit a radial metallicity gradient of -0.10 ± 0.02 dex kpc-1, consistent with the gradient measured by other literature studies of field red giant stars and open clusters in the range RGC ~ 6-12 kpc. We also measure a trend of increasing [Fe/H] with increasing cluster age, as has also been found in the literature. Conclusions: We find no evidence for a steepening of the inner disk metallicity gradient inside the solar circle as earlier studies indicated. The age-metallicity relation shown by the clusters is consistent with that predicted by chemical evolution models that include the effects of radial migration, but a more detailed comparison between cluster observations and models would be premature. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 188.B-3002 and 193.B-0936. These data products have been processed by the Cambridge Astronomy Survey Unit (CASU) at the Institute of Astronomy, University of Cambridge, and by the FLAMES/UVES reduction team at INAF/Osservatorio Astrofisico di Arcetri. These data have been obtained from the Gaia-ESO Survey Data Archive, prepared and hosted by the Wide Field Astronomy Unit, Institute for Astronomy, University of Edinburgh, which is funded by the UK Science and Technology Facilities Council.Full Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/591/A37

REOSC Delivers the Best Astronomical Mirror in the World to ESO

NASA Astrophysics Data System (ADS)

1999-12-01

On December 14, 1999, REOSC , the Optical Department of the SAGEM Group , finished the polishing of the fourth 8.2-m main mirror for the Very Large Telescope (VLT) of the European Southern Observatory. The mirror was today delivered to ESO at a ceremony at the REOSC factory in Saint Pierre du Perray, just south of Paris. The precision of the form of the mirror that was achieved during the polishing process is 8.5 nanometer (1 nanometer = 1 millionth of a millimetre) over the optical surface. This exceptional value corresponds to an optical resolution (theoretical image sharpness) of 0.03 arcseconds in the visible spectrum. This corresponds to distinguishing two objects separated by only 15 cm at a distance of 1000 km and will allow to detect astronomical objects that are 10,000 million times fainter than what can be perceived with the unaided eye. This impressive measure of quality, achieved by the REOSC teams during much painstaking work, implies that this VLT mirror is the most accurate in the world. In fact, all four 8.2-m VLT main mirrors polished by REOSC are well within the very strict specifications set by ESO, but this is the best of them all. The celebration today is the successful highlight of a contract initiated more than ten years ago, during which REOSC has perfected new polishing and control techniques - innovations improved and developed in a unique workshop dedicated to these giant mirrors. These methods and means are directly applicable to the new generations of segmented mirrors that are now being developed for astronomy and space observations. They are, in this sense, at the foremost front of optical technology. REOSC, the Optical Department of the SAGEM Group , is specialised in the study and realisation of high-precision optics for astronomy, space, defence, science and industry. For earlier information about the work on the VLT mirrors, cf. ESO Press Release 15/95 (13 November 1995). The SAGEM Group is a French high-technology group. It employs about 15,500 people - more information is available at URL: www.sagem.com. Information about the ESO and the VLT project is available via the ESO website: www.eso.org. Some Key Dates The polishing at REOSC of the main mirrors for the four VLT Unit Telescopes has been a major industrial feat. Here are some of the main dates: July 1989 ESO and REOSC sign contract for the polishing of the four 8.2-m and various associated activities July 1989 - April 1992 Design activities, construction of REOSC production plant April 1992 Mirror Container and concrete dummy mirror blank completed - test transport May 1992 Inauguration of REOSC production plant July 1993 Delivery of first 8.2-m mirror blank to ESO at Schott Glaswerke AG (Mainz, Germany) October 1994 Delivery of second 8.2-m mirror blank to ESO at Schott Glaswerke AG September 1995 Delivery of third 8.2-m mirror blank to ESO at Schott Glaswerke AG May 1996 Acceptance by ESO of first polished mirror at REOSC September 1996 Delivery of fourth 8.2-m mirror blank to ESO at Schott Glaswerke AG October 1996 Acceptance by ESO of second polished mirror at REOSC June 1997 Acceptance by ESO of third polished mirror at REOSC October - December 1997 Transport and delivery of first mirror to Paranal by Gondrand (France) August - September 1998 Transport and delivery of second mirror to Paranal by Gondrand December 1998 - January 1999 Transport and delivery of third mirror to Paranal by Gondrand December 1999 Acceptance by ESO of fourth polished mirror at REOSC February 1999 - April 2000 Transport and delivery of fourth mirror to Paranal by Gondrand Note [1] A Press Release on the REOSC event and the delivery of the fourth VLT main mirror to ESO is also published by SAGEM (in French and English). How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../ ). ESO PR Photo 44/99 may be reproduced, if credit is given to SAGEM and the European Southern Observatory.

Ground-based detection of the near-infrared emission from the dayside of WASP-5b

NASA Astrophysics Data System (ADS)

Chen, G.; van Boekel, R.; Madhusudhan, N.; Wang, H.; Nikolov, N.; Seemann, U.; Henning, Th.

2014-04-01

Context. Observations of secondary eclipses of hot Jupiters allow one to measure the dayside thermal emission from the planets' atmospheres. The combination of ground-based near-infrared observations and space-based observations at longer wavelengths constrains the atmospheric temperature structure and chemical composition. Aims: This work aims at detecting the thermal emission of WASP-5b, a highly irradiated dense hot Jupiter orbiting a G4V star every 1.6 days, in the J, H and K near-infrared photometric bands. The spectral energy distribution is used to constrain the temperature-pressure profile and to study the energy budget of WASP-5b. Methods: We observed two secondary-eclipse events of WASP-5b in the J, H, K bands simultaneously using the GROND instrument on the MPG/ESO 2.2 m telescope. The telescope was in nodding mode for the first observation and in staring mode for the second observation. The occultation light curves were modeled to obtain the flux ratios in each band, which were then compared with atmospheric models. Results: Thermal emission of WASP-5b is detected in the J and K bands in staring mode. The retrieved planet-to-star flux ratios are 0.168-0.052+0.050% in the J band and 0.269 ± 0.062% in the K band, corresponding to brightness temperatures of 2996-261+212 K and 2890-269+246 K, respectively. No thermal emission is detected in the H band, with a 3σ upper limit of 0.166% on the planet-to-star flux ratio, corresponding to a maximum temperature of 2779 K. On the whole, our J, H, K results can be explained by a roughly isothermal temperature profile of ~2700 K in the deep layers of the planetary dayside atmosphere that are probed at these wavelengths. Together with Spitzer observations, which probe higher layers that are found to be at ~1900 K, a temperature inversion is ruled out in the range of pressures probed by the combined data set. While an oxygen-rich model is unable to explain all the data, a carbon-rich model provides a reasonable fit but violates energy balance. The nodding-mode observation was not used for the analysis because of unremovable systematics. Our experience reconfirms that of previous authors: staring-mode observations are better suited for exoplanet observations than nodding-mode observations. Based on observations collected with the Gamma Ray Burst Optical and Near-Infrared Detector (GROND) at the MPG/ESO 2.2-m telescope at La Silla Observatory, Chile. Programme 087.A-9006 (PI: Chen).Photometric time series are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/564/A6Appendix A is available in electronic form at http://www.aanda.org

Lyα emitters in the GOODS-S field. A powerful pure nebular SED with N IV] emission at z = 5.563

NASA Astrophysics Data System (ADS)

Raiter, A.; Fosbury, R. A. E.; Teimoorinia, H.

2010-02-01

Context. The Great Observatories Origins Deep Survey (GOODS) has provided us with one of the deepest multi-wavelength views of the distant universe. The combination of multi-band photometry and optical spectroscopy has resulted in the identification of sources whose redshifts extend to values in excess of six. Amongst these distant sources are Lyα emitters whose nature must be deduced by clearly identifying the different components that contribute to the measured SED. Aims: From a sample of Lyα emitters in the GOODS-S field with uncontaminated photometry and optical (red) spectroscopy, we select a spatially compact object at a redshift of 5.563 (Lyα) that shows a second emission line, identified as N IV] 1486 Å. The SED is modelled in a way that accounts for both the N IV] line emission and the photometry in a self-consistent way. Methods: The photoionization code CLOUDY is used to calculate a range of nebular models as a function of stellar ionizing source temperature, ionization parameter, density and nebular metallicity. We compare the theoretical and observed magnitudes and search for the model parameters that also reproduce the observed N IV] luminosity and equivalent width. Results: A nebular model with a hot blackbody ionizing source of around 100 kK and a nebular metallicity of ~5% of solar is able to fit the observed SED and, in particular, explain the large apparent Balmer break which is inferred from the pure stellar population model fitting conventionally applied to multi-band photometric observations. In our model, an apparent spectral break is produced by strong [O III] 4959, 5007 Å emission falling in one of the IR bands (IRAC1 in this case). A lower limit on the total baryonic mass of a model of this type is 3.2 ×10^8~M⊙. Conclusions: It is argued that objects with Lyα emission at high redshift that show an apparent Balmer break may have their SED dominated by nebular emission and so could possibly be identified with very young starbursting galaxies rather than massive evolved stellar populations. Detailed studies of these emission nebulæ with large telescopes will provide a unique insight into very early chemical evolution. Based on observations made at the European Southern Observatory, Paranal, Chile (ESO programme 170.A-0788) The Great Observatories Origins Deep Survey: ESO Public Observations of the SIRTF Legacy/HST Treasury/Chandra Deep Field South.); on observations obtained with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc.; and on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.

Antitumor Activity Associated with Prolonged Persistence of Adoptively Transferred NY-ESO-1c259T cells in Synovial Sarcoma.

PubMed

D'Angelo, Sandra P; Melchiori, Luca; Merchant, Melinda S; Bernstein, Donna B; Glod, John; Kaplan, Rosandra N; Grupp, Stephan A; Tap, William D; Chagin, Karen; Binder, Gwendolyn K; Basu, Samik; Lowther, Daniel E; Wang, Ruoxi; Bath, Natalie; Tipping, Alex; Betts, Gareth; Ramachandran, Indu; Navenot, Jean-Marc; Zhang, Hua; Wells, Daniel K; Van Winkle, Erin; Kari, Gabor; Trivedi, Trupti; Holdich, Tom; Pandite, Lini N; Amado, Rafael; Mackall, Crystal L

2018-06-11

We evaluated safety and activity of autologous T cells expressing NY-ESO-1c259, an affinity-enhanced T cell receptor (TCR) recognizing an HLA-A2-restricted NY-ESO-1/LAGE-1a-derived peptide, in patients with metastatic synovial sarcoma (NY-ESO-1c259T cells). Confirmed antitumor responses occurred in 50% of patients (6/12) and were characterized by tumor shrinkage over several months. Circulating NY-ESO-1c259T cells were present post-infusion in all patients and persisted for at least 6 months in all responders. Most infused NY-ESO-1c259T cells exhibited an effector memory phenotype following the ex vivo expansion, but the persisting pools comprised largely central memory and stem cell memory subsets, which remained polyfunctional and showed no evidence for T cell exhaustion despite persistent tumor burdens. Next generation sequencing of endogenous TCRs in CD8+ NY-ESO-1c259T cells revealed clonal diversity without contraction over time. These data suggest that regenerative pools of NY-ESO-1c259T cells produced a continuing supply of effector cells to mediate sustained, clinically meaningful antitumor effects. Copyright ©2018, American Association for Cancer Research.

Audiology in Latin America: hearing impairment, resources and services.

PubMed

Madriz, J J

2001-01-01

Evidence is presented about the limitation of information available on prevalence/incidence of deafness and hearing impairment in the developing world; particularly in Latin America. Two questionnaires on audiological resources and services were mailed to Latin American and Caribbean countries in general and to Central American nations in particular. The information returned by Argentina, Chile, Colombia, Costa Rica, Cuba, Belize, El Salvador, Grenada, Guatemala, Honduras, Mexico, Nicaragua, Panama, Puerto Rico and Uruguay was analysed. Data was gathered about epidemiological studies on hearing impairment, about specific programmes, such as early identification of hearing impairment, national registers on deafness and programmes on hearing screening. Training programmes and availability of professionals in the field of hearing and deafness is also shown. Hearing services, hearing aids provision, hearing testing equipment, professional organization and legislation in audiology is also documented. It is our conclusion that hearing impairment is a low priority for health systems in the developing world, technology continues to be excessively costly and material and human resources are limited, and services are poor and restricted.

Centrosymmetric molecules as possible carriers of diffuse interstellar bands

NASA Astrophysics Data System (ADS)

Kaźmierczak, M.; Schmidt, M. R.; Galazutdinov, G. A.; Musaev, F. A.; Betelesky, Y.; Krełowski, J.

2010-11-01

In this paper, we present new data with interstellar C2 (Phillips bands A 1 Πu-X1 Σ+g), from observations made with the Ultraviolet-Visual Echelle Spectrograph of the European Southern Observatory. We have determined the interstellar column densities and excitation temperatures of C2 for nine Galactic lines. For seven of these, C2 has never been observed before, so in this case the still small sample of interstellar clouds (26 lines of sight), where a detailed analysis of C2 excitation has been made, has increased significantly. This paper is a continuation of previous works where interstellar molecules (C2 and diffuse interstellar bands) have been analysed. Because the sample of interstellar clouds with C2 has increased, we can show that the width and shape of the profiles of some diffuse interstellar bands (6196 and 5797 Å) apparently depend on the gas kinetic and rotational temperatures of C2; the profiles are broader because of the higher values of the gas kinetic and rotational temperatures of C2. There are also diffuse interstellar bands (4964 and 5850 Å) for which this effect does not exist. Based on observations made with ESO telescopes at the Paranal Observatory under programme IDs 266.D-5655(A), 67.C-0281(A), 71.C-0513(C), 67.D-0439(A) and 082.C-0566(A) and at La Silla under programme IDs 078.C-0403(A), 076.C-0164(A) and 073.C-0337(A). Also based on observations made with the 1.8-m telescope in South Korea and the 2-m telescope at the International Centre for Astronomical and Medico-Ecological Research, Terskol, Russia. E-mail: kazmierczak@astri.uni.torun.pl (MK); schmidt@ncac.torun.pl (MRS); runizag@gmail.com (GAG); ybialets@eso.org (YB); jacek@astri.uni.torun.pl (JK)

The La Silla-QUEST Kuiper Belt Survey

NASA Astrophysics Data System (ADS)

Rabinowitz, David; Schwamb, Megan E.; Hadjiyska, Elena; Tourtellotte, Suzanne

2012-11-01

We describe the instrumentation and detection software and characterize the detection efficiency of an automated, all-sky, southern-hemisphere search for Kuiper Belt Objects (KBOs) brighter than R mag 21.4. The search relies on Yale University's 160 Megapixel QUEST camera, previously used for the successful surveys at Palomar that detected most of the distant dwarf planets, and now installed on the ESO 1.0 m Schmidt telescope at La Silla, Chile. Extensive upgrades were made to the telescope control system to support automation, and significant improvements were made to the camera. To date, 63 new KBOs have been discovered, including a new member of the Haumea collision family (2009 YE7) and a new distant object with an inclination exceeding 70° (2010 WG9). In a survey covering ~7500 deg2, we have thus far detected 77 KBOs and Centaurs, more than any other full-hemisphere search to date. Using a pattern of dithered pointings, we demonstrate a search efficiency exceeding 80%. We are currently on track to complete the southern-sky survey and detect any bright KBOs that have eluded detection from the north.

Search for spectroscopical signatures of transiting HD 209458b's exosphere

NASA Astrophysics Data System (ADS)

Moutou, C.; Coustenis, A.; Schneider, J.; St Gilles, R.; Mayor, M.; Queloz, D.; Kaufer, A.

2001-05-01

Following recent attempts to detect the exosphere of the extra-solar planet 51 Pegb in the infrared (Coustenis et al. \\cite{cou97}, \\cite{cou98}; Rauer et al. \\cite{rau00a}), we discuss here a search for optical spectroscopic signatures from a gaseous extended envelope (called exosphere) surrounding the planet HD 209458b. This planet has a demonstrated photometric transit (Charbonneau et al. \\cite{cha00a}; Henry et al. \\cite{hen00}), thus offering an increased probability for the spectroscopic detection of such an envelope. Therefore it is the best known candidate for probing the exospheric composition of a giant planet, orbiting a Sun-like star at a short distance. The observations were performed with UVES at the VLT and cover most of the 328-669 nm range. We did not detect HD 209458b's exosphere at a level of 1%, a value close to the predictions. We discuss here the first results obtained and their limitations, as well as future prospective. Based on public data from the UVES Commissioning at the ESO 8.2~m Kueyen telescope operated on Paranal Observatory, Chile.

Cost-effectiveness models for dental caries prevention programmes among Chilean schoolchildren.

PubMed

Mariño, R; Fajardo, J; Morgan, M

2012-12-01

This study aims to estimate the cost-effectiveness from a societal perspective of seven dental caries prevention programmes among schoolchildren in Chile: three community-based programmes: water-fluoridation, salt-fluoridation and dental sealants; and four school-based programmes: milk-fluoridation; fluoridated mouthrinses (FMR); APF-Gel, and supervised toothbrushing with fluoride toothpaste. Standard cost-effectiveness analysis methods were used. The costs associated with implementing and operating each programme, using a societal perspective, were identified and estimated. The comparator was non-intervention. Health outcomes were measured as dental caries averted over a 6-year period. Costs were estimated as direct treatment costs, programmes costs and costs of productivity losses as a result of each dental caries prevention programme. Incremental cost-effectiveness ratios were calculated for each programme. Sensitivity analyses were conducted over key parameters. Primary cost-effectiveness analysis (discounted) indicated that four programmes showed net social savings by the DMFT averted. These savings encompassed a range of values per diseased tooth averted; US$16.21 (salt-fluoridation), US$14.89 (community water fluoridation); US$14.78 (milk fluoridation); and US$8.63 (FMR). Individual programmes using an APF-Gel application, dental sealants, and supervised tooth brushing using fluoridated toothpaste, represent costs for the society per diseased tooth averted of US$21.30, US$11.56 and US$8.55, respectively. Based on cost required to prevent one carious tooth among schoolchildren, salt fluoridation was the most cost-effective, with APF-Gel ranking as least cost-effective. Findings confirm that most community/school-based dental caries interventions are cost-effective uses of society's financial resources. The models used are conservative and likely to underestimate the real benefits of each intervention.

United Kingdom to Join ESO on July 1, 2002

NASA Astrophysics Data System (ADS)

2001-12-01

ESO and PPARC Councils Endorse Terms of Accession [1] The Councils of the European Southern Observatory (ESO) and the UK Particle Physics and Astronomy Research Council (PPARC) , at their respective meetings on December 3 and 5, 2001, have endorsed the terms for UK membership of ESO, as recently agreed by their Negotiating Teams. All members of the Councils - the governing bodies of the two organisations - welcomed the positive spirit in which the extensive negotiations had been conducted and expressed great satisfaction at the successful outcome of a complex process. The formal procedure of accession will now commence in the UK and is expected to be achieved in good time to allow accession from July 2002. The European Southern Observatory is the main European organisation for astronomy and the United Kingdom will become its tenth member state [2]. ESO operates two major observatories in the Chilean Atacama desert where the conditions for astronomical observations are second-to-none on earth and it has recently put into operation the world's foremost optical/infrared telescope, the Very Large Telescope (VLT) at Paranal. With UK membership, British astronomers will join their European colleagues in preparing new projects now being planned on a global scale. They will also be able to pursue their research on some of the most powerful astronomical instruments available. The ESO Director General, Dr. Catherine Cesarsky , is "delighted that we have come this far after the lengthy negotiations needed to prepare properly the admission of another major European country to our organisation. When ESO was created nearly 40 years ago, the UK was planning for its own facilities in the southern hemisphere, in collaboration with Australia, and decided not to join. However, the impressive scientific and technological advances since then and ESOs emergence as a prime player on the European research scene have convinced our UK colleagues of the great advantages of presenting a united European face in astronomy through ESO". The President of the ESO Council, Dr. Arno Freytag , shares this opinion fully. "This is a most important step in the continuing process of European integration. The entry of the UK will of course be very useful to the scientists in that country, but I have no doubt that the benefits will be mutual. With its world-level astronomical and engineering expertise and with one of the most active research communities in Europe, the UK will bring significant intellectual, technical and financial resources to strengthen ESO. I have no doubt that the impressive research that is now being carried out by numerous astronomers with the ESO facilities has been our best advertisement and I am sure that this has had an important effect on the very welcome decision by the UK to join ESO." The UK will pay the usual annual contribution to ESO from the date of its entry. It has also been decided that as an important part of the special contribution to be made on entry, the UK will deliver the VISTA infrared survey telescope to ESO as an in-kind contribution. This wide-field telescope facility is now being constructed in the UK for a consortium of universities and it was decided already last year to place it at Paranal, cf. ESO PR 03/00. It will now become a fully integrated part of the ESO Paranal Observatory providing important survey observations in support of the VLT. Ian Halliday , Chief Executive of PPARC, is "delighted that the negotiations with ESO and subsequent Council meetings have passed this critical decision point. We now expect a straightforward parliamentary process to ratify the intergovernmental treaty. This decision will allow UK astronomers to have access to the world-class VLT telescopes at Paranal. Just as importantly UK Astronomy will have a sound basis for the future ALMA and OWL projects in a European context. This is a major increase in investment in, and capability for, UK Astronomy." Notes [1]: Both ESO and PPARC issue co-ordinated Press Releases about the UK accession today. The PPARC release is available at URL: http://www.pparc.ac.uk/NW/ESOstars.asp [2]: ESO's current member state are Belgium, Denmark, France, Germany, Italy, the Netherlands, Portugal, Sweden and Switzerland.

ESO 243-49 HLX-1: scaling of X-ray spectral properties and black hole mass determination

NASA Astrophysics Data System (ADS)

Titarchuk, Lev; Seifina, Elena

2016-11-01

We report the results of Swift/XRT observations (2008-2015) of a hyper-luminous X-ray source, ESO 243-49 HLX-1. We demonstrate a strong observational evidence that ESO 243-49 HLX-1 undergoes spectral transitions from the low/hard state to the high/soft state during these observations. The spectra of ESO 243-49 HLX-1 are well fitted by the so-called bulk motion Comptonization model for all spectral states. We have established the photon index (Γ) saturation level, Γsat = 3.0 ± 0.1, in the Γ versus mass accretion rate (Ṁ) correlation. This Γ-Ṁ correlation allows us to estimate black hole (BH) mass in ESO 243-49 HLX-1 to be MBH 7 × 104 M⊙ assuming the distance to ESO 243-49 of 95 Mpc. For the BH mass estimate we use the scaling method taking Galactic BHs XTE J1550-564, H 1743-322 and 4U 1630-472, and an extragalactic BH source, M101 ULX-1 as reference sources. The Γ versus Ṁ correlation revealed in ESO 243-49 HLX-1 is similar to those in a number of Galactic and extragalactic BHs and it clearly shows the correlation along with the strong Γ saturation at ≈3. This is a robust observational evidence for the presence of a BH in ESO 243-49 HLX-1. We also find that the seed (disk) photon temperatures are quite low, of order of 50-140 eV which are consistent with high BH mass in ESO 243-49 HLX-1.

ESO's VLT Helps ESA's Rosetta Spacecraft Prepare to Ride on a Cosmic Bullet

NASA Astrophysics Data System (ADS)

2002-02-01

New Images of Comet Wirtanen's Nucleus [1] Summary New images of Comet Wirtanen's 1-km 'dirty snowball' nucleus have been obtained with the ESO Very Large Telescope at Paranal (Chile). They show this object at a distance of approx. 435 million km from the Sun, about the same as when the Rosetta spacecraft of the European Space Agency (ESA) arrives in 2011. The new observations indicate that the comet has a very low degree of activity at this point in its orbit - almost no material is seen around the nucleus. This means that there will not be so much dust near the nucleus as to make the planned landing dramatically difficult. PR Photo 06a/02 : The Nucleus of Comet Wirtanen (composite photo). PR Photo 06b/02 : Comet Wirtanen's motion in the sky (animated). A distant target ESO PR Photo 06a/02 ESO PR Photo 06a/02 [Preview - JPEG: 400 x 445 pix - 120k] [Normal - JPEG: 800 x 890 pix - 1.1M] ESO PR Photo 06b/02 ESO PR Photo 06b/02 [Animated GIF: 400 x 420 pix - 312k] Caption : PR Photo 06a/02 shows a (false-colour) composite image of the nucleus of Comet Wirtanen (the point of light at the centre), recorded on December 9, 2001, with the FORS2 multi-mode instrument at the 8.2-m VLT YEPUN Unit Telescope. It is based on four exposures and since the telescope was set to track the motion of the comet in the sky, the images of stars in the field are seen as four consecutive trails. The measured brightness and the fact that the image of the comet's 'dirty snowball' nucleus is almost star-like indicates that it is surrounded by a very small amount of gas or dust. The diameter of the nucleus is about 1 km and the distance to the comet from the Earth was approx. 534 million km. In PR Photo 06b/02 , the four exposures have been combined to show the motion of the comet during the four exposures. Technical information about the photos is available below. Chase a fast-moving comet, land on it and 'ride' it while it speeds up towards the Sun: not the script of a science-fiction movie, but the very real task of ESA's Rosetta spacecraft. New observations with the ESO Very Large Telescope (VLT) provide vital information about Comet Wirtanen - Rosetta's target - to help ESA reduce uncertainties in the mission, one of the most difficult ever to be performed. Every 5.5 years Comet Wirtanen completes an orbit around the Sun. Wirtanen has been seen during several apparitions since its discovery in 1948, but only recently have astronomers obtained detailed observations that have allowed them to estimate the comet's size and behaviour, cf. ESO PR Photos 27a-b/99. The most recent of these observations was performed in December 2001 with the ESO VLT at the Paranal Observatory in Northern Chile, cf. PR Photos 06a-b/02 , reproduced here. As a result of these observations ESA will be able to refine plans for its Rosetta mission. Good news for Rosetta Rosetta will be launched next year and it will reach Comet Wirtanen in 2011. By that time the comet will be nearly as far from the Sun as Jupiter, charging headlong towards the inner Solar System at speeds of up to 135,000 km/h. To get there and to be able to match the comet's orbit, Rosetta will need to be accelerated by several planetary swing-bys, after which the spacecraft - following a series of difficult manoeuvres - will get close to the comet, enter into orbit around it and release a lander from a height of about 1 km. The VLT observations were planned specifically to investigate the 'activity' of Wirtanen at about the same solar distance as at the time of the landing manoeuvres . Because of this timing requirement, they had to be carried out at a certain moment - unfortunately, when the comet was low in the twilight evening sky and descending rapidly towards the western horizon. However, even though the exposures therefore had to be quite short, the VLT with its superb light-gathering capability and opto-mechanical perfection was still able to produce excellent images of this rather faint, moving object (about 6 million times fainter than what can be perceived with the unaided eye). These observations have now confirmed that - at the same distance from the Sun at which the landing will take place (about 450 million km from the Sun) - the activity on Wirtanen is very low, cf. PR Photo 06a/02 . This is very good news for the mission, because it means that there will not be so much dust near the nucleus as to make the landing dramatically difficult . Landing on a 1-km snowball Cometary nuclei are small frozen bodies made of ice and dust ('dirty snowballs'). When they get close to the Sun the heat causes ices on the surface to 'evaporate'. Gas and dust grains are ejected into the surrounding space forming the comet's atmosphere (coma) and the tail. In addition to dropping a lander on Wirtanen's nucleus for detailed in-situ observations, Rosetta's task is to investigate the evolution of the comet on its way to the Sun: in fact, Rosetta will keep orbiting around Wirtanen up to the end of the mission in July 2013, at which time the comet is at its closest approach to the Sun, at about 160 million km from it. These and earlier VLT observations have also provided Rosetta mission planners with an accurate measurement of their target's size: Wirtanen's nucleus is only 1.2 km in diameter, a true cosmic bullet . "Rosetta is certainly a very challenging space mission. No one has ever tried to land on a comet before," says Gerhard Schwehm , Rosetta's Project Scientist. "We need to learn as much as possible about our target. The new VLT data will allow us to improve our models and make decisions once we get there." "It is a pleasure to help our colleagues at ESA", says ESO astronomer and comet specialist Hermann Boehnhardt . "We will continue to keep an eye on this comet, in particular when Rosetta is approaching its target. We can then provide the spacecraft controllers and the astronomers with very useful, regular updates, e.g., about the 'cometary weather' at the time of arrival." More about Rosetta Rosetta's prime scientific goal is to unravel the origin of the Solar System. The chemical composition of comets is known to reflect that of the primordial nebula that gave birth to the Solar System - in the planets, that primeval material has gone through complex processing, but not in the comets. Therefore, Rosetta will allow scientists to look back 4.6 billion years, to an epoch when the Solar System formed. Previous studies by ESA's Giotto spacecraft and by ground-based observatories have shown that comets contain complex organic molecules - compounds that are rich in carbon, hydrogen, oxygen and nitrogen. Intriguingly, these are the elements which make up nucleic acids and amino acids, essential ingredients for life as we know it. Did life on Earth begin with the help of comet seeding? Rosetta may help us to find the answer to this fundamental question. Rosetta carries 21 experiments in total. These are provided by scientific consortia from institutes across Europe and the United States. The Wirtanen observations by the VLT fall into a tradition of fruitful collaboration between the European Space Agency (ESA) and the European Southern Observatory (ESO). The two organizations, both members of the EIROFORUM collaboration ( ESO PR 12/01 ), are already combining their efforts in several strategic areas, in order to facilitate the synergy between space and ground facilities, where mutual sharing of technology and procedures can result in substantial gains and savings.

The Dark Side of Nature: the Crime was Almost Perfect

NASA Astrophysics Data System (ADS)

2006-12-01

Nature has again thrown astronomers for a loop. Just when they thought they understood how gamma-ray bursts formed, they have uncovered what appears to be evidence for a new kind of cosmic explosion. These seem to arise when a newly born black hole swallows most of the matter from its doomed parent star. Gamma-ray bursts (GRBs), the most powerful explosions in the Universe, signal the formation of a new black hole and come in two flavours, long and short ones. In recent years, international efforts have shown that long gamma-ray bursts are linked with the explosive deaths of massive stars (hypernovae; see e.g. ESO PR 16/03). ESO PR Photo 49a/06 ESO PR Photo 49a/06 GRB 060614 (FORS/VLT) Last year, observations by different teams - including the GRACE and MISTICI collaborations that use ESO's telescopes - of the afterglows of two short gamma-ray bursts provided the first conclusive evidence that this class of objects most likely originates from the collision of compact objects: neutron stars or black holes (see ESO PR 26/05 and ESO PR 32/05). The newly found gamma-ray bursts, however, do not fit the picture. They instead seem to share the properties of both the long and short classes. "Some unknown process must be at play, about which we have presently no clue," said Massimo Della Valle of the Osservatorio Astrofisico di Arcetri in Firenze, Italy, lead author of one of the reports published in this week's issue of the journal Nature. "Either it is a new kind of merger which is able to produce long bursts, or a new kind of stellar explosion in which matter can't escape the black hole." One of the mysterious events went bang on 14 June 2006, hence its name, GRB 060614. The gamma-ray burst lasted 102 seconds and belongs clearly to the category of long GRBs. As it happened in a relatively close-by galaxy, located only 1.6 billion light-years away in the constellation Indus, astronomers worldwide eagerly pointed their telescopes toward it to capture the supernova, watching and waiting as if for a jack-in-the-box to spring open. The MISTICI collaboration used ESO's Very Large Telescope to follow the burst for 50 days. "Despite our deep monitoring, no rebrightening due to a supernova was seen," said Gianpiero Tagliaferri from the Observatory of Brera, Italy and member of the team. "If a supernova is present, if should at least be 100 times fainter than any other supernova usually associated with a long burst." The burst exploded in a dwarf galaxy that shows moderate signs of star formation. Thus young, massive stars are present and, at the end of its life one of them could have uttered this long, agonising cry before vanishing into a black hole. "Why did it do so in a dark way, with no sign of a supernova?" asked Guido Chincarini, from the University of Milano-Bicocca, Italy, also member of the team. "A possibility is that a massive black hole formed that did not allow any matter to escape. All the material that is usually ejected in a supernova explosion would then fall back and be swallowed." ESO PR Photo 49c/06 ESO PR Photo 49b/06 GRB 060505 (FORS/VLT) The same conclusion was previously reached by another team, who monitored both GRB 060614 and another burst, GRB 060505 (5 May 2006) for 5 and 12 weeks, respectively. For this, they used the ESO VLT and the 1.54-m Danish telescope at La Silla. GRB 060505 was a faint burst with a duration of 4 seconds, and as such also belongs to the category of long bursts [1]. For GRB 060505, the astronomers could only see the burst in visible light for one night and then it faded away, while for GRB 060614, they could only follow it for four nights after the burst. Thus, if supernovae were associated with these long-bursts, as one would have expected, they must have been about a hundred times fainter than a normal supernova. "Although both bursts are long, the remarkable conclusion from our monitoring is that there were no supernovae associated with them," said Johan Fynbo from the DARK Cosmology Centre at the Niels Bohr Institute of the Copenhagen University in Denmark, who led the study. "It is a bit like not hearing the thunder from a nearby storm when one could see a very long lasting flash." For the May burst, the team has obtained deep images in very good observing conditions allowing the exact localisation of the burst in its host galaxy. The host galaxy turns out to be a small spiral galaxy, and the burst occurred in a compact star-forming region in one of the spiral arms of the galaxy. This is strong evidence that the star that made the GRB was massive [2]. "For the 5 May event, we have evidence that it was due to a massive star that died without making a supernova," said Fynbo. "We now have to find out what is the fraction of massive stars that die without us noticing, that is, without producing either a gamma-ray burst or a supernova." "Whatever the solution to the problem is, it is clear that these new results challenge the commonly accepted scenario, in which long bursts are associated with a bright supernova," said Daniele Malesani, from the International School for Advanced Studies in Trieste, and now also at the DARK Cosmology Centre. "Our hope is to be able to find more of these unconventional bursts. The chase is on!" High resolution images and their captions are available on the associated page. More information The two gamma-ray bursts were discovered with the NASA/ASI/PPARC Swift satellite, which is dedicated to the discovery of these powerful explosions. The work presented here is published in the 21 December 2006 issue of the journal Nature: "No supernovae associated with two long-duration gamma-ray bursts", by Johan P. U. Fynbo et al., and "An enigmatic long-lasting gamma-ray burst not accompanied by a bright supernova", by Massimo Della Valle et al. Two other reports about the same events are published in the same issue of Nature. The Italian-led team - the MISTICI collaboration - is composed of Massimo Della Valle (INAF, Osservatorio Astrofisico di Arcetri, Italy), Guido Chincarini (INAF, Osservatorio Astronomico di Brera & Università degli Studi di Milano-Bicocca, Italy), Nino Panagia (Space Telescope Science Institute, USA), Gianpiero Tagliaferri, Dino Fugazza, Sergio Campana, Stefano Covino, and Paolo D'Avanzo (INAF, Osservatorio Astronomico di Brera, Italy), Daniele Malesani (SISSA/ISAS, Italy and Dark Cosmology Centre, Copenhagen), Vincenzo Testa, L. Angelo Antonelli, Silvia Piranomonte, and Luigi Stella (INAF, Osservatorio Astronomico di Roma, Italy), Vanessa Mangano (INAF/IASF Palermo, Italy), Kevin Hurley (University of California, Berkeley, USA), I. Felix Mirabel (ESO), and Leonardo J. Pellizza (Instituto de Astronomia y Fisica del Espacio). The Danish-led team is composed of Johan P. U. Fynbo, Darach Watson, Christina C. Thöne, Tamara M. Davis, Jens Hjorth, José Mará Castro Cerón, Brian L. Jensen, Maximilian D. Stritzinger, and Dong Xu (Dark Cosmology Centre, University of Copenhagen, Denmark), Jesper Sollerman (Dark Cosmology Centre and Department of Astronomy, Stockholm University, Sweden), Uffe G. Jørgensen, Tobias C. Hinse, and Kristian G. Woller (Niels Bohr Institute, University of Copenhagen), Joshua S. Bloom, Daniel Kocevski, Daniel Perley (Department of Astronomy, University of California at Berkeley, USA), Páll Jakobsson (Centre for Astrophysics Research, University of Hertfordshire, UK), John F. Graham and Andrew S. Fruchter (Space Telescope Science Institute, Baltimore, USA), David Bersier (Astrophysics Research Institute, Liverpool John Moores University, UK), Lisa Kewley (University of Hawaii, Institute of Astronomy, USA), Arnaud Cassan and Marta Zub (Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Germany), Suzanne Foley (School of Physics, University College Dublin, Ireland), Javier Gorosabel (Instituto de Astrofisica de Andalucia, Granada, Spain), Keith D. Horne (SUPA Physics/Astronomy, University of St Andrews, Scotland, UK), Sylvio Klose (Thüringer Landessternwarte Tautenburg, Germany), Jean-Baptiste Marquette (Institut d'Astrophysique de Paris, France), Enrico Ramirez-Ruiz (Institute for Advanced Study, Princeton and Department of Astronomy and Astrophysics, University of California, Santa Cruz, USA), Paul M. Vreeswijk (ESO and Departamento de Astronomia, Universidad de Chile, Santiago, Chile), and Ralph A. M. Wijers (Astronomical Institute 'Anton Pannekoek', University of Amsterdam, The Netherlands).

Multi-wavelength Observations of the Enduring Type IIn Supernovae 2005ip and 2006jd

NASA Astrophysics Data System (ADS)

Stritzinger, Maximilian; Taddia, Francesco; Fransson, Claes; Fox, Ori D.; Morrell, Nidia; Phillips, M. M.; Sollerman, Jesper; Anderson, J. P.; Boldt, Luis; Brown, Peter J.; Campillay, Abdo; Castellon, Sergio; Contreras, Carlos; Folatelli, Gastón; Habergham, S. M.; Hamuy, Mario; Hjorth, Jens; James, Phil A.; Krzeminski, Wojtek; Mattila, Seppo; Persson, Sven E.; Roth, Miguel

2012-09-01

We present an observational study of the Type IIn supernovae (SNe IIn) 2005ip and 2006jd. Broadband UV, optical, and near-IR photometry, and visual-wavelength spectroscopy of SN 2005ip complement and extend upon published observations to 6.5 years past discovery. Our observations of SN 2006jd extend from UV to mid-infrared wavelengths, and like SN 2005ip, are compared to reported X-ray measurements to understand the nature of the progenitor. Both objects display a number of similarities with the 1988Z-like subclass of SN IIn including (1) remarkably similar early- and late-phase optical spectra, (2) a variety of high-ionization coronal lines, (3) long-duration optical and near-IR emission, and (4) evidence of cold and warm dust components. However, diversity is apparent, including an unprecedented late-time r-band excess in SN 2006jd. The observed differences are attributed to differences between the mass-loss history of the progenitor stars. We conclude that the progenitor of SN 2006jd likely experienced a significant mass-loss event during its pre-SN evolution akin to the great 19th century eruption of η Carinae. Contrarily, as advocated by Smith et al., the circumstellar environment of SN 2005ip is found to be more consistent with a clumpy wind progenitor. This paper includes data gathered with the 6.5 m Magellan Telescopes, located at Las Campanas Observatory, Chile; the Gemini-North Telescope, Mauna Kea, USA (Gemini Program GN-2010B-Q-67, PI: Stritzinger); the ESO NTT, La Silla, Chile (Program 076.A-0156 and 078.D-0048, PI: Hamuy); and the INT and the NOT (Proposal number 45 - 004, PI: Taddia), La Palma, Spain.

Metal-poor Stars Observed with the Magellan Telescope. II. Discovery of Four Stars with [Fe/H] <= -3.5

NASA Astrophysics Data System (ADS)

Placco, Vinicius M.; Frebel, Anna; Beers, Timothy C.; Christlieb, Norbert; Lee, Young Sun; Kennedy, Catherine R.; Rossi, Silvia; Santucci, Rafael M.

2014-01-01

We report on the discovery of seven low-metallicity stars selected from the Hamburg/ESO Survey, six of which are extremely metal-poor (EMP, [Fe/H] <= -3.0), with four having [Fe/H] <= -3.5. Chemical abundances or upper limits are derived for these stars based on high-resolution (R ~ 35,000) Magellan/MIKE spectroscopy, and are in general agreement with those of other very and extremely metal-poor stars reported in the literature. Accurate metallicities and abundance patterns for stars in this metallicity range are of particular importance for studies of the shape of the metallicity distribution function of the Milky Way's halo system, in particular for probing the nature of its low-metallicity tail. In addition, taking into account suggested evolutionary mixing effects, we find that six of the program stars (with [Fe/H] <= -3.35) possess atmospheres that were likely originally enriched in carbon, relative to iron, during their main-sequence phases. These stars do not exhibit overabundances of their s-process elements, and hence may be, within the error bars, additional examples of the so-called CEMP-no class of objects. Based on observations gathered with: The 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile; the Southern Astrophysical Research (SOAR) telescope (SO2011B-002), which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU); and the New Technology Telescope (NTT) of the European Southern Observatory (088.D-0344A), La Silla, Chile.

VizieR Online Data Catalog: Optical transit light curves of WASP-57 (Southworth+, 2015)

NASA Astrophysics Data System (ADS)

Southworth, J.; Mancini, L.; Tregloan-Reed, J.; Calchi Novati, S.; Ciceri, S.; D'Ago, G.; Delrez, L.; Dominik, M.; Evans, D. F.; Gillon, M.; Jehin, E.; Jorgensen, U. G.; Haugbolle, T.; Lendl, M.; Arena, C.; Barbieri, L.; Barbieri, M.; Corfini, G.; Lopresti, C.; Marchini, A.; Marino, G.; Alsubai, K. A.; Bozza, V.; Bramich, D. M.; Figuera Jaimes, R.; Hinse, T. C.; Henning, Th.; Hundertmark, M.; Juncher, D.; Korhonen, H.; Popovas, A.; Rabus, M.; Rahvar, S.; Schmidt, R. W.; Skottfelt, J.; Snodgrass, C.; Starkey, D.; Surdej, J.; Wertz, O.

2018-01-01

Two complete transits of WASP-57 were observed using the 1.54 m Danish Telescope and DFOSC instrument at ESO La Silla, Chile (see Dominik et al. 2010AN....331..671D), on the dates 2014/05/18 and 2014/06/24. Both transits were obtained through a Bessell R filter. The transit on 2014/06/24 observed with DFOSC was also monitored using GROND (Greiner et al. 2008PASP..120..405G) mounted on the MPG 2.2 m telescope at La Silla, Chile. GROND was used to obtain light curves simultaneously in four passbands, which approximate the SDSS g, r, i and z bands. We observed WASP-57 on the night of 2012/05/10 using the BUSCA instrument on the 2.2 m telescope at Calar Alto Astronomical Observatory. BUSCA is capable of observing simultaneously in four passbands, for which we chose Gunn u, g, r and z. One transit of WASP-57 was observed on 2012/04/01 with EulerCam, using the same methods as for the EulerCam transit in Faedi et al. (2013, J/A+A/551/A73). We obtained 212 images through a Gunn r filter, without applying a defocus to the instrument. Two transits of WASP-57 were observed on 2012/03/15 and 2012/04/01 using the 0.6 m TRAPPIST robotic telescope located at La Silla (Gillon et al. 2011EPJWC..1106002G; Jehin et al. 2011Msngr.145....2J). Images were obtained with a slight defocus and through a blue-blocking filter that has a transmittance greater than 90 per cent from 500 nm to beyond 1000 nm. (1 data file).

Open House at the ESO Headquarters

NASA Astrophysics Data System (ADS)

Madsen, C.

2006-12-01

On 15 October, the ESO Headquarters opened its doors to the public as part of the All-Campus Open House organised in connection with the inauguration of the extension of the underground line U6 from Munich to the Garching campus. The day was blessed with clear skies and plenty of sunshine, and a large number of citizens took advantage of the opportunity to visit the campus. The estimated number of visitors at ESO was close to 3000 people, a record number. Another record was set by the number of ESO staff who, in anticipation of the high num-ber of guests, volunteered to spend their Sunday at work to explain what ESO is doing and why it is important.

Diffusibility Enhancement of Rejuvenator by Epoxidized Soybean Oil and Its Influence on the Performance of Recycled Hot Mix Asphalt Mixtures

PubMed Central

Kuang, Dongliang; Jiao, Yuan; Ye, Zhou; Lu, Zaihong; Chen, Huaxin; Yu, Jianying; liu, Ning

2018-01-01

Epoxidized soybean oil (ESO) was employed as a novel penetrant cooperating with a conventional rejuvenator (CR) for the recycling of reclaimed asphalt pavement (RAP). The influence of ESO on the diffusibility and the regenerating effects of CR on RAP were investigated. The diffusibility testing result shows that the diffusibility of CR is enhanced by the addition of ESO because the epoxy group in ESO can facilitate asphaltene dispersion due to its high polarity, which simultaneously reduces the viscosity and improves the fluidity of aged bitumen so as to allow diffusion of the rejuvenator into the aged bitumen. Road performance testing of a recycled hot mix asphalt mixture (RHMA) indicates that the fatigue and cracking resistance properties as well as the water stability of RHMA containing CR can be improved by the addition of ESO due to the diffusibility enhancement of CR, which boosts the regenerating effect of CR on aged bitumen in RAP. The fatigue and cracking resistance properties as well as the water stability of the recycled hot mix asphalt mixture containing CR with 7 wt % ESO approximate those of the hot mix asphalt mixture composed of the same virgin aggregates and bitumen. Taking into account the rutting resistance decline versus the addition of ESO, the content of ESO should not exceed 7 wt % of the conventional rejuvenator. PMID:29783675

Diffusibility Enhancement of Rejuvenator by Epoxidized Soybean Oil and Its Influence on the Performance of Recycled Hot Mix Asphalt Mixtures.

PubMed

Kuang, Dongliang; Jiao, Yuan; Ye, Zhou; Lu, Zaihong; Chen, Huaxin; Yu, Jianying; Liu, Ning

2018-05-18

Epoxidized soybean oil (ESO) was employed as a novel penetrant cooperating with a conventional rejuvenator (CR) for the recycling of reclaimed asphalt pavement (RAP). The influence of ESO on the diffusibility and the regenerating effects of CR on RAP were investigated. The diffusibility testing result shows that the diffusibility of CR is enhanced by the addition of ESO because the epoxy group in ESO can facilitate asphaltene dispersion due to its high polarity, which simultaneously reduces the viscosity and improves the fluidity of aged bitumen so as to allow diffusion of the rejuvenator into the aged bitumen. Road performance testing of a recycled hot mix asphalt mixture (RHMA) indicates that the fatigue and cracking resistance properties as well as the water stability of RHMA containing CR can be improved by the addition of ESO due to the diffusibility enhancement of CR, which boosts the regenerating effect of CR on aged bitumen in RAP. The fatigue and cracking resistance properties as well as the water stability of the recycled hot mix asphalt mixture containing CR with 7 wt % ESO approximate those of the hot mix asphalt mixture composed of the same virgin aggregates and bitumen. Taking into account the rutting resistance decline versus the addition of ESO, the content of ESO should not exceed 7 wt % of the conventional rejuvenator.

The Gaia-ESO Survey: Calibration strategy

NASA Astrophysics Data System (ADS)

Pancino, E.; Lardo, C.; Altavilla, G.; Marinoni, S.; Ragaini, S.; Cocozza, G.; Bellazzini, M.; Sabbi, E.; Zoccali, M.; Donati, P.; Heiter, U.; Koposov, S. E.; Blomme, R.; Morel, T.; Símon-Díaz, S.; Lobel, A.; Soubiran, C.; Montalban, J.; Valentini, M.; Casey, A. R.; Blanco-Cuaresma, S.; Jofré, P.; Worley, C. C.; Magrini, L.; Hourihane, A.; François, P.; Feltzing, S.; Gilmore, G.; Randich, S.; Asplund, M.; Bonifacio, P.; Drew, J. E.; Jeffries, R. D.; Micela, G.; Vallenari, A.; Alfaro, E. J.; Allende Prieto, C.; Babusiaux, C.; Bensby, T.; Bragaglia, A.; Flaccomio, E.; Hambly, N.; Korn, A. J.; Lanzafame, A. C.; Smiljanic, R.; Van Eck, S.; Walton, N. A.; Bayo, A.; Carraro, G.; Costado, M. T.; Damiani, F.; Edvardsson, B.; Franciosini, E.; Frasca, A.; Lewis, J.; Monaco, L.; Morbidelli, L.; Prisinzano, L.; Sacco, G. G.; Sbordone, L.; Sousa, S. G.; Zaggia, S.; Koch, A.

2017-02-01

The Gaia-ESO survey (GES) is now in its fifth and last year of observations and has produced tens of thousands of high-quality spectra of stars in all Milky Way components. This paper presents the strategy behind the selection of astrophysical calibration targets, ensuring that all GES results on radial velocities, atmospheric parameters, and chemical abundance ratios will be both internally consistent and easily comparable with other literature results, especially from other large spectroscopic surveys and from Gaia. The calibration of GES is particularly delicate because of (I) the large space of parameters covered by its targets, ranging from dwarfs to giants, from O to M stars; these targets have a large wide of metallicities and also include fast rotators, emission line objects, and stars affected by veiling; (II) the variety of observing setups, with different wavelength ranges and resolution; and (III) the choice of analyzing the data with many different state-of-the-art methods, each stronger in a different region of the parameter space, which ensures a better understanding of systematic uncertainties. An overview of the GES calibration and homogenization strategy is also given, along with some examples of the usage and results of calibrators in GES iDR4, which is the fourth internal GES data release and will form the basis of the next GES public data release. The agreement between GES iDR4 recommended values and reference values for the calibrating objects are very satisfactory. The average offsets and spreads are generally compatible with the GES measurement errors, which in iDR4 data already meet the requirements set by the main GES scientific goals. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme IDs 188.B-3002 and 193.B-0936.Full Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/598/A5

The Gaia-ESO Survey: Galactic evolution of sulphur and zinc

NASA Astrophysics Data System (ADS)

Duffau, S.; Caffau, E.; Sbordone, L.; Bonifacio, P.; Andrievsky, S.; Korotin, S.; Babusiaux, C.; Salvadori, S.; Monaco, L.; François, P.; Skúladóttir, Á.; Bragaglia, A.; Donati, P.; Spina, L.; Gallagher, A. J.; Ludwig, H.-G.; Christlieb, N.; Hansen, C. J.; Mott, A.; Steffen, M.; Zaggia, S.; Blanco-Cuaresma, S.; Calura, F.; Friel, E.; Jiménez-Esteban, F. M.; Koch, A.; Magrini, L.; Pancino, E.; Tang, B.; Tautvaišienė, G.; Vallenari, A.; Hawkins, K.; Gilmore, G.; Randich, S.; Feltzing, S.; Bensby, T.; Flaccomio, E.; Smiljanic, R.; Bayo, A.; Carraro, G.; Casey, A. R.; Costado, M. T.; Damiani, F.; Franciosini, E.; Hourihane, A.; Jofré, P.; Lardo, C.; Lewis, J.; Morbidelli, L.; Sousa, S. G.; Worley, C. C.

2017-08-01

Context. Due to their volatile nature, when sulphur and zinc are observed in external galaxies, their determined abundances represent the gas-phase abundances in the interstellar medium. This implies that they can be used as tracers of the chemical enrichment of matter in the Universe at high redshift. Comparable observations in stars are more difficult and, until recently, plagued by small number statistics. Aims: We wish to exploit the Gaia-ESO Survey (GES) data to study the behaviour of sulphur and zinc abundances of a large number of Galactic stars, in a homogeneous way. Methods: By using the UVES spectra of the GES sample, we are able to assemble a sample of 1301 Galactic stars, including stars in open and globular clusters in which both sulphur and zinc were measured. Results: We confirm the results from the literature that sulphur behaves as an α-element. We find a large scatter in [Zn/Fe] ratios among giant stars around solar metallicity. The lower ratios are observed in giant stars at Galactocentric distances less than 7.5 kpc. No such effect is observed among dwarf stars, since they do not extend to that radius. Conclusions: Given the sample selection, giants and dwarfs are observed at different Galactic locations, and it is plausible, and compatible with simple calculations, that Zn-poor giants trace a younger population more polluted by SN Ia yields. It is necessary to extend observations in order to observe both giants and dwarfs at the same Galactic location. Further theoretical work on the evolution of zinc is also necessary. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 188.B-3002, 193.B-0936.The full table of S abundances is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/604/A128

Comet or Asteroid?

NASA Astrophysics Data System (ADS)

1997-11-01

When is a minor object in the solar system a comet? And when is it an asteroid? Until recently, there was little doubt. Any object that was found to display a tail or appeared diffuse was a comet of ice and dust grains, and any that didn't, was an asteroid of solid rock. Moreover, comets normally move in rather elongated orbits, while most asteroids follow near-circular orbits close to the main plane of the solar system in which the major planets move. However, astronomers have recently discovered some `intermediate' objects which seem to possess properties that are typical for both categories. For instance, a strange object (P/1996 N2 - Elst-Pizarro) was found last year at ESO ( ESO Press Photo 36/96 ) which showed a cometary tail, while moving in a typical asteroidal orbit. At about the same time, American scientists found another (1996 PW) that moved in a very elongated comet-type orbit but was completely devoid of a tail. Now, a group of European scientists, by means of observations carried out at the ESO La Silla observatory, have found yet another object that at first appeared to be one more comet/asteroid example. However, continued and more detailed observations aimed at revealing its true nature have shown that it is most probably a comet . Consequently, it has received the provisional cometary designation P/1997 T3 . The Uppsala-DLR Trojan Survey Some time ago, Claes-Ingvar Lagerkvist (Astronomical Observatory, Uppsala, Sweden), in collaboration with Gerhard Hahn, Stefano Mottola, Magnus Lundström and Uri Carsenty (DLR, Institute of Planetary Exploration, Berlin, Germany), started to study the distribution of asteroids near Jupiter. They were particularly interested in those that move in orbits similar to that of Jupiter and which are located `ahead' of Jupiter in the so-called `Jovian L4 Lagrangian point'. Together with those `behind' Jupiter, these asteroids have been given the names of Greek and Trojan Heroes who participated in the famous Trojan war. Thus such asteroids are known as the Trojans and the mentioned programme is referred to as the Uppsala-DLR Trojan Survey . In September and October/November 1996, the ESO Schmidt telescope was used to cover about 900 square degrees twice centered on the sky field in the direction of the Jovian L4 point. The observations were made by ESO night-assistants Guido and Oscar Pizarro . By inspection of those from September, Claes-Ingvar Lagerkvist found a total of about 400 Trojan asteroids, most of which were hitherto unknown. Their accurate positions were measured on a two-coordinate measuring machine at the ESO Headquarters in Garching (Germany). During the same period, the 0.6-m Bochum telescope at La Silla was used for additional observations of positions and magnitudes. An asteroid with a tail? ESO Press Photo 31a/97 ESO Press Photo 31a/97 [JPG, 120k] Caption: Discovery image of P/1997 T3 , obtained on October 1, 1997, with the 1-metre ESO Schmidt telescope at the La Silla observatory in the Chilean Atacama desert. The object is seen as a small straight and sharp `asteroidal' trail (in 4 o'clock orientation) on the lower right side of the strong white line in the middle of the field, directly opposite the white dot (these marks were placed in order to mark the position of the new object on the film). A new object was found by Claes-Ingvar Lagerkvist on a film obtained with the ESO 1-metre Schmidt telescope on October 1, 1997. The appearance was that of a point light source, i.e. it was presumably of asteroidal nature , cf. ESO Press Photo 31a/97. ESO Press Photo 31b/97 ESO Press Photo 31b/97 [JPG, 45k] Caption: P/1997 T3 on October 6, 1997 at 05:13:54 UT. This image of the new object (slightly above and to the left of the centre of the field) was obtained with the 0.6-m Bochum telescope at La Silla; the observer was Andreas Nathues . The tail is faintly visible to the lower left of the point-like object (in the 7 o'clock direction). However, when Andreas Nathues (DLR, Institute of Planetary Exploration) soon thereafter obtained seven unfiltered CCD images on three consecutive nights with the 60-cm `Bochum telescope' at La Silla, Uri Carsenty found a tail extending 15 arcseconds in the WSE direction from the point source, cf. ESO Press Photo 31b/97. The (red) magnitude was about 19, or 150,000 times fainter than what is visible to the naked eye. More observations were obtained at La Silla during the following nights, confirming the persistent presence of this tail. NTT observations confirm the cometary nature of P/1997 T3 ESO Press Photo 31c/97 ESO Press Photo 31c/97 [JPG, 52k] Caption: Deep NTT image of P/1997 T3. This image covers a field of 105 x 60 arcsec and is a composite of several CCD exposures. It was taken with the ESO New Technology Telescope (NTT) and the EMMI multi-mode instrument by ESO astronomers Hermann Boehnhardt and Olivier Hainaut on different days between 21 and 25 October 1997. By computer processing, the images of P/1997 T3 are aligned to the same pixel position and co-added in order to increase the visibility of the comet. Due to the motion of the comet, multiple images of several galaxies and stars appear in this photo. At the time of the observations, the comet was about 3.34 AU from Earth and about 4.30 AU from the Sun. A larger version [JPG, 384k] is also available. In late October 1997, further images of the new object and its tail were taken with the ESO 3.5-m New Technology Telescope (NTT) at La Silla, cf. ESO Press Photo 31c/97. On these, the narrow tail was seen to be at least 90 arcsec long and pointing roughly in the Sun direction . The steady appearance and the sunward orientation of the tail indicates that it consists of dust. Moreover, a preliminary image analysis shows the presence of a weak and very condensed coma of dust grains around the nucleus. Interestingly, a series of images through several broadband filters with a total of almost 30 min exposure time did not show any trace of a normal, anti-sunward tail seen in most comets. Still, these observations indicate that the object resembles a typical comet much more than originally thought. This is also supported by the fact that its orbit, calculated on the basis of positional observations during the past month, has been found to be moderately elongated (eccentricity 0.36). The mean distance to the Sun is 6.67 AU (1000 million kilometres), but it comes as close as 4.25 AU (635 million kilometres) at its perihelion. The orbital period is about 17 years. More observations needed! It will be interesting to follow this new object in coming years. Will it remain `cometary' or will the unusual tail disappear after a while? Could it be that some `asteroids' in `cometary' orbits, if observed in more detail with a larger telescope, as was done in this case with the NTT, will also turn out to have a faint coma and even a tail? It is at this moment still unknown which implications the discovery of apparently `intermediate' objects may have on our understanding of the origin and evolution of the solar system. In particular, it is not at all clear whether they represent a completely new class of objects with an internal structure (and composition?) that is significantly different from a `dirty-snowball' cometary nucleus or a rocky asteroid. It may also be that some asteroids have substantial deposits of icy material on or near the surface that may be set free under certain circumstances and mimic cometary activity. This might in theory happen by collisions with other, smaller objects or due to an internal heat source. Only further observations of such objects will allow to tell. Where to find more information Here are some WWW-addresses where more useful information may be obtained about the comet/asteroid phenomenon: * http://www.dlr.de/Berlin/ - Small Bodies Group at the DLR (Berlin, Germany) * http://www.astro.uu.se/planet/asteroid - Asteroids' page of the Uppsala planetary system group (Sweden) * http://www.skypub.com/comets/1996n2pw.html - Are They Comets or Asteroids? (adapted version of article by Stuart J. Goldman in Sky & Telescope, November 1996) * http://cfa-www.harvard.edu/~graff/pressreleases/1996PW.html - Two Unusual Objects: 1996 PW and C/1996 N2 (Press information from the Harvard-Smithsonian Center for Astrophysics (CfA), Cambridge, Massachusetts, U.S.A.) * Abstract of research article : Origin and Evolution of the Unusual Object 1996 PW: Asteroids from the Oort Cloud? by Paul R. Weissman and Harold F. Levison * Abstract of research article : The Main Asteroid Belt - Comet Graveyard or Nursery? by Mark Hammergren * Preprint of research article : The Lightcurve and Colours of Unusual Minor Planet 1996 PW by J.K. Davies et al. This Press Release is accompanied by ESO PR Photo 31a/97 [JPG, 120k] , ESO PR Photo 31b/97 [JPG, 45k] and ESO PR Photo 31c/97 [JPG, 52k]. A larger version of ESO PR Photo 31c/97 [JPG, 384k] is also available. They may be reproduced, if credit is given to the European Southern Observatory. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org ).

Spain to Join ESO

NASA Astrophysics Data System (ADS)

2006-03-01

On 13 February, at a ceremony in Madrid, an agreement was signed by the Spanish Minister of Education and Science, Mrs. María Jesús San Segundo, and the ESO Director General, Dr. Catherine Cesarsky, affirming their commitment to securing Spanish membership of ESO.

A Glimpse of the Young Milky Way

NASA Astrophysics Data System (ADS)

2002-10-01

VLT UVES Observes Most Metal-Deficient Star Known [1] Summary A faint star in the southern Milky Way, designated HE 0107-5240 , has been found to consist virtually only of hydrogen and helium . It has the lowest abundance of heavier elements ever observed , only 1/200,000 of that of the Sun - 20 times less than the previous record-holding star. This is the result of a major ongoing research project by an international team of astronomers [2]. It is based on a decade-long survey of the southern sky, with detailed follow-up observations by means of the powerful UV-Visual Echelle Spectrograph (UVES) on the 8.2-m VLT KUEYEN telescope at the ESO Paranal Observatory in Chile. This significant discovery now opens a new window towards the early times when the Milky Way galaxy was young, possibly still in the stage of formation. It proves that, contrary to most current theories, comparatively light stars like HE 0107-5240 (with 80% of the mass of the Sun) may form in environments (nearly) devoid of heavier elements. Since some years, astronomers have been desperately searching for stars of the very first stellar generation in the Milky Way, consisting only of hydrogen and helium from the Big Bang. None have been detected so far and doubts have arisen that they exist at all. The present discovery provides new hope that it will ultimately be possible to find such stellar relics from the young Universe and thereby to study "unpolluted" Big Bang material. PR Photo 25a/02 : The sky region around the very metal-deficient star HE 0107-5240 . PR Photo 25b/02 : Comparison of UVES spectra of stars with different metal abundances. Stellar generations in the Milky Way galaxy The Milky Way galaxy in which we live formed from a gigantic cloud of gas, when the Universe was still young, soon after the initial Big Bang. At the beginning, this gas was presumably composed almost exclusively of hydrogen and helium atoms produced during the Big Bang. However, once the first stars formed by contraction in that gas, many heavier elements were built up by nuclear processes in their interiors. As time passed, many of the stars of this and following stellar generations returned the processed matter to their surroundings at the ends of their lives, either during violent supernova explosions or via strong "stellar winds". In this way, the interstellar gas in the Milky Way system has ever since been continuously enriched with heavier elements. Stars of later generations like our Sun now contain those elements produced by their ancestors and we are indeed ourselves made up of them. Consequently, the early (and hence, old) stars in the Milky Way mainly differ from younger stars by containing very small amounts of such elements . Hunting the earliest stars Have some of those earliest stars survived to our days? In theory, at least, it would be possible that some of the lighter ones - having the longest lifetimes - are still around. But if so, where are they? During the past three decades, astronomers have desperately tried to find bona-fide representatives of the very first stellar generation(s) in the Milky Way, i.e. stars with no or, at most, extremely low abundance of elements other than hydrogen and helium. The researchers usually refer to such objects as Population III stars , the other two populations being stars with heavy-element abundances like the Sun (Population I) or somewhat less (Population II) [3]. The Hamburg/ESO survey Now, a group of astronomers from Germany, Sweden, Australia, Brazil and the USA [2] has found a giant star that has a concentration of heavy elements 200,000 times lower than the Sun, or about 20 times less than the previous "record" for this kind of star. It thus provides the researchers with a unique window towards the early stages of the formation of the Milky Way and a fine opportunity to study stellar gas with a composition close to that produced during the Big Bang. This is one important outcome of a systematic search for the most metal-deficient stars that is currently being carried out at Hamburger Sternwarte [4]. Over a period of more than 10 years, a large collection of photographic pictures of the southern sky were obtained with the ESO 1-m Schmidt Telescope, a wide-angle telescope at the La Silla observatory in Chile that has now been decommissioned. Thanks to a large glass prism in the front of the telescope, every object in the observed sky field - stars as well as galaxies - was imaged as a small spectrum, providing a first rough idea about its type and composition. The main aim of this "Hamburg/ESO survey" (with Dieter Reimers , Associate Director of the Hamburger Sternwarte, as Principal Investigator and Lutz Wisotzki , now at Astrophysikalisches Institut Potsdam, Germany, as Project Scientist) was to find quasars (particularly active centres of galaxies), a task that was accomplished most successfully, cf. e.g., ESO PR 10/97 and ESO PR 08/00 (Report F). A very welcome by-product of this survey has been a rich harvest of very metal-poor stars . This part of the project is led by Norbert Christlieb , also from the Hamburg Observatory, and now on sabbatical leave at the Research School of Astronomy and Astrophysics of the Australian National University (Canberra, Australia). Using fast computers and advanced pattern-recognition software to analyze the photographic exposures and thus to sift through millions of registered stellar spectra, about 8000 candidates for very metal-poor stars were found. These stars are now being scrutinized spectroscopically one-by-one with many medium-sized telescopes all over the world. Confirmed candidates are then observed with the largest telescopes in the world in order to obtain very detailed spectra (of high spectral resolution), which allow the astronomers to determine their chemical composition accurately. The very metal-deficient star HE 0107-5240 ESO PR Photo 25a/02 ESO PR Photo 25a/02 [Preview - JPEG: 400 x 458 pix - 86k [Normal - JPEG: 800 x 915 pix - 648k] ESO PR Photo 25b/02 ESO PR Photo 25b/02 [Preview - JPEG: 494 x 400 pix - 55k [Normal - JPEG: 987 x 800 pix - 216k] Caption : PR Photo 25a/02 shows a small sky field with the very metal-deficient star HE 0107-5240 at the centre (reproduced from the Digital Sky Survey [STScI Digitized Sky Survey, (C) 1993, 1994, AURA, Inc. all rights reserved - cf. http://archive.eso.org/dss/dss]). PR Photo 25b/02 displays a comparison of a region of the spectrum of the Sun (top) with that of CD -38 245 , the previously most iron-deficient star known (2nd from top), the new record-holder HE 0107-5240 (3rd from top), and a (hypothetical) Population III star [4], consisting only of elements produced in the Big Bang, i.e. hydrogen and helium, and traces of lithium. As can be seen, the spectral absorption lines become progressively weaker with decreasing content of heavier elements. While there is 1 iron atom for every 31,000 hydrogen atoms in the atmosphere of the Sun, in HE 0107-5240 this ratio is about 200,000 times smaller, or only 1 iron atom for every 6.8 billion hydrogen atoms! The two spectra in the middle show that HE 0107-5240 is indeed much more metal-poor than the previous record-holder CD -38 245 - the iron (Fe) lines in the spectrum of HE 0107-5240 are weaker (or absent) and the Nickel (Ni) line is not visible at all. One of these stars has been designated HE 0107-5240 ("HE" stands for Hamburg/ESO Survey, and the number denotes the approximate position of the star on the sky). It is about ten thousand times fainter than the faintest stars that can be seen with the unaided eye. It is located in the direction of the southern constellation Phoenix, at a distance of about 36,000 light-years. This star was observed in December 2001 with the UV-Visual Echelle Spectrograph (UVES) on the 8.2-m VLT KUEYEN telescope at the ESO Paranal Observatory (Chile). From these spectra, Norbert Christlieb and his colleagues at the Dept. of Astronomy and Space Physics, University of Uppsala (Sweden) and at the Munich University Observatory (Germany) were able to determine the chemical composition of the star. The implications HE 0107-5240 turns out to be the most metal-poor star known to date . " This is, in a way, the closest we have ever come to the conditions directly after the Big Bang by studying stars ", says Norbert Christlieb . " But obviously, a lot must have happened between the Big Bang and the formation of this star. In spite of its extreme metal-poorness, it evidently contains some metals, and they were most probably formed in a even earlier, massive star that exploded as a supernova ". Bengt Gustafsson from the University of Uppsala, who lead the chemical analysis jointly with Christlieb, adds that " this star also has an abnormally large content of carbon and nitrogen. Those elements may possibly have been formed by nuclear reactions with helium and hydrogen deep inside the star and subsequently transported upwards to the stellar surface where they can now be observed. It is also possible that a neigbouring star at the end of its life 'polluted' our star by transferring some of its enriched material to HE 0107-5240 at that moment. The ongoing observations with UVES will help us to decide which scenario is the most probable ." Renewed hope to find first-generation stars The mass of HE 0107-5240 is about 80% of that of the Sun. This discovery thus clearly demonstrates that stars with masses slightly less than the Sun can form from very metal-poor gas. This is unexpected, as most current theoretical calculations indicate that it is very difficult to form low-mass stars shortly after the Big Bang, because metals are needed to efficiently cool gas clouds as they contract into stars. But now HE 0107-5240 reveals that Nature has found a way to achieve the necessary cooling. It therefore appears that many of the model calculations must be refined. Equally important: if a star like HE 0107-5240 , with about 0.8 solar mass and 1/200,000 of the metal content of the Sun, did indeed form in the early Universe, then it should also have been possible for low-mass Population III stars to form . If so, they would have survived until today. This implies that there is new hope to find them by means of large, systematic searches like the Hamburg/ESO Survey. Until now, follow-up spectroscopic observations - which are necessarily quite time-consuming - have only been made of about one-quarter of the 8000 low-metal-abundance candidate stars identified in that survey. It is therefore not excluded that a bona-fide Population III star may eventually be found in the course of this programme. More information The information presented in this Press Release is based on a research article ("A stellar relic from the early Milky Way" by Norbert Christlieb et al.) that appears in the research journal "Nature" on October 31, 2002. Notes [1]: This press release is issued in coordination between ESO and Hamburger Sternwarte in Germany. [2]: The team consists of Norbert Christlieb (Hamburger Sternwarte, University of Hamburg, Germany; on sabbatical leave at the Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Australia), Michael S. Bessell (Research School of Astronomy and Astrophysics, Mount Stromlo Observatory, Australia), Timothy C. Beers (Department of Physics and Astronomy, Michigan State University, East Lansing, USA), Bengt Gustafsson, Paul S. Barklem, Torgny Karlsson, Michelle Mizuno-Wiedner (Department of Astronomy and Space Physics, University of Uppsala, Sweden), Andreas Korn (University Observatory Munich, Germany) and Silvia Rossi (Instituto de Astronomia, Geofísica e Ciencias Atmosféricas, Universidade de São Paulo, Brazil). [3]: Most stars in the Milky Way galaxy move within the disk, and for most of these, 1 to 2 percent of their mass consists of chemical elements that are heavier than hydrogen and helium; this is also the case for the Sun, which at 4.6 billion years is about one third of the age of our galaxy. There exists, however, another population of stars for which the heavy-element abundance is only 1/10 - 1/1000 of that of the Sun. Those stars are found in globular clusters, but most move in a huge swarm around the disk, in the halo of the Galaxy. These "halo stars" were born when the Milky Way galaxy was young and their motions still carry the imprint of the process by which our galaxy formed, when gravity brought the gas together and the first stars appeared. The "halo stars" are said to belong to "Population II", in contrast to the younger stars in the disk (like the Sun) that are referred to as "Population I" stars. But what is then the origin of the small amount of heavy elements in Population II stars? There must have been supernovae and other exploding stars in the very early (or even pre-) Milky Way gas, out of which Population II stars were formed. This first (still hypothetical) stellar generation has been named "Population III". There have been many attempts to find Population III stars, which are then presumably totally void of metals, but those searches have not succeeded so far. [4]: Astronomers refer to elements heavier than hydrogen and helium as "metals". Stars with a low abundance of heavier elements are thus referred to as "metal-poor" stars .