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1

Edwin Hubble's Silence  

NASA Astrophysics Data System (ADS)

In late 1928 Edwin Hubble was right in the middle of using V. M. Slipher's redshift data to prove that the universe is expanding, when Hubble's boss, George Hale, directed him to drop everything and rush to the Grand Canyon and test it as a possible site for Hale's planned 200-inch telescope. On his way, Hubble stopped at Lowell Observatory and met with V. M. Slipher. The letters both men wrote about this visit suggest that Hubble never said a word about his being in the middle of using Slipher's research to transform the universe. At the least, this silence is symbolic of the silence with which astronomical history has often treated Slipher's work. A survey of the historical literature suggests several reasons for this. Theorists and observers in astronomy (and other sciences) have long had different perspectives about how science works, and those who place more importance on theory have tended to credit the idea of the expanding universe to the theorists. Also, many sources indicate that Edwin Hubble was not a modest man or generous about sharing credit.

Lago, D.

2013-04-01

2

Edwin Hubble, The Discoverer of the Big Bang Universe  

Microsoft Academic Search

This book is the first complete account of the scientific life and work of Edwin Hubble, whose discoveries form the basis of all theories of the evolution of the universe. One of the outstanding astronomers of the twentieth century, Hubble studied the velocities or redshifts of galaxies and discovered that the universe is expanding. He convincingly proved that our galaxy

Alexander S. Sharov; Igor D. Novikov

1993-01-01

3

Edwin Hubble, The Discoverer of the Big Bang Universe  

NASA Astrophysics Data System (ADS)

This book is the first complete account of the scientific life and work of Edwin Hubble, whose discoveries form the basis of all theories of the evolution of the universe. One of the outstanding astronomers of the twentieth century, Hubble studied the velocities or redshifts of galaxies and discovered that the universe is expanding. He convincingly proved that our galaxy is only one of countless galaxies and thus paved the way for the exploration of an immense world beyond the limits of our knowledge. The exploding universe proposed by Hubble, now termed the Big Bang, is used to explain the origin of the elements, of stars, and of galaxies. The second part of the book describes the fundamental discoveries on the nature of the universe made subsequently, and thus sets his achievements in context. Hubble's vision, particularly his efforts to help build the big telescope at Mt. Palomar, firmly established the United States as a leader in observational astronomy. Written by two prominent astronomers (Dr. Novikov is the author of Black Holes and the Universe, CUP, 1990) who have built on Hubble's work, this book is a classic of science, setting out the thrilling story of the exploding universe.

Sharov, Alexander S.; Novikov, Igor D.

1993-10-01

4

Edwin Hubble's Famous Plate of 1923, and a Hubble-Hubble Connection  

NASA Astrophysics Data System (ADS)

On October 6, 1923 Edwin Hubble used the Mount Wilson 100-inch telescope to take a 45 minute exposure of a field in the Andromeda galaxy. This is the now-famous plate marked with his "VAR!" notation. I will discuss this plate and that notation. I will also tell the story of flying copies of that plate on the deployment mission for HST in 1990 as a Hubble memento and then locating those copies afterwards, and how copies were flown on Servicing Mission 4 on 2009 as well. This has led to an effort in which AAVSO members joined to identify and reobserve that noted star, arguably the most important object in the history of cosmology, but largely ignored since Hubble's time.

Soderblom, David R.

2011-05-01

5

Hubble  

NASA Astrophysics Data System (ADS)

At last, a book presenting the fantastic scientific results of the first five years of Hubble Space Telescope observations! While a number of books for the general public emphasize the technological accomplishments of this multi-billion dollar project or deal with the well-publicized flaw in the telescope's optics, The Hubble: A New Window to the Universe concentrates on its astromonical achievements. The authors use new and ground-breaking Hubble results to illustrate a wide range of astronomical topics, from the great questions about the universe as a whole to quasars and black holes, and from the life and death of stars to our planetary neighbors in the solar system. The first part of this book presents a brief historical overview, "From Babylon to Cape Canaveral," concentrating on progress in astromony from the instrumentation point of view and on the Hubble project itself. The central and largest portion presents the wealth of exciting astronomical results obtained with the Hubble. The last part describes the Hubble operations, as well as the plans for the future of the telescope itself and beyond. The text contains a large number of spectacular images, mainly taken with the Hubble, as well as self-contained portraits of astronomers and explanations of astronomical topics and instruments. Written in a style appealing to both the interested public and to individuals familiar with the field, this compendium serves as a testament to the significant role the Hubble has played in astronomical accomplishment and discovery the past five years.

Fischer, Daniel; Duerbeck, Hilmar; Williams, R.; Jenkner, H.; Duncan, D.

6

Astronomers celebrate a year of new Hubble results  

NASA Astrophysics Data System (ADS)

"We are beginning to understand that because of these observations we are going to have to change the way we look at the Universe," said ESA's Dr Duccio Macchetto, Associate Director for Science Programs at the Space Telescope Science Institute (STScI), Baltimore, Maryland, USA. The European Space Agency plays a major role in the Hubble Space Telescope programme. The Agency provided one of the telescope's four major instruments, called the Faint Object Camera, and two sets of electricity-generating solar arrays. In addition, 15 ESA scientific and technical staff work at the STScI. In return for this contribution, European astronomers are entitled to 15 percent of the telescope's observing time, although currently they account for 20 percent of all observations. "This is a testimony to the quality of the European science community", said Dr Roger Bonnet, Director of Science at ESA. "We are only guaranteed 15 percent of the telescope's use, but consistently receive much more than that." Astronomers from universities, observatories and research institutes across Europe lead more than 60 investigations planned for the telescope's fifth observing cycle, which begins this summer. Many more Europeans contribute to teams led by other astronomers. Looking back to the very start of time European astronomer Dr Peter Jakobsen used ESA's Faint Object Camera to confirm that helium was present in the early Universe. Astronomers had long predicted that 90 percent of the newly born Universe consisted of hydrogen, with helium making up the remainder. Before the refurbished Hubble came along, it was easy to detect the hydrogen, but the primordial helium remained elusive. The ultraviolet capabilities of the telescope, combined with the improvement in spatial resolution following the repair, made it possible for Dr Jakobsen to obtain an image of a quasar close to the edge of the known Universe. A spectral analysis of this picture revealed the quasar's light, which took 13 billion years to reach the telescope, had indeed passed through helium, and not only that, the helium was of just the right variety to match the established theory. Dr Jakobsen has spent more than 20 years working on this subject. His recent efforts concentrated on seeking out a quasar unobscured by clouds of hydrogen, which block the tell-tale signature of helium. His search drew him to the Space Telescope project and during the telescope's early years in orbit he studied 25 likely quasars and found one promising candidate. Dr Jacobsen then had to wait for the telescope's new optics before he could get the quality of data he needed to prove the existence of helium. "We were looking for a break in the cloud cover, so to speak," the astronomer said. "We had a tantalising glimpse of the quasar with the aberrated telescope but it was only after we fixed it that we could really get a clear answer. One of the first things that we did once we had the corrective optics in place was look at this object and it was exactly as we'd hoped." Getting the Universe to measure up When it comes to studying the expansion of the Universe, however, the telescope has raised morn; questions than answers. By determining how fast the Universe is expanding astronomers will be able to calculate its age and size. It may then become possible to discover what is the ultimate fate of the Universe; will it simply continue to expand until it evaporates? Will the expansion come to a complete stop? Or will the Universe stop expanding, start contracting and end in a "big crunch"? The rate at which the Universe expands is known as the Hubble Constant or H0. To measure this value, astronomers need to calculate how far away a galaxy is and how fast it is moving away from us. The former is difficult to determine because reliable distance indicators, sometimes known as "cosmic yardsticks ", such as variable stars and supernovae, must be found in the galaxies. An international team of astronomers recently used the Hubble Space Telescope to make a

1995-02-01

7

European astronomers' successes with the Hubble Space Telescope*  

NASA Astrophysics Data System (ADS)

[Figure: Laguna Nebula] Their work spans all aspects of astronomy, from the planets to the most distant galaxies and quasars, and the following examples are just a few European highlights from Hubble's second phase, 1994-96. A scarcity of midget stars Stars less massive and fainter than the Sun are much numerous in the Milky Way Galaxy than the big bright stars that catch the eye. Guido De Marchi and Francesco Paresce of the European Southern Observatory as Garching, Germany, have counted them. With the wide-field WFPC2 camera, they have taken sample censuses within six globular clusters, which are large gatherings of stars orbiting independently in the Galaxy. In every case they find that the commonest stars have an output of light that is only one-hundredth of the Sun's. They are ten times more numerous than stars like the Sun. More significant for theories of the Universe is a scarcity of very faint stars. Some astronomers have suggested that vast numbers of such stars could account for the mysterious dark matter, which makes stars and galaxies move about more rapidly than expected from the mass of visible matter. But that would require an ever-growing count of objects at low brightnesses, and De Marchi and Paresce find the opposite to be the case -- the numbers diminish. There may be a minimum size below which Nature finds starmaking difficult. The few examples of very small stars seen so far by astronomers may be, not the heralds of a multitude of dark-matter stars, but rareties. Unchanging habits in starmaking Confirmation that very small stars are scarce comes from Gerry Gilmore of the Institute of Astronomy in Cambridge (UK). He leads a European team that analyses long-exposure images in the WFPC2 camera, obtained as a by-product when another instrument is examining a selected object. The result is an almost random sample of well-observed stars and galaxies. The most remarkable general conclusion is that the make-up of stellar populations never seems to vary. In dense or diffuse regions, in very young or very old agglomerations, in the Milky Way Galaxy or elsewhere, the relative numbers of stars of different masses are always roughly the same. Evidently Nature mass-produces quotas of large and small stars irrespective of circumstances. This discovery will assist astronomers in making sense of very distant and early galaxies. They can assume that the stars are of the most familiar kinds. Another surprise was spotted by Rebecca Elson in Gilmore's team, in long-exposure images of the giant galaxy M87, in the nearby Virgo cluster. It possesses globular clusters of very different ages. In the Milky Way and its similar spiral neighbour, the Andromeda galaxy, globular clusters contain the oldest stars. While M87 has ancient globular clusters too, some are different in colour and much younger. The theory is that they were manufactured during collisions of the galaxies that merged into M87, making it the egg-shaped giant seen today. If so, the absence of young globular clusters in the Milky Way may mean that our Galaxy has never suffered a major collision. Accidents in the galactic traffic Brighter than a million million suns, a quasar is the most powerful lamp in the Universe. Astronomers understand it to be powered by matter falling into a massive black hole in the heart of a galaxy. Mike Disney of the University of Wales, Cardiff, leads a European team that asks why some thousands of galaxies harbour quasars, in contrast to the billions that do not. In almost every case that he and his colleagues have investigated, using Hubble's WFPC2 camera at its highest resolution, they see the quasar's home galaxy involved in a collision with another galaxy. "It's my opinion that almost any galaxy can be a quasar," Disney says, "if only its central black hole gets enough to eat. In the galactic traffic accidents that Hubble reveals, we can visualize fresh supplies of stars and gas being driven into the black hole's clutches. My American opposite number, John Bahcall, prefers to stress those quasar hosts that look li

1997-02-01

8

Dismantling Hubble's Legacy?  

NASA Astrophysics Data System (ADS)

Edwin Hubble is famous for a number of discoveries that are well known to amateur and professional astronomers, students and the general public. The origins of these discoveries are examined and it is demonstrated that, in each case, a great deal of supporting evidence was already in place. In some cases the discoveries had either already been made, or competing versions were not adopted for complex scientific and sociological reasons.

Way, M. J.

2013-04-01

9

Sloan Digital Sky Survey: The Hubble Diagram  

NSDL National Science Digital Library

This section of the Sloan Digital Sky Survey's website provides an excellent explanation of how Astronomers are able to use red-shift to explain the expansion of the universe. An activity is provided for a user to retrace Edwin Hubble's steps of measuring magnitudes and calculating redshifts to make a Hubble Diagram. These pages are part of a large set of projects and activities provided by the Sloan Digital Sky Survey for advanced astronomy students.

2005-05-15

10

Edwin Borchard  

Microsoft Academic Search

Edwin Borchard was my colleague and intimate friend for many years. When I came to the Yale faculty in 1919 he was one of the younger members, although a mature and recognized scholar in spite of his youthful appearance. We were thus thrown together and found much in common. For many years we were tennis opponents; on one famous New

Charles E. Clark

1951-01-01

11

Sloan Digital Sky Survey - Hubble Diagram  

NSDL National Science Digital Library

This website, containing information from the Sloan Digital Sky Survey, provides projects and activities for advanced astronomy students. In this particular one, the user retraces Edwin Hubble's steps to discover that the Universe is expanding, by making a Hubble Diagram.

2010-01-07

12

From Failure to Symbol of Astronomical Discovery: The Inspiring Story of the Hubble Space Telescope  

NASA Astrophysics Data System (ADS)

Hubble was launched in 1990, with great expectations of scientific breakthroughs: determining the distance scale of the universe, detecting planets around stars other than the Sun. The enthusiasm that accompanied a very successful launch was quickly dampened by the realization that something was seriously wrong with the telescope. While the pictures were clearer than those of ground-based telescopes, they were not the pristine images promised. Hubble's mirror had a flaw. It was affected by "spherical aberration". Hubble's images were permanently out of focus. This is where the inspiring part of the story starts: scientists and engineers, in a coordinated effort across continents, pulled together to design the solution. The Corrective Optics Space Telescope Axial Replacement (COSTAR) was installed three years later by a brave crew of astronauts who showed to the world that performing complex tasks in space is possible, and paved the way to the construction of the International Space Station. The first images from Hubble with the new optics were superb. The telescope was all that had been promised and more, and changed the way we think of the universe. Designed to be repaired in space, Hubble has been refurbished four additional times. Every time, critical subsystems such as gyros and batteries are replaced, and its scientific instrument complement is upgraded. The last mission to Hubble (SM4) has been successfully completed in May 2009. Two new instruments have been installed, two existing instruments have been repaired in space, and new scientific results are pouring in. Hubble will continue pushing the boundaries of our knowledge of the universe for years to come. But, more importantly, Hubble has showed that partnership, ingenuity and determination can transform the most devastating failure in a long lasting success.

Nota, A.

2011-06-01

13

The Director's Choice: Mellish, Hubble and the discovery of the variable nebula  

NASA Astrophysics Data System (ADS)

In the summer of 1915, amateur astronomer John Edward Mellish joined the staff of Yerkes Observatory as an unpaid observer. Soon after arriving, Mellish discovered what he thought was a comet in the dawn twilight. Yerkes director Edwin Brant Frost promptly notified Harvard Observatory of the discovery only to learn later in the day, too late to prevent distribution of an international telegram, that the object Mellish observed was actually the diffuse nebula NGC 2261. Edwin Powell Hubble, a graduate student in his first year at Yerkes, was assigned the task of determining whether, as Mellish insisted, the nebula had changed. This led to Hubble's first professional papers and his initial fame as the discoverer of `Hubble's Variable Nebula.' Frost's choice, assigning the investigation to Hubble rather than Mellish, reflected his irritation with Mellish over matters that went well beyond the mistaken comet discovery. When Mellish discovered another comet a few weeks later, Frost delayed his notification to Harvard for several days to allow photographic confirmation of the discovery by George Van Biesbroeck, another newcomer at Yerkes. These events highlight staffing problems at Yerkes in 1915, problems that were common to other American observatories. Mellish and Van Biesbroeck were likely the last two amateur astronomers to have an opportunity to `try out' as professionals at Yerkes. By 1915 a stronger requirement for educational credentials was emerging in the astronomical community. On the other hand, like other observatory directors, Frost was experiencing considerable difficulty employing graduate astronomers. With S. W. Burnham already retired, Frost adopted stopgap measures for staffing as E. E. Barnard and others from an earlier generation prepared for retirement. The assignment of the nebula investigation to Hubble indicates that Frost had likely already concluded that Mellish would not be an acceptable substitute for a degreed professional.

Williams, T. R.

2000-12-01

14

Astronomers in the Chemist's War  

NASA Astrophysics Data System (ADS)

World War II, with radar, rockets, and "atomic" bombs was the physicists' war. And many of us know, or think we know, what our more senior colleagues did during it, with Hubble and Hoffleit at Aberdeen; M. Schwarzschild on active duty in Italy; Bondi, Gold, and Hoyle hunkered down in Dunsfeld, Surrey, talking about radar, and perhaps steady state; Greenstein and Henyey designing all-sky cameras; and many astronomers teaching navigation. World War I was The Chemists' War, featuring poison gases, the need to produce liquid fuels from coal on one side of the English Channel and to replace previously-imported dyesstuffs on the other. The talke will focus on what astronomers did and had done to them between 1914 and 1919, from Freundlich (taken prisoner on an eclipse expedition days after the outbreak of hostilities) to Edwin Hubble, returning from France without ever having quite reached the front lines. Other events bore richer fruit (Hale and the National Research Council), but very few of the stories are happy ones. Most of us have neither first nor second hand memories of The Chemists' War, but I had the pleasure of dining with a former Freundlich student a couple of weeks ago.

Trimble, Virginia L.

2012-01-01

15

Emacs Lisp in Edwin Scheme.  

National Technical Information Service (NTIS)

The MIT-Scheme program development environment includes a general-purpose text editor, Edwin, that has an extension language, Edwin Scheme. Edwin is very similiar to another general-purpose text editor, GNU Emacs, which also has an extension language, Ema...

M. Birkholz

1993-01-01

16

Hubble's diagram and cosmic expansion.  

PubMed

Edwin Hubble's classic article on the expanding universe appeared in PNAS in 1929 [Hubble, E. P. (1929) Proc. Natl. Acad. Sci. USA 15, 168-173]. The chief result, that a galaxy's distance is proportional to its redshift, is so well known and so deeply embedded into the language of astronomy through the Hubble diagram, the Hubble constant, Hubble's Law, and the Hubble time, that the article itself is rarely referenced. Even though Hubble's distances have a large systematic error, Hubble's velocities come chiefly from Vesto Melvin Slipher, and the interpretation in terms of the de Sitter effect is out of the mainstream of modern cosmology, this article opened the way to investigation of the expanding, evolving, and accelerating universe that engages today's burgeoning field of cosmology. PMID:14695886

Kirshner, Robert P

2003-12-26

17

A Conversation with Edwin Shneidman  

ERIC Educational Resources Information Center

|This article is a transcript of a conversation that took place with Edwin Shneidman, PhD, on August 19, 2008. Recent advances in machine learning, particularly neurocognitive computing, have provided a fresh approach to the idea of using computers to analyze the language of the suicidal person. Here this notion and many others are discussed.|

Pestian, John

2010-01-01

18

Hubble: 20 Years of Discovery  

NASA Video Gallery

Hubble's discoveries have revolutionized nearly all areas of current astronomical research from planetary science to cosmology. Actor and writer Brent Spiner narrates a visual journey back in time and into the farthest reaches of the cosmos.

NASA

2010-04-26

19

Hubble Space Telescope Deep Field Lesson Package  

NSDL National Science Digital Library

This product consists of four classroom activities, lithographs, and teachers guide. Students examine the Hubble Deep Field image and simulate the process astronomers use to count, classify, and identify objects in the image.

1997-01-01

20

Edwin Burket Twitmyer: 1873-1943  

Microsoft Academic Search

Presents an obituary for Edwin Burket Twitmyer, who died in Philadelphia in 1943. Twitmyer attended Lafayette College, receiving the degree of Ph.B. in 1896. The next year he was appointed Instructor of Psychology at the University of Pennsylvania, and remained continuously a member of the faculty of that institution for nearly 46 years until his death. Twitmyer's early academic years

S. W. Fernberger

1943-01-01

21

Hubble vision : further adventures with the Hubble Space Telescope  

NASA Astrophysics Data System (ADS)

The first edition of Hubble Vision became an international bestseller and won world-wide, critical acclaim. This eagerly awaited second edition is the most comprehensive, most authoritative and best illustrated popular book available on the Hubble Space Telescope. It provides a magnificent portfolio of the latest and greatest images from the HST, woven together with a lucid text explaining the most exciting discoveries and setting them in the context of our current understanding in astronomy. This second edition has been completely revised, updated and expanded to include all the latest astronomical discoveries - from supernovae and protostars to gravitational lensing, black holes and the early universe. It is now even better illustrated, with nearly 25% more figures, and more than 100 entirely new. The unique combination of authors - an award-winning science writer and a key scientist involved in the development of the mission - ensure that the text is both engaging and authoritative. Hubble Vision offers a view of the Universe as never seen before. It will capture the imagination of all those interested in the astronomical quest of understanding our Universe - from high-school students to general readers and amateur astronomers. * Stellar fireworks within Colliding galaxies * The sharpest views of Mars yet * Newborn stars in M16 * A gallery of the latest images of planetary nebulae as never seen before * The deepest, most penetrating view into space ever : the Hubble Deep Field * Views into the heart of a comet (Hale-Bopp) * New views of Jupiter and Io

Petersen, Carolyn Collins; Brandt, John C.

22

Hubble's Famous Plate of 1923: A Story of Pink Polyethylene  

NASA Astrophysics Data System (ADS)

On October 6, 1923 Edwin Hubble used the Mount Wilson 100-inch telescope to take a 45-minute exposure of a field in the Andromeda galaxy. This is the now-famous plate marked with his “VAR!” notation. I will discuss this plate and that notation. I will also tell the story of flying copies of that plate on the deployment mission for HST in 1990 as a Hubble memento and then locating those copies afterwards, and how copies were flown on Servicing Mission 4 on 2009 as well. This has led to an effort in which AAVSO members joined to identify and reobserve that noted star, arguably the most important object in the history of cosmology, but largely ignored since Hubble’s time.

Soderblom, D. R.

2012-06-01

23

Obituary: Edwin E. Salpeter (1924-2008)  

NASA Astrophysics Data System (ADS)

Edwin E. Salpeter, who died 26 November 2008 at his home in Ithaca, NY, belonged to the "second wave" of Jewish scientific refugees from Nazi-dominated Europe, those who left as children just before the onset of WWII and so completed their educations elsewhere. Salpeter was born in Vienna on 3 December 1924, and arrived with his family in Australia in 1939, his father was a physicist and a close friend of Erwin Schrodinger. In Australia, he finished high school, and he entered the University of Sydney at the early age of 16. He received his BS and MSc degrees in physics and mathematics from the University of Sydney, before moving on to a PhD from the University of Birmingham in 1948, for work with Rudolf Peierls on the electrodynamic self-energy of the electron, the first of more than 380 inventoried publications. He had chosen Birmingham over Cambridge or Oxford because of Peierls, and then chose Cornell over Princeton because of Hans Bethe's presence there. His autobiography describes those as two of his very best decisions ever. Marrying psychobiology student Miriam (Mika) Mark less than a year after arriving at Cornell was surely the third, and they remained in Ithaca the rest of their lives, eventually collaborating on some projects in neurobiology before her death in 2000. Their household was a secular one, but (Ed told a colleague) their two daughters received a basic Jewish education "just in case." Daughter Shelley Salpeter and her son Nicholas Buckley were also collaborators with Salpeter on 21st century projects in meta-analysis, epidemiology, and other statistics-heavy problems in biomedicine. Ed Salpeter is survived by his second wife, Antonia (Lhamo) Shouse. Astronomers may be interested to learn that the Cornell press release announcing his death was prepared by Lauren Gold, daughter of Thomas Gold (and Carrie Gold) the co-author of the steady state theory. Apparently, Ed's father Jakob Salpeter late in life considered the anisotropy reported in the Cosmic Microwave Background and wrote in 1968 to Ron Bracewell and Edward Conklin, who had measured it, expressing puzzlement and doubt that there could be preferred frame effects within special relativity. Ed Salpeter described himself as a generalist, always ready to look at new problems in new fields, and a young colleague quoted him as saying there were problems to be solved on backs of envelopes of various sizes. The result was that he made significant contributions in quantum electro- dynamics (the Bethe-Salpeter equation), nuclear physics (electron screening corrections) and astrophysics (helium burning and beyond), stellar populations (the Salpeter initial mass function and galactic chemical evolution), ionospheric physics (his most-cited paper, because of a Raman-like backscatter effect that is useful for measuring electron densities in laboratory plasmas), equations of state for dense matter (e.g. Jovian planet cores), neutrino emission processes, black hole accretion as an AGN energy source (contemporary with a similar idea from Zeldovich, and before the black hole name had even been coined), interstellar atomic and molecular gas, HI rotation curves, and other aspects of astrophysical dark matter. This is not a complete list! In 2004 a special symposium was organized by his students and colleagues near Siena, Italy, to celebrate the 50 years since his publication of the Initial Mass Function that coincided with his 80th birthday. The symposium proceedings 'The Initial Mass Function: 50 Years Later' was dedicated to Ed 'from whom we have learned so much, to his insight and friendship'. Ed Salpeter received a security clearance in the mid-1950's and kept it up, so that, in addition to evaluating various anti-ballistic-missile defense schemes as a member of the JASONS, he was one of 17 participants in the 1985-87 APS study of directed energy weapons, also known as Star Wars. The panel was unanimous in technical disapproval of the project, and many undoubtedly shared Ed's moral disapproval. His 21 year term as the astrophysics member

Trimble, Virginia; Terzian, Yervant

2009-12-01

24

Hubble Sees a Horsehead of a Different Color  

NASA Website

Astronomers have used NASA's Hubble Space Telescope to photograph the iconic Horsehead Nebula in a new, infrared light to mark the 23rd anniversary of the famous observatory's launch aboard the space shuttle Discovery on April 24, 1990. ...

25

Hubble vision. Further adventures with the Hubble Space Telescope.  

NASA Astrophysics Data System (ADS)

This second edition of Hubble vision (for the first one see Abstr. 64.003.030) is a comprehensive, most authoritative, and best illustrated popular book on the Hubble Space Telescope. It provides a magnificent portfolio of the latest and greatest images from the HST, woven together with a lucid text explaining the most exciting discoveries and setting them in the context of our current understanding in astronomy. This second edition has been completely revised, updated, and expanded to include all the latest astronomical discoveries - from supernovae and protostars to gravitational lensing, black holes, and the early universe. It is now even better illustrated, with more than 100 new figures. Throughout, the text provides sufficient scientific background for any reader to understand and appreciate the remarkable discoveries being made by this, the foremost observatory of our age.

Collins Petersen, C.; Brandt, J. C.

26

Astronomer proposal tool exposure time calculator  

NASA Astrophysics Data System (ADS)

The Astronomer Proposal Tool (APT) Exposure Time Calculator (ETC) is a generic Java library for performing ETC calculations. Currently it is primarily used by the web based ETCs supporting Hubble Space Telescope (HST) proposals at Space Telescope Science Institute (STScI). This paper describes the software architecutre, current and potential uses of this library.

McLean, Donald F.; Busko, Ivo

2004-09-01

27

Finding the Right Formula: Edwin H. Walker Jr  

ERIC Educational Resources Information Center

|Edwin H. Walker Jr earned his doctorate in chemistry at age 27 and has barely looked back. With 13 publications under his belt before coming out of graduate school, he has also given more than 20 poster presentations in national venues, most recently at the American Chemical Society. He can also include securing a half-million-dollar National…

Keels, Crystal L.

2005-01-01

28

"Ask Argonne" - Edwin Campos, Research Meteorologist, Part 1  

ScienceCinema

Dr. Edwin Campos is a Research Meteorologist at Argonne National Laboratory. For the last two decades, he has studied weather, and in particular, clouds. Clouds are one of the most uncertain variables in climate predictions and are often related to transportation hazards. Clouds can also impact world-class sporting events like the Olympics. You may have questions about the role of clouds, or weather, on our daily lives. How is severe weather monitored for airports? What is the impact of clouds and wind on the generation of electricity? One of the projects Edwin is working on is short-term forecasting as it relates to solar electricity. For this, Edwin's team is partnering with industry and academia to study new ways of forecasting clouds, delivering technologies that will allow the incorporation of more solar power into the electric grid. Post a question for Edwin as a comment below, and it might get answered in the follow-up video we'll post in the next few weeks.

29

The Poet's Language: Foregrounding in Edwin Thumboo's "Gods Can Die."  

ERIC Educational Resources Information Center

|Explores Singapore poet Edwin Thumboo's aesthetic use of consistent foregrounding, or use of certain linguistic devices to attract attention, in one poem from three perspectives: propositional; textual; and interpersonal. The approach adopted is functional-semantic in orientation and is designed to gain a better appreciation of the poem's texture…

Webster, Jonathan J.

1998-01-01

30

4. Photocopy of photograph, date unknown. VIEW OF EDWIN CLARK ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Photocopy of photograph, date unknown. VIEW OF EDWIN CLARK RESIDENCE ON EASTERN SIDE OF BRIDGE STREET. (Original in possession of the Erie County Historical Society.) 8'x10' enlargement from 4'x5' negative. - Bridge Street Bridge, Spanning Little French Creek at Bridge Street, Union City, Erie County, PA

31

Pathos in Criticism: Edwin Black's Communism-as-Cancer Metaphor  

ERIC Educational Resources Information Center

|Edwin Black's essay on "The Second Persona," introduced to rhetorical critics a rationale and model for a type of ideological criticism. Because it ignored the role of pathos in both the rhetoric Black purported to critique and in the construction of his own audience, Black's essay mis-described key features of Robert Welch's "Blue Book", which…

Condit, Celeste M.

2013-01-01

32

Astronomical kaleidoscope  

NASA Astrophysics Data System (ADS)

The entry contains two Moon eclipses (a picture of a total eclipse and a photo of a penumbral one), photographs of monuments of few greatest astronomers: Nikolay Kopernik, Tiho Brahe and Johannes Kepler, a photo from the JENAM-1995 (Catania, Sicily) as well as photographs of few astronomers related with Moldova and Romania: V. Grigorevskii, N. Donitch, V.Nadolschi, D. Mangeron, two nice clocks in Prague, as well as a map of the Sanctuary in Orheiul -Vechi (Bessarabia) with an supposed ancient calendar.

Gaina, Alex

2005-10-01

33

Astronomical Photometry  

NASA Astrophysics Data System (ADS)

Astronomers use the term "photometry" to refer to the precise measurement of the apparent brightness of astronomical objects in particular specified ranges of electromagnetic wavelength in and near the optically visible band. Historically, this task has been most commonly carried out with the human eye, photographic plates, photomultiplier tubes, and - most recently as of this writing - charge-coupled devices. At wavelengths significantly shorter or longer than the optical region, different detector technologies must be used, and some other term than "photometry" is often used to name the process.

Stetson, Peter B.

34

The Scientific Impact of the Hubble Space Telescope  

Microsoft Academic Search

The Hubble Space Telescope (HST) is the flagship of a growing fleet of modern astronomical telescopes. The unique power of the HST derives from its combination of extremely sharp images, covering relatively wide angular fields in the sky, with a deep dynamic range, low background noise and sensitivity to wavelengths from the vacuum ultraviolet to the near-infrared. HST's greatest achievement

F. D. Macchetto

2002-01-01

35

Hubble Space Telescope First Servicing Mission Prelaunch Mission Operation Report.  

National Technical Information Service (NTIS)

The Hubble Space Telescope (HST) is a high-performance astronomical telescope system designed to operate in low-Earth orbit. It is approximately 43 feet long, with a diameter of 10 feet at the forward end and 14 feet at the aft end. Weight at launch was a...

1993-01-01

36

New Hubble Servicing Mission to upgrade instruments  

NASA Astrophysics Data System (ADS)

The history of the NASA/ESA Hubble Space Telescope is dominated by the familiar sharp images and amazing discoveries that have had an unprecedented scientific impact on our view of the world and our understanding of the universe. Nevertheless, such important contributions to science and humankind have only been possible as result of regular upgrades and enhancements to Hubble’s instrumentation. Using the Space Shuttle for this fifth Servicing Mission underlines the important role that astronauts have played and continue to play in increasing the Space Telescope’s lifespan and scientific power. Since the loss of Columbia in 2003, the Shuttle has been successfully launched on three missions, confirming that improvements made to it have established the required high level of safety for the spacecraft and its crew. “There is never going to be an end to the science that we can do with a machine like Hubble”, says David Southwood, ESA’s Director of Science. “Hubble is our way of exploring our origins. Everyone should be proud that there is a European element to it and that we all are part of its success at some level.” This Servicing Mission will not just ensure that Hubble can function for perhaps as much as another ten years; it will also increase its capabilities significantly in key areas. This highly visible mission is expected to take place in 2008 and will feature several space walks. As part of the upgrade, two new scientific instruments will be installed: the Cosmic Origins Spectrograph and Wide Field Camera 3. Each has advanced technology sensors that will dramatically improve Hubble’s potential for discovery and enable it to observe faint light from the youngest stars and galaxies in the universe. With such an astounding increase in its science capabilities, this orbital observatory will continue to penetrate the most distant regions of outer space and reveal breathtaking phenomena. “Today, Hubble is producing more science than ever before in its history. Astronomers are requesting five times more observing time than that available to them” says Bob Fosbury, Head of the HST European Coordinating Facility. “The new instruments will open completely new windows on the universe. Extraordinary observations are planned over the coming years, including some of the most fascinating physical phenomena ever seen: investigation of planets around other stars, digging deeper into the ancestry of our Milky Way and above all gaining a much deeper insight into the evolution of the universe.” Around the same time that the Shuttle lifts off for the Servicing Mission, ESA will launch Herschel, the orbiting telescope with the largest mirror ever deployed in space. Herschel will complement Hubble in the infrared part of the spectrum and is an ESA mission with NASA participation. Instead of being left at the mercy of its aging instruments, the Hubble Space Telescope will now be given the new lease of life it deserves. In the hope that more discoveries from Hubble will help explain more of the mysteries of the universe, astronauts will make this fifth trip to the world’s most powerful visual light observatory and increase its lifespan and scientific power. Hubble’s direct successor, the James Webb Space Telescope - a collaborative project being undertaken by NASA, ESA and the Canadian Space Agency - is scheduled for launch in 2013. The Servicing Mission just decided on will reduce the gap between the end of the HST mission and the start of the JWST mission. Notes for editors The Hubble Space Telescope project is being carried out by ESA and NASA on the basis of international cooperation.

2006-10-01

37

FAST: a folded astronomical space telescope  

Microsoft Academic Search

A Folded Astronomical Space Telescope is a 2.4-m Hubble Space Telescope class of telescope that can be packaged in a 1.5-m diameter cylinder through use of a single ring of eight deployable segments. Because it has less mass and uses a much smaller booster to inject it into orbit, the cost is greatly reduced. The enabling rationale, general configuration, and

Aden B. Meinel; Marjorie P. Meinel; James B. Breckinridge

1994-01-01

38

Astronomical chemistry.  

PubMed

The discovery of polar polyatomic molecules in higher-density regions of the interstellar medium by means of their rotational emission detected by radioastronomy has changed our conception of the universe from essentially atomic to highly molecular. We discuss models for molecule formation, emphasizing the general lack of thermodynamic equilibrium. Detailed chemical kinetics is needed to understand molecule formation as well as destruction. Ion molecule reactions appear to be an important class for the generally low temperatures of the interstellar medium. The need for the intrinsically high-quality factor of rotational transitions to definitively pin down molecular emitters has been well established by radioastronomy. The observation of abundant molecular ions both positive and, as recently observed, negative provides benchmarks for chemical kinetic schemes. Of considerable importance in guiding our understanding of astronomical chemistry is the fact that the larger molecules (with more than five atoms) are all organic. PMID:21128763

Klemperer, William

2011-01-01

39

Astronomical Spectroscopy  

NASA Astrophysics Data System (ADS)

Spectroscopy is one of the most important tools that an astronomer has forstudying the universe. This chapter begins by discussing the basics, including thedifferent types of optical spectrographs, with extension to the ultraviolet and thenear-infrared. Emphasis is given to the fundamentals of how spectrographs areused, and the trade-offs involved in designing an observational experiment. It thencovers observing and reduction techniques, noting that some of the standardpractices of flat-fielding often actually degrade the quality of the data rather thanimprove it. Although the focus is on point sources, spatially resolved spectroscopyof extended sources is also briefly discussed. Discussion of differential extinction,the impact of crowding, multi-object techniques, optimal extractions,flat-fielding considerations, and determining radial velocities and velocitydispersions provide the spectroscopist with the fundamentals needed to obtainthe best data. Finally the chapter combines the previous material byproviding some examples of real-life observing experiences with several typicalinstruments.

Massey, Philip; Hanson, Margaret M.

40

Astronomical Chemistry  

NASA Astrophysics Data System (ADS)

The discovery of polar polyatomic molecules in higher-density regions of the interstellar medium by means of their rotational emission detected by radioastronomy has changed our conception of the universe from essentially atomic to highly molecular. We discuss models for molecule formation, emphasizing the general lack of thermodynamic equilibrium. Detailed chemical kinetics is needed to understand molecule formation as well as destruction. Ion molecule reactions appear to be an important class for the generally low temperatures of the interstellar medium. The need for the intrinsically high-quality factor of rotational transitions to definitively pin down molecular emitters has been well established by radioastronomy. The observation of abundant molecular ions both positive and, as recently observed, negative provides benchmarks for chemical kinetic schemes. Of considerable importance in guiding our understanding of astronomical chemistry is the fact that the larger molecules (with more than five atoms) are all organic.

Klemperer, William

2011-05-01

41

Thermal Performance of the Hubble Space Telescope (HST) Solar Array-3 During the Disturbance Verification Test (DVT).  

National Technical Information Service (NTIS)

The Hubble Space Telescope (HST) is one of NASA's most productive astronomical observatories. Launched in 1990, the HST continues to gather scientific data to help scientists around the world discover amazing wonders of the universe. To maintain HST in th...

D. H. Nguyen L. M. Skladany B. D. Prats

2001-01-01

42

"Ask Argonne" - Edwin Campos, Research Meteorologist, Part 2  

ScienceCinema

Argonne's Edwin Campos has for the last two decades studied weather, and in particular, clouds. His research can help make solar power a more viable option for the U.S. and the world. In this video, Dr. Campos answers questions that were submitted by the public in response to his introductory video: http://www.youtube.com/watch?v=pfdoHz.... We will be posting a new "Ask Argonne" video every other month, on various topics. Keep an eye out for your next opportunity to submit a question and see if it gets answered - and if you get a shout-out on camera.

43

Edwin E. Moise Bibliography of the Vietnam War  

NSDL National Science Digital Library

Professor Edwin E. Moise of Clemson University has provided a vast bibliography of the Vietnam war. Containing mostly books, it is divided into three major sections: microfilmed document collections, general publications, and U.S. government publications. It is this organization, especially the latter two sections, that is the power of the site. General publications is divided into 45 sections (mostly chronological) and government publications is divided into 20 sections. Many entries are briefly annotated. Unfortunately, the site is not searchable, but the hundreds of citations and their categorization make this one of the more impressive bibliographies of its kind on the Internet.

Moise, Edwin E.

1996-01-01

44

Correcting Hubble Vision.  

ERIC Educational Resources Information Center

|Describes the theory behind the workings of the Hubble Space Telescope, the spherical aberration in the primary mirror that caused a reduction in image quality, and the corrective device that compensated for the error. (JRH)|

Shaw, John M.; Sheahen, Thomas P.

1994-01-01

45

Preparing Colorful Astronomical Images II  

NASA Astrophysics Data System (ADS)

We present additional techniques for using mainstream graphics software (Adobe Photoshop and Illustrator) to produce composite color images and illustrations from astronomical data. These techniques have been used on numerous images from the Hubble Space Telescope to produce photographic, print and web-based products for news, education and public presentation as well as illustrations for technical publication. We expand on a previous paper to present more detail and additional techniques, taking advantage of new or improved features available in the latest software versions. While Photoshop is not intended for quantitative analysis of full dynamic range data (as are IRAF or IDL, for example), we have had much success applying Photoshop's numerous, versatile tools to work with scaled images, masks, text and graphics in multiple semi-transparent layers and channels.

Levay, Z. G.; Frattare, L. M.

2002-12-01

46

HST's 10th anniversary, ESA and Hubble : changing our vision  

NASA Astrophysics Data System (ADS)

With the astronauts who took part in the most recent Servicing Mission (SM3A) in attendance, ESA is taking the opportunity to give a - first - complete overview of Europe's major contribution to the HST mission. It will also review the first ten years of operations and the outstanding results that have "changed our vision" of the cosmos. A new fully European outreach initiative - the "European Space Agency Hubble Information Centre" - will be presented and officially launched; it has been set up by ESA to provide information on Hubble from a European perspective. A public conference will take place in the afternoon to celebrate Hubble's achievements midway through its life. Ten years of outstanding performance Launched on 24 April 1990, Hubble is now midway through its operating life and it is considered one of the most successful space science missions ever. So far more than 10,000 scientific papers based on Hubble results have been published and European scientists have contributed to more than 25% of these. Not only has Hubble produced a rich harvest of scientific results, it has impressed the man in the street with its beautiful images of the sky. Thousands of headlines all over the world have given direct proof of the public's great interest in the mission - 'The deepest images ever', 'The sharpest view of the Universe', 'Measurements of the earliest galaxies' and many others, all reflecting Hubble's performance as a top-class observatory. The Servicing Missions that keep the observatory and its instruments in prime condition are one of the innovative ideas behind Hubble. Astronauts have serviced Hubble three times, and ESA astronauts have taken part in two of these missions. Claude Nicollier (CH) worked with American colleagues on the First Servicing Mission, when Hubble's initial optical problems were repaired. On the latest, Servicing Mission 3A, both Claude Nicollier and Jean-François Clervoy (F) were members of the crew. Over the next 10 years European scientists still plan to use Hubble as one of their prime research tools, but they also expect to benefit from synergy between Hubble and the ground-based 8-metre class telescopes that are becoming available to scientists in Europe. Notes for editors The Hubble Space Telescope is an international cooperation project between the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). The partnership agreement between ESA and NASA was signed on 7 October 1977. ESA has provided, among other items, two pairs of solar panels and one of Hubble's scientific instruments (the Faint Object Camera). 15 European scientists are contributing to the science operation of the Hubble Observatory and are currently working at the Space Telescope Science Institute in Baltimore (STScI). In return for this contribution, European astronomers have guaranteed access to 15% of Hubble's observing time. Scientific operation of the Hubble Observatory is the responsibility of the Space Telescope Science Institute, which is run for NASA by the Association of Universities for Research in Astronomy (AURA). The Space Telescope European Coordinating Facility (ST-ECF), hosted by the European Southern Observatory (ESO) in Garching near Munich, Germany, provides support to European Hubble users. ESA and ESO jointly operate ST-ECF. From 27 April 2000 the "European Space Agency Hubble Information Centre" will be available with its services on the World Wide Web at http://hubble.esa.int as part of the recently upgraded ESA Science website http://sci.esa.int For more information, please contact : ESA - Communication Department Media Relations Office Tel: +33(0)1.53.69.7155 Fax: +33(0)1.53.69.7690 Press conference Thursday 27 April at 10:30h Location Space Telescope-European Coordinating Facility (ST-ECF) (c/o European Southern Observatory (ESO), K. Schwarzschild-Str. 2, Garching bei München, Germany), Auditorium.

2000-04-01

47

Hubble’s Law: Who Discovered What and When  

NASA Astrophysics Data System (ADS)

Controversy continues over who discovered the Universe’s expansion. Was it Hubble, Lemaitre, or perhaps even Lundmark? However, extragalactic distance estimates published by Hubble and his contemporaries to prove expansion have been tabulated and made publicly available online by the NASA/IPAC Extragalactic Database of galaxy Distances, which I co-lead. In 1924, three years before Lemaitre’s research and five years before Hubble’s, Lundmark’s distance estimates were consistent with a Hubble constant of H0 = 75 km/s/Mpc. This is within 1% of the best Hubble constant estimates today, but Lundmark’s research was not adopted. Hubble’s research of 1929 was. Although inaccurate by almost an order of magnitude, giving H0 = 500 km/s/Mpc, Hubble’s research relied on multiple methods including one still in use (brightest stars), calibrated by multiple galaxies with distances based on proven Cepheids variables. Lundmark established observational evidence that the Universe is expanding. Lemaitre established theoretical evidence. Hubble established observational proof. This presentation will expand on earlier briefs given online, and in JRASC 105, 18 (2011), and Nature 490, 176 (2012) Correspondence.

Steer, Ian

2013-01-01

48

Astronomical Equipment for Amateurs  

Microsoft Academic Search

Telescopes - refractors and reflectors - are the main items of equipment used by almost every amateur astronomer. The purpose of astronomical telescopes is to collect and focus more light than the human eye can, forming an image that can be viewed, photographed, or analysed. Astronomical Equipment for Amateurs makes buying and using both telescopes and their ancillary instruments easy

Martin Mobberley

1999-01-01

49

Astronomer in the Classroom  

NASA Astrophysics Data System (ADS)

Interstellar Studios and 21st Century Learning are sponsoring a new program, Astronomer in the Classroom, in support of the International Year of Astronomy 2009. The Astronomer in the Classroom Program will provide astronomers and students the opportunity to interact, in real-time, during the IYA2009. Astronomers will present their recent research and communicate directly with students from the convenience of their research facility and/or office, and students will pose questions to the Astronomer of the Day from the convenience of their school computers.

Oman, J.; Koenig, K.

2008-11-01

50

A Unique test for Hubble's new Solar Arrays  

NASA Astrophysics Data System (ADS)

In mid-October, a team from the European Space Agency (ESA) and NASA will perform a difficult, never-before-done test on one of the Hubble Space Telescope's new solar array panels. Two of these panels, or arrays, will be installed by astronauts in November 2001, when the Space Shuttle Columbia visits Hubble on a routine service mission. The test will ensure that the new arrays are solid and vibration free before they are installed on orbit. The test will be conducted at ESA's European Space Research and Technology Center (ESTEC) in Noordwijk, The Netherlands. Because of the array's size, the facility's special features, and ESA's longstanding experience with Hubble's solar arrays, ESTEC is the only place in the world the test can be performed. This test is the latest chapter in a longstanding partnership between ESA and NASA on the Hubble Space Telescope. The Large Space Simulator at ESTEC, ESA's world-class test facility, features a huge vacuum chamber containing a bank of extremely bright lights that simulate the Sun's intensity - including sunrise and sunset. By exposing the solar wing to the light and temperature extremes of Hubble's orbit, engineers can verify how the new set of arrays will act in space. Hubble orbits the Earth once every 90 minutes. During each orbit, the telescope experiences 45 minutes of searing sunlight and 45 minutes of frigid darkness. This test will detect any tiny vibrations, or jitters, caused by these dramatic, repeated changes. Even a small amount of jitter can affect Hubble's sensitive instruments and interfere with observations. Hubble's first set of solar arrays experienced mild jitter and was replaced in 1993 with a much more stable pair. Since that time, advances in solar cell technology have led to the development of even more efficient arrays. In 2001, NASA will take advantage of these improvements, by fitting Hubble with a third-generation set of arrays. Though smaller, this new set generates more power than the previous pairs. The arrays use high efficiency solar cells and an advanced structural system to support the solar panels. Unlike the earlier sets, which roll up like window shades, the new arrays are rigid. ESA provided Hubble's first two sets of solar arrays, and built and tested the motors and electronics of the new set provided by NASA Goddard Space Flight Center. Now, this NASA/ESA test has benefits that extend beyond Hubble to the world-wide aerospace community. It will greatly expand basic knowledge of the jitter phenomenon. Engineers across the globe can apply these findings to other spacecraft that are subjected to regular, dramatic changes in sunlight and temperature. Note to editors The Hubble Project The Hubble Space Telescope is a project of international co-operation between the National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA). The partnership agreement between ESA and NASA was signed on 7 October 1977. ESA has provided two pairs of solar panels and one of Hubble's scientific instruments (the Faint Object Camera), as well as a number of other components and supports NASA during routine Servicing Missions to the telescope. In addition, 15 European scientists are working at the Space Telescope Science Institute in Baltimore (STScI), which is responsible for the scientific operation of the Hubble Observatory and is managed by the Association of Universities for Research in Astronomy (AURA) for NASA. In return, European astronomers have guaranteed access to 15% of Hubble's observing time. The Space Telescope European Coordinating Facility (ST-ECF) hosted at the European Southern Observatory (ESO) in Garching bei München, Germany, supports European Hubble users. ESA and ESO jointly operate the ST-ECF.

2000-10-01

51

The Hubble Helix  

NASA Astrophysics Data System (ADS)

For the 14 hours of peak Leonid meteoroid flux in November 2002, the Hubble Space Telescope was pointed away from incoming meteoroids, and the solar arrays were oriented to minimize their cross-section. By coincidence, one of the most prominent planetary nebulae, the Helix Nebula, a.k.a. NGC 7293, was nearly opposite the incoming Leonids and could be observed. A ``Hubble Helix Team'' of volunteers led by M. Meixner (STScI) organized a nine-orbit campaign to observe the Helix with the ACS, WFPC2, NICMOS, and STIS. A contiguous 3 by 3 grid of 4kx4k-pixel ACS images covering much but not all of the Helix was exposed in two filters, H? +[N II] (F658N) and [O III] (F502N). A few of the WFPC2 images observed in parallel also observed the nebula in [O I] (F631N) or He II 4686 (F469N) or H? (F656N). NICMOS/NIC3 observations were obtained at two locations on the nebula and two off, in H2 (F212N) and Paschen-? (F187N). A few of the STIS parallel observations in [OII] (F28X0OII) were located on the nebula. The main purpose of this presentation is to advertise to all interested parties the availability of the non-proprietary data via the HST archive. Initial data analysis by the Hubble Helix Team will be presented in this poster.

McCullough, P. R.; Hubble Helix Team

2002-12-01

52

Hubble Space Telescope via the Web  

NASA Astrophysics Data System (ADS)

The Space Telescope Science Institute (STScI) makes available a wide variety of information concerning the Hubble Space Telescope (HST) via the Space Telescope Electronic Information Service (STEIS). STEIS is accessible via anonymous ftp, gopher, WAIS, and WWW. The information on STEIS includes how to propose for time on the HST, the current status of HST, reports on the scientific instruments, the observing schedule, data reduction software, calibration files, and a set of publicly available images in JPEG, GIF and TIFF format. STEIS serves both the astronomical community as well as the larger Internet community. WWW is currently the most widely used interface to STEIS. Future developments on STEIS are expected to include larger amounts of hypertext, especially HST images and educational material of interest to students, educators, and the general public, and the ability to query proposal status.

O'Dea, Christopher P.

53

Direct Measures of the Hubble Constant  

NASA Astrophysics Data System (ADS)

When astronomers talk about Lutz-Kelker corrections, metallicity dependent zeropoints, statistical parallaxes, Tully-Fisher relations, "fundamental" planes, light curve decline rates and, worst of all, Malmquist bias, physicists begin heading for the exits, showing signs of severe allergic reaction. They respond less violently to so-called "direct" methods of measuring distances which bypass the traditional distance ladder. Two of these, gravitational lens time delay measurements (Refsdal's method) and the Sunyaev-Zeldovich (S-Z) effect, give distance measurements to objects at high redshift which appear to rival more traditional approaches. Present, model mediated interpretations of such measurements give low values for the Hubble constant. But as is often the case with new techniques, initial enthusiasm is followed by increasing concern about systematic errors connected with messy astrophysical details. The single largest source of error in modelling lenses is the difficulty in constraining the degree of central concentration of the lensing galaxy. Sources of systematic error in S-Z distances include the clumpiness of intracluster gas, temperature variations within that gas and a bias toward selecting clusters that are elongated along the line of sight. Present best estimates of the Hubble constant, along with best estimates of the systematic uncertainties, and the prospects for improving upon these, will be presented. Support from NSF grant AST96-16866 is gratefully acknowledged.

Schechter, P. L.

1999-05-01

54

COBE Astronomical Databases  

NASA Astrophysics Data System (ADS)

A project to store and convert external astronomical survey maps to the Cosmic Background Explorer (COBE) spacecraft pixelization is described. Established software is reused in order to reduce development costs. The proposed packages and systems include the Image Reduction and Analysis Facility (IRAF), Interactive Data Language Astronomy Library (IDL), the FITSIO data transfer package and the Astronomical Image Processing System (AIPS). The software structure of the astronomical databases, projected conversion schemes, quality assurance procedures and outstanding problems will be discussed.

Freedman, I.; Raugh, A. C.; Cheng, E. S.

55

Hubble Space Telescope: High Speed Photometer Instrument Handbook. Version 2.0 (Revised).  

National Technical Information Service (NTIS)

This manual is a guide for astronomers who intend to use the High Speed Photometer (HSP), one of the scientific instruments onboard the Hubble Space Telescope (HST). All the information needed for ordinary uses of the HSP is presented, including: (1) an o...

R. L. White

1990-01-01

56

Regularized multiframe restoration of Hubble space and ground-based telescope images with parallel implementation  

Microsoft Academic Search

The spherical aberration of the primary mirror of the Hubble Space Telescope (HST) has seriously reduced the sensitivity and degraded the resolution of images from the instruments. After the first period of observation, most of the astronomic researchers do not try to make photometric measurements on original or somewhat restored images, but they see the opportunity to take the better

Rudolf Klaus; Hans Burkhardt

1993-01-01

57

An atlas of Hubble Space Telescope photometric, spectrophotometric, and polarimetric calibration objects  

Microsoft Academic Search

The Hubble Space Telescope (HST) has capabilities for direct imaging, photometry, spectrophotometry, polarimetry, and astrometry. The combined scientific instruments cover the wavelength range from about 1150 to 11,000 Å. This paper presents an overview of the standard astronomical sources, referred to here as calibration targets, which will be used to calibrate HST images, photometry, spectrophotometry, and polarimetry in the UV

D. A. Turnshek; R. C. Bohlin; R. L. Williamson II; O. L. Lupie; J. Koornneef; D. H. Morgan

1990-01-01

58

The Modern Amateur Astronomer  

Microsoft Academic Search

Here is a comprehensive guide for every amateur astronomer who hopes to do more than just star-gaze. If you already own an astronomical telescope and want to know how to use it to the best effect, or if you are thinking about buying one and are wondering where to start, then this is the book for you. Each chapter deals

Patrick Moore

1995-01-01

59

The Observational Amateur Astronomer  

Microsoft Academic Search

Patrick Moore has pulled together a group of professional and amateur astronomers, each an expert in a particular field, to describe how to observe every category of object that is within reach of an astronomical telescope of modest size. Each chapter deals with a different class of object, covering the whole range of possibilities from the Moon, planets and stars

Patrick Moore

1995-01-01

60

Interpreting Astronomical Spectra  

NASA Astrophysics Data System (ADS)

Interpreting Astronomical Spectra D. Emerson Institute for Astronomy, Department of Physics and Astronomy, The University of Edingurgh "Interpreting Astronomical Spectra" describes how physical conditions such as temperature, density and composition can be obtained from the spectra of a broad range of astronomical environments ranging from the cold interstellar medium to very hot coronal gas and from stellar atmospheres to quasars. In this book the author has succeeded in providing a coherent and integrated approach to the interpretation of astronomical spectroscopy, placing the emphasis on the physical understanding of spectrum formation rather than on instrumental considerations. MKS units and consistent symbols are employed throughout so that the fundamental ideas common to diverse environments are made clear and the importance of different temperature ranges and densities can be seen. Aimed at senior undergraduates and graduates studying physics, astronomy and astrophysics, this book will also appeal to the professional astronomer.

Emerson, D.

1996-06-01

61

Interpreting Astronomical Spectra  

NASA Astrophysics Data System (ADS)

Interpreting Astronomical Spectra D. Emerson Institute for Astronomy, Department of Physics and Astronomy, The University of Edingurgh "Interpreting Astronomical Spectra" describes how physical conditions such as temperature, density and composition can be obtained from the spectra of a broad range of astronomical environments ranging from the cold interstellar medium to very hot coronal gas and from stellar atmospheres to quasars. In this book the author has succeeded in providing a coherent and integrated approach to the interpretation of astronomical spectroscopy, placing the emphasis on the physical understanding of spectrum formation rather than on instrumental considerations. MKS units and consistent symbols are employed throughout so that the fundamental ideas common to diverse environments are made clear and the importance of different temperature ranges and densities can be seen. Aimed at senior undergraduates and graduates studying physics, astronomy and astrophysics, this book will also appeal to the professional astronomer.

Emerson, D.

1999-03-01

62

The Hubble constant.  

PubMed Central

Five methods of estimating distances have demonstrated internal reproducibility at the level of 5-20% rms accuracy. The best of these are the cepheid (and RR Lyrae), planetary nebulae, and surface-brightness fluctuation techniques. Luminosity-line width and Dn-sigma methods are less accurate for an individual case but can be applied to large numbers of galaxies. The agreement is excellent between these five procedures. It is determined that Hubble constant H0 = 90 +/- 10 km.s-1.Mpc-1 [1 parsec (pc) = 3.09 x 10(16) m]. It is difficult to reconcile this value with the preferred world model even in the low-density case. The standard model with Omega = 1 may be excluded unless there is something totally misunderstood about the foundation of the distance scale or the ages of stars.

Tully, R B

1993-01-01

63

Hubble Source Catalog  

NASA Astrophysics Data System (ADS)

We have created an initial catalog of objects observed by the WFPC2 and ACS instruments on the Hubble Space Telescope (HST). The catalog is based on observations taken on more than 6000 visits (telescope pointings) of ACS/WFC and more than 25000 visits of WFPC2. The catalog is obtained by cross matching by position in the sky all Hubble Legacy Archive (HLA) Source Extractor source lists for these instruments. The source lists describe properties of source detections within a visit. The calculations are performed on a SQL Server database system. First we collect overlapping images into groups, e.g., Eta Car, and determine nearby (approximately matching) pairs of sources from different images within each group. We then apply a novel algorithm for improving the cross matching of pairs of sources by adjusting the astrometry of the images. Next, we combine pairwise matches into maximal sets of possible multi-source matches. We apply a greedy Bayesian method to split the maximal matches into more reliable matches. We test the accuracy of the matches by comparing the fluxes of the matched sources. The result is a set of information that ties together multiple observations of the same object. A byproduct of the catalog is greatly improved relative astrometry for many of the HST images. We also provide information on nondetections that can be used to determine dropouts. With the catalog, for the first time, one can carry out time domain, multi-wavelength studies across a large set of HST data. The catalog is publicly available. Much more can be done to expand the catalog capabilities.

Lubow, S.; Budavári, T.

2013-10-01

64

Organization and Development of the Instrument Department at Edwin I. Hatch Nuclear Plant  

Microsoft Academic Search

Developing an effective instrument department is an important part of a safe and reliable nuclear power plant. Plant Edwin I. Hatch, the first nuclear generating station in the Georgia Power system, presented problems unique in the Company for establishment and operation of its instrument shop. The initial organization of the shop was based on the Company's fossil power plants with

T. V. Greene

1976-01-01

65

Cynthia J. Najdowski: Psi Chi/APA Edwin B. Newman Graduate Research Award  

ERIC Educational Resources Information Center

|Presents a short biography of the winner of the American Psychological Association's Psi Chi/APA Edwin B. Newman Graduate Research Award. The 2012 winner is Cynthia J. Najdowski for an outstanding research paper that examines how jurors' judgments are influenced by a juvenile defendant's confession and status as intellectually disabled. Through…

American Psychologist, 2012

2012-01-01

66

Lives and Deaths: Biographical Notes on Selections from the Works of Edwin S. Shneidman  

ERIC Educational Resources Information Center

Edwin S. Shneidman (DOB: 1918-05-13; DOD: 2009-05-15) is a father of contemporary suicidology. His work reflects the intensive study of lives lived and deaths, especially suicides, and is the mirror to his mind. His contributions can be represented by five categories: psychological assessment, logic, Melville and Murray, suicide, and death. His…

Leenaars, Antoon A.

2010-01-01

67

Landscapes of Removal and Resistance: Edwin James's Nineteenth-Century Cross-Cultural Collaborations  

ERIC Educational Resources Information Center

|The life of Edwin James (1797-1861) is bookended by the Lewis and Clark expedition (1803-6) and the Civil War (1861-65). James's work engaged key national concerns of western exploration, natural history, Native American relocation, and slavery. His principled stands for preservation of lands and animals in the Trans-Mississippi West and his…

Lyndgaard, Kyhl

2010-01-01

68

Psi Chi/APA Edwin B. Newman Graduate Research Award: Joseph H. Hammer  

ERIC Educational Resources Information Center

|Joseph H. Hammer, recipient of the Psi Chi/APA Edwin B. Newman Graduate Research Award, is cited for an outstanding research paper whose findings provide important evidence regarding the promise of a male-sensitive approach to mental health marketing and empirically support the inclusion of theory-driven enhancements in group-targeted mental…

American Psychologist, 2009

2009-01-01

69

Astronomical Video Suites  

NASA Astrophysics Data System (ADS)

Astronomer and visual artist Jose Francisco Salgado has directed two astronomical video suites to accompany live performances of classical music works. The suites feature awe-inspiring images, historical illustrations, and visualizations produced by NASA, ESA, and the Adler Planetarium. By the end of 2009, his video suites Gustav Holst's The Planets and Astronomical Pictures at an Exhibition will have been presented more than 40 times in over 10 countries. Lately Salgado, an avid photographer, has been experimenting with high dynamic range imaging, time-lapse, infrared, and fisheye photography, as well as with stereoscopic photography and video to enhance his multimedia works.

Francisco Salgado, Jose

2010-01-01

70

Reinventing the Hubble Space Telescope... ...The Next Hubble Servicing Mission  

Microsoft Academic Search

SHUTTLE ASTRONAUTS will make one final ‘house call’ to the Hubble Space Telescope as part of a mission to extend and improve\\u000a the observatory’s capabilities through the year 2013. NASA Administrator Michael Griffin announced plans for a fifth servicing\\u000a mission to Hubble on Tuesday, 31 October 2006. “We have conducted a detailed analysis of the performance and procedures necessary\\u000a to

J. Chris Blades

71

Astronomical Observatories in Kazakhstan  

NASA Astrophysics Data System (ADS)

A short description of three astronomical observatories of Kazakhstan situated in the northern Tien-Shan mountains is given, including instrumentation, scientific research directions and climate conditions. The observatories may be considered as convenient sites for WET observations.

Mironov, A. V.; Tereshchenko, V. M.

1998-03-01

72

Astronomical Software Directory Service.  

National Technical Information Service (NTIS)

With the support of NASA's Astrophysics Data Program (NRA 92-OSSA-15), we have developed the Astronomical Software Directory Service (ASDS): a distributed, searchable, WWW-based database of software packages and their related documentation. ASDS provides ...

R. J. Hanisch H. Payne J. Hayes

1997-01-01

73

Brooks Astronomical Observatory  

NSDL National Science Digital Library

The Brooks Astronomical Observatory, located at Central Michigan University, was built for research and public use. The website presents the history of the Observatory and its technological capabilities. Users can find a long list of scientific publications based on research performed at the observatory. The numerous astronomical topics researched include asteroids, stellar clusters, occultations, and light pollution. Individuals can view fantastic images of comets, planets, and other space phenomena collected at the Observatory.

74

Astronomical Software Directory Service  

Microsoft Academic Search

With the support of NASA's Astrophysics Data Program (NRA 92-OSSA-15), we have developed the Astronomical Software Directory Service (ASDS): a distributed, searchable, WWW-based database of software packages and their related documentation. ASDS provides integrated access to 56 astronomical software packages, with more than 16,000 URLs indexed for full-text searching. Users are performing about 400 searches per month. A new aspect

Robert J. Hanisch; Harry Payne; Jeffrey Hayes

1997-01-01

75

Determination of the Hubble constant.  

National Technical Information Service (NTIS)

The possibility of an alternative determination of the distance scale of the Universe and the Hubble constant based on the numerical analysis of the hierarchical nature of the large scale Universe (galaxies, clusters and superclusters) is proposed. The re...

V. G. Gurzadyan V. V. Harutyunyan A. A. Kocharyan

1990-01-01

76

THE CARNEGIE HUBBLE PROGRAM  

SciTech Connect

We present an overview of and preliminary results from an ongoing comprehensive program that has a goal of determining the Hubble constant to a systematic accuracy of {+-}2%. As part of this program, we are currently obtaining 3.6 {mu}m data using the Infrared Array Camera on Spitzer, and the program is designed to include James Webb Space Telescope in the future. We demonstrate that the mid-infrared period-luminosity relation for Cepheids at 3.6 {mu}m is the most accurate means of measuring Cepheid distances to date. At 3.6 {mu}m, it is possible to minimize the known remaining systematic uncertainties in the Cepheid extragalactic distance scale. We discuss the advantages of 3.6 {mu}m observations in minimizing systematic effects in the Cepheid calibration of H{sub 0} including the absolute zero point, extinction corrections, and the effects of metallicity on the colors and magnitudes of Cepheids. We undertake three independent tests of the sensitivity of the mid-IR Cepheid Leavitt Law to metallicity, which when combined will allow a robust constraint on the effect. Finally, we provide a new mid-IR Tully-Fisher relation for spiral galaxies.

Freedman, Wendy L.; Madore, Barry F.; Scowcroft, Victoria; Monson, Andy; Persson, S. E.; Seibert, Mark [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 (United States); Rigby, Jane R. [Observational Cosmology Lab, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sturch, Laura [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Stetson, Peter, E-mail: wendy@obs.carnegiescience.edu, E-mail: barry@obs.carnegiescience.edu, E-mail: vs@obs.carnegiescience.edu, E-mail: amonson@obs.carnegiescience.edu, E-mail: persson@obs.carnegiescience.edu, E-mail: mseibert@obs.carnegiescience.edu, E-mail: Jane.R.Rigby@nasa.gov, E-mail: lsturch@bu.edu, E-mail: Peter.Stetson@nrc-cnrc.gc.ca [Dominion Astrophysical Observatory, National Research Council of Canada, Herzberg Institute of Astrophysics, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada)

2011-12-15

77

Amateur Astronomers' Excellent Adventures  

NASA Astrophysics Data System (ADS)

Last May, the Space Telescope Science Institute canceled the Hubble amateur program for lack of interest. It was a sad end to a program that gave citizen-scientists, brimming with fresh approaches, the means to study the universe. The benefits -- to them, to their communities, to science -- live on.

Cox, Nancy

1996-07-01

78

Preparing Colorful Astronomical Images III: Cosmetic Cleaning  

NASA Astrophysics Data System (ADS)

We present cosmetic cleaning techniques for use with mainstream graphics software (Adobe Photoshop) to produce presentation-quality images and illustrations from astronomical data. These techniques have been used on numerous images from the Hubble Space Telescope when producing photographic, print and web-based products for news, education and public presentation as well as illustrations for technical publication. We expand on a previous paper to discuss the treatment of various detector-attributed artifacts such as cosmic rays, chip seams, gaps, optical ghosts, diffraction spikes and the like. While Photoshop is not intended for quantitative analysis of full dynamic range data (as are IRAF or IDL, for example), we have had much success applying Photoshop's numerous, versatile tools to final presentation images. Other pixel-to-pixel applications such as filter smoothing and global noise reduction will be discussed.

Frattare, L. M.; Levay, Z. G.

2003-12-01

79

Lessons from a High-Impact Observatory: The Hubble Space Telescope's Science Productivity between 1998 and 2008  

Microsoft Academic Search

Almost two decades of continuous operation of the versatile and productive Hubble Space Telescope (HST) provide uniquely well-documented, robust statistics to study the scientific impact of a major astronomical observatory. We compiled a detailed database of refereed articles that use HST data for analysis and show it to be > 95 % complete. This HST Publication Database is publicly available

Dániel Apai; Jill Lagerstrom; Iain Neill Reid; Karen L. Levay; Elizabeth Fraser; Antonella Nota; Edwin Henneken

2010-01-01

80

Methods in Astronomical Image Processing  

NASA Astrophysics Data System (ADS)

A Brief Introductory Note History of Astronomical Imaging Astronomical Image Data Images in Various Formats Digitized Image Data Digital Image Data Philosophy of Astronomical Image Processing Properties of Digital Astronomical Images Human Image Processing Astronomical vs. Computer Science Image Processing Basic Tools of Astronomical Image Processing Display Applications Calibration of Intensity Scales Calibration of Length Scales Image Re-shaping Feature Enhancement Noise Suppression Noise and Error Analysis Image Processing Packages: Design of AIPS and MIDAS AIPS MIDAS Reduction of CCD Data Bias Subtraction Clipping Preflash Subtraction Dark Subtraction Flat Fielding Sky Subtraction Extinction Correction Deconvolution Methods Rebinning/Combining Summary and Prospects for the Future

Jörsäter, S.

81

Hubble Space Telescope: The Telescope, the Observations & the Servicing Mission  

NASA Astrophysics Data System (ADS)

Today the HST Archives contain more than 260 000 astronomical observations. More than 13 000 astronomical objects have been observed by hundreds of different groups of scientists. Direct proof of the scientific significance of this project is the record-breaking number of papers published : over 2400 to date. Some of HST's most memorable achievements are: * the discovery of myriads of very faint galaxies in the early Universe, * unprecedented, accurate measurements of distances to the farthest galaxies, * significant improvement in the determination of the Hubble constant and thus the age of the Universe, * confirmation of the existence of blacks holes, * a far better understanding of the birth, life and death of stars, * a very detailed look at the secrets of the process by which planets are created. Europe and HST ESA's contribution to HST represents a nominal investment of 15%. ESA provided one of the two imaging instruments - the Faint Object Camera (FOC) - and the solar panels. It also has 15 scientists and computer staff working at the Space Telescope Science Institute in Baltimore (Maryland). In Europe the astronomical community receives observational assistance from the Space Telescope European Coordinating Facility (ST-ECF) located in Garching, Munich. In return for ESA's investment, European astronomers have access to approximately 15% of the observing time. In reality the actual observing time competitively allocated to European astronomers is closer to 20%. Looking back at almost ten years of operation, the head of ST-ECF, European HST Project Scientist Piero Benvenuti states: "Hubble has been of paramount importance to European astronomy, much more than the mere 20% of observing time. It has given the opportunity for European scientists to use a top class instrument that Europe alone would not be able to build and operate. In specific areas of research they have now, mainly due to HST, achieved international leadership." One of the major reasons for Hubble's success is the advantage of being in orbit, beyond the Earth's atmosphere. From there it enjoys a crystal-clear view of the universe - without clouds and atmospheric disturbances to blur its vision. European astronomer Guido De Marchi from ESO in Munich has been using Hubble since the early days of the project. He explains: "HST can see the faintest and smallest details and lets us study the stars with great accuracy, even where they are packed together - just as with those in the centre of our Galaxy". Dieter Reimers from Hamburg Observatory adds: "HST has capabilities to see ultraviolet light, which is not possible from the ground due to the blocking effect of the atmosphere. And this is really vital to our work, the main aim of which is to discover the chemical composition of the Universe." The Servicing Missions In the early plans for telescope operations, maintenance visits were to have been made every 2.5 years. And every five years HST should have been transported back to the ground for thorough overhaul. This plan has changed somewhat over time and a servicing scheme, which includes Space Shuttle Servicing Missions every three years, was decided upon. The two first Servicing Missions, in December 1993 (STS-61) and February 1997 (STS-82) respectively, were very successful. In the first three years of operations HST did not meet expectations because its primary mirror was 2 microns too flat at the edge. The first Servicing Mission in 1993 (on which the European astronaut Claude Nicollier flew) dealt with this problem by installing a new instrument with corrective optics (COSTAR - Corrective Optics Space Telescope Axial Replacement). With this pair of "glasses" HST's golden age began. The images were as sharp as originally hoped and astonishing new results started to emerge on a regular basis. The first Servicing Mission also replaced the solar panels and installed a new camera (Wide Field and Planetary Camera 2 - WFPC2). The High-Speed Photometer (HSP) was replaced by COSTAR. During the second Servicing Missi

1999-11-01

82

Professional Ethics for Astronomers  

Microsoft Academic Search

There is a growing recognition that professional ethics is an important topic for all professional scientists, especially physical scientists. Situations at the National Laboratories have dramatically proven this point. Professional ethics is usually only considered important for the health sciences and the legal and medical professions. However, certain aspects of the day to day work of professional astronomers can be

K. B. Marvel

2005-01-01

83

Ancient Egyptian Astronomical Calander  

Microsoft Academic Search

In this paper, we discuss how certain astronomical concepts are related to the ancient Egyptian culture and their daily life. One of them is different ways of creating their calendar systems. The ancient Egyptian calendar seems to have quite a bit of its origin in astronomy and its development over the course of history. There is an important role played

Patrice Marshall; M. A. K. Lodhi

2001-01-01

84

Misconceptions of Astronomical Distances  

ERIC Educational Resources Information Center

Previous empirical studies using multiple-choice procedures have suggested that there are misconceptions about the scale of astronomical distances. The present study provides a quantitative estimate of the nature of this misconception among US university students by asking them, in an open-ended response format, to make estimates of the distances…

Miller, Brian W.; Brewer, William F.

2010-01-01

85

Misconceptions of Astronomical Distances  

ERIC Educational Resources Information Center

|Previous empirical studies using multiple-choice procedures have suggested that there are misconceptions about the scale of astronomical distances. The present study provides a quantitative estimate of the nature of this misconception among US university students by asking them, in an open-ended response format, to make estimates of the distances…

Miller, Brian W.; Brewer, William F.

2010-01-01

86

Ancient Chinese Astronomical Technologies  

NASA Astrophysics Data System (ADS)

I am interested in the astronomical advances of the Ancient Chinese in measuring the solar day. Their development of gnomon & ruler, sundial, and water clock apparatuses enabled Chinese astronomers to measure the annual solar orbit and solar day more precisely than their contemporaries. I have built one of each of these devices to use in collecting data from Olympia, Washington. I will measure the solar day in the Pacific Northwest following the methodology of the ancient Chinese. I will compare with my data, the available historical Chinese astronomical records and current records from the United States Naval Observatory Master Clock. I seek to understand how ancient Chinese investigations into solar patterns enabled them to make accurate predictions about the movement of the celestial sphere and planets, and to develop analytic tests of their theories. Mayall, R. Newton; Sundials: their construction and use. Dover Publications 2000 North, John; The Norton History of Astronomy and Cosmology W.W. Norton& Co. 1995 Zhentao Xu, David W. Pankenier, Yaotiao Jiang; East Asian archaeoastronomy : historical records of astronomical observations of China, Japan and Korea Published on behalf of the Earth Space Institute by Gordon and Breach Science Publishers, c2000

Walsh, Jennifer Robin

2004-05-01

87

The young astronomer's handbook  

NASA Astrophysics Data System (ADS)

An illustrated guide to astronomy with information on astronomical instruments, the solar system, the celestial sphere, the origins of the universe, and theories of astronomy from ancient times to the present. Also includes a section on constellations, pointing out objects of interest that can be observed with simple equipment.

Ridpath, Ian

88

Astronomical lobster eye telescopes  

NASA Astrophysics Data System (ADS)

We describe and discuss astronomical LOBSTER EYE X-ray telescopes based on Multi Foil Optics including recent results of the development and tests of advanced laboratory samples. An alternative proposal for a space experiment based on this optics - Lobster All Sky Monitor - is also briefly presented and discussed.

Hudec, Rene; Sveda, Libor; Inneman, Adolf; Pina, Ladislav

2004-10-01

89

Russian astronomical software  

NASA Astrophysics Data System (ADS)

Institute of Applied Astronomy of RAS has published “ The Astronomical Yearbook ” ( AY) with 1921, “ The Nautical Astronomical Yearbook ” (NAY) with 1930, “ The Nautical Astronomical Almanac ”’ biennial (NAA - 2) with 2001. The new IAU2006/2000 precession - nutation models, and the FK6/HIPPARCOS stellar catalogues were used in these editions. Ephemeris editions are based on the domestic EPM2004 (IAA RAS) theory of movement of planets, Sun and Moon. The electronic versions are developed for two editions. The important stage of work is creation of “The Personal Astronomical Yearbook ”’ (PersAY). The system gives ample opportunities to the user to put and to solve tasks of calculation of ephemerides for any moment in various time scales, and for any location of the observer on a terrestrial surface. Also in PersAY it is possible to calculate by means of DE405/LE405 theory to make comparison with others ephemeris editions. The time interval of validity of the system makes 2010 - 2015. Besides system of the removed access the "Navigator" was developed. It intended to solve some the navigating tasks describe d in NAA - 2. The system is accessible on a site http://shturman.ipa.nw.ru/ (in Russian). In electronic systems as in Y the same reduce theories and the theory of movement of planets, the Sun, the Moon are used. All calculations are work out on the basis of the multifunctional software system ERA.

Lukashova, Marina V.; Glebova, Nina I.; Netsvetaev, Ilja N.; Netsvetaeva, Galina A.; Parijskaja, Ekaterina Ju.; Pitieva, Elena V.; Sveshnikov, Michael L.; Skripnichenko, Vladimir I.

2012-08-01

90

Stuff: Simulating "Perfect" Astronomical Catalogues  

NASA Astrophysics Data System (ADS)

Stuff is a program that simulates "perfect' astronomical catalogues. It generate object lists in ASCII which can read by the SkyMaker program to produce realistic astronomical fields. Stuff is part of the EFIGI development project.

Bertin, Emmanuel

2010-10-01

91

Beyond the Hubble Constant  

NASA Astrophysics Data System (ADS)

International Astronomer Team Witnesses Very Ancient Stellar Explosion A few months ago, a violent stellar explosion -- a supernova -- was discovered in an extremely distant galaxy by an international team of astronomers [1]. This is the very promising first result of a recently initiated, dedicated search for such objects. Subsequent spectral observations have shown this to be the most distant supernova ever observed. Although it is very faint, it has been possible to classify it as a supernova of Type Ia, a kind that is particularly well suited for cosmological distance determinations. A Very Efficient Supernova Search Programme The present discovery was made during the team's first observations with the 4-metre telescope at the Cerro Tololo Inter-American Observatory in Chile. This telescope is equipped with a wide-field camera at its prime focus that enables the simultaneous recording of the images of even very faint objects in a 15-arcminute field. Hundreds of distant galaxies are located in a field of this size and this observational method is therefore very well suited for a search of faint and transient supernovae in such galaxies. With a carefully planned observing sequence, it is possible to image up to 55 sky fields per night. A comparison with earlier exposures makes it possible to detect suddenly appearing supernovae as faint points of light near the galaxy in which the exploding star is located (the parent galaxy). A crucial feature of the new programme is the possibility to perform follow-up spectroscopic observations, whenever a new supernova is discovered. For this, the team has obtained access to several other large telescopes, including the ESO 3.5-metre New Technology Telescope (NTT), the 3.9-metre Anglo-Australian Telescope (AAT) and the Multi-Mirror Telescope (MMT) in Arizona, U.S.A.. The Spectrum of the Supernova The present supernova was first detected at Tololo on March 30, 1995. It was given the official designation SN 1995K, and its spectrum was observed a few nights later with the EMMI instrument at the ESO NTT at La Silla. Further direct images were taken with EMMI and also with the high-resolution NTT SUSI camera, three of which are shown on the photo with text accompanying this Press Release. The supernova is located only 1 arcsecond from the centre of the parent galaxy. As the supernova was very faint (its magnitude was about 22.7, or about 5 million times fainter than what can be seen with the unaided eye), an exposure of 2.5 hours was necessary to collect enough photons to allow a classification of its spectrum. Because of the very small angular distance, the light from the supernova was heavily contaminated with that of the parent galaxy, but the excellent angular resolution of the NTT optics made it possible to overcome this problem. It was also possible to measure the redshift [2] of the galaxy (and thereby of the supernova) as 0.478. This demonstrates that SN 1995K is the most distant supernova (indeed, the most distant star!) ever observed [3]. The spectrum clearly showed SN 1995K to be of Type Ia. This is evident by a comparison with that of a ``standard'' Type Ia supernova (SN 1989B), cf. the graph with explanatory text attached to this Press Release. When the redshift of SN 1995K is taken into account, the two spectra are very similar. The current belief is that supernovae of this type are due to the explosions of white dwarf stars in compact binary systems which are triggered by the successive accretion of stellar material from the other component. As the sequence of NTT images shows, SN 1995K quickly faded and in late May 1995, it could no longer be observed. The rate of change (the ``light-curve'') also closely matched that of a normal Type Ia supernova. Why Are Type Ia Supernovae So Important? While supernovae are important astrophysical objects by themselves, Type Ia supernovae are also of great interest to cosmologists. The main reason is that they provide independent information about the distances to galaxies and thereby about the expansion rate of the Universe. A simple

1995-08-01

92

The Edwin Smith Papyrus: the birth of analytical thinking in medicine and otolaryngology.  

PubMed

The Edwin Smith Papyrus, discovered in 1862 outside of Luxor, Egypt, is the oldest known surgical text in the history of civilization. The surviving scroll, a copy of an earlier text from around 3,000 B.C., gives us remarkable insight into the medical practice of ancient Egyptians in the Nile River bed during the dawn of civilization. The Papyrus is divided into 48 cases, most of which describe traumatic injuries. The text instructs the physician to examine the patient and look for revealing physical signs that may indicate the outcome of the injury. Although in modern medicine we take for granted that the use of physical examination and rational thinking lead to an accurate conclusion, 5,000 years ago, this was extraordinary. The Edwin Smith Papyrus cast aside the prevailing magic and mysticism of that time in favor of logic and deductive reasoning. As Egyptian civilization declined during the next millennium, the teachings of the Papyrus would be lost. It would not be until 300 B.C. when Hippocrates and his disciples in ancient Greece would once again revive logic in medical thinking and teaching. It is believed that the ancient Greeks had knowledge of the contents of the Edwin Smith Papyrus and its teachings and used them as the basis for their writings. As Europe entered the Dark Ages, so did medicine yet again, reverting to spells and prayers instead of judgment and reason. Although Hippocrates teachings were recognized by some scholars during the Middle Ages, they did not make up the basis for mainstream medical knowledge. With the dawn of the Renaissance, medicine would finally purge itself of its past supernatural foundation. Hippocratic teachings were used to form the basis of modern medicine, and medical pioneers in the 17 century studied the ancient Greek texts as the origin for their ideas. Many of the concepts physicians and patients today take as common knowledge originated in the Edwin Smith Papyrus. The authors attempt to uncover some of these fundamental ideas and trace them through time until their incorporation in our modern medical knowledge base. It is the rational, logical, and advanced thinking exhibited in the Edwin Smith Papyrus that mandates its respect from modern otolaryngologists and all physicians alike. PMID:16467701

Stiefel, Marc; Shaner, Arlene; Schaefer, Steven D

2006-02-01

93

The Planetarium and the Astronomer (An Overview)  

NASA Astrophysics Data System (ADS)

The science of astronomy is one of the most accessible of the so-called "hard" sciences. Most people are familiar with some sky phenomena, and do not feel threatened at the prospect of learning more about the stars and planets. In the media, some of the best-known scientists are astronomers, and programs about astronomy tend to gather appreciatively large audiences. Planetarium facilities are a very special form of science media, with the fortunate task of presenting astronomy to the public. Like science writers, planetarium professionals take complex science information and make it accessible to the public with a variety of audio-visual techniques. Because many planetarium professionals have science backgrounds as well as educational training, they have an advantage over traditional media practitioners, who -- except for a few notable exceptions -- do not always have the luxury of a science background when it comes to writing about science. The unique background of the planetarian, however, builds a logical and natural link between astronomers and the public. This paper summarizes the wide variety of ways in which planetaria disseminate astronomy information -- ranging from live public lectures, to "astronomy updates", to hands-on activities for school children, and professionally-produced multi-media programs created especially for the needs of the domed theater. It ends with a few broad suggestions about possible roles for astronomers in any or all of these activities. Carolyn Collins Petersen has been a writer and producer of planetarium programs since 1980. Her programs have appeared in more than 500 facilities around the world. Her print work has appeared in the Denver Post, Sky and Telescope, Astronomy Magazine, and the Griffith Observer. She is the lead author of the upcoming book "Hubble Vision: Science With the Hubble Space Telescope" (due out from Cambridge University Press in Fall, 1995). Petersen has won several awards for her work. She is also a Graduate Research Assistant at the LASP at the University of Colorado, where she works on tasks for the GHRS team and the Ulysses Comet Watch. She has just completed work on a masters' thesis in science journalism.

Petersen, Carolyn Collins

1995-05-01

94

Hubble peers inside a celestial geode  

NASA Astrophysics Data System (ADS)

celestial geode hi-res Size hi-res: 148 Kb Credits: ESA/NASA, Yäel Nazé (University of Liège, Belgium) and You-Hua Chu (University of Illinois, Urbana, USA) Hubble peers inside a celestial geode In this unusual image, the NASA/ESA Hubble Space Telescope captures a rare view of the celestial equivalent of a geode - a gas cavity carved by the stellar wind and intense ultraviolet radiation from a young hot star. Real geodes are handball-sized, hollow rocks that start out as bubbles in volcanic or sedimentary rock. Only when these inconspicuous round rocks are split in half by a geologist, do we get a chance to appreciate the inside of the rock cavity that is lined with crystals. In the case of Hubble's 35 light-year diameter ‘celestial geode’ the transparency of its bubble-like cavity of interstellar gas and dust reveals the treasures of its interior. Low resolution version (JPG format) 148 Kb High resolution version (TIFF format) 1929 Kb Acknowledgment: This image was created with the help of the ESA/ESO/NASA Photoshop FITS Liberator. Real geodes are handball-sized, hollow rocks that start out as bubbles in volcanic or sedimentary rock. Only when these inconspicuous round rocks are split in half by a geologist, do we get a chance to appreciate the inside of the rock cavity that is lined with crystals. In the case of Hubble's 35 light-year diameter ‘celestial geode’ the transparency of its bubble-like cavity of interstellar gas and dust reveals the treasures of its interior. The object, called N44F, is being inflated by a torrent of fast-moving particles (what astronomers call a 'stellar wind') from an exceptionally hot star (the bright star just below the centre of the bubble) once buried inside a cold dense cloud. Compared with our Sun (which is losing mass through the so-called 'solar wind'), the central star in N44F is ejecting more than a 100 million times more mass per second and the hurricane of particles moves much faster at 7 million km per hour (as opposed to less than 1.5 million km per hour for our Sun). Because the bright central star does not exist in empty space but is surrounded by an envelope of gas, the stellar wind collides with this gas, pushing it out, like a snow plough. This forms a bubble, whose striking structure is clearly visible in the crisp Hubble image. The nebula N44F is one of a handful of known interstellar bubbles. Bubbles like these have been seen around evolved massive stars (called 'Wolf-Rayet stars'), and also around clusters of stars (where they are called 'super-bubbles'). But they have rarely been viewed around isolated stars, as is the case here. On closer inspection N44F harbours additional surprises. The interior wall of its gaseous cavity is lined with several four to eight light-year high finger-like columns of cool dust and gas. (The structure of these 'columns' is similar to the Eagle Nebula’s iconic 'Pillars of Creation' photographed by Hubble a decade ago, and is seen in a few other nebulae as well). The fingers are created by a blistering ultraviolet radiation from the central star. Like wind socks caught in a gale, they point in the direction of the energy flow. These pillars look small in this image only because they are much farther away from us then the Eagle Nebula’s pillars. N44F is located about 160 000 light-years in the neighbouring dwarf galaxy the Large Magellanic Cloud, in the direction of the southern constellation Dorado. N44F is part of the larger N44 complex, which contains a large super-bubble, blown out by the combined action of stellar winds and multiple supernova explosions. N44 itself is roughly 1000 light-years across. Several compact star-forming regions, including N44F, are found along the rim of the central super-bubble. This image was taken with Hubble's Wide Field Planetary Camera 2, using filters that isolate light emitted by sulphur (shown in blue, a 1200-second exposure) and hydrogen gas (shown in red, a 1000-second exposure).

2004-08-01

95

Hubble Space Telescope Science Metrics  

Microsoft Academic Search

Since its launch in 1990 April, the Hubble Space Telescope (HST) has produced an increasing flow of scientific results. The large number of refereed publications based on HST data permits a detailed evaluation of the effectiveness of this observatory and its scientific programs. This paper presents the results of selected science metrics related to paper counts, citation counts, citation history,

Georges Meylan; Juan P. Madrid; Duccio Macchetto

2004-01-01

96

Astronomers without borders  

NASA Astrophysics Data System (ADS)

``Astronomers Without Borders'' is a new global organisational dedicated to furthering understanding and goodwill across national and cultural boundaries using the universal appeal of astronomy and space science. A growing network of affiliate organisations brings together clubs, magazines and other organizations involved in astronomy and space science. Forums, galleries, video conferences and other interactive technologies are used to connect participants around the world. Sharing of resources and direct connections through travel programs are also planned. One project, ``The World at Night'' (TWAN), has become an Special Project of IYA2009. TWAN creates wide-angle images of the night sky in important natural and historic settings around the world, dramatically demonstrating the universal nature and appeal of the night sky. ``Astronomers Without Borders'' is also a leader of the 100 Hours of Astronomy IYA2009 Global Cornerstone Project.

Simmons, Mike

2011-06-01

97

On Tokugawa Bakufu's astronomical officials  

NASA Astrophysics Data System (ADS)

Tokugawa Bakufu's astronomical office, established in 1684, is the post for calendar reform. The reform was conducted when the calendar did not predict peculiar celestial phenomena, such as solar or lunar eclipses. It was, so to speak, the theme of the ancient astronomy. From removal of the embargo on importing western science books in 1720, Japanese astronomers studied European astronomy and attempted to apply its knowledge to calendar making. Moreover, they knew the Copernican system and also faced several modern astronomical subjects. The French astronomer Lalande's work "ASTRONOMY" exerted particularly strong influence on astronomers. This paper overviews the activities of Paris observatory and French astronomers in the 17th and 18th centuries, and survey what modern astronomical subjects were. Finally, it sketches a role of the Edo observatory played in the Japanese cultural history.

Yamada, Keiji

2005-06-01

98

Astronomical Society of Victoria  

NSDL National Science Digital Library

The Astronomical Society of Victoria website promotes its efforts to act as a forum for a wide variety of people interested in astronomy. Users can find learn about the monthly meetings open to the public. The website introduces the Society's many sections including Computing, Cosmology and Astrophysics, Current Phenomena, and Radio Astronomy. The Newcomers link furnishes helpful lists of astronomy books, magazines, and computer software. Everyone will enjoy the fantastic images of the Great Orion Nebula, the Trifid Nebula, and other space phenomena.

99

The Astronomical Journal  

NSDL National Science Digital Library

The University of Chicago Press has announced unrestricted access to an online journal until mid-1998. Full text articles, announcements, and editorials are all available. Available electronic issues of The Astronomical Journal (AJ) begin with Volume 115, number 1 (January, 1998). AJ covers "The expanded coverage of quasars, supernova remnants, and studies of the interstellar medium [as well as] traditional areas of astronomy." The publication is available in various formats.

1998-01-01

100

Alternative Astronomical Software Packages  

NASA Astrophysics Data System (ADS)

At a time when the United Nations, in collaboration with Wolfram Research, has selected the Mathematica software package to inform developing countries about available scientific tools, it is important to review other choices of software being used by active scientists around the world. For observational astronomers with large volumes of digital data to be analyzed, the main challenges are data reductions, image handling, model comparisons, interactive fits, data simulations and visualizations, etc. There are several good alternative software packages such as: AIPS, IRAF, MIDAS and IDL The first three packages can be obtained free of charge by contacting the sponsoring institutions. Information can be obtained, via the World Wide Web, from the URLs indicated in the footnotes. IDL is a commercial package that can be used in all kinds of computer platforms and is extensively used in space astronomy (e.g., main language of software reduction packages of missions like IUE, HST, ROSAT, SOHO, etc). All of these packages are able to handle some of the most common commercial and scientific data formats (FITS, CDF and HDF). These software packages provide general tools for image processing and data reduction with emphasis on, but not limited to, astronomical applications. All of these packages have good active customer support strategies, the most useful ones being periodic newsletters, related meetings (e.g., annual meeting on Astronomical Data Analysis Software and Systems), software user groups, bulletin board discussions, FAQs, etc. The purpose of this paper is to present the relative usefulness, available platforms, associated libraries, related resources, of these software packages and the many already existing and potential astronomical applications.

Pérez, M. R.

1997-05-01

101

Astronomical Software Directory Service  

NASA Astrophysics Data System (ADS)

With the support of NASA's Astrophysics Data Program (NRA 92-OSSA-15), we have developed the Astronomical Software Directory Service (ASDS): a distributed, searchable, WWW-based database of software packages and their related documentation. ASDS provides integrated access to 56 astronomical software packages, with more than 16,000 URLs indexed for full-text searching. Users are performing about 400 searches per month. A new aspect of our service is the inclusion of telescope and instrumentation manuals, which prompted us to change the name to the Astronomical Software and Documentation Service. ASDS was originally conceived to serve two purposes: to provide a useful Internet service in an area of expertise of the investigators (astronomical software), and as a research project to investigate various architectures for searching through a set of documents distributed across the Internet. Two of the co-investigators were then installing and maintaining astronomical software as their primary job responsibility. We felt that a service which incorporated our experience in this area would be more useful than a straightforward listing of software packages. The original concept was for a service based on the client/server model, which would function as a directory/referral service rather than as an archive. For performing the searches, we began our investigation with a decision to evaluate the Isite software from the Center for Networked Information Discovery and Retrieval (CNIDR). This software was intended as a replacement for Wide-Area Information Service (WAIS), a client/server technology for performing full-text searches through a set of documents. Isite had some additional features that we considered attractive, and we enjoyed the cooperation of the Isite developers, who were happy to have ASDS as a demonstration project. We ended up staying with the software throughout the project, making modifications to take advantage of new features as they came along, as well as influencing the software development. The Web interface to the search engine is provided by a gateway program written in C++ by a consultant to the project (A. Warnock).

Hanisch, Robert J.; Payne, Harry; Hayes, Jeffrey

1997-01-01

102

The ESA Hubble 15th Anniversary Campaign  

NASA Astrophysics Data System (ADS)

The 15th anniversary of the launch of the NASA/ESA Hubble Space Telescope occurred on 24th April 2005. As Hubble is one of the most successful scientific projects in the world, ESA decided to celebrate this anniversary, among other things, with the production of a Hubble 15th Anniversary movie and a book, both called "Hubble, 15 years of discovery". The movie covers all aspects of the Hubble Space Telescope project - a journey through the history, the problems and the scientific successes of Hubble. With more than 700,000 multi-lingual DVDs distributed to the public, media, educators, decision-makers and scientists, the Hubble 15th anniversary campaign has been one of the largest such projects in Europe.

Christensen, L. L.; Kornmesser, M.

2005-12-01

103

Astropix: Everyone's New Portal to the Universe of Astronomical Imagery  

NASA Astrophysics Data System (ADS)

Astropix is a new online repository for astronomical imagery that is now available for everyone to use. Currently in a beta development state, Astropix provides powerful ways to browse, search, and download images, diagrams, artwork, and photographs from many astronomical missions. The site is built around the Astronomical Visualization Metadata (AVM) standard developed by the Virtual Astronomy Multimedia Project (VAMP) that captures all the key descriptive information for a public image, including color representations and astronomical and sky coordinates. Existing image galleries containing AVM-tagged images can easily supply them to Astropix, which downloads them, extracts the metadata into its database, and generates versions of the images at a variety of common sizes. Visitors to Astropix can search the database using simple free-text queries, or use a structured search (similar to "Smart Playlists" found in iTunes, for example). The Astropix archive also features an Xquery-based method for posting http queries and retrieving XML lists of matching imagery, allowing for scripted access to the site. Current assets include imagery from Spitzer, Chandra, ESO, Galex, Herschel, Hubble, Spitzer, and WISE, with more on the way. Website: astropix.ipac.caltech.edu

Hurt, Robert L.; Squires, G. K.; Llamas, J.; Rosenthal, C.; Brinkworth, C. S.

2012-01-01

104

COSMOS: Hubble Space Telescope Observations  

Microsoft Academic Search

The Cosmic Evolution Survey (COSMOS) was initiated with an extensive allocation (590 orbits in Cycles 12-13) using the Hubble Space Telescope (HST) for high-resolution imaging. Here we review the characteristics of the HST imaging with the Advanced Camera for Surveys (ACS) and parallel observations with NICMOS and WFPC2. A square field (1.8 deg2) has been imaged with single-orbit ACS I-band

N. Scoville; R. G. Abraham; H. Aussel; J. E. Barnes; A. Benson; A. W. Blain; D. Calzetti; A. Comastri; P. Capak; C. Carilli; J. E. Carlstrom; C. M. Carollo; J. Colbert; E. Daddi; N. Scoville; M. Elvis; S. P. Ewald; M. Fall; A. Franceschini; M. Giavalisco; R. E. Griffiths; L. Guzzo; G. Hasinger; C. Impey; J.-P. Kneib; J. Koda; A. Koekemoer; O. Lefevre; S. Lilly; C. T. Liu; H. J. McCracken; R. Massey; Y. Mellier; S. Miyazaki; B. Mobasher; J. Mould; C. Norman; A. Refregier; A. Renzini; J. Rhodes; M. Rich; D. B. Sanders; D. Schiminovich; E. Schinnerer; M. Scodeggio; K. Sheth; P. L. Shopbell; Y. Taniguchi; N. D. Tyson; C. M. Urry; L. Van Waerbeke; P. Vettolani; S. D. M. White; L. Yan

2007-01-01

105

On astronomical drawing [1846  

NASA Astrophysics Data System (ADS)

Reprinted from the Memoirs of the Royal Astronomical Society 15, 1846, pp. 71-82. With annotations and illustrations added by Klaus Hentschel. The activities of the Astronomer Royal for Scotland, Charles Piazzi Smyth (1819-1900), include the triangulation of South African districts, landscape painting, day-to-day or tourist sketching, the engraving and lithographing of prominent architectural sites, the documentary photography of the Egyptian pyramids or the Tenerife Dragon tree, and `instant photographs' of the clouds above his retirement home in Clova, Ripon. His colorful records of the aurora polaris, and solar and terrestrial spectra all profited from his trained eye and his subtle mastery of the pen and the brush. As his paper on astronomical drawing, which we chose to reproduce in this volume, amply demonstrates, he was conversant in most of the print technology repertoire that the 19th century had to offer, and carefully selected the one most appropriate to each sujet. For instance, he chose mezzotint for the plates illustrating Maclear's observations of Halley's comet in 1835/36, so as to achieve a ``rich profundity of shadows, the deep obscurity of which is admirably adapted to reproduce those fine effects of chiaroscuro frequently found in works where the quantity of dark greatly predominates.'' The same expertise with which he tried to emulate Rembrandt's chiaroscuro effects he applied to assessing William and John Herschel's illustrations of nebulae, which appeared in print between 1811 and 1834. William Herschel's positive engraving, made partly by stippling and partly by a coarse mezzotint, receives sharp admonishment because of the visible ruled crossed lines in the background and the fact that ``the objects, which are also generally too light, [have] a much better definition than they really possess.'' On the other hand, John Herschel's illustration of nebulae and star clusters, given in negative, ``in which the lights are the darkest part of the picture'', finds his praise.

Smyth, Charles Piazzi

106

Refracting Astronomical Telescope  

NSDL National Science Digital Library

This applet demonstrates the working of a refracting astronomical telescope. The telescope has two lenses called objective and eyepiece. The focal length of the two lensees can be changed by the user. As an example six brightest stars of the Pleiades, is viewed through the telescope and the resluting change in the image with a change in the focal lengths can be viewed. This applet part of large collection of physics applets by the author and may be accessed in a variety of languages here: http://www.walter-fendt.de/ph14e/

Fendt, Walter

2007-07-13

107

Really Bad Astronomers  

NASA Astrophysics Data System (ADS)

What happens when even Percival Lowell stops believing in your Mars observations? History can be troubling. This I learned while editing the Biographical Encyclopedia of Astronomers (Springer, 2007). There have been astronomers who do not fit our commonly held, and clung to, conceptual model: a sociological system that sifts out generally like-minded and sensible colleagues. I refer to those individuals who (for at least a time) successfully entered the mainstream profession, but now disturb our worldview that says prosperity as a scientist usually is achieved by a rational being holding certain common values. My List of Shame includes examples from each of the last four centuries. Not "crack pot” cosmologists, these were hard-working observers for whom the end justified the means. And they all got away with it. Each person I discuss was vetted by the professional establishment of the day. Yet you will learn how to be fired from a major observatory, banned from prominent journals. But only after damage to the science is done. Be afraid.

Hockey, Thomas A.

2009-01-01

108

Professional Ethics for Astronomers  

NASA Astrophysics Data System (ADS)

There is a growing recognition that professional ethics is an important topic for all professional scientists, especially physical scientists. Situations at the National Laboratories have dramatically proven this point. Professional ethics is usually only considered important for the health sciences and the legal and medical professions. However, certain aspects of the day to day work of professional astronomers can be impacted by ethical issues. Examples include refereeing scientific papers, serving on grant panels or telescope allocation committees, submitting grant proposals, providing proper references in publications, proposals or talks and even writing recommendation letters for job candidates or serving on search committees. This session will feature several speakers on a variety of topics and provide time for questions and answers from the audience. Confirmed speakers include: Kate Kirby, Director Institute for Theoretical Atomic and Molecular Physics - Professional Ethics in the Physical Sciences: An Overview Rob Kennicutt, Astrophysical Journal Editor - Ethical Issues for Publishing Astronomers Peggy Fischer, Office of the NSF Inspector General - Professional Ethics from the NSF Inspector General's Point of View

Marvel, K. B.

2005-05-01

109

Strasbourg's "First" astronomical observatory  

NASA Astrophysics Data System (ADS)

The turret lantern located at the top of the Strasbourg Hospital Gate is generally considered as the first astronomical observatory of the city, but such a qualification must be treated with caution. The thesis of this paper is that the idea of a tower-observatory was brought back by a local scholar, Julius Reichelt (1637-1717), after he made a trip to Northern Europe around 1666 and saw the "Rundetårn" (Round Tower) recently completed in Copenhagen. There, however, a terrace allowed (and still allows) the full viewing of the sky, and especially of the zenith area where the atmospheric transparency is best. However, there is no such terrace in Strasbourg around the Hospital Gate lantern. Reichelt had also visited Johannes Hevelius who was then developing advanced observational astronomy in Gdansk, but nothing of the kind followed in Strasbourg. Rather, the Hospital Gate observatory was built essentially for the prestige of the city and for the notoriety of the university, and the users of this observing post did not make any significant contributions to the progress of astronomical knowledge. We conclude that the Hospital Gate observatory was only used for rudimentary viewing of bright celestial objects or phenomena relatively low on the horizon.

Heck, André

2011-08-01

110

Apparent nonlinearity of the redshift-distance relation in infrared astronomical satellite galaxy samples.  

PubMed Central

The Hubble (linear) redshift-distance law predicts values for directly observed quantities that are quite deviant from their actual values in infrared astronomical satellite (IRAS) galaxy samples. These samples are objectively defined, have modern measurements, are presently the largest such samples to which the Hubble law is theoretically applicable, and are otherwise generally considered to be statistically appropriate. The Hubble law predicts in particular that the dispersion in log flux will be much greater than it is observed to be. This type of deviation is fundamentally incapable of explanation via the assumption of any physically known type of perturbation. The Lundmark (quadratic) redshift-distance law predicts values for these directly observed quantities that are consistent with, and in fact quite close to, their actual values in the same samples. The predictions of a cubic law are typically deviant from observation but somewhat less so than those of the Hubble law. The Lundmark law accurately predicts the deviations from observation of statistical estimates predicated on either the Hubble or the cubic law. Parallel predictions for the latter laws for the results of statistical estimation predicated on the alternative laws are typically quite inaccurate. The Hubble and Lundmark laws are predicted at the low redshifts of the IRAS galaxy samples by generic big bang cosmology (BBC) and chronometric cosmology (CC), respectively. The present results confirm earlier studies of a variety of objectively defined samples of discrete sources in other wave bands that were contraindicative of BBC and indicative of CC.

Segal, I E; Nicoll, J F

1992-01-01

111

Authorship and modernity in Chandigarh: the Ghandi Bhavan and the Kiran Cinema designed by Pierre Jeanneret and Edwin Maxwell Fry  

Microsoft Academic Search

The Modernist city of Chandigarh was designed as a result of the 1948 Partition of India. After the initial appointment of Albert Mayer as lead architect and planner, Le Corbusier along with Pierre Jeanneret, Edwin Maxwell Fry and Jane Drew were selected. Whilst Le Corbusier's work in Chandigarh is relatively well known, the work of the other three European architects

Iain Jackson; Soumyen Bandyopadhyay

2009-01-01

112

Astronomical Society of the Pacific  

NASA Astrophysics Data System (ADS)

The Astronomical Society of the Pacific (ASP) has worked since 1890 to advance astronomy, and to explain the universe to students, teachers and the public. It is the world's largest general astronomy organization. Its annual meetings bring together professional and amateur astronomers, historians, teachers, students and the public. It publishes a respected professional journal Publications of the...

Murdin, P.

2000-11-01

113

GASP - Galway Astronomical Stokes Polarimeter  

Microsoft Academic Search

The Galway Astronomical Stokes Polarimeter (GASP) is an ultra-high-speed, full Stokes, astronomical imaging polarimeter based upon a Division of Amplitude Polarimeter. It has been developed to resolve extremely rapid stochastic, millisecond variations in objects such as optical pulsars, RRATs and magnetic cataclysmic variables. GASP has no moving parts or modulated components, so the complete Stokes vector can be measured from

Patrick P. Collins; Brendan Shehan; Michael Redfern; Andrew Shearer

2009-01-01

114

Immanuel Halton, the astronomer  

NASA Astrophysics Data System (ADS)

Immanuel Halton was born in Cumberland, studied at Grays Inn, London during the later stages of the English Civil War and, during the Commonwealth, entered the service of Henry Howard, later 6th Duke of Norfolk. He pursued his mathematical and astronomical interests while auditor to the Duke of Norfolk. He met with John Flamsteed, encouraged the latter's interest in mathematics and astronomy and became his first patron, as well as contributing observations to Flamsteed's published works. Immanuel ended his days at Wingfield Manor, Derbyshire. A short biographical piece on Immanuel Halton appeared in the Journal in the early 1950s, consisting mostly of quotations from Flamsteed's 'Self Inspections' and Baily's 'Life of Flamsteed'. 1996 is the 350th anniversary of Flamsteed's birth, and it is hoped that this fuller account will flesh out the bones of his first patron.

Barber, P. M.

1996-02-01

115

East Asian astronomical records  

NASA Astrophysics Data System (ADS)

Chinese, Japanese and Korean celestial observations have made major contributions to Applied Historical Astronomy, especially in the study of supernovae, comets, Earth's rotation (using eclipses) and solar variability (via sunspots and aurorae). Few original texts now survive; almost all extant records exist only in printed versions, often with the loss of much detail. The earliest Chinese astronomical observations extend back to before 1000 BC. However, fairly systematic records are only available since 200 BC - and even these have suffered losses through wars, etc. By around AD 800, many independent observations are available from Japan and Korea and these provide a valuable supplement to the Chinese data. Throughout East Asia dates were expressed in terms of a luni-solar calendar and conversion to the Julian or Gregorian calendar can be readily effected.

Stephenson, F. Richard

116

Sonification of Astronomical Data  

NASA Astrophysics Data System (ADS)

This document presents Java-based software called xSonify that uses a sonification technique (the adaptation of sound to convey information) to promote discovery in astronomical data. The prototype is designed to analyze two-dimensional data, such as time-series data. We demonstrate the utility of the sonification technique with examples applied to X-ray astronomy and solar data. We have identified frequencies in the Chandra X-Ray observations of EX Hya, a cataclysmic variable of the intermediate polar type. In another example we study the impact of a major solar flare, with its associated coronal mass ejection (CME), on the solar wind plasma (in particular the solar wind between the Sun and the Earth), and the Earth's magnetosphere.

Diaz-Merced, Wanda L.; Candey, Robert M.; Brickhouse, Nancy; Schneps, Matthew; Mannone, John C.; Brewster, Stephen; Kolenberg, Katrien

2012-04-01

117

Fluctuations in astronomical masers  

SciTech Connect

The radiation of astronomical masers fluctuates on the time scale 1/Gamma, where Gamma is the levels' loss rate. These intensity fluctuations reflect fluctuations of the level poulations around their mean, steady state values over the length scale lambda(c) = c/Gamma. In saturated masers, the intensity fluctuations are dominated by passage through the unsaturated core. The effects of the saturated zones and of the seed radiation that the masers amplify can be neglected. These fluctuations may have been detected in recent observations by Clegg and Cordes (1991) of Galactic H II/OH masers, providing a possible direct determination of the saturation intensity Js (= Gamma/2B), an important input parameter for theoretical modeling. Long time-scale variations in the fluctuation amplitudes can provide information on phenomena such as passage of hydrodynamic waves in the maser region. 9 refs.

Elitzur, M. (Kentucky Univ., Lexington (USA))

1991-03-01

118

Two ESA astronauts named to early Hubble Space Telescope servicing mission  

NASA Astrophysics Data System (ADS)

Nicollier and three NASA astronauts, who had already been training for a Hubble servicing mission planned for June 2000, have been reassigned to this earlier mission (STS-103). Jean-Francois Clervoy and two other NASA astronauts will complete the STS-103 crew. The repairs and maintenance of the telescope will require many hours spent working outside the Shuttle and will make extensive use of the Shuttle's robotic arm Nicollier, of Swiss nationality and making his fourth flight, will be part of the team that will perform the "spacewalks". An astronomer by education, he took part in the first Hubble servicing mission (STS-61) in 1993, controlling the Shuttle's robotic arm while astronauts on the other end of the arm performed the delicate repairs to the telescope. He also served on STS-46 in 1992 using the robotic arm to deploy ESA's Eureca retrievable spacecraft from the Shuttle, and on STS-75 with the Italian Tethered Satellite System in 1996. Nicollier is currently the chief of the robotics branch in NASA's astronaut office and ESA's lead astronaut in Houston. Jean-Francois Clervoy, of French nationality and making his third flight, will have the lead role in the operation of the robotic arm for this mission. He previously served on STS-66 in 1994 using the robotic arm to deploy and later retrieve the German CRISTA-SPAS atmospheric research satellite, and on STS-84 in 1997, a Shuttle mission to the Russian Mir space station. The other STS-103 crewmembers are: Commander Curtis Brown, pilot Scott Kelly, and mission specialists Steven Smith, Michael Foale and John Grunsfeld. During the flight, the astronauts will replace Hubble's failing pointing system, which allows the telescope to aim at stars, planets and other targets, and install other equipment that will be ready for launch at that time. A second mission to complete the previously-scheduled Hubble refurbishment work is foreseen at a later date. The crew for that mission has not yet been assigned. The Hubble Space Telescope, launched in 1990, is one of the most powerful optical telescopes available to astronomers today, producing images and spectral observations at the forefront of astronomy. ESA contributed a 15 share to the development of Hubble and European astronomers receive in return a guaranteed 15 share of observing time (and 20 on average in practice).

1999-03-01

119

New explanation of Hubble's redshift  

NASA Astrophysics Data System (ADS)

``Like mass attract, like energy repel each other.'' So the energy can make a repulsive gravity and a negative curvature. There is a balance of a flat universe between a gravity and a repulsive gravity. (1) ?m=?d=?g=?rg=0.5. Among it, ?m: the density of matter, ?d: the density of dark energy, ?g: the density of matter of gravity, ?rg: the density of matter of repulsive gravity. When the wave travel in the universe, its quantum space-time will conversion to an universal space-time. It will cause the quantum space-time to change. According to the Hubble's redshift, (2)H0 (?D)??. Among it, H0: Hubble constant, ?: the frequence, ?: the wavelength, D: the universal displacement, ?D: the rate of the translation between the quantum space-time and the universal space-time. ``An energy momentum tensor scalar field is a space-time field. The quantum time is the frequance and the quantum space is the amplitude square.'' (see Dayong Cao, ``MEST,'' BAPS.2011.DFD.LA.25, ``MEST,'' BAPS.2010.DFD.QE.2, ``MEST,'' BAPS.2012.MAR.K1.256, ``MEST,'' BAPS.2012.APR.E1.2 and ``MEST,'' BAPS.2010.MAR.S1.240) So the universe do not expanding. Supported by AEEA.

Cao, Dayong

2012-10-01

120

The CAPRI Project: Coordinates for Astronomical Press Release Images  

NASA Astrophysics Data System (ADS)

The beauty and splendor of astronomical press release images has made an enormously positive impact with the media and public alike. As a leading provider of astronomical imagery and a major contributor of Hubble Space Telescope press release images, the outreach division of Space Telescope Science Institute (STScI) recognizes the importance of making press release images compliant with virtual observatory standards for inclusion in databases and repositories. Our goal is to make outreach images accessible by virtual observatory applications by calculating World Coordinate System (WCS) data for these images. We provide updated and improved software that allows observatories to easily and accurately transform coordinates on their astronomical press release images, using reference FITS files. The resultant metadata conforms to the Simple Image Access (SIA) protocol established by the International Virtual Observatory Alliance and has been used by popular end users such as Google Sky and World Wide Telescope. Several hundred images from the STScI Office of Public Outreach NewsCenter database have been processed, and their coordinates and other relevant metadata are accessible through an SIA-compliant web service.

Frattare, Lisa M.; Ferguson, B. A.; Summers, F.; Levay, Z. G.

2009-01-01

121

Hubble 2008: Science Year in Review.  

National Technical Information Service (NTIS)

Hubbles remarkable mission has now spanned 18 years. During that time, it has been at the nexus of perhaps the most exciting period of discovery in the history of astronomy. Simultaneously, Hubble has offered up some of the most daunting engineering chall...

2009-01-01

122

Hubble 2009 Science Year in Review.  

National Technical Information Service (NTIS)

Hubble's remarkable mission has now spanned 19 years. During that period, it has been at the nexus of perhaps the most exciting period of discovery in the history of astronomy. At the same time, Hubble has offered up some of the most daunting challenges t...

2010-01-01

123

Duty or dream? Edwin G. Conklin's critique of eugenics and support for American individualism.  

PubMed

This paper assesses ideas about moral and reproductive duty in American eugenics during the early twentieth century. While extreme eugenicists, including Charles Davenport and Paul Popenoe, argued that social leaders and biologists must work to prevent individuals who were "unfit" from reproducing, moderates, especially Edwin G. Conklin, presented a different view. Although he was sympathetic to eugenic goals and participated in eugenic organizations throughout his life, Conklin realized that eugenic ideas rarely could meet strict hereditary measures. Relying on his experience as an embryologist, Conklin instead attempted to balance more extreme eugenic claims - that emphasized the absolute limits posed by heredity - with his own view of "the possibilities of development." Through his critique he argued that most human beings never even begin to approach their hereditary potential; he moderated his own eugenic rhetoric so that it preserved individual opportunity and responsibility, or what has often been labeled the American Dream. PMID:12269346

Cooke, Kathy J

2002-01-01

124

XEphem: Interactive Astronomical Ephemeris  

NASA Astrophysics Data System (ADS)

XEphem is a scientific-grade interactive astronomical ephemeris package for UNIX-like systems. Written in C, X11 and Motif, it is easily ported to systems. Among other things, XEphem: * computes heliocentric, geocentric and topocentric information for all objects; * has built-in support for all planets; the moons of Mars, Jupiter, Saturn, Uranus and Earth; central meridian longitude of Mars and Jupiter; Saturn's rings; and Jupiter's Great Red Spot; * allows user-defined objects including stars, deepsky objects, asteroids, comets and Earth satellites; * provides special efficient handling of large catalogs including Tycho, Hipparcos, GSC; * displays data in configurable tabular formats in conjunction with several interactive graphical views; * displays a night-at-a-glance 24 hour graphic showing when any selected objects are up; * displays 3-D stereo Solar System views that are particularly well suited for visualizing comet trajectories; * quickly finds all close pairs of objects in the sky; and * sorts and prints all catalogs with very flexible criteria for creating custom observing lists.Its capabilities are listed more fully in the user manual introduction.

Downey, Elwood Charles

2011-12-01

125

Hubble's Next Generation Spectral Library  

NASA Astrophysics Data System (ADS)

Spectroscopic surveys of galaxies at z 1 or more bring the rest-frame ultraviolet into view of large, ground-based telescopes. This spectral region is rich in diagnostics, but these diagnostics have not yet been calibrated in terms of the properties of the responsible stellar population(s). Such calibrations are now possible with Hubble's Next Generation Spectral Library (NGSL). This library contains UV-optical spectra (0.2-1.0 microns) of 378 stars having a wide range in temperature, luminosity, and metallicity. We have derived the basic stellar parameters from the optical spectral region (0.35 - 1.0 microns) and are using them to calibrate UV spectral diagnostic indices and colors.

Heap, Sara R.; Lindler, D.

2008-03-01

126

Astronomic Circular No. 605, 1971.  

National Technical Information Service (NTIS)

The report contains a translation of the following titles, contained in Astronomic Circular No. 605; On the problem of small eccentricities in the theory of satellite motion; On comet and minor planets collision; and, Hypsometry of the moon's surface. (Au...

I. E. Zalkalne V. V. Terentev Y. N. Lipskii Z. F. Rodionova

1972-01-01

127

Astronomical databases of Nikolaev Observatory  

NASA Astrophysics Data System (ADS)

Several astronomical databases were created at Nikolaev Observatory during the last years. The databases are built by using MySQL search engine and PHP scripts. They are available on NAO web-site http://www.mao.nikolaev.ua.

Protsyuk, Y.; Mazhaev, A.

2008-07-01

128

Early results from the Infrared Astronomical Satellite  

Microsoft Academic Search

For 10 months the Infrared Astronomical Satellite (IRAS) provided astronomers with what might be termed their first view of the infrared sky on a clear, dark night. Without IRAS, atmospheric absorption and the thermal emission from both the atmosphere and Earthbound telescopes make the task of the infrared astronomer comparable to what an optical astronomer would face if required to

G. Neugebauer; C. A. Beichman; B. T. Soifer; H. H. Aumann; T. J. Chester; T. N. Gautier; F. C. Gillett; M. G. Hauser; J. R. Houck; C. J. Lonsdale; F. J. Low; E. T. Young

1984-01-01

129

Sixteenth Century Astronomical Telescopy  

NASA Astrophysics Data System (ADS)

Ophelia in Shakespeare's Hamlet is named for the ``moist star" which in mythology is the partner of Hamlet's royal Sun. Together the couple seem destined to rule on earth just as their celestial counterparts rule the heavens, but the tragedy is that they are afflicted, just as the Sun and Moon are blemished. In 1.3 Laertes lectures Ophelia on love and chastity, describing first Cytherean phases (crescent to gibbous) and then Lunar craters. Spots mar the Sun (1.1, 3.1). Also reported are Jupiter's Red Spot (3.4) and the resolution of the Milky Way into stars (2.2). These interpretations are well-founded and support the cosmic allegory. Observations must have been made with optical aid, probably the perspective glass of Leonard Digges, father of Thomas Digges. Notably absent from Hamlet is mention of the Galilean moons, owing perhaps to the narrow field-of-view of the telescope. That discovery is later celebrated in Cymbeline, published soon after Galileo's Siderius Nuncius in 1610. In 5.4 of Cymbeline the four ghosts dance ``in imitation of planetary motions" and at Jupiter's behest place a book on the chest of Posthumus Leonatus. His name identifies the Digges father and son as the source of data in Hamlet since Jupiter's moons were discovered after the deaths of Leonard (``leon+hart") and Thomas (the ``lion's whelp"). Lines in 5.4 urge us not to read more into the book than is contained between its covers; this is understandable because Hamlet had already reported the other data in support of heliocentricism and the cosmic model discussed and depicted by Thomas Digges in 1576. I conclude therefore that astronomical telescopy began in England before the last quarter of the sixteenth century.

Usher, P. D.

2001-12-01

130

Astronomical Parallax 3D  

NSDL National Science Digital Library

This Astronomical Parallax 3D Model illustrates the phenomenon of annual stellar parallax in astronomy. Parallax is the apparent displacement of an object relative to the background that is caused by the motion of the observer (rather than the motion of the object itself, or of the background). This simulation illustrates the parallax of an object in space that results from the Earth's annual orbital motion. The Space View window shows the Earth (blue point) orbiting the Sun (organe point). The white point represents a stationary star. The open white circle shows the location of the object on the celestial sphere as seen from the Sun. The magenta point shows the location of the star on the celestial sphere as seen by an observer on the orbiting Earth. Various options allow the user to display the line of sight from Earth through the star, the line from the Sun through the star, cardinal direction arrows, the trace of the star's apparent motion, the trace of Earth's orbit, and the planes and axes of the celestial equator and ecliptic. Controls allow the user to adjust the distance to the star as well as its celestial coordinates (as seen from the Sun). Another menu allows the user to select a particular day (equinox or solstice) of the year. The Sky View window shows the apparent location of the star on the sky as seen by an Earth observer. The "true location" (the location as seen from the Sun) is shown as an open white circle, while the apparent location is shown as a magenta disk. Note that some features have been simplified or exaggerated. The Earth's orbit is treated as a circle. The distances to the "star" are vastly smaller than the distance to any real star (at the distance to the nearest real star the annual parallax would be imperceptible in this simulation). The size of the Earth, sun, and star are exaggerated so as to make them visible on the scale of the simulation.

Timberlake, Todd

2011-05-18

131

Hubble Space Telescope Servicing begins.  

NASA Astrophysics Data System (ADS)

The day's work began when astronauts Story Musgrave and Jeff Hoffman stepped out into the cargo bay at 9h41 pm CST, Saturday (4h41 am CET, Sunday). They immediately set to work replacing two gyroscope assemblies, known as the Rate Sensor Units, two associated electronics boxes, called Electronic Control Units, and eight electrical fuse plugs. The work was completed ahead of schedule, but the astronauts had trouble closing the doors of the compartment housing the gyros and took over an hour to get them shut. The astronauts also prepared equipment for the replacement of the solar arrays. "The feeling down here is one of great satisfaction for a tremendous job today" said spacecraft communicator Greg Harbaugh in mission control. "We are very proud of the work that you all did and we are very confident in the continued success of the mission. Everything is going great and tomorrow is going to be another great day". ESA astronaut Claude Nicollier played a vital role during the spacewalk moving the astronauts and their equipment around the cargo bay with the shuttle's robot arm. The Hubble Space Telescope servicing mission features more robot arm operations than any other shuttle flight. The telescope's left-hand solar array was rolled up successfully at 6h24 am CST (1h24 pm CET). The 11-tonne observatory was rotated 180 degrees on its turntable before commands were sent to retract the second array at 8h23 am CST (3h23 pm CET). The crew stopped the retraction when it appeared the system may have jammed. Mission control instructed the crew to jettison the array, a procedure that they have trained for. Tomorrow astronauts Kathy Thornton and Tom Akers will make a six-hour spacewalk to jettison the troublesome wing, store the other in the cargo bay, and install two new panels supplied by ESA. The second set of arrays feature thermal shields and a modified thermal compensation system to prevent the flexing that affected the first pair. The Hubble Space Telescope was plucked from orbit this Saturday by ESA astronaut Claude Nicollier, operating the shuttle's robot arm. The Swiss-born astronaut gripped the 11- tonne observatory with the shuttle's 15-metre long robot arm at 2h34 am CST (9h34 am CET) after a two-day chase through space as the two spacecraft flew over the South Pacific Ocean. "Endeavour has a firm handshake with Mr. Hubble's telescope" said mission commander Dick Covey. "It's quite a sight". About half an hour later Nicollier had the telescope berthed on a special turntable in the back of the Shuttle's cargo bay. Later he used the camera at the end of the arm to surveyed the telescope for any damage. As the shuttle approached the telescope the astronauts first reported that one of the twin solar arrays appeared to be bowed and twisted. ESA officials said the problem was caused by the failure in early 1992 of the tensioning system on one side of the right-hand array. The system is designed to allow the blanket-like array to expand and contract in orbit. That failure placed stress on one of the supporting bi-stem booms resulting in its bent condition. Endeavour's mission began Thursday 2 December and will end 13 December. A total of five spacewalks are planned to service the telescope.

1993-12-01

132

THE PANCHROMATIC HUBBLE ANDROMEDA TREASURY  

SciTech Connect

The Panchromatic Hubble Andromeda Treasury is an ongoing Hubble Space Telescope Multi-Cycle Treasury program to image {approx}1/3 of M31's star-forming disk in six filters, spanning from the ultraviolet (UV) to the near-infrared (NIR). We use the Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) to resolve the galaxy into millions of individual stars with projected radii from 0 to 20 kpc. The full survey will cover a contiguous 0.5 deg{sup 2}area in 828 orbits. Imaging is being obtained in the F275W and F336W filters on the WFC3/UVIS camera, F475W and F814W on ACS/WFC, and F110W and F160W on WFC3/IR. The resulting wavelength coverage gives excellent constraints on stellar temperature, bolometric luminosity, and extinction for most spectral types. The data produce photometry with a signal-to-noise ratio of 4 at m{sub F275W} = 25.1, m{sub F336W} = 24.9, m{sub F475W} = 27.9, m{sub F814W} = 27.1, m{sub F110W} = 25.5, and m{sub F160W} = 24.6 for single pointings in the uncrowded outer disk; in the inner disk, however, the optical and NIR data are crowding limited, and the deepest reliable magnitudes are up to 5 mag brighter. Observations are carried out in two orbits per pointing, split between WFC3/UVIS and WFC3/IR cameras in primary mode, with ACS/WFC run in parallel. All pointings are dithered to produce Nyquist-sampled images in F475W, F814W, and F160W. We describe the observing strategy, photometry, astrometry, and data products available for the survey, along with extensive testing of photometric stability, crowding errors, spatially dependent photometric biases, and telescope pointing control. We also report on initial fits to the structure of M31's disk, derived from the density of red giant branch stars, in a way that is independent of assumed mass-to-light ratios and is robust to variations in dust extinction. These fits also show that the 10 kpc ring is not just a region of enhanced recent star formation, but is instead a dynamical structure containing a significant overdensity of stars with ages >1 Gyr.

Dalcanton, Julianne J.; Williams, Benjamin F.; Rosenfield, Philip; Weisz, Daniel R.; Gilbert, Karoline M.; Gogarten, Stephanie M. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Lang, Dustin [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Lauer, Tod R.; Dong Hui [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Kalirai, Jason S.; Boyer, Martha L.; Gordon, Karl D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Seth, Anil C. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Dolphin, Andrew [Raytheon Company, 1151 East Hermans Road, Tucson, AZ 85756 (United States); Bell, Eric F. [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States); Bianchi, Luciana C. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Caldwell, Nelson [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Dorman, Claire E.; Guhathakurta, Puragra [University of California Observatories/Lick Observatory, University of California, 1156 High St., Santa Cruz, CA 95064 (United States); Girardi, Leo [Osservatorio Astronomico di Padova-INAF, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy); and others

2012-06-01

133

The New Amateur Astronomer  

NASA Astrophysics Data System (ADS)

Amateur astronomy has changed beyond recognition in less than two decades. The reason is, of course, technology. Affordable high-quality telescopes, computer-controlled 'go to' mountings, autoguiders, CCD cameras, video, and (as always) computers and the Internet, are just a few of the advances that have revolutionized astronomy for the twenty-first century. Martin Mobberley first looks at the basics before going into an in-depth study of what’s available commercially. He then moves on to the revolutionary possibilities that are open to amateurs, from imaging, through spectroscopy and photometry, to patrolling for near-earth objects - the search for comets and asteroids that may come close to, or even hit, the earth. The New Amateur Astronomer is a road map of the new astronomy, equally suitable for newcomers who want an introduction, or old hands who need to keep abreast of innovations. From the reviews: "This is one of several dozen books in Patrick Moore's "Practical Astronomy" series. Amid this large family, Mobberley finds his niche: the beginning high-tech amateur. The book's first half discusses equipment: computer-driven telescopes, CCD cameras, imaging processing software, etc. This market is changing every bit as rapidly as the computer world, so these details will be current for only a year or two. The rest of the book offers an overview of scientific projects that serious amateurs are carrying out these days. Throughout, basic formulas and technical terms are provided as needed, without formal derivations. An appendix with useful references and Web sites is also included. Readers will need more than this book if they are considering a plunge into high-tech amateur astronomy, but it certainly will whet their appetites. Mobberley's most valuable advice will save the book's owner many times its cover price: buy a quality telescope from a reputable dealer and install it in a simple shelter so it can be used with as little set-up time as possible. A poor purchase choice and the hassle of setting up are why most fancy telescopes gather dust in their owners' dens. Summing Up: Highly recommended. General readers; lower- and upper-division undergraduates."( T. D. Oswalt, CHOICE, March 2005)

Mobberley, Martin

134

Endeavour returns from Hubble servicing  

NASA Astrophysics Data System (ADS)

During the hour-long descent from space ESA astronaut Claude Nicollier helped mission commander Dick Covey and pilot Ken Bowersox monitor the shuttle's cockpit displays. During their 11-day mission the astronauts fitted the telescope with corrective optics and a new set of European solar panels. If all goes according to plan the observatory will be restored to very nearly its original capability. The first images from the rejuvenated telescope should be released in about 6-8 weeks. ESA had a major role in this mission. In addition to providing the solar arrays, the European Space Agency helped NASA test the Costar corrective optics system. ESA astronaut Claude Nicollier operated the shuttle's robot arm throughout the complex spacewalks to service the telescope and during the crucial capture and release phases. "This was a particularly important international mission from the standpoint of our Swiss and European Space Agency crew member Claude Nicollier, who played an incredibly important part in the repair of the Hubble Space Telescope", mission commander Dick told Swiss Minister of Internal Affairs Mrs Ruth Dreifuss, during a VIP telephone call on Sunday morning. "If there was an unsung hero of this mission it would be Claude and his arm because without them we could not have worked the way we did and been as successful as we were".

1993-12-01

135

Enabling Science with the Hubble Legacy Archive  

Microsoft Academic Search

Significant enhancements to the Hubble archive will prepare it for legacy use and provide major new science capabilities.\\u000a The focus is on higher-level data products than are available from the classic Hubble archive, including fully calibrated\\u000a exposures and enhanced image products as well as source lists. All data products are immediately available on disk, eliminating\\u000a the latency of queued data

Helmut Jenkner; W. Warren Miller; Bradley C. Whitmore

2010-01-01

136

The Management of Astronomical Data  

NASA Astrophysics Data System (ADS)

Astronomy has a distinguished tradition of using technology to accelerate the quality and effectiveness of science. However, amongst the shining examples of excellent data management by major projects lie examples of projects and institutions where data management has not been properly resourced, or where hard-earned data remain inaccessible to most astronomers. We need to establish and agree on a set of guiding principles for the management of astronomical data. For example, all OECD governments, representing nearly all countries with major astronomical facilities, have committed to the principle that publicly-funded data should be placed in the public domain. The last IAU GA in Sydney passed a resolution that archive data from publicly funded observatories should be placed in the public domain. The HST archive, which quadruples the number of science publications resulting from HST data, has demonstrated the value to science of doing so. And yet many observatory archives are still inaccessible. Another example is the barrier between journals and data centres. The astronomical data centres are enormously successful, and provide powerful tools which have accelerated the advance of science, and some of our journals are forward-looking and receptive to new ideas. And yet most data published in those journals never appear in the data centres. These two examples show that we are not making most effective use of our data, and consequently are not extracting the maximum scientific value from our observatories and astronomers. The Virtual Observatory promises us tools to provide better access to data, but these tools lose their value if the data are not available. It is time for the astronomical community to adopt a professional approach to data management, to maximise the science that can be achieved with our new and existing facilities.

Norris, R. P.

2006-08-01

137

The Astronomical Mapping Program (AMP)  

NASA Astrophysics Data System (ADS)

The present Astronomical Mapping Program (AMP) has solved the problem of astronomical data plotting, which requires the accurate projection of data based on a spherical coordinate system onto a two-dimensional surface, by using the Mercator, Lambert conformal, and polar stereographic map projection systems. AMP also furnishes users the greatest flexibility in acceptance of the type of data that is to be plotted; both stars and nonstellar objects can be treated by a given mapping run. There is no inherent limitation on the amount of data that the AMP system can map.

Rappaport, Barry N.

1986-01-01

138

Astronomical Archive at Tartu Observatory  

NASA Astrophysics Data System (ADS)

Archiving astronomical data is important task not only at large observatories but also at small observatories. Here we describe the astronomical archive at Tartu Observatory. The archive consists of old photographic plate images, photographic spectrograms, CCD direct--images and CCD spectroscopic data. The photographic plate digitizing project was started in 2005. An on-line database (based on MySQL) was created. The database includes CCD data as well photographic data. A PHP-MySQL interface was written for access to all data.

Annuk, K.

2007-10-01

139

The astronomer - N. N. Donitch  

NASA Astrophysics Data System (ADS)

This paper describes a history of friendship and collaboration between the astronomers N. Donitch and A.A. Baikov. Information on other astronomers, L.V. Okulitch and E.A. Von der Pahlen, and meteorologists V.H. Dubinskii and Nina Gouma, can also be found. Details on the expeditions aimed at observing the total solar eclipses on 30 August 1905 (organized by the Imperial Academy of Sciences in Sankt-Petersburg) and 19 June 1936 (organized by the Romanian Royal Cultural foundation) are given. The main part represents the first English translation of the paper by Baikov, published earlier in Russian and Romanian, with a new preface, annotations, and comments.

Baikov, A. A.; Gaina, A.

140

Astronomical Limiting Magnitude at Langkawi Observatory  

NASA Astrophysics Data System (ADS)

Astronomical limiting magnitude is an indicator for astronomer to conduct astronomical measurement at a particular site. It gives an idea to astronomer of that site what magnitude of celestial object can be measured. Langkawi National Observatory (LNO) is situated at Bukit Malut with latitude 6°18' 25'' North and longitude 99°46' 52'' East in Langkawi Island. Sky brightness measurement has been performed at this site using the standard astronomical technique. The value of the limiting magnitude measured is V = 18.6+/-1.0 magnitude. This will indicate that astronomical measurement at Langkawi observatory can only be done for celestial objects having magnitude less than V = 18.6 magnitudes.

Zainuddin, Mohd. Zambri; Loon, Chin Wei; Harun, Saedah

2010-07-01

141

Evaluation of the vent header crack at Edwin 1. Hatch Unit No. 2 Nuclear Power Station  

SciTech Connect

A metallurgical failure analysis was performed on pieces of the cracked vent header pipe from the Edwin I. Hatch Unit 2 Nuclear Power Plant. The analysis consisted of optical microscopy, chemical analysis, mechanical Charpy impact testing and fractography. The general conclusions drawn from this analysis were: (1) the material of the vent header met the mechanical and chemical properties of ASTM A516 Gr. 70 material and that the microstructures were consistent with this material; (2) the fracture faces of the cracked pipe were predominantly brittle in appearance with no evidence of fatigue contribution; (3) the NDTT (Nil Ductility Transition Temperature) for this material is approximately -60/sup 0/F (-51/sup 0/C); and (4) the fact that the material's NDTT is significantly out of the normal operating range of the pipe suggests that an impingement of low temperature nitrogen (caused by a faulty torus inerting system) induced a thermal shock in the pipe which, when cooled below its NDTT, cracked in a brittle manner.

Czajkowski, C.J.

1985-01-01

142

Old Star's "Rebirth" Gives Astronomers Surprises  

NASA Astrophysics Data System (ADS)

Astronomers using the National Science Foundation's Very Large Array (VLA) radio telescope are taking advantage of a once-in-a-lifetime opportunity to watch an old star suddenly stir back into new activity after coming to the end of its normal life. Their surprising results have forced them to change their ideas of how such an old, white dwarf star can re-ignite its nuclear furnace for one final blast of energy. Sakurai's Object Radio/Optical Images of Sakurai's Object: Color image shows nebula ejected thousands of years ago. Contours indicate radio emission. Inset is Hubble Space Telescope image, with contours indicating radio emission; this inset shows just the central part of the region. CREDIT: Hajduk et al., NRAO/AUI/NSF, ESO, StSci, NASA Computer simulations had predicted a series of events that would follow such a re-ignition of fusion reactions, but the star didn't follow the script -- events moved 100 times more quickly than the simulations predicted. "We've now produced a new theoretical model of how this process works, and the VLA observations have provided the first evidence supporting our new model," said Albert Zijlstra, of the University of Manchester in the United Kingdom. Zijlstra and his colleagues presented their findings in the April 8 issue of the journal Science. The astronomers studied a star known as V4334 Sgr, in the constellation Sagittarius. It is better known as "Sakurai's Object," after Japanese amateur astronomer Yukio Sakurai, who discovered it on February 20, 1996, when it suddenly burst into new brightness. At first, astronomers thought the outburst was a common nova explosion, but further study showed that Sakurai's Object was anything but common. The star is an old white dwarf that had run out of hydrogen fuel for nuclear fusion reactions in its core. Astronomers believe that some such stars can undergo a final burst of fusion in a shell of helium that surrounds a core of heavier nuclei such as carbon and oxygen. However, the outburst of Sakurai's Object is the first such blast seen in modern times. Stellar outbursts observed in 1670 and 1918 may have been caused by the same phenomenon. Astronomers expect the Sun to become a white dwarf in about five billion years. A white dwarf is a dense core left after a star's normal, fusion-powered life has ended. A teaspoon of white dwarf material would weigh about 10 tons. White dwarfs can have masses up to 1.4 times that of the Sun; larger stars collapse at the end of their lives into even-denser neutron stars or black holes. Computer simulations indicated that heat-spurred convection (or "boiling") would bring hydrogen from the star's outer envelope down into the helium shell, driving a brief flash of new nuclear fusion. This would cause a sudden increase in brightness. The original computer models suggested a sequence of observable events that would occur over a few hundred years. "Sakurai's object went through the first phases of this sequence in just a few years -- 100 times faster than we expected -- so we had to revise our models," Zijlstra said. The revised models predicted that the star should rapidly reheat and begin to ionize gases in its surrounding region. "This is what we now see in our latest VLA observations," Zijlstra said. "It's important to understand this process. Sakurai's Object has ejected a large amount of the carbon from its inner core into space, both in the form of gas and dust grains. These will find their way into regions of space where new stars form, and the dust grains may become incorporated in new planets. Some carbon grains found in a meteorite show isotope ratios identical to those found in Sakurai's Object, and we think they may have come from such an event. Our results suggest this source for cosmic carbon may be far more important than we suspected before," Zijlstra added. The scientists continue to observe Sakurai's Object to take advantage of the rare opportunity to learn about the process of re-ignition. They are making new VLA observations just

2005-04-01

143

Lunar astronomical observatories - Design studies  

Microsoft Academic Search

The best location in the inner solar system for the grand observatories of the 21st century may be the moon. A multidisciplinary team including university students and faculty in engineering, astronomy, physics, and geology, and engineers from industry is investigating the moon as a site for astronomical observatories and is doing conceptual and preliminary designs for these future observatories. Studies

Stewart W. Johnson; Jack O. Burns; Koon Meng Chua; Nebojsa Duric; Walter H. Gerstle

1990-01-01

144

Astronomical Image Processing with Hadoop  

Microsoft Academic Search

In the coming decade astronomical surveys of the sky will generate tens of terabytes of images and detect hundreds of millions of sources every night. With a requirement that these images be analyzed in real time to identify moving sources such as potentially hazardous asteroids or transient objects such as supernovae, these data streams present many computational challenges. In the

K. Wiley; A. Connolly; S. Krughoff; J. Gardner; M. Balazinska; B. Howe; Y. Kwon; Y. Bu

2011-01-01

145

John Couch Adams, the astronomer.  

NASA Astrophysics Data System (ADS)

The planet Neptune was discovered more than 140 years ago. The circumstances of the discovery gave rise to great controversy, and very nearly led to an international incident between Britain and France, but this was only one of John Couch Adams' many contributions to astronomical science.

Foster, N.

1989-03-01

146

Analysis of astronomical time series  

Microsoft Academic Search

This paper presents basic concepts of time series analysis (TSA), emphasizes statistical aspects of TSA, and reviews available TSA tools, particularly those with applications in astronomy. The importance of statistical principles in evaluation of time series in astronomical practice is discussed. The author draws attention to the distortions in the analysis of time series, their causes, effects and possible cures.

A. Schwarzenberg-Czerny

1993-01-01

147

An Astronomical Software Directory Service  

NASA Astrophysics Data System (ADS)

We will be developing an on-line Astronomical Software Directory Service (ASDS) with funding from NASA's Astrophysics Data Program. Our primary objective is to allow astronomers and astronomical software developers to easily locate existing programs for their use and re-use, providing a uniform level of high-level documentation (package capabilities, system dependencies, installation requirements, etc.). The ASDS will catalog a comprehensive set of astronomical data reduction and analysis software, including the packages being developed with ADP support. The ASDS is intended as a directory service -- a query for a certain type of software will result in the user being given information about what software is available as well as instructions for retrieving relevant packages from anonymous FTP servers. Software retrieval may also be automated. We will not archive software per se, given that problems of revision control, currency, and algorithm validation are untenable. Users will interact with the system using a public domain distributed database interface such as WAIS, Gopher, and/or WWW.

Hanisch, R. J.; Payne, H.; Hayes, J. J. E.

148

Hubble gets revitalised in new Servicing Mission for more and better science!  

NASA Astrophysics Data System (ADS)

As a unique collaboration between the European Space Agency (ESA), and NASA, Hubble has had a phenomenal scientific impact. The unsurpassed sharp images from this space observatory have penetrated into the hidden depths of space and revealed breathtaking phenomena. But Hubble's important contributions to science have only been possible through a carefully planned strategy to service and upgrade Hubble every two or three years. ESA, the European Space Agency has a particular role to play in this Servicing Mission. One of the most exciting events of this mission will come when the ESA-built solar panels are replaced by newer and more powerful ones. The new panels, developed in the US, are equipped with ESA developed drive mechanisms and were tested at the facilities at ESA's European Space Research and Technology Centre (ESTEC) in the Netherlands. This facility is the only place in the world where such tests can be performed. According to Ton Linssen, HST Project Manager at ESA, who supervised all ESA involvement in the new solar panels development including the test campaign at Estec - "a particularly tense moment occurs when the present solar panels have to be rolled up to fit into the Shuttle's cargo bay. The hard environment of space has taken its toll on the panels and it will be a very delicate operation to roll them up. Our team will be waiting and watching with bated breath. If the panels can't be rolled up they will possibly have to be left in space." "With this Servicing Mission Hubble is once again going to be brought back to the frontline of scientific technology", says Piero Benvenuti, Hubble Project Scientist at ESA. "New super-advanced instrumentation will revitalise the observatory. For example, Hubble's new digital camera - The new Advanced Camera for Surveys, or ACS - can take images of twice the area of the sky and with five times the sensitivity of Hubble's previous instruments, therefore increasing by ten times Hubble's discovery capability! The European astronomers look forward to use the new camera and perform new science building on the great breakthroughs they have already achieved." ACS is going to replace the Faint Object Camera, or FOC, built by ESA. The FOC, which has functioned perfectly since the beginning, has been a key instrument to get the best out of the unprecedented imaging capability of Hubble. The FOC was a "state-of-the art" instrument in the 80s, but the field of digital imaging has progressed so much in the past 20 years that, having fulfilled its scientific goals, this ESA flagship on Hubble is chivalrously giving way to newer technology. However, the story of FOC is not over yet: experts will still learn from it, as it will be brought back to Earth and inspected, to study the effects on the hardware of the long duration exposure in space. Hubble is expected to continue to explore the sky during the next decade, after which its work will be taken over by its successor, the powerful ESA/NASA/CSA(*) Next Generation Space Telescope. NGST's main focus will be observations of the faint infrared light from the first stars and galaxies in the Universe. Notes for editors The Hubble Space Telescope is a project of international co-operation between ESA and NASA. It was launched in 1990. The partnership agreement between ESA and NASA was signed on 7 October 1977; as a result of this agreement European astronomers have guaranteed access to more than 20% of Hubble's observing time. Astronauts have already paid visits to Hubble in 1993, '97, '99 and now, in the spring of 2002, it is time for the fourth Servicing Mission (named Servicing Mission 3B), planned for launch on 28th February. Originally planned as one mission, the third Servicing Mission was split into two parts (Servicing Mission 3A and 3B) because of the sheer number of tasks to be carried out and the urgency with which Hubble's gyroscopes had to be replaced in late '99. In addition to the new solar panels and the ACS camera, astronauts will install a very high-tech cooling system for Hubble

2002-02-01

149

Hubble Identifies What May Be the Most Luminous Star Known  

NSDL National Science Digital Library

The Space Telescope Science Institute and National Aeronautics and Space Administration's Jet Propulsion Laboratory contain sites of current interest related to the stars and planets this week. A UCLA-led team using cameras recently installed aboard the Hubble Space Telescope has identified a massive star approximately 25,000 light-years from Earth. Named the "Pistol Star" for the pistol-shaped nebula surrounding it, it is believed to be one of the largest ever discovered, releasing up to ten million times the energy of our sun and spanning the diameter of the Earth's orbit. Astronomers claim that the Pistol Star "unleashes as much energy in six seconds as our sun does in one year." This site offers the official press release and a caption for photos of the star, which are available in five resolutions and three formats (JPEG, GIF, .pdf). The Cassini flight system, containing a launch vehicle and the Huygens probe orbiter which will explore Saturn's moon Titan in the year 2004, is set to launch October 13, 1997. At this JPL site, interested users can follow launch activity. It features a large section explaining the mission, and includes a section on the controversial nuclear safety issues involved. Users can read both the Cassini Final and Supplemental Environmental Impact Statements issued by NASA (in 1995 and 1997 respectively). There is also an image section and a kids page, among other features.

1997-01-01

150

Astronomical Phenomena for the Year 1990.  

National Technical Information Service (NTIS)

This publication contains information extracted from the Astronomical Almanac for the Year 1990. Dates and times of planetary and lunar phenomena and other astronomical data of general interest are presented.

1988-01-01

151

Lamps of Atlantis: An Astronomical Detective Story.  

National Technical Information Service (NTIS)

The origin of the stellar constellations familiar to western astronomers from ancient times is discussed using astronomical, literary, and archaeological evidence. The precession of the equinoxes, the zone of avoidance and the orientation of the constella...

A. E. Roy

1986-01-01

152

Effect upon universal order of Hubble expansion  

NASA Astrophysics Data System (ADS)

The level of order R in a spherical system of radius r0 with a probability amplitude function ?(x),x=r,?,? obeys R=(1/2)r02I, where I=4?dx| is its Fisher information level. We show that a flat space universe obeying the Robertson-Walker metric has an invariant value of the order as it undergoes either uniform Hubble expansion or contraction. This means that Hubble expansion per se does not cause a loss of universal order as time progresses. Instead, coarse graining processes characterizing decoherence and friction might cause a loss of order. Alternatively, looking backward in time, i.e. under Hubble contraction, as the big bang is approached and the Hubble radius r0 approaches small values, the structure in the amplitude function ?(x) becomes ever more densely packed, increasing all local slopes ?? and causing the Fisher information I to approach unboundedly large values. As a speculation, this ever-well locates the initial position of the universe in a larger, multiverse. We define a measure of order or complexity proportional to the Fisher information. The measure is applied to our flat-space, dust and gas dominated, universe. Despite the universe’s relentless, ever-accelerating Hubble expansion, its level of order is found to remain constant.

Frieden, B. R.; Plastino, A.; Plastino, A. R.

2012-01-01

153

Particle Production and Big Rip Singularities  

Microsoft Academic Search

In 1929, Edwin Hubble found that objects in our Universe generally recede from us at a rate proportional to their distance, suggesting that the Universe as a whole is expanding. More recently, astronomers have observed that this expansion is accelerating. According to Einstein's theory of gravity, all normal matter in the Universe should act to slow the rate of expansion,

Jason Bates

2010-01-01

154

CATALOG MATCHING WITH ASTROMETRIC CORRECTION AND ITS APPLICATION TO THE HUBBLE LEGACY ARCHIVE  

SciTech Connect

Object cross-identification in multiple observations is often complicated by the uncertainties in their astrometric calibration. Due to the lack of standard reference objects, an image with a small field of view can have significantly larger errors in its absolute positioning than the relative precision of the detected sources within. We present a new general solution for the relative astrometry that quickly refines the World Coordinate System of overlapping fields. The efficiency is obtained through the use of infinitesimal three-dimensional rotations on the celestial sphere, which do not involve trigonometric functions. They also enable an analytic solution to an important step in making the astrometric corrections. In cases with many overlapping images, the correct identification of detections that match together across different images is difficult to determine. We describe a new greedy Bayesian approach for selecting the best object matches across a large number of overlapping images. The methods are developed and demonstrated on the Hubble Legacy Archive, one of the most challenging data sets today. We describe a novel catalog compiled from many Hubble Space Telescope observations, where the detections are combined into a searchable collection of matches that link the individual detections. The matches provide descriptions of astronomical objects involving multiple wavelengths and epochs. High relative positional accuracy of objects is achieved across the Hubble images, often sub-pixel precision in the order of just a few milliarcseconds. The result is a reliable set of high-quality associations that are publicly available online.

Budavari, Tamas [Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 (United States); Lubow, Stephen H., E-mail: budavari@jhu.edu, E-mail: lubow@stsci.edu [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States)

2012-12-20

155

Catalog Matching with Astrometric Correction and its Application to the Hubble Legacy Archive  

NASA Astrophysics Data System (ADS)

Object cross-identification in multiple observations is often complicated by the uncertainties in their astrometric calibration. Due to the lack of standard reference objects, an image with a small field of view can have significantly larger errors in its absolute positioning than the relative precision of the detected sources within. We present a new general solution for the relative astrometry that quickly refines the World Coordinate System of overlapping fields. The efficiency is obtained through the use of infinitesimal three-dimensional rotations on the celestial sphere, which do not involve trigonometric functions. They also enable an analytic solution to an important step in making the astrometric corrections. In cases with many overlapping images, the correct identification of detections that match together across different images is difficult to determine. We describe a new greedy Bayesian approach for selecting the best object matches across a large number of overlapping images. The methods are developed and demonstrated on the Hubble Legacy Archive, one of the most challenging data sets today. We describe a novel catalog compiled from many Hubble Space Telescope observations, where the detections are combined into a searchable collection of matches that link the individual detections. The matches provide descriptions of astronomical objects involving multiple wavelengths and epochs. High relative positional accuracy of objects is achieved across the Hubble images, often sub-pixel precision in the order of just a few milliarcseconds. The result is a reliable set of high-quality associations that are publicly available online.

Budavári, Tamás; Lubow, Stephen H.

2012-12-01

156

The Red Rectangle: An Astronomical Example of Mach Bands?  

NASA Astrophysics Data System (ADS)

Recently, the Hubble Space Telescope (HST) produced spectacular images of the "Red Rectangle". This appears to be a binary star system undergoing recurrent mass loss episodes. The image-processed HST photographs display distinctive diagonal lightness enhancements. Some of the visual appearance undoubtedly arises from actual variations in the luminosity distribution of the light of the nebula itself, i.e., due to limb brightening. Psychophysical enhancement similar to the Vasarely or pyramid effect also seems to be involved in the visual impression conveyed by the HST images. This effect is related to Mach bands (as well as to the Chevreul and Craik-O'Brien-Cornsweet effects). The effect can be produced by stacking concentric squares (or other geometrical figures such as rectangles or hexagons) of linearly increasing or decreasing size and lightness, one on top of another. We have constructed controllable Flash applets of this effect as part of the NSF supported "Project LITE: Light Inquiry Through Experiments". They can be found in the vision section of the LITE web site at http://lite.bu.edu. Mach band effects have previously been seen in medical x-ray images. Here we report for the first time the possibility that such effects play a role in the interpretation of astronomical images. Specifically, we examine to what extent the visual impressions of the Red Rectangle and other extended astronomical objects are purely physical (photometric) in origin and to what degree they are enhanced by psychophysical processes. To help assess the relative physical and psychophysical contributions to the perceived lightness effects, we have made use of a center-surround (Difference of Gaussians) filter we developed for MatLab. We conclude that local (lateral inhibition) and longer range human visual perception effects probably do contribute to the lightness features seen in astronomical objects like the Red Rectangle. Project LITE is supported by NSF Grant # DUE-0125992.

Brecher, K.

2005-12-01

157

The Astronomical Society of New York  

Microsoft Academic Search

The New York Astronomical Corporation was formed in 1968 by astronomers at New York State universities, colleges and observatories with the aim of building a large telescope for the use of astronomers in the state. Hawaii was selected as a possible site for a 150-in telescope and for a period of five years a vigorous effort was made at fund

A. G. D. Philip

2000-01-01

158

Hubble and the Language of Images  

NASA Astrophysics Data System (ADS)

Images released from the Hubble Space Telescope have been very highly regarded by the astronomy-attentive public for at least a decade. Due in large part to these images, Hubble has become an iconic figure, even among the general public. This iconic status is both a boon and a burden for those who produce the stream of images fl owing from this telescope. While the benefits of attention are fairly obvious, the negative aspects are less visible. One of the most persistent challenges is the need to continue to deliver images that "top" those released before. In part this can be accomplished because of Hubble's upgraded instrumentation. But it can also be a source of pressure that could, if left unchecked, erode ethical boundaries in our communication with the public. These pressures are magnified in an atmosphere of uncertainty with regard to the future of the mission.

Levay, Z. G.

2005-12-01

159

The Hubble Deep Field South: Flanking Fields  

NASA Astrophysics Data System (ADS)

Due to the availability of the STIS and NICMOS instruments at the time of the observations, the Hubble Deep Field - South Flanking Fields are more complex and varied than those of the Hubble Deep Field - North. In addition to the WFPC2 Flanking Fields, there are parallel observations in STIS and NICMOS for each, and there are also a series of STIS observations of the NICMOS deep field, and associated WFPC2 and NICMOS parallels as well. In this paper, we will present the data and describe the data reduction process used for the HDF-S Flanking Fields.

Lucas, R. A.; Baum, S. A.; Casertano, S.; de Mello, D.; Dickinson, M.; Ferguson, H. C.; Fruchter, A. S.; Gonzalez-Lopezlira, R.; Heyer, I.; Mack, J.; Makidon, R.; Martin, C. L.; Mutchler, M.; Smith, E.; Stiavelli, M.; Teplitz, H. I.; Wiggs, M. S.; Williams, R.; Zurek, D.; Brown, T. M.; Gardner, J. P.; Kaiser, M. E.; Hook, R. N.

1998-12-01

160

Hubble Surveys the Homes of Quasars  

NSDL National Science Digital Library

The Space Telescope Electronic Information Service has recently released breathtaking Hubble Telescope photos of galaxies that "host" quasars. The quasars seem to "live in a remarkable variety of galaxies, many of which are violently colliding....Hubble researchers are intrigued by the fact that the quasars studied do not appear to have obviously damaged the galaxies in which they live." The photos are of galactic objects 1.4 and 1.5 billion light years from Earth. Photos are in black and white and color, and at various resolutions. The photos are accompanied by an explanatory caption, background material on quasars, and an MPEG model of a quasar.

Disney, Mike.; Bahcall, John.

1996-01-01

161

Force That Increases at Larger Distance Has Some Psychological and Astronomical Evidence Supporting its Existence  

NASA Astrophysics Data System (ADS)

Force that Increases with distance is different than dark energy as I am arguing for existence of force based on psychological and astronomical bases. Hubble shift, doppler shift, comet return, quasar zoo and quasars and psychological evidence of interest in distant objects lends support to a force like gravity, nuclear, weak, strong, virtual, decay, biological, growth forces which increases its intensity with distance unlike gravity which decreases in intensity with distance. Jane Frances Back Struck contributed to this finding with her request that her grandparents have "perfect justice" even though her grandparents had died before she was born; interest increasing with distance from grandparents.

Struck, James

2011-09-01

162

Astronomical Data and Information Visualization  

NASA Astrophysics Data System (ADS)

As the size and complexity of data sets increases, the need to "see" them more clearly increases as well. In the past, many scientists saw "fancy" data and information visualization as necessary for "outreach," but not for research. In this talk, I wlll demonstrate, using specific examples, why more and more scientists--not just astronomers--are coming to rely upon the development of new visualization strategies not just to present their data, but to understand it. Principal examples will be drawn from the "Astronomical Medicine" project at Harvard's Initiative in Innovative Computing, and from the "Seamless Astronomy" effort, which is co-sponsored by the VAO (NASA/NSF) and Microsoft Research.

Goodman, Alyssa A.

2010-01-01

163

Observatory Sponsoring Astronomical Image Contest  

NASA Astrophysics Data System (ADS)

Forget the headphones you saw in the Warner Brothers thriller Contact, as well as the guttural throbs emanating from loudspeakers at the Very Large Array in that 1997 movie. In real life, radio telescopes aren't used for "listening" to anything - just like visible-light telescopes, they are used primarily to make images of astronomical objects. Now, the National Radio Astronomy Observatory (NRAO) wants to encourage astronomers to use radio-telescope data to make truly compelling images, and is offering cash prizes to winners of a new image contest. Radio Galaxy Fornax A Radio Galaxy Fornax A Radio-optical composite image of giant elliptical galaxy NGC 1316, showing the galaxy (center), a smaller companion galaxy being cannibalized by NGC 1316, and the resulting "lobes" (orange) of radio emission caused by jets of particles spewed from the core of the giant galaxy Click on image for more detail and images CREDIT: Fomalont et al., NRAO/AUI/NSF "Astronomy is a very visual science, and our radio telescopes are capable of producing excellent images. We're sponsoring this contest to encourage astronomers to make the extra effort to turn good images into truly spectacular ones," said NRAO Director Fred K.Y. Lo. The contest, offering a grand prize of $1,000, was announced at the American Astronomical Society's meeting in Minneapolis, Minnesota. The image contest is part of a broader NRAO effort to make radio astronomical data and images easily accessible and widely available to scientists, students, teachers, the general public, news media and science-education professionals. That effort includes an expanded image gallery on the observatory's Web site. "We're not only adding new radio-astronomy images to our online gallery, but we're also improving the organization and accessibility of the images," said Mark Adams, head of education and public outreach (EPO) at NRAO. "Our long-term goal is to make the NRAO Image Gallery an international resource for radio astronomy imagery and to provide a showcase for a broad range of astronomical research and celestial objects," Adams added. In addition, NRAO is developing enhanced data visualization techniques and data-processing recipes to assist radio astronomers in making quality images and in combining radio data with data collected at other wavelengths, such as visible-light or infrared, to make composite images. "We encourage all our telescope users to take advantage of these techniques to showcase their research," said Juan Uson, a member of the NRAO scientific staff and the observatory's EPO scientist. "All these efforts should demonstrate the vital and exciting roles that radio telescopes, radio observers, and the NRAO play in modern astronomy," Lo said. "While we want to encourage images that capture the imagination, we also want to emphasize that extra effort invested in enhanced imagery also will certainly pay off scientifically, by revealing subtleties and details that may have great significance for our understanding of astronomical objects," he added. Details of the NRAO Image Contest, which will become an annual event, are on the observatory's Web site. The observatory will announce winners on October 15. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

2005-05-01

164

Old Coins with Astronomical Symbols  

NASA Astrophysics Data System (ADS)

Here we present, or simply describe, some interesting coins, where various astronomical symbols like the sun, a star, the zodiac etc. are shown. The coins come mainly from different cities of the ancient Greece, as well as from their colonies, (in Italy, Sicily, Asia Minor, or Pontus). Moreover, information concerning the place they were found, and the Museum they are kept are given together with the estimated time they were issued.

Rovithis-Livaniou, E.; Rovithis, F.

2010-09-01

165

The Pisgah Astronomical Research Institute  

Microsoft Academic Search

Pisgah Astronomical Research Institute is a not-for-profit foundation located at a former NASA tracking station in the Pisgah National Forest in western North Carolina. PARI is celebrating its 10th year. During its ten years, PARI has developed and implemented innovative science education programs. The science education programs are hands-on experimentally based, mixing disciplines in astronomy, computer science, earth and atmospheric

J. Donald Cline; M. Castelaz

2009-01-01

166

The Pisgah Astronomical Research Institute  

NASA Astrophysics Data System (ADS)

Pisgah Astronomical Research Institute is a not-for-profit foundation located at a former NASA tracking station in the Pisgah National Forest in western North Carolina. PARI is celebrating its 10th year. During its ten years, PARI has developed and implemented innovative science education programs. The science education programs are hands-on experimentally based, mixing disciplines in astronomy, computer science, earth and atmospheric science, engineering, and multimedia. The basic tools for the educational programs include a 4.6-m radio telescope accessible via the Internet, a StarLab planetarium, the Astronomical Photographic Data Archive (APDA), a distributed computing online environment to classify stars called SCOPE, and remotely accessible optical telescopes. The PARI 200 acre campus has a 4.6-m, a 12-m and two 26-m radio telescopes, optical solar telescopes, a Polaris monitoring telescope, 0.4-m and 0.35-m optical research telescopes, and earth and atmospheric science instruments. PARI is also the home of APDA, a repository for astronomical photographic plate collections which will eventually be digitized and made available online. PARI has collaborated with visiting scientists who have developed their research with PARI telescopes and lab facilities. Current experiments include: the Dedicated Interferometer for Rapid Variability (Dennison et al. 2007, Astronomical and Astrophysical Transactions, 26, 557); the Plate Boundary Observatory operated by UNAVCO; the Clemson University Fabry-Perot Interferometers (Meriwether 2008, Journal of Geophysical Research, submitted) measuring high velocity winds and temperatures in the Thermosphere, and the Western Carolina University - PARI variable star program. Current status of the education and research programs and instruments will be presented. Also, development plans will be reviewed. Development plans include the greening of PARI with the installation of solar panels to power the optical telescopes, a new distance learning center, and enhancements to the atmospheric and earth science suite of instrumentation.

Cline, J. Donald; Castelaz, M.

2009-01-01

167

Being an Astronomer: A Testimony  

Microsoft Academic Search

\\u000a In this short essay, I examine how and why I became an astronomer and what finally this job has brought to my life. I believe\\u000a that an irresistible compulsion to better understand the sky has driven my observational work. After my beginnings in solar\\u000a astronomy, I bet on the rise of solid state technology and, in this way, I was

Bernard Fort

168

Physical Characteristics of Astronomical Masers  

SciTech Connect

The radio line emission of interstellar molecules routinely shows deviations from thermal equilibrium which culminate with strong maser radiation in some sources. Like its laboratory counterpart, the maser radiation is amplified through the effect of induced processes in a region where a population inversion exists and displays many of the basic features of laboratory lasers. This review is intended to explain the basic theory of astronomical masers and to survey the theoretical models which were developed for specific sources.

Elitzur, M.

1982-10-01

169

The Quito Astronomical Instruments Heritage  

NASA Astrophysics Data System (ADS)

The Quito Astronomical Observatory was build in the 1873s thanks to the generous sponsoring of the president of the Republic of Ecuador Dr. Gabriel García Moreno who desire was to build a long-lasting monument to Ecuadorian science . Thanks to the collaboration of father J. B. Menten one of the leading german astronomer the President' s dream came true. The Observatory with its splendid buildings was in fact equipped with a series of very important instruments such as the 30-cm Mertz refractor a large Molteni meridian instrument and a Bamber of 10 cm. Other instruments were subsequently added in the course of the 20th century. Recently we have performed a detailed inventory of all the historical instruments still preserved at the Observatory. This paper is dedicated to briefly trace the history of the Quito Observatory and describe its most characteristic instruments. Moreover it is presented the work done for preserving this important scientific heritage and discuss some of the typical problems that the researchers the students amateur astronomers and the public find in a still active scientific institution in a developing country.

Lopez, Ericsson

170

The Hubble Space Telescope and Laboratory Astrophysics  

NASA Astrophysics Data System (ADS)

The Hubble Space Telescope (HST) continues to push the limits on world-class astrophysics. Cameras including the Advanced Camera for Surveys and the new panchromatic Wide Field Camera 3, which was installed on the recent successful servicing mission SM4, offer imaging from near-infrared through ultra- violet wavelengths. Spectroscopic studies of sources from black holes to exoplanet atmospheres are making great advances through the versatile use of STIS, the Space Telescope Imaging Spectrograph. The new Cosmic Origins Spectrograph, also installed last year, is the most sensitive UV spectrograph to y in space and is uniquely suited to address particular scientific questions on galaxy halos, the intergalactic medium, and the cosmic web. With these outstanding capabilities on HST come complex needs for laboratory astrophysics support including atomic and line identification data. This paper provides an overview of Hubble's current capabilities and the scientific programs and goals that particularly benefit from the studies of laboratory astrophysics. With no current plans for further servicing of Hubble (and thus limited further observations), and no future major optical/UV space observatory currently planned for at least the next decade, it is essential to maximize the critical laboratory astrophysics support needed for Hubble observations in the near-term.

Wiseman, J. J.

2011-05-01

171

The Hubble Space Telescope: Problems and Solutions.  

ERIC Educational Resources Information Center

|Presented is the best understanding of the flaw discovered in the optics of the Hubble Space Telescope and the possible solutions to the problems. The spherical aberration in the telescope's mirror and its effect on the quality of the telescope's imaging ability is discussed. (CW)|

Villard, Ray

1990-01-01

172

Hubble Space Telescope solar array damper  

Microsoft Academic Search

This paper describes the design of a solar array damper that will be built into each of two new solar arrays to be installed on the Hubble Space Telescope (HST) during Servicing Mission 3. On this mission, currently scheduled for August 2000, two 'rigid' solar array wings will replace the 'flexible' wings currently providing power for HST. In addition to

Joseph R. Maly; Scott C. Pendleton; J. Salmanoff; Garcia J. Blount; Kevin Mathews

1999-01-01

173

Glacial cycles and astronomical forcing  

SciTech Connect

Narrow spectral features in ocean sediment records offer strong evidence that the cycles of glaciation were driven by astronomical forces. Two million years ago, the cycles match the 41,000-year period of Earth`s obliquity. This supports the Croll/Milankovitch theory, which attributes the cycles to variations in insolation. But for the past million years, the spectrum is dominated by a single 100,000-year feature and is a poor match to the predictions of insolation models. The spectrum can be accounted for by a theory that derives the cycles of glaciation from variations in the inclination of Earth`s orbital plane.

Muller, R.A. [Lawrence Berkeley Lab., CA (United States); MacDonald, G.J. [International Institute for Applied Systems Analysis, Laxenburg (Austria)

1997-07-11

174

Hubble and ESO's VLT provide unique 3D views of remote galaxies  

NASA Astrophysics Data System (ADS)

Astronomers have obtained exceptional 3D views of distant galaxies, seen when the Universe was half its current age, by combining the twin strengths of the NASA/ESA Hubble Space Telescope's acute eye, and the capacity of ESO's Very Large Telescope to probe the motions of gas in tiny objects. By looking at this unique "history book" of our Universe, at an epoch when the Sun and the Earth did not yet exist, scientists hope to solve the puzzle of how galaxies formed in the remote past. ESO PR Photo 10a/09 A 3D view of remote galaxies ESO PR Photo 10b/09 Measuring motions in 3 distant galaxies ESO PR Video 10a/09 Galaxies in collision For decades, distant galaxies that emitted their light six billion years ago were no more than small specks of light on the sky. With the launch of the Hubble Space Telescope in the early 1990s, astronomers were able to scrutinise the structure of distant galaxies in some detail for the first time. Under the superb skies of Paranal, the VLT's FLAMES/GIRAFFE spectrograph (ESO 13/02) -- which obtains simultaneous spectra from small areas of extended objects -- can now also resolve the motions of the gas in these distant galaxies (ESO 10/06). "This unique combination of Hubble and the VLT allows us to model distant galaxies almost as nicely as we can close ones," says François Hammer, who led the team. "In effect, FLAMES/GIRAFFE now allows us to measure the velocity of the gas at various locations in these objects. This means that we can see how the gas is moving, which provides us with a three-dimensional view of galaxies halfway across the Universe." The team has undertaken the Herculean task of reconstituting the history of about one hundred remote galaxies that have been observed with both Hubble and GIRAFFE on the VLT. The first results are coming in and have already provided useful insights for three galaxies. In one galaxy, GIRAFFE revealed a region full of ionised gas, that is, hot gas composed of atoms that have been stripped of one or several electrons. This is normally due to the presence of very hot, young stars. However, even after staring at the region for more than 11 days, Hubble did not detect any stars! "Clearly this unusual galaxy has some hidden secrets," says Mathieu Puech, lead author of one of the papers reporting this study. Comparisons with computer simulations suggest that the explanation lies in the collision of two very gas-rich spiral galaxies. The heat produced by the collision would ionise the gas, making it too hot for stars to form. Another galaxy that the astronomers studied showed the opposite effect. There they discovered a bluish central region enshrouded in a reddish disc, almost completely hidden by dust. "The models indicate that gas and stars could be spiralling inwards rapidly," says Hammer. This might be the first example of a disc rebuilt after a major merger (ESO 01/05). Finally, in a third galaxy, the astronomers identified a very unusual, extremely blue, elongated structure -- a bar -- composed of young, massive stars, rarely observed in nearby galaxies. Comparisons with computer simulations showed the astronomers that the properties of this object are well reproduced by a collision between two galaxies of unequal mass. "The unique combination of Hubble and FLAMES/GIRAFFE at the VLT makes it possible to model distant galaxies in great detail, and reach a consensus on the crucial role of galaxy collisions for the formation of stars in a remote past," says Puech. "It is because we can now see how the gas is moving that we can trace back the mass and the orbits of the ancestral galaxies relatively accurately. Hubble and the VLT are real ‘time machines' for probing the Universe's history", adds Sébastien Peirani, lead author of another paper reporting on this study. The astronomers are now extending their analysis to the whole sample of galaxies observed. "The next step will then be to compare this with closer galaxies, and so, piece together a picture of the evolution of galax

2009-03-01

175

Amateur Astronomers: Secret Agents of EPO  

NASA Astrophysics Data System (ADS)

Amateur astronomers prime the public to be more interested, receptive, and excited about space science, missions, and programs. Through recent research and targeted programs, amateur astronomy outreach is being increasingly recognized by professional astronomers, educators, and other amateurs as a valued and important service. The Night Sky Network program, administered by the ASP, is the first nationwide research-based program specifically targeted to support outreach by amateur astronomers. This Network of trained and informed amateur astronomers can provide a stimulating introduction to your EPO programs as Network members share the night sky with families, students, and youth groups.

Berendsen, M.; White, V.; Devore, E.; Reynolds, M.

2008-06-01

176

FITSManager: Management of Personal Astronomical Data  

NASA Astrophysics Data System (ADS)

With the increase of personal storage capacity, it is easy to find hundreds to thousands of FITS files in the personal computer of an astrophysicist. Because Flexible Image Transport System (FITS) is a professional data format initiated by astronomers and used mainly in the small community, data management toolkits for FITS files are very few. Astronomers need a powerful tool to help them manage their local astronomical data. Although Virtual Observatory (VO) is a network oriented astronomical research environment, its applications and related technologies provide useful solutions to enhance the management and utilization of astronomical data hosted in an astronomer's personal computer. FITSManager is such a tool to provide astronomers an efficient management and utilization of their local data, bringing VO to astronomers in a seamless and transparent way. FITSManager provides fruitful functions for FITS file management, like thumbnail, preview, type dependent icons, header keyword indexing and search, collaborated working with other tools and online services, and so on. The development of the FITSManager is an effort to fill the gap between management and analysis of astronomical data.

Cui, Chenzhou; Fan, Dongwei; Zhao, Yongheng; Kembhavi, Ajit; He, Boliang; Cao, Zihuang; Li, Jian; Nandrekar, Deoyani

2011-07-01

177

Astronomical Symbolism in Australian Aboriginal Rock Art  

NASA Astrophysics Data System (ADS)

Traditional Aboriginal Australian cultures include a significant astronomical component, perpetuated through oral tradition and ceremony. This knowledge has practical navigational and calendrical functions, and sometimes extends to a deep understanding of the motion of objects in the sky. Here we explore whether this astronomical tradition is reflected in the rock art of Aboriginal Australians. We find several plausible examples of depictions of astronomical figures and symbols, and also evidence that astronomical observations were used to set out stone arrangements. However, we recognise that the case is not yet strong enough to make an unequivocal statement, and describe our plans for further research.

Norris, Ray P.; Hamacher, Duane W.

2011-05-01

178

San Marcos Astronomical Project and Doctoral Prospectus  

NASA Astrophysics Data System (ADS)

The Universidad Nacional Mayor de San Marcos, UNMSM, in Lima, Perú, is the only Peruvian institution working for the peruvian astronomical development as a career since 1970. We are conforming a network with international friend astronomers to invite them as Visiting Lectures to assure the academic level for the future doctoral studies in the UNMSM. The Chancellor of UNMSM has decided that the Astronomical Project is a UNMSM Project, to encourage and advance in this scientific and strategical area, to impulse the modernity of Peru, the major effort will be the building of the San Marcos Astronomical Observatory, with a telescope of 1 meter aperture.

Aguilar, M. L.

2009-05-01

179

Storing Astronomical Information on the Romanian Territory  

NASA Astrophysics Data System (ADS)

Romanian astronomy has a more than 2000-year old tradition, which is, however, little known abroad. The first known archive of astronomical information is the Dacian sanctuary at Sarmizegetusa Regia, erected in the first century AD, having similarities with that of Stonehenge. After a gap of more than 1000 years, more sources of astronomical information become available, mainly records of astronomical events. Monasteries were the safest storage places of these genuine archives. We present a classification of the ways of storing astronomical information, along with characteristic examples.

Stavinschi, M.; Mioc, V.

2004-12-01

180

Storing Astronomical Information on the Romanian Territory  

NASA Astrophysics Data System (ADS)

The Romanian astronomy has a more than 2000-year old tradition which is however too little known abroad. The first known archive of astronomical information is the Dacian sanctuary at Sarmizegetusa Regia very similar to that of Stonehenge. After a gap of more than 1000 years sources of astronomical information became to be recovered. They consist mainly of records of astronomical events seen on the Romanian territory. The most safe places to store these genuine archives were the monasteries. We present a classification of the manners of storing astronomical information along with characteristic examples.

Stavinschi, Magda; Mioc, Vasile

181

Astronomers Reveal Extinct Extra-Terrestrial Fusion Reactor  

NASA Astrophysics Data System (ADS)

An international team of astronomers, studying the left-over remnants of stars like our own Sun, have found a remarkable object where the nuclear reactor that once powered it has only just shut down. This star, the hottest known white dwarf, H1504+65, seems to have been stripped of its entire outer regions during its death throes leaving behind the core that formed its power plant. Scientists from the United Kingdom, Germany and the USA focused two of NASA's space telescopes, the Chandra X-ray Observatory and the Far Ultraviolet Spectroscopic Explorer (FUSE), onto H1504+65 to probe its composition and measure its temperature. The data revealed that the stellar surface is extremely hot, 200,000 degrees, and is virtually free of hydrogen and helium, something never before observed in any star. Instead, the surface is composed mainly of carbon and oxygen, the 'ashes' of the fusion of helium in a nuclear reactor. An important question we must answer is why has this unique star lost the hydrogen and helium, which usually hide the stellar interior from our view? Professor Martin Barstow (University of Leicester) said. 'Studying the nature of the ashes of dead stars give us important clues as to how stars like the Sun live their lives and eventually die. The nuclear waste of carbon and oxygen produced in the process are essential elements for life and are eventually recycled into interstellar space to form new stars, planets and, possibly, living beings.' Professor Klaus Werner (University of Tübingen) said. 'We realized that this star has, on astronomical time scales, only very recently shut down nuclear fusion (about a hundred years ago). We clearly see the bare, now extinct reactor that once powered a bright giant star.' Dr Jeffrey Kruk (Johns Hopkins University) said: 'Astronomers have long predicted that many stars would have carbon-oxygen cores near the end of their lives, but I never expected we would actually be able to see one. This is a wonderful opportunity to improve our understanding of the life-cycle of stars.' The Chandra X-ray data also reveal the signatures of neon, an expected by-product of helium fusion. However, a big surprise was the presence of magnesium in similar quantities. This result may provide a key to the unique composition of H1504+65 and validate theoretical predictions that, if massive enough, some stars can extend their lives by tapping yet another energy source: the fusion of carbon into magnesium. However, as magnesium can also be produced by helium fusion, proof of the theory is not yet ironclad. The final link in the puzzle would be the detection of sodium, which will require data from yet another observatory: the Hubble Space Telescope. The team has already been awarded time on the Hubble Space Telescope to search for sodium in H1504+65 next year, and will, hopefully, discover the final answer as to the origin of this unique star. This work will be published in July in the 'Astronomy & Astrophysics' journal. The Chandra X-ray Observatory and the Far Ultraviolet Spectroscopic Explorer (FUSE) were both launched into orbit by NASA in 1999. Their instruments make use of a technique called spectroscopy, which spreads the light obtained from astronomical objects into its constituent X-ray and ultraviolet 'colours', in the same way visible light is dispersed into a rainbow naturally, by water droplets in the atmosphere, or artificially, by a prism. When studied in fine detail each spectrum is a unique 'fingerprint' which tells us what elements are present and reveals the physical conditions in the object being studied. Related Internet Address http://www.ras.org.uk/index.php?option=com_content&task=view&id=673&Itemid=2

2004-06-01

182

Harold F. Weaver: California Astronomer  

NASA Astrophysics Data System (ADS)

This talk will give an overview of an oral history recently completed with Harold F. Weaver, Professor Emeritus of Astronomy at the University of California at Berkeley. Weaver grew up in California and studied as an undergraduate at Berkeley, where he also pursued graduate work incorporating research at Lick and Mount Wilson Observatories. After pursuing postdoctoral research at Yerkes Observatory and war work in Cambridge (Massachusetts) and Berkeley, Weaver was appointed to the staff of Lick Observatory. In 1951 he joined the faculty at Berkeley, where he later played a major role in founding Hat Creek Radio Observatory. As Director of the Berkeley Radio Astronomy Laboratory, Weaver oversaw construction of the 85-foot telescope at Hat Creek, which is the subject of a special session at this meeting. Two aspects of Weaver's career will be highlighted. The first is the somewhat unusual and very successful transition in Weaver's observational research from emphasis on classical photographic techniques at optical wavelengths to use of emerging radio technology for the study of Galactic structure. The second is service provided by Weaver to the American Astronomical Society and Astronomical Society of the Pacific at several key junctures in the development of both organizations.

Shields, J. C.

1993-05-01

183

LGBT Workplace Issues for Astronomers  

NASA Astrophysics Data System (ADS)

Federal Equal Employment Opportunity laws and regulations do not provide protection from discrimination on the basis of sexual orientation or gender identity or gender expression. Sexual minority astronomers (including lesbian, gay, bisexual and transgender people; LGBT) can face additional challenges at school and work. Studies show that LGBT students on many campuses report experiences of harassment. Cities, counties, and states may or may not have statutes to protect against such discrimination. There is wide variation in how states and insurance plans handle legal and medical issues for transgender people. Federal law does not acknowledge same-sex partners, including those legally married in the U.S. or in other countries. Immigration rules in the U.S. (and many other, but not all) countries do not recognize same-sex partners for visas, employment, etc. State `defense of marriage act' laws have been used to remove existing domestic partner benefits at some institutions, or benefits can disappear with a change in governor. LGBT astronomers who change schools, institutions, or countries during their career may experience significant differences in their legal, medical, and marital status.

Kay, Laura E.; Danner, R.; Sellgren, K.; Dixon, V.; GLBTQastro

2011-01-01

184

SAADA: Astronomical Databases Made Easier  

NASA Astrophysics Data System (ADS)

Many astronomers wish to share datasets with their community but have not enough manpower to develop databases having the functionalities required for high-level scientific applications. The SAADA project aims at automatizing the creation and deployment process of such databases. A generic but scientifically relevant data model has been designed which allows one to build databases by providing only a limited number of product mapping rules. Databases created by SAADA rely on a relational database supporting JDBC and covered by a Java layer including a lot of generated code. Such databases can simultaneously host spectra, images, source lists and plots. Data are grouped in user defined collections whose content can be seen as one unique set per data type even if their formats differ. Datasets can be correlated one with each other using qualified links. These links help, for example, to handle the nature of a cross-identification (e.g., a distance or a likelihood) or to describe their scientific content (e.g., by associating a spectrum to a catalog entry). The SAADA query engine is based on a language well suited to the data model which can handle constraints on linked data, in addition to classical astronomical queries. These constraints can be applied on the linked objects (number, class and attributes) and/or on the link qualifier values. Databases created by SAADA are accessed through a rich WEB interface or a Java API. We are currently developing an inter-operability module implanting VO protocols.

Michel, L.; Nguyen, H. N.; Motch, C.

2005-12-01

185

Type IA Supernovae and the Hubble Constant  

Microsoft Academic Search

The focus of this review is the work that has been done during the 1990s on using Type Ia supernovae (SNe Ia) to measure the Hubble constant (H_0). SNe Ia are well suited for measuring (H_0). A straightforward maximum-light color criterion can weed out the minority of observed events that are either intrinsically subluminous or substantially extinguished by dust, leaving

David Branch

1998-01-01

186

Hubble Tarantula Treasury Project: Unraveling Tarantula's Web  

NASA Astrophysics Data System (ADS)

The Hubble Tarantula Treasury Project is an ongoing panchromatic survey designed to study the Tarantula Nebula in the Large Magellanic Cloud in the near UV, optical and near IR down to the sub-solar mass regime. We will discuss the observing strategy, and the data products that will be distributed to the community. We will present preliminary results on the stellar populations and the clustering properties of the region obtained from the analysis of the IR observations acquired so far.

Sabbi, E.; Lennon, D. J.; Anderson, J.; van de Marel, R. P.; Aloisi, A.; Boyer, M.; Cignoni, M.; Evans, C. J.; Gallagher, J. S., III; Gordon, K.; Goulliermis, D.; Grebel, E. K.

2013-06-01

187

Recent Hubble Observations of Jupiter's Ring System  

Microsoft Academic Search

The period December 2002 through February 2003 provided a rare opportunity to watch Jupiter sweep through its full range of Earth-based phase angles while the rings remained nearly edge-on to Earth. We used this period for a series of Jovian ring observations using the High Resolution Channel (HRC) of Hubble's new Advanced Camera for Surveys (ACS). Phase angles span 0.17o--10o.

M. R. Showalter; J. A. Burns; I. de Pater; D. P. Hamilton; M. Horanyi

2003-01-01

188

Charge transfer inefficiency in the Hubble Space Telescope since Servicing Mission 4  

NASA Astrophysics Data System (ADS)

We update a physically motivated model of radiation damage in the Hubble Space Telescope Advanced Camera for Surveys/Wide Field Channel, using data up to mid-2010. We find that charge transfer inefficiency increased dramatically before shuttle Servicing Mission 4, with ~1.3 charge traps now present per pixel. During detector readout, charge traps spuriously drag electrons behind all astronomical sources, degrading image quality in a way that affects object photometry, astrometry and morphology. Our detector readout model is robust to changes in operating temperature and background level, and can be used to iteratively remove the trailing by pushing electrons back to where they belong. The result is data taken in mid-2010 that recovers the quality of imaging obtained within the first six months of orbital operations.

Massey, Richard

2010-11-01

189

BOOK REVIEW: The Wandering Astronomer  

NASA Astrophysics Data System (ADS)

Fans of Patrick Moore will like this book. I enjoyed it more than I expected, having anticipated a collection of personal anecdotes of the type favoured by certain tedious after-dinner speakers. Some of the 41 short items it contains do tend towards that category, but there are also some nuggets which might enliven your physics teaching. For example, did you know that, in a murder trial in 1787, the defendant's belief that the Sun was inhabited was cited as evidence of his insanity? This was despite his views being shared by many astronomers of the day including William Herschel. Or that Clyde Tombaugh had a cat called Pluto after the planet he discovered, which was itself named by an eleven-year-old girl? Another gem concerns a brief flurry, in the early 1990s, over a suspected planet orbiting a pulsar; variations in the arrival time of its radio pulses indicated the presence of an orbiting body. These shifts were later found to arise from an error in a computer program that corrected for the Earth's motion. The programmer had assumed a circular orbit for the Earth whereas it is actually elliptical. The book is clearly intended for amateur astronomers and followers of Patrick Moore's TV programmes. There is plenty of astronomy, with an emphasis on the solar system, but very little astrophysics. The author's metricophobia means that quantities are given in imperial units throughout, with metric equivalents added in brackets (by an editor, I suspect) which can get irritating, particularly as powers-of-ten notation is avoided. It is quite a novelty to see the temperature for hydrogen fusion quoted as 18 000 000 °F (10 000 000 °C). By way of contrast, astronomical terms are used freely - ecliptic, first-magnitude star, and so on. Such terms are defined in a glossary at the end, but attention is not drawn to this and I only stumbled across it by chance. Patrick Moore obviously knows his public, and this book will serve them well. For physics teachers and students it contains insufficient meat to support the demands of current courses at GCSE and A-level, but that is not its purpose, and it does provide some accessible reading that might lead the way into further study.

Swinbank, Elizabeth

2000-09-01

190

On the Graduate Schools of University Astronomers  

Microsoft Academic Search

We investigated the hypothesis that over the past few decades the number of graduate schools supplying academic astronomers has increased significantly. This study was motivated by a desire to identify those schools, if any, which dominate the training of astronomers at work in universities. Our source of data was a recent compilation of graduate schools of physics and\\/or astronomy which

Ronald E. Domen; Harley A. Thronson Jr.

1988-01-01

191

Astronomical Symbolism in Australian Aboriginal Rock Art  

Microsoft Academic Search

Traditional Aboriginal Australian cultures include a significant astronomical component, perpetuated through oral tradition and ceremony. This knowledge has practical navigational and calendrical functions, and sometimes extends to a deep understanding of the motion of objects in the sky. Here we explore whether this astronomical tradition is reflected in the rock art of Aboriginal Australians. We find several plausible examples of

Ray P. Norris; Duane W. Hamacher

2011-01-01

192

GASP-Galway astronomical Stokes polarimeter  

Microsoft Academic Search

The Galway Astronomical Stokes Polarimeter (GASP) is an ultra-high-speed, full Stokes, astronomical imaging polarimeter based upon a Division of Amplitude Polarimeter. It has been developed to resolve extremely rapid stochastic (~ms) variations in objects such as optical pulsars, magnetars and magnetic cataclysmic variables. The polarimeter has no moving parts or modulated components so the complete Stokes vector can be measured

G. Kyne; B. Sheehan; P. Collins; M. Redfern; A. Shearer

2010-01-01

193

Astronomical Applications of Oblique Decision Trees  

NASA Astrophysics Data System (ADS)

We have used the oblique decision tree classifier OC1 in a variety of astronomical applications, including cosmic ray identification [1], star-galaxy separation in images [2], quasar candidate selection in radio and optical catalogs [3], X-ray source classification [4], and sidelobe flagging in radio surveys [5, 6]. This paper reviews the algorithm and its advantages for typical astronomical problems.

White, Richard L.

2008-12-01

194

The associate principal astronomer telescope operations model  

Microsoft Academic Search

This paper outlines a new telescope operations model that is intended to achieve low operating costs with high operating efficiency and high scientific productivity. The model is based on the existing Principal Astronomer approach used in conjunction with ATIS, a language for commanding remotely located automatic telescopes. This paper introduces the notion of an Associate Principal Astronomer, or APA. At

Mark Drummond; John Bresina; Keith Swanson; Will Edgington; Greg Henry

1994-01-01

195

Comprehensive Astronomical Visualization for a Multimedia Encyclopedia  

Microsoft Academic Search

The domain of astronomy contributes a wealth of knowledge to the corpus of any general encyclopedia. Modern multimedia encyclopedias are capable of displaying complex, three-dimensional visualizations in real-time, enabling the integration of a planetarium, a virtual theater presenting astronomical facts in an educational and entertaining way. The manifold peculiarities of astronomical data sets require careful balancing of visual means to

Wolfgang Kienreich; Mario Zechner; Vedran Sabol

2007-01-01

196

Amateur Astronomers: Secret Agents of EPO  

Microsoft Academic Search

Amateur astronomers prime the public to be more interested, receptive, and excited about space science, missions, and programs. Through recent research and targeted programs, amateur astronomy outreach is being increasingly recognized by professional astronomers, educators, and other amateurs as a valued and important service. The Night Sky Network program, administered by the ASP, is the first nationwide research-based program specifically

M. Berendsen; V. White; E. Devore; M. Reynolds

2008-01-01

197

Astronomical refraction in the Venus atmosphere  

Microsoft Academic Search

The astronomical refraction of a planetary atmosphere can be determined on the basis of data on: (1) mean temperature and partial pressure of all the gaseous constituents, (2) atmospheric composition, and (3) refractive index of each gaseous component. The present paper calculates astronomical refraction for the Venus atmosphere on the basis of an atmospheric model which employs Venera-probe data.

V. V. Kirichuk; F. D. Zablotskii

1978-01-01

198

Some new astronomical facilities in China  

NASA Astrophysics Data System (ADS)

For the 1990's, plans for some astronomical facilities and related research are being carried out in China. This report describes in some detail plans for radio astronomical facilities, a 150/220 cm Schmidt telescope, and experiments on a porcelain mirror material.

Wang, Shouguan

1989-10-01

199

William Doberck - double star astronomer  

NASA Astrophysics Data System (ADS)

We outline the role of astronomy in the career of William Doberck (1852-1941). After taking a PhD in astronomy at the University of Jena in 1873, he accepted a position as superintendent of Markree Observatory in the west of Ireland. There he refurbished the great 13-inch refractor and spent nine years observing mostly double star systems, paying only such attention to meteorological monitoring as was required of his position. In 1883 he became the founding Director of a new observatory in Hong Kong, a post which he held for 24 years. His frustrations in attempting to continue his purely astronomical work, not assuaged by his combative and prickly personality, and in the face of the strictly practical demands of that mercantile society for comprehensive storm forecasting, are described. Finally, his observations in retirement in England, and his overall contribution to astronomy, are summarised.

MacKeown, P. Kevin

2007-03-01

200

Ancient Astronomical Monuments of Athens  

NASA Astrophysics Data System (ADS)

In this work, four ancient monuments of astronomical significance found in Athens and still kept in the same city in good condition are presented. The first one is the conical sundial on the southern slope of the Acropolis. The second one is the Tower of the Winds and its vertical sundials in the Roman Forum of Athens, a small octagonal marble tower with sundials on all 8 of its sides, plus a water-clock inside the tower. The third monument-instrument is the ancient clepsydra of Athens, one of the findings from the Ancient Agora of Athens, a unique water-clock dated from 400 B.C. Finally, the fourth one is the carved ancient Athenian calendar over the main entrance of the small Byzantine temple of the 8th Century, St. Eleftherios, located to the south of the temple of the Annunciation of Virgin Mary, the modern Cathedral of the city of Athens.

Theodossiou, E.; Manimanis, V. N.

2010-07-01

201

Astronomical Software---A Review  

NASA Astrophysics Data System (ADS)

It is now impossible to imagine `doing astronomy' without using software. Sometimes it is hard to remember that it has not always been like this. Over a timescale now measured in decades, the art (or science) of astronomical programming has evolved. Once it involved the squeezing of hand-crafted assembler routines into insufficient memory. Now it includes the design of ambitiously large frameworks for data acquisition and reduction. The organisation required for the production of such software has had to grow to match these new ambitions. This review looks back on the path taken by this fascinating evolutionary process, in the hope that it can provide a background that may let us imagine where the next years will lead.

Shortridge, K.

202

6-degrees of Astronomical Separation  

NASA Astrophysics Data System (ADS)

In this paper we present a data visualization of how the citizen scientists in the Zooniverse citizen science project and astronomy content consumers associated with the Astronomy Cast and 365 Days of Astronomy podcasts can be linked to other astronomy programs via their social connections in Twitter. This visualization shows how some people select to engage in a myriad of astronomy projects, while other focus narrowly on just one online community. We also show how professional astronomy online entities (both real people, and the avatars of missions and projects) engage with other astronomy projects as a form of social networking. The result of the project is a network showing the structure of the astronomical community within the twitterverse and other online, astronomy-specific projects.

Gay, Pamela L.

2011-01-01

203

Sparse representation of astronomical images  

NASA Astrophysics Data System (ADS)

Sparse representation of astronomical images is discussed. It is shown that a significant gain in sparsity is achieved when particular mixed dictionaries are used for approximating these types of images with greedy selection strategies. Experiments are conducted to confirm: i)Effectiveness at producing sparse representations. ii)Competitiveness, with respect to the time required to process large images.The latter is a consequence of the suitability of the proposed dictionaries for approximating images in partitions of small blocks.This feature makes it possible to apply the effective greedy selection technique Orthogonal Matching Pursuit, up to some block size. For blocks exceeding that size a refinement of the original Matching Pursuit approach is considered. The resulting method is termed Self Projected Matching Pursuit, because is shown to be effective for implementing, via Matching Pursuit itself, the optional back-projection intermediate steps in that approach.

Rebollo-Neira, Laura; Bowley, James

2013-04-01

204

The Iraqi National Astronomical Observatory  

NASA Astrophysics Data System (ADS)

Iraq is currently experiencing a praid cultural, scientific, and technical renaissance, and astronomy is a natural focus for the country's pride in the past achievements of the civilization which have flourished in Iraq. The current plans of the Space and Astronomy Research Center (SARC) include building a major observatory to work in the optical, JR and radio region of the spectrum. The core of the optical facility will be a 3.5 m optical telescope, together with 1.25 m telescope designed for efficient performance in the JR. These telescopes will be equipped with instruments for photographic, photometric and spectroscopic observations. A 30 m dish is also being built for millimeter/radio observa- tions. SARC has selected an excellent observing site in the northern mountains of Iraq which has good seeing and clear dark skies. The sites selection was made with the collaboration of several leading astronomers and observatories from various countries

Al-Naimiy, H. M. K.

1986-01-01

205

Astronomical catalog desk reference, 1994 edition  

NASA Astrophysics Data System (ADS)

The Astronomical Catalog Desk Reference is designed to aid astronomers in locating machine readable catalogs in the Astronomical Data Center (ADC) archives. The key reference components of this document are as follows: A listing of shortened titles for all catalogs available from the ADC (includes the name of the lead author and year of publication), brief descriptions of over 300 astronomical catalogs, an index of ADC catalog numbers by subject keyword, and an index of ADC catalog numbers by author. The heart of this document is the set of brief descriptions generated by the ADC staff. The 1994 edition of the Astronomical Catalog Desk Reference contains descriptions for over one third of the catalogs in the ADC archives. Readers are encouraged to refer to this section for concise summaries of those catalogs and their contents.

1994-01-01

206

The current burst in astronomical publications  

NASA Astrophysics Data System (ADS)

The Astrophysical Journal grew in numbers of papers during 1972-1986 at about the same rate as the growth in members of the American Astronomical Society (AAS). However since 1987 it has grown at twice that rate. By classifying papers we found that half the excess growth is due to a doubling of papers from spacecraft and the other half from theoretical papers, probably those that interpret these data. The number of papers based on ground-based data has stayed nearly constant. These changes did not occur in the Astronomical Journal, which has a different proportion in types of papers. Nor do Icarus, Monthly Notices of the Royal Astronomical Society (MNRAS), Astronomy & Astrophysics (A & A), nor Publications of the Astronomical Society of the Pacific (PASP) show recent increases greater than the growth in numbers of astronomers.

Abt, Helmut A.

1994-09-01

207

Developing an astronomical observatory in Paraguay  

NASA Astrophysics Data System (ADS)

Background: Paraguay has some heritage from the astronomy of the Guarani Indians. Buenaventura Suarez S.J. was a pioneer astronomer in the country in the XVIII century. He built various astronomical instruments and imported others from England. He observed eclipses of Jupiter's satellites and of the Sun and Moon. He published his data in a book and through letters. The Japanese O.D.A. has collaborated in obtaining equipment and advised their government to assist Paraguay in building an astronomical observatory, constructing a moving-roof observatory and training astronomers as observatory operators. Future: An astronomical center is on the horizon and some possible fields of research are being considered. Goal: To improve education at all possible levels by not only observing sky wonders, but also showing how instruments work and teaching about data and image processing, saving data and building a data base. Students must learn how a modern scientist works.

Troche-Boggino, Alexis E.

208

The Duty Cycle of Star Formation : Far-UV imaging of the Hubble Deep Field  

NASA Astrophysics Data System (ADS)

We propose deep far-UV imaging of the Hubble Deep Field {HDF} with the ACS-SBC . Previously, we surveyed 1/5 of the HDF in the UV and now propose to complete the area. Near- and far-UV number counts suggest that there is a large population of UV- bright starbursts at moderate redshifts {z<0.6}, and our proposed observations will investigate their nature. We will measure the star formation properties of these galaxies and their morphologies in the UV, optical, and near-IR. This catalog of starbursts will also be important to the astronomical community after Cycle 11 in interpreting planned SIRTF observations of the field. We will also set strict limits on the flux escaping in intermediate redshift {1Hubble Deep Fields, we waive proprietary rights to these data.

Teplitz, Harry

2002-07-01

209

Median Statistics and the Hubble Constant  

NASA Astrophysics Data System (ADS)

Following Gott et al., we use Huchra''s final compilation of 553 measurements of the Hubble constant (H0) to estimate median statistical constraints on H0. Our median statistical analysis yields H0 = 68 ± 5.5 (or ±1) km s-1 Mpc, where the errors are the 95% statistical and systematic (or statistical) errors. These results are close to what Gott et al. found a decade ago, with smaller statistical errors and similar systematic errors. With about two-thirds more measurements, we are also able to clearly illustrate the presence and magnitude of systematic errors for different methods.

Chen, Gang; Ratra, Bharat

2011-09-01

210

A Survey of Astronomical Research: A Baseline for Astronomical Development  

NASA Astrophysics Data System (ADS)

Measuring scientific development is a difficult task. Different metrics have been put forward to evaluate scientific development; in this paper we explore a metric that uses the number of peer-reviewed, and when available non-peer-reviewed, research articles as an indicator of development in the field of astronomy. We analyzed the available publication record, using the Smithsonian Astrophysical Observatory/NASA Astrophysics Database System, by country affiliation in the time span between 1950 and 2011 for countries with a gross national income of less than 14,365 USD in 2010. This represents 149 countries. We propose that this metric identifies countries in "astronomical development" with a culture of research publishing. We also propose that for a country to develop in astronomy, it should invest in outside expert visits, send its staff abroad to study, and establish a culture of scientific publishing. Furthermore, we propose that this paper may be used as a baseline to measure the success of major international projects, such as the International Year of Astronomy 2009.

Ribeiro, V. A. R. M.; Russo, P.; Cárdenas-Avendaño, A.

2013-12-01

211

Astronomical background of global huge earthquakes  

NASA Astrophysics Data System (ADS)

This paper analyzes the astronomical background of the global huge earthquakes with M?8.5. The result shows that most of the earthquakes has occurred in the seismic belts (regions) where is being corresponding seismic active period with the lunar path, solar active falling period and accelerating period of earth rotation. This is as for the variation of long period of astronomical factors. For the variation of short period of astronomical factors, whether for local time or local sidereal time and lunar phase there is the phenomenon of occurrence of concentrating a interval time for the earthquakes. For the short variation of earth rotation this phenomenon is clear; either the earthquakes occur in most fast or in lowest of earth rotation. The above-mentioned results indicate that the eartquakes occurrence is affected by astronomical factors. The astronomical factors are one of motive force causing earthquake from external world. The astronomical factors with long period may act as modulation for the earthquake-pregnant process. And the astronomical factors with short period will causing huge fluctuations of the system and earthquake occur when it act on seismic structure of away from balance state.

Hu, Hui; Han, Yan-Ben

2006-03-01

212

Nikolay N. Donitch - the astronomer  

NASA Astrophysics Data System (ADS)

The article is devoted to milestones of life and scientific activity of the eminent astronomer Nikolay Nikolaevich Donitch (Nicolae N. Donici) (1874-1956), a graduate from the Odessa (Novorossiski) university. He was a wellknown expert in the field of reseacrh of objects of Solar system. A person highly cultured, which built the first in Bessarabia (actually a part of the Republic of Moldova) observatory. He was borne in Kishinev (Chisinau) in a nobles family of notable Moldavian landersmen. N.D. graduated from the Richelieu lyceym in Odessa and afterwards, in 1897, graduated from the Odessa (Novorossiysky) University. A.K. Kononovich (1850-1910)headed the chair of astronomy and the Observatory at that time - a foremost authority in the field of astrophysics and stellar astronomy. Many of his disciples became eminent scientists of their time. N. Donitch was among them. N.D. worked till 1918 at Pulkovo Observatory and became a master in the field of studying of such phenomena as solar and lunar eclipses. To observe the Sun N.D., could afford to design and manufacture a spectroheliograph, the first in Russia, with the assistance of a famous Odessa mechanic J.A. Timchenko. This instrument enabled him to obtain topquality photos of the Sun's surface and prominences. It was mounted together with coelostat in the private observatory of N.D. , built in the village Staryie Doubossary in 1908. Besides the heliograoph, the observatory was equiped with a five inch refractor-equatorial with numerous instruments for various observations. Of the other instruments should be mentioned : "a comet triplet" - an instrument consisting of guiding refractor, a photographic camera and a spectrograph with an objective prism. N.D. was lucky enough to observe rare astronomical phenomena. He observed the transit of Mercury through the disk of the Sun on November 14, 1907 and showed the athmosphere absence around this planet, observed the Halley's comet in 1910, the bright Pons-Winneke comet in 1927. In 1933 he was cartying out observations of Saturn and determined the rotational period of the planet. Eight scientific papers on the zodiacal light investigations were published by N.D.. Due to a H. Shapley's recommmendation he obtained in his observatory a number of stelar sky photos. N.N. Donitch was a brillant personality in the astronomical community of his time. He was a member of many scientific societies. Hard and sad times came to Donitch during the last years of his life. At first he leaved Bessarabia for Bucharest (1940), then Romania for Germany (1944), then Germany for France (1945), where he worked at the Meudon Observatory. At last he found himself under tryiung financial situation. According to some findings he spent the last days in an old men house near Nice and died in 1956.

Gaina, Alex B.; Volyanskaya, M. Yu.

1999-08-01

213

Astronomers Unveiling Life's Cosmic Origins  

NASA Astrophysics Data System (ADS)

Processes that laid the foundation for life on Earth -- star and planet formation and the production of complex organic molecules in interstellar space -- are yielding their secrets to astronomers armed with powerful new research tools, and even better tools soon will be available. Astronomers described three important developments at a symposium on the "Cosmic Cradle of Life" at the annual meeting of the American Association for the Advancement of Science in Chicago, IL. Chemistry Cycle The Cosmic Chemistry Cycle CREDIT: Bill Saxton, NRAO/AUI/NSF Full Size Image Files Chemical Cycle Graphic (above image, JPEG, 129K) Graphic With Text Blocks (JPEG, 165K) High-Res TIFF (44.2M) High-Res TIFF With Text Blocks (44.2M) In one development, a team of astrochemists released a major new resource for seeking complex interstellar molecules that are the precursors to life. The chemical data released by Anthony Remijan of the National Radio Astronomy Observatory (NRAO) and his university colleagues is part of the Prebiotic Interstellar Molecule Survey, or PRIMOS, a project studying a star-forming region near the center of our Milky Way Galaxy. PRIMOS is an effort of the National Science Foundation's Center for Chemistry of the Universe, started at the University of Virginia (UVa) in October 2008, and led by UVa Professor Brooks H. Pate. The data, produced by the NSF's Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, came from more than 45 individual observations totalling more than nine GigaBytes of data and over 1.4 million individual frequency channels. Scientists can search the GBT data for specific radio frequencies, called spectral lines -- telltale "fingerprints" -- naturally emitted by molecules in interstellar space. "We've identified more than 720 spectral lines in this collection, and about 240 of those are from unknown molecules," Remijan said. He added, "We're making available to all scientists the best collection of data below 50 GHz ever produced for the study of interstellar chemistry," Remijan said. Astronomers have already identified more than 150 molecules in interstellar space in the past 40 years, including complex organic compounds such as sugars and alcohols. "This is a major change in how we search for molecules in space," Remijan explained. "Before, people decided beforehand which molecules they were looking for, then searched in a very narrow band of radio frequencies emitted by those molecules. In this GBT survey, we've observed a wide range of frequencies, collected the data and immediately made it publicly available. Scientists anywhere can 'mine' this resource to find new molecules," he said. Another key development, presented by Crystal Brogan of the NRAO, showed that highly-detailed images of "protoclusters" of massive young stars reveal a complex mix of stars in different stages of formation, complicated gas motions, and numerous chemical clues to the physical conditions in such stellar nurseries. "We saw a much more complex picture than we had expected and now have new questions to answer," she said. Using the Smithsonian Astrophysical Observatory's Submillimeter Array (SMA) in Hawaii, Brogan and her colleagues studied a nebula 5,500 light-years from Earth in the constellation Scorpius where stars significantly more massive than our Sun are forming. "It's essential to understand what's going on in systems like this because most stars, Sun-like stars included, form in clusters," Brogan said. "The most massive stars in the cluster have a tremendous impact on the formation and environment of the rest of the cluster, including the less-massive stars and their planets," Brogan said, adding that "if we want to understand how solar systems that could support life form and evolve, we need to know how these giant stars affect their environment." Also, Brogan said, the massive young stars are surrounded by "hot cores" that include copious organic material that later may be spewed in

2009-02-01

214

Franklin Edward Kameny (1925-2011, Astronomer)  

NASA Astrophysics Data System (ADS)

Dr. Frank Kameny is best known today as one of the most important members of the gay rights movement in the United States, but he was also a PhD astronomer. In fact, it was his firing from his civil service position as astronomer for the US Army Map Service on the grounds of homosexuality that sparked his lifelong career of activism. Here, I explore some aspects of his short but interesting astronomical career and the role of the AAS in his life.

Wright, Jason

2012-01-01

215

A Decade of Hubble Space Telescope Science  

NASA Astrophysics Data System (ADS)

1. HST studies of Mars J. F. Bell; 2. HST images of Jupiter's UV aurora J. T. Clarke; 3. Star formation J. Bally; 4. SN1987A: the birth of a supernova remnant R. McCray; 5. Globular clusters: the view from HST W. E. Harris; 6. Ultraviolet absorption line studies of the Galactic interstellar medium with the Goddard High Resolution Spectrograph B. D. Savage; 7. HST's view of the center of the Milky Way galaxy M. J. Rieke; 8. Stellar populations in dwarf galaxies: a review of the contribution of HST to our understanding of the nearby universe E. Tolstoy; 9. The formation of star clusters B. C. Whitmore; 10. Starburst galaxies observed with the Hubble Space Telescope C. Leitherer; 11. Supermassive black holes F. D. Macchetto; 12. The HST Key Project to measure the Hubble Constant W. L. Freedman, R. C. Kennicutt, J. R. Mould and B. F. Madore; 13. Ho from Type Ia Supernovae G. A. Tammann, A. Sandage and A. Saha; 14. Strong gravitational lensing: cosmology from angels and redshifts A. Tyson.

Livio, Mario; Noll, Keith; Stiavelli, Massimo

2003-06-01

216

Lunar astronomical observatories - Design studies  

NASA Astrophysics Data System (ADS)

The best location in the inner solar system for the grand observatories of the 21st century may be the moon. A multidisciplinary team including university students and faculty in engineering, astronomy, physics, and geology, and engineers from industry is investigating the moon as a site for astronomical observatories and is doing conceptual and preliminary designs for these future observatories. Studies encompass lunar facilities for radio astronomy and astronomy at optical, ultraviolet, and infrared wavelengths of the electromagnetic spectrum. Although there are significant engineering challenges in design and construction on the moon, the rewards for astronomy can be great, such as detection and study of earth-like planets orbiting nearby stars, and the task for engineers promises to stimulate advances in analysis and design, materials and structures, automation and robotics, foundations, and controls. Fabricating structures in the reduced-gravity environment of the moon will be easier than in the zero-gravity environment of earth orbit, as Apollo and space-shuttle missions have revealed. Construction of observatories on the moon can be adapted from techniques developed on the earth, with the advantage that the moon's weaker gravitational pull makes it possible to build larger devices than are practical on earth.

Johnson, Stewart W.; Burns, Jack O.; Chua, Koon Meng; Duric, Nebojsa; Gerstle, Walter H.

1990-10-01

217

VEGAS: VErsatile GBT Astronomical Spectrometer  

NASA Astrophysics Data System (ADS)

The National Science Foundation Advanced Technologies and Instrumentation (NSF-ATI) program is funding a new spectrometer backend for the Green Bank Telescope (GBT). This spectrometer is being built by the CICADA collaboration - collaboration between the National Radio Astronomy Observatory (NRAO) and the Center for Astronomy Signal Processing and Electronics Research (CASPER) at the University of California Berkeley.The backend is named as VErsatile GBT Astronomical Spectrometer (VEGAS) and will replace the capabilities of the existing spectrometers. This backend supports data processing from focal plane array systems. The spectrometer will be capable of processing up to 1.25 GHz bandwidth from 8 dual polarized beams or a bandwidth up to 10 GHz from a dual polarized beam.The spectrometer will be using 8-bit analog to digital converters (ADC), which gives a better dynamic range than existing GBT spectrometers. There will be 8 tunable digital sub-bands within the 1.25 GHz bandwidth, which will enhance the capability of simultaneous observation of multiple spectral transitions. The maximum spectral dump rate to disk will be about 0.5 msec. The vastly enhanced backend capabilities will support several science projects with the GBT. The projects include mapping temperature and density structure of molecular clouds; searches for organic molecules in the interstellar medium; determination of the fundamental constants of our evolving Universe; red-shifted spectral features from galaxies across cosmic time and survey for pulsars in the extreme gravitational environment of the Galactic Center.

Bussa, Srikanth; VEGAS Development Team

2012-01-01

218

Chrysanthos Notaras as an Astronomer  

NASA Astrophysics Data System (ADS)

The aim of the present work is to emphasize the contribution of Chrysanthos Notaras (16??-1731) in the dispersion of Astronomy in the begining of the eighteenth century. Chysanthos Notaras, Partiarch of Jerusalem (1707-1731), is included among the most educated Greeks of his epoch. Although his first studies were suitable for ecclesiastic offices and religion, (since he studied ecclesiastic low, at Patavio, Italy), he continued at Paris for additional studies in Astronomy and Geography (1700). He became student of G.D. Cassini, who was the Director of Paris Observatory at that time, and he served as observer and astronomical instruments constructor, under Cassini's supervision. Chrysanthos Notaras included the teaching of "Astronomy" as a lesson in the schools of the Holy Sepulchre, in order to disperse the new ideas and knowledge about the earth and the universe among the young students. He published the first International Map (of the known world) in the Greek language in 1700 and in 1716 his book "Intoduction in Geography and Sphericals" was published in Paris. This book, written before 1707, was mainly an introduction to Astronomy and was used by the afterwards authors as an essential and basic manual and offered a lot to the enlightenment of the enslavement Greeks.

Rovithis, P.

219

Real Explorations in Astronomical Learning  

NASA Astrophysics Data System (ADS)

Real Explorations in Astronomical Learning (REAL) is an innovative and new approach to student learning that thoughtfully integrates the excitement of space science discovery with science and mathematics. Students explore NASA images of planetary surfaces using the contexts of crater density, cratering rates, and surface age while developing critical thinking skills in science and mathematics that can be applied to any number of real life situations. Project REAL participants develop, implement, and evaluate an integrated astronomy curriculum designed for middle level students that focuses on the tools necessary for astronomy research concerning the origins and evolution of surface features on planetary bodies within our Solar System. Through the REAL curriculum, students experience the excitement of exploration by becoming authentic space science researchers. Students are provided with opportunities to: • Engage in hands-on space science research • Both quantitatively and qualitatively understand the phases of the Moon, and the origins and evolution of specific features on the surfaces of planetary bodies within our Solar System • Communicate their own scientific thinking and to understand others’ scientific thinking We present year one's findings concerning the state and effectiveness of this REAL curriculum funded by a NASA-IDEAS grant.

Wilhelm, Jennifer; Wilhelm, R.

2007-12-01

220

Prospective Extra-Atmospheric Astronomical Investigations.  

National Technical Information Service (NTIS)

The advantages of extra-atmospheric telescopes over terrestrial telescopes are outlined. An enumeration of the requirements of extra-atmospheric telescopes is given and the significance of extra-atmospheric astronomy with respect to the future of astronom...

V. G. Kurt

1973-01-01

221

Astronomical education in Tajikistan. Project TAJASTRO  

NASA Astrophysics Data System (ADS)

The centre of astronomy in Tajikistan is the Institute of Astrophysics of the Academy of Sciences of Tajikistan. This institute carries out scientific research and contributes to the preparation of the astronomical staff and to astronomical education. The reform of education in Tajikistan continues and now astronomy is studied in schools (together with physics) and at universities. The Tajik State Pedagogical University resumed in 2007 the training of teachers in physics and astronomy. Since 1999 the Tajik National University (TNU) offers a a specialty in astronomy. In 2006 is restored the Small Academy of Sciences (SAS) of Tajikistan. There is a planetarium in Khujand and in 2006 the Institute of Astrophysics, TNU and the Astronomical Society of Tajikistan, along with the support IBSP/UNESCO, organised the Training Methodical Center (TMC) ``TAJASTRO'' at the Hisar astronomical observatory for students, graduate students, young scientists, and teachers at secondary schools.

Ibadinov, Khursandkul I.; Rahmonov, A. A.

2011-06-01

222

Astronomical Phenomena for the Year 1991.  

National Technical Information Service (NTIS)

Astronomical phenomena for the year 1991 are presented in tabular form. Data is given on seasons, Moon phases, eclipses, occultations, perigee and apogee of the Moon, geocentric and heliocentric planetary phenomena, times of meridian passages of planets, ...

1990-01-01

223

Replacement vs. Renovation: The Reincarnation of Hubble Middle School  

ERIC Educational Resources Information Center

At the original Hubble Middle School, neither the views (a congested Roosevelt Road and glimpses of downtown Wheaton) nor the century-old facility that offered them was very inspiring. Built at the start of the 20th century, the 250,000-square-foot building was converted from Wheaton Central High School to Hubble Middle School in the early 1980s.…

Ogurek, Douglas J.

2010-01-01

224

The Hubble constant and dark energy from cosmological distance measures  

SciTech Connect

We study how the determination of the Hubble constant from cosmological distance measures is affected by models of dark energy and vice versa. For this purpose, constraints on the Hubble constant and dark energy are investigated using the cosmological observations of cosmic microwave background, baryon acoustic oscillations and type Ia supernovae. When one investigates dark energy, the Hubble constant is often a nuisance parameter; thus it is usually marginalized over. On the other hand, when one focuses on the Hubble constant, simple dark energy models such as a cosmological constant and a constant equation of state are usually assumed. Since we do not know the nature of dark energy yet, it is interesting to investigate the Hubble constant assuming some types of dark energy and see to what extent the constraint on the Hubble constant is affected by the assumption concerning dark energy. We show that the constraint on the Hubble constant is not affected much by the assumption for dark energy. We furthermore show that this holds true even if we remove the assumption that the universe is flat. We also discuss how the prior on the Hubble constant affects the constraints on dark energy and/or the curvature of the universe.

Ichikawa, Kazuhide [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa 277-8582 (Japan); Takahashi, Tomo, E-mail: kazuhide@icrr.u-tokyo.ac.jp, E-mail: tomot@cc.saga-u.ac.jp [Department of Physics, Saga University, Saga 840-8502 (Japan)

2008-04-15

225

The Hubble constant and the expansion age of the Universe  

Microsoft Academic Search

The Hubble constant, which measures the expansion rate, together with the total energy density of the Universe, sets the size of the observable Universe, its age, and its radius of curvature. Excellent progress has been made recently toward the measurement of the Hubble constant: a number of different methods for measuring distances have been developed and refined, and a primary

Wendy L. Freedman; Pasadena CA

2000-01-01

226

Astronomical Symbolism in Australian Aboriginal Rock Art  

Microsoft Academic Search

Traditional Aboriginal Australian cultures include a significant astronomical\\u000acomponent, perpetuated through oral tradition and ceremony. This knowledge has\\u000apractical navigational and calendrical functions, and sometimes extends to a\\u000adeep understanding of the motion of objects in the sky. Here we explore whether\\u000athis astronomical tradition is reflected in the rock art of Aboriginal\\u000aAustralians. We find several plausible examples of

Ray P. Norris; Duane W. Hamacher

2010-01-01

227

Interactions between astronomical ephemerides and society  

NASA Astrophysics Data System (ADS)

Ephemerides are regularly made by astronomers for their own uses. However, the general public is also interested, as well as official organisms, because of the interactions of ephemerides with society. Astronomers in charge of the making of calendars and keeping the time are of great importance every day. Their calculations are also required for the positioning of ships and airplanes. Some ephemerides are also requested by the general public.

Arlot, Jean-Eudes

2011-06-01

228

The Strange Case of Hubble's V19 in M33: Monitoring the Remarkable Changes and Possible Real-Time Evolution of a Classical Cepheid  

NASA Astrophysics Data System (ADS)

In the influential work "A Spiral Nebula as a Stellar System: Messier 33” (Hubble 1926) Edwin Hubble determined the distance to M33 by using 35 Cepheids he discovered. One of those Cepheids was designated V19. Observations revealed V19 to have a 54.7-day period and B-band (converted from photographic magnitudes) light amplitude of 1.1-mag. Its mean B-magnitude was 19.59+/-0.23. Its properties were consistent with the Period-Luminosity Law for M33 derived by Hubble at that time. Follow up observations in 1996-1997 as part of the DIRECT Program (Macri et al. 2001), however, revealed large and surprising changes in the properties of V19. Its mean B-magnitude had risen to 19.05+/-0.05 and its amplitude had fallen to < 0.1-mag. The DIRECT study thoroughly checked for possible misclassifications of the variable or contamination by nearby objects, and found none. For all intents and purposes, V19 was no longer a Classical Cepheid, or at least varying below the detectable levels of the photometry. The only other well-documented instance of Cepheid pulsations declining over time is in the case of Polaris - whose V-band amplitude fell from just over 0.1-mag to below 0.03-mag over the course of a century (Engle et al 2004). Also, a study of Polaris’ visual magnitudes over the past two millennia has shown a possible increase in brightness of 1-mag over the past 1000 years. The changes present in V19 are obviously on a much more dramatic scale. We report on our continuing efforts to monitor the behavior and properties of Hubble's V19 in M33. Photometry has been carried out with the WIYN 3.5-m telescope and the 1.3-m RCT (Robotically Controlled Telescope) at KPNO. It is our hope that these observations will help solve the mystery of V19 and its unprecedented evolutionary behavior. We gratefully acknowledge NASA/HST grant and NSF/RUI grant AST1009903.

Engle, Scott G.; Guinan, E.; Macri, L.; Pellerin, A.

2011-01-01

229

Laryngeal findings and acoustic changes in hubble-bubble smokers.  

PubMed

The purpose of our investigation was to evaluate the laryngeal findings and acoustic changes in hubble-bubble smokers. A total of 42 subjects with history of hubble-bubble smoking were recruited for this study. A corresponding group with a history of cigarette smoking and controls were matched. All subjects underwent laryngeal video-endostroboscopic evaluation and acoustic analysis. In the hubble-bubble smoking group, 61.9% were males. The average age was 30.02 +/- 9.48 years and the average number of years of smoking was 8.09 +/- 6.45 years. Three subjects had dysphonia at the time of examination. The incidence of benign lesions of the vocal folds in the hubble-bubble group was 21.5%, with edema being the most common at 16.7% followed by cyst at 4.8%. The incidence of laryngeal findings was significantly higher in the hubble-bubble group compared to controls. In the cigarette-smoking group, the most common finding was vocal fold cyst in 14.8% followed by polyps in 7.4%, and edema, sulcus vocalis and granuloma. These findings were not significantly different from the hubble-bubble group except for the thick mucus, which was significantly higher in the latter. There were no significant changes in any of the acoustic parameters between hubble-bubble smokers and controls except for the VTI and MPT, which were significantly lower in the hubble-bubble group. In comparison with the cigarette-smoking group, hubble-bubble smokers had significantly higher Fundamental frequency and habitual pitch (p value 0.042 and 0.008, respectively). The laryngeal findings in hubble-bubble smokers are comparable to cigarette smokers. These laryngeal findings are not translated acoustically, as all the acoustic parameters are within normal range compared to controls. PMID:20480370

Hamdan, Abdul-latif; Sibai, Abla; Oubari, Dima; Ashkar, Jihad; Fuleihan, Nabil

2010-05-18

230

The Panchromatic Hubble Andromeda Treasury: Project Overview  

NASA Astrophysics Data System (ADS)

The Panchromatic Hubble Andromeda Treasury is an HST multicycle program to image the north east quadrant of M31 to deep limits in the UV, optical, and near-IR. The HST imaging has resolved the galaxy into nearly 100 million stars (comparable to ~1/2 the number of stars in SDSS), all with common distances and foreground extinctions. UV through NIR stellar photometry (F275W, F336W with WFC3/UVIS, F475W and F814W with ACS/WFC, and F110W and F160W with WFC3/NIR) provides effective temperatures for a wide range of spectral types, while simultaneously mapping M31's extinction. As its legacy, this survey adds M31 to the Milky Way and Magellanic Clouds as a fundamental calibrator of stellar evolution and star-formation processes for understanding the stellar populations of distant galaxies. I will briefly describe the survey strategy, data reduction, and key data products.

Dalcanton, Julianne; Williams, B. F.; PHAT Collaboration

2013-01-01

231

Hubble Legacy Archive (HLA) Pipeline Progression  

NASA Astrophysics Data System (ADS)

The HLA maintains a strong commitment to continuing improvement of our Hubble Space Telescope data processing pipelines with the goal of generating better science-ready data products. The HLA image processing pipeline is transitioning from the use of MultiDrizzle to AstroDrizzle for image registration and combination. It is expected that this change will allow for the creation of higher quality science products with improved astrometric solutions. Headerlets, a newly developed tool for AstroDrizzle, will be utilized and made available to simplify access to multiple astrometric solutions for a given data set. The capabilities of AstroDrizzle will allow for functionally simplified data processing, standardizing and streamlining the data reduction process and making it easier for users to reproduce our results. We are beginning with the HLA WFC3 data processing pipeline, and then plan to extend its application to other HST instrument data.

Anderson, Rachel E.; Casertano, S.; Lindsay, K.

2013-01-01

232

Hubble-induced mass from MSSM plasma  

NASA Astrophysics Data System (ADS)

We evaluate the effective mass of a scalar field phi coupled to thermal plasma through Planck-suppressed interactions. We find it useful to rescale the coupled fields so that all the phi-dependences are absorbed into the yukawa and gauge couplings, which allows us to read off the leading order contributions to the effective mass tilde mphi from the 2-loop free energy calculated with the rescaled couplings. We give an analytical expression for tilde mphi at a sufficiently high temperature in the case where phi is coupled to the MSSM chiral superfields through non-minimal Kähler potential. We find that |tilde mphi2| is about 10-3H2 ~ 10-2H2 at the leading order in terms of the couplings for typical parameter sets, where H is the Hubble expansion rate in the radiation-dominated era.

Kawasaki, Masahiro; Takahashi, Fuminobu; Takesako, Tomohiro

2013-04-01

233

Disc heating agents across the Hubble sequence  

NASA Astrophysics Data System (ADS)

We measure the shape of the velocity ellipsoid in two late-type spiral galaxies (Hubble types Sc and Scd) and combine these results with our previous analyses of six early-type spirals (Sa to Sbc) to probe the relation between galaxy morphology and the ratio of the vertical and radial dispersions. We confirm at much higher significance (99.9 per cent) our prior detection of a tight correlation between these quantities. We explore the trends of the magnitude and shape of the velocity ellipsoid axes with galaxy properties (colour, gas surface mass density and spiral arm structure). The observed relationships allow for an observational identification of the radial and vertical disc heating agents in external disc galaxies. Based on observations made with ESO Telescopes at the La Silla Observatory under programmes 074.B-0550(A) and 078.B-0152(A).

Gerssen, J.; Shapiro Griffin, K.

2012-07-01

234

Uranus's auroras observed from Hubble Space Telescope  

NASA Astrophysics Data System (ADS)

New observations from the Hubble Space Telescope provide the first ever images of Uranus's auroras. The new observations, described by Lamy et al., are also the first unambiguous detections of Uranus's auroras since they were first discovered using the Voyager 2 spacecraft, which few by the planet in 1986. Auroras arise from the solar wind's interaction with a planet's magnetosphere. Uranus's magnetosphere, which is not well studied, is unusual because the planet's magnetic axis is both offset and sharply tilted with respect to the planet's spin axis. The newly detected auroras, seen on the dayside of the planet in November 2011, are quite different from Earth's—Uranus's auroras were faint dots of light that lasted online a few minutes, unlike the dancing colored curtains organized along rings of emissions around Earth's magnetic poles, intensified on the nightside and lasting for hours. (Geophysical Research Letters, doi:10.1029/ 2012GL051312, 2012)

Balcerak, Ernie

2012-05-01

235

The Hubble Space Telescope Scientific Instruments  

NASA Astrophysics Data System (ADS)

The paper describes the status of the five Scientific Instruments (SI's) to be flown on the Hubble Space Telescope (HST) which is planned to be launched by the Space Transportation System in the last half of 1986. Concentration is on the testing experience for each of the instruments both at the instrument level and in conjunction with the other instruments and subsystems of the HST. Since the Acceptance/Flight Qualification Program of the HST is currently underway a description of the test and verification plans to be accomplished prior to shipment to the Kennedy Space Center (KSC) and pre-launch tests plans prior to launch are provided. The paper concludes with a brief description of anticipated orbital performance.

Moore, J. V.

1986-01-01

236

Cosmographic Hubble fits to the supernova data  

NASA Astrophysics Data System (ADS)

The Hubble relation between distance and redshift is a purely cosmographic relation that depends only on the symmetries of a Friedmann-Lemaitre-Robertson-Walker spacetime, but does not intrinsically make any dynamical assumptions. This suggests that it should be possible to estimate the parameters defining the Hubble relation without making any dynamical assumptions. To test this idea, we perform a number of interrelated cosmographic fits to the legacy05 and gold06 supernova data sets. Based on this supernova data, the “preponderance of evidence” certainly suggests an accelerating universe. However, we would argue that (unless one uses additional dynamical and observational information) this conclusion is not currently supported “beyond reasonable doubt.” As part of the analysis we develop two particularly transparent graphical representations of the redshift-distance relation—representations in which acceleration versus deceleration reduces to the question of whether the relevant graph slopes up or down. Turning to the details of the cosmographic fits, three issues in particular concern us: First, the fitted value for the deceleration parameter changes significantly depending on whether one performs a ?2 fit to the luminosity distance, proper motion distance, angular diameter distance, or other suitable distance surrogate. Second, the fitted value for the deceleration parameter changes significantly depending on whether one uses the traditional redshift variable z or what we shall argue is, on theoretical grounds, an improved parametrization y=z/(1+z). Third, the published estimates for systematic uncertainties are sufficiently large that they certainly impact on, and to a large extent undermine, the usual purely statistical tests of significance. We conclude that the supernova data should be treated with some caution.

Cattoën, Céline; Visser, Matt

2008-09-01

237

Cosmographic Hubble fits to the supernova data  

SciTech Connect

The Hubble relation between distance and redshift is a purely cosmographic relation that depends only on the symmetries of a Friedmann-Lemaitre-Robertson-Walker spacetime, but does not intrinsically make any dynamical assumptions. This suggests that it should be possible to estimate the parameters defining the Hubble relation without making any dynamical assumptions. To test this idea, we perform a number of interrelated cosmographic fits to the legacy05 and gold06 supernova data sets. Based on this supernova data, the 'preponderance of evidence' certainly suggests an accelerating universe. However, we would argue that (unless one uses additional dynamical and observational information) this conclusion is not currently supported 'beyond reasonable doubt'. As part of the analysis we develop two particularly transparent graphical representations of the redshift-distance relation--representations in which acceleration versus deceleration reduces to the question of whether the relevant graph slopes up or down. Turning to the details of the cosmographic fits, three issues in particular concern us: First, the fitted value for the deceleration parameter changes significantly depending on whether one performs a {chi}{sup 2} fit to the luminosity distance, proper motion distance, angular diameter distance, or other suitable distance surrogate. Second, the fitted value for the deceleration parameter changes significantly depending on whether one uses the traditional redshift variable z or what we shall argue is, on theoretical grounds, an improved parametrization y=z/(1+z). Third, the published estimates for systematic uncertainties are sufficiently large that they certainly impact on, and to a large extent undermine, the usual purely statistical tests of significance. We conclude that the supernova data should be treated with some caution.

Cattoeen, Celine; Visser, Matt [School of Mathematics, Statistics, and Computer Science, Victoria University of Wellington, P.O. Box 600, Wellington (New Zealand)

2008-09-15

238

An Astronomer In The Classroom: Observatoire de Paris's Partnership Between Teachers and Astronomers  

Microsoft Academic Search

The Observatoire de Paris is offering a partnership between teachers and astronomers. The principle is simple: any teacher wishing to undertake a pedagogical project in astronomy, in the classroom or involving the entire school, can request the help of a mentor. An astronomer from the Observatoire de Paris will then follow the teacher's project progress and offer advice and scientific

A. Doressoundiram; C. Barban

2006-01-01

239

Astronomers debate diamonds in space  

NASA Astrophysics Data System (ADS)

This is not the first time the intriguing carbonaceous compound has been detected in space. A peculiar elite of twelve stars are known to produce it. The star now added by ISO to this elite is one of the best representatives of this exclusive family, since it emits a very strong signal of the compound. Additionally ISO found a second new member of the group with weaker emission, and also observed with a spectral resolution never achieved before other already known stars in this class. Astronomers think these ISO results will help solve the mystery of the true nature of the compound. Their publication by two different groups, from Spain and Canada, has triggered a debate on the topic, both in astronomy institutes and in chemistry laboratories. At present, mixed teams of astrophysicists and chemists are investigating in the lab compounds whose chemical signature or "fingerprint" matches that detected by ISO. Neither diamonds nor fullerenes have ever been detected in space, but their presence has been predicted. Tiny diamonds of pre-solar origin --older than the Solar System-- have been found in meteorites, which supports the as yet unconfirmed theory of their presence in interstellar space. The fullerene molecule, made of 60 carbon atoms linked to form a sphere (hence the name "buckyball"), has also been extensively searched for in space but never found. If the carbonaceous compound detected by ISO is a fullerene or a diamond, there will be new data on the production of these industrially interesting materials. Fullerenes are being investigated as "capsules" to deliver new pharmaceuticals to the body. Diamonds are commonly used in the electronics industry and for the development of new materials; if they are formed in the dust surrounding some stars, at relatively low temperatures and conditions of low pressure, companies could learn more about the ideal physical conditions to produce them. A textbook case The latest star in which the compound has been found is called IRAS 16594-4656. Like the others, it's a carbon-rich star now in the process of dying. It has been blasting out huge amounts of material over the last thousand years, becoming enclosed within a shell of dust hundreds of times larger than the Solar System --a structure called a "protoplanetary nebula". It was in this dust -- very cold and therefore invisible to non-infrared telescopes-- that the Spanish group using ISO's SWS and LWS spectrometers detected the signature of the carbonaceous compound, in the form of a broad emission band at the wavelength of 21 micron. "We searched for the compound in twenty candidate stars and only this one had it. It is a real textbook case, with one of the strongest emissions ever detected. It gets us closer to solving the mystery and will help us to understand how the "chemical factories" of the Universe work", says ESA astronomer Pedro Garcia-Lario at the ISO Data Centre in Villafranca, Madrid. His group published their results in the March 10 issue of the Astrophysical Journal. They favour the fullerene option. Fullerenes would get formed during decomposition of the solid carbon grains condensed out of the material emitted by the star. The Canadian group obtained high-resolution ISO spectra of seven other stars in this class, and also detected a weak emission of the carbonaceous compound in a new one. They present their data in the May 11 issue of the Astrophysical Journal Letters. "Diamonds, graphite, coal and fullerenes are different forms of carbon. It is quite possible that the 21 micron feature arises from any one of these forms, although not exactly like they are on Earth", says main author Sun Kwok, at the University of Calgary. His group detected the carbonaceous compound a decade ago, for the first time, with the earlier infrared satellite IRAS. Meanwhile, results from the French group led by Louis d'Hendecourt, at the Institut d'Astrophysique Spatiale, in Paris, are adding to the debate. They isolated very tiny diamonds --a million times smaller

1999-04-01

240

High Resolution Laboratory Studies for Astronomical Spectroscopy  

NASA Astrophysics Data System (ADS)

Understanding astronomical observations of molecules requires detailed spectroscopic data that can only be derived from laboratory studies. These data, including accurate transition frequencies, intensities, broadening coefficients, and collisional rates are essential for the proper characterization of the physics, chemistry, and dynamics of astronomical sources. Equally important is the comprehensive spectroscopic characterization of astronomical molecules in multiple wavelength regions. A strong effort is in place in the JPL Molecular Spectroscopy Group to provide fundamental knowledge to support ground-, aircraft-, and space-based astronomical spectroscopy. A synopsis of the high-resolution laboratory spectroscopy of astronomical molecules at JPL is presented, highlighting benchmark studies that span wavelengths from the radio to the optical. The systems under study include molecules that are ubiquitous in the interstellar medium and/or exoplanetary atmospheres (CH4, CO2, H2O, and NH3), as well as ones that have recently been shown to be important constituents of the interstellar gas (O2, CH3OH, H3O+, and HCl+).

Gupta, Harshal; Brown, L. R.; Drouin, B. J.; Miller, C. E.; Pearson, J. C.; Sung, K.; Yu, S.

2012-05-01

241

How Did the Universe Begin?  

NSDL National Science Digital Library

This fun Web site is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here, they learn about the work of Edwin Hubble and how his work contributed to the formation of the Big Bang Theory. The site begins by briefly explaining Hubble's discoveries. It then explains how Belgian astronomer Georges Lema used Hubble's discovery to answer the question of the universe's origin with what later became known as the Big Bang Theory. A link to "The Big Bang" explains the theory in five kid-friendly steps. The site also includes a link to a "Create Your Own Timeline of the Universe" activity.

242

The Hubble Legacy Archive ACS grism data  

NASA Astrophysics Data System (ADS)

A public release of slitless spectra, obtained with ACS/WFC and the G800L grism, is presented. Spectra were automatically extracted in a uniform way from 153 archival fields (or "associations") distributed across the two Galactic caps, covering all observations to 2008. The ACS G800L grism provides a wavelength range of 0.55-1.00 ?m, with a dispersion of 40 Å/pixel and a resolution of ~80 Å for point-like sources. The ACS G800L images and matched direct images were reduced with an automatic pipeline that handles all steps from archive retrieval, alignment and astrometric calibration, direct image combination, catalogue generation, spectral extraction and collection of metadata. The large number of extracted spectra (73,581) demanded automatic methods for quality control and an automated classification algorithm was trained on the visual inspection of several thousand spectra. The final sample of quality controlled spectra includes 47 919 datasets (65% of the total number of extracted spectra) for 32 149 unique objects, with a median iAB-band magnitude of 23.7, reaching 26.5 AB for the faintest objects. Each released dataset contains science-ready 1D and 2D spectra, as well as multi-band image cutouts of corresponding sources and a useful preview page summarising the direct and slitless data, astrometric and photometric parameters. This release is part of the continuing effort to enhance the content of the Hubble Legacy Archive (HLA) with highly processed data products which significantly facilitate the scientific exploitation of the Hubble data. In order to characterize the slitless spectra, emission-line flux and equivalent width sensitivity of the ACS data were compared with public ground-based spectra in the GOODS-South field. An example list of emission line galaxies with two or more identified lines is also included, covering the redshift range 0.2 - 4.6. Almost all redshift determinations outside of the GOODS fields are new. The scope of science projects possible with the ACS slitless release data is large, from studies of Galactic stars to searches for high redshift galaxies.

Kümmel, M.; Rosati, P.; Fosbury, R.; Haase, J.; Hook, R. N.; Kuntschner, H.; Lombardi, M.; Micol, A.; Nilsson, K. K.; Stoehr, F.; Walsh, J. R.

2011-06-01

243

Book review: Odessa astronomical Almanac-2006  

NASA Astrophysics Data System (ADS)

A reveiw of the Odessa Astronomical Almanac (Odesskii Astronomicheskii Kalendari, Astroprint, Odessa, 2006, 255 pp. ) is given for the constant part ( V.G. Karetnikov, V.V. Mihalchuk, A.A. Bazey, S.M. Andrievskii, I.L. Andronov, M.Yu. Volyanskaia, G.A. Garbuzov, N.I. Koshkin, V.A. Pozigun and M.I. Ryabov- astronomers from the Odessa Astronomical Observatory) and the papers published in the 2006 issue ( B.A. Murnikov , Yu.N. Kudria, A.V. Iushchenko, T.V. Mishenina, S.M. Andrievskii, V.N. Ishkov, V.A. Pozigun, M.I Ryabov, L.S. Kudashkina. V.I. Marsakova ?i V.V. Mihalchuk).

Gaina, Alex

244

Ancient Maya astronomical tables from Xultun, Guatemala.  

PubMed

Maya astronomical tables are recognized in bark-paper books from the Late Postclassic period (1300 to 1521 C.E.), but Classic period (200 to 900 C.E.) precursors have not been found. In 2011, a small painted room was excavated at the extensive ancient Maya ruins of Xultun, Guatemala, dating to the early 9th century C.E. The walls and ceiling of the room are painted with several human figures. Two walls also display a large number of delicate black, red, and incised hieroglyphs. Many of these hieroglyphs are calendrical in nature and relate astronomical computations, including at least two tables concerning the movement of the Moon, and perhaps Mars and Venus. These apparently represent early astronomical tables and may shed light on the later books. PMID:22582260

Saturno, William A; Stuart, David; Aveni, Anthony F; Rossi, Franco

2012-05-11

245

The Transformation of an Astronomical Institution  

NASA Astrophysics Data System (ADS)

In 1954 the Astrophysical Observatory of the Smithsonian Institution was closed down in Washington and transferred to Harvard, becoming the Smithsonian Astrophysical Observatory. It was a bureau of the Harvard College Observatory but was wholly governed by the Smithsonian in Washington. Historians such as the speaker and Ron Doel have explored the nature of the transfer, but not so much its implications. Specifically, soon after the transfer, the SAO geared up for the IGY, the only astronomical institution to do so in a big way, and the NSF became the conduit for a vastly increased level of activity of a character and scale only dreamed of by astronomers prior to the Cold War era. This support, and soon additional NASA and Air Force support, led to the SAO becoming one of the largest astronomical institutions on the planet by the mid-1960s. We will explore some of the implications.

DeVorkin, David H.

2012-01-01

246

Astronomers Without Borders: A Global Astronomy Community  

NASA Astrophysics Data System (ADS)

Astronomers Without Borders (AWB) brings together astronomy enthusiasts of all types - amateur astronomers, educators, professionals and "armchair" astronomers for a variety of online and physicalworld programs. The AWB web site provides social networking and a base for online programs that engage people worldwide in astronomy activities that transcend geopolitical and cultural borders. There is universal interest in astronomy, which has been present in all cultures throughout recorded history. Astronomy is also among the most accessible of sciences with the natural laboratory of the sky being available to people worldwide. There are few other interests for which people widely separated geographically can engage in activities involving the same objects. AWB builds on those advantages to bring people together. AWB also provides a platform where projects can reach a global audience. AWB also provides unique opportunities for multidisciplinary collaboration in EPO programs. Several programs including The World at Night, Global Astronomy Month and others will be described along with lessons learned.

Simmons, M.

2011-10-01

247

Education Efforts of the International Astronomical Union  

NASA Astrophysics Data System (ADS)

I describe the education activities of the International Astronomical Union, particularly the work of Commission 46 on Education and Development. We are most interested in education in schools and for general university education rather than for pre-professional training or graduate schools. We have over 75 National Liaisons, mostly from member countries of the I.A.U. but some from nonmembers or regional groupings. We operate through 10 program groups, which are described at our Website at http://www.astronomyeducation.org. We also organize Special Sessions at General Assemblies of the International Astronomical Union, such as this Special Session 2 on Innovation in Teaching/ Learning Astronomy Methods, organized by Rosa Ros and me, and Special Session 5 on Astronomy for the Developing World, organized by John Hearnshaw. A modified version of our Special Session from the 2003 Sydney General Assembly was published as Teaching and Learning Astronomy: Effective Strategies for Educators Worldwide (Jay M. Pasachoff and John R. Percy, eds., Cambridge University Press, 2005). Michele Gerbaldi and Ed Guinan run the International Schools for Young Astronomers. Jay White heads the Teaching Astronomy for Development Program Group. John Hearnshaw runs the Program Group for the Worldwide Development of Astronomy. Charles Tolbert and John Percy run an Exchange of Astronomers program with a limited number of grants for stays of over three months between astronomers in developing countries and established astronomical institutions. Barrie Jones, as vice-president, aided by Tracey Moore, runs the Newsletter and keeps track of the National Liaisons list. I run the Program group of Public Education at the Times of Solar Eclipses.

Pasachoff, J. M.

2006-08-01

248

Astronomers gossip about the (cosmic) neighborhood.  

PubMed

The Hague, Netherlands, last month welcomed 2000 astronomers from around the world for the 22nd General Assembly of the International Astronomical Union (IAU). From 15 to 27 August, they participated in symposia and discussions on topics ranging from the down-to-Earth issue of light and radio-frequency pollution to the creation of elements at the farthest reaches of time and space, in the big bang. Some of the most striking news, however, came in new findings from our galaxy and its immediate surroundings. PMID:17801522

Jayawardhana, R

1994-09-01

249

Electronic Publishing at the American Astronomical Society  

NASA Astrophysics Data System (ADS)

Electronic communication is changing the way astronomers work and how they communicate. By forming teams of people with a wide variety of expertise, taking small steps, being flexible and soliciting the opinion of users, the American Astronomical Society has been successful in several electronic publishing projects. Experience has shown that electronic publishing entails as much effort as the paper counterpart, but that many benefits accrue to the user. Only by remaining open to new ideas and incorporating new tools as they become available will the true benefits of the connectivity provided by the World Wide Web be brought to the community.

Boyce, P. B.; Dalterio, H.

250

APLpy: Astronomical Plotting Library in Python  

NASA Astrophysics Data System (ADS)

APLpy (the Astronomical Plotting Library in Python) is a Python module for producing publication-quality plots of astronomical imaging data in FITS format. The module uses Matplotlib, a powerful and interactive plotting package. It is capable of creating output files in several graphical formats, including EPS, PDF, PS, PNG, and SVG. Plots can be made interactively or by using scripts, and can generate co-aligned FITS cubes to make three-color RGB images. It also offers different overlay capabilities, including contour sets, markers with customizable symbols, and coordinate grids, and a range of other useful features.

Robitaille, Thomas; Bressert, Eli

2012-08-01

251

Absolute Calibration of Astronomical Flux Standards  

NASA Astrophysics Data System (ADS)

The goal of astronomical data calibration is to convert measurements recordedin some particular instrumental units into physical quantities, such as ergcm- 2s- 1Hz- 1,removing as much as possible all instrumental signatures. In principle,photometric calibration is a solved problem - laboratory reference standards suchas blackbody furnaces achieve precisions well in excess of those neededfor astrophysics. In practice, however, transferring the calibration fromthese laboratory standards to astronomical objects of interest is far fromtrivial - the transfer must reach outside the atmosphere, extend over 4? steradian of sky, cover a wide range of wavelengths, and span an enormous dynamic range in intensity.

Deustua, Susana; Kent, Stephen; Smith, J. Allyn

252

Tadpole Galaxies in the Hubble Ultra Deep Field  

Microsoft Academic Search

The Hubble Ultra Deep Field presents a wealth of galaxies, some very oddly shaped. In particular, we notice many galaxies that appear to have a bright knot at one end with an extended tail at the other. These \\

A. N. Straughn; R. E. Ryan; S. H. Cohen; N. P. Hathi; R. A. Windhorst; A. Pasquali

2004-01-01

253

Hubble Space Telescope: Should NASA Proceed with a Servicing Mission.  

National Technical Information Service (NTIS)

The National Aeronautics and Space Administration (NASA) estimates that without a servicing mission to replace key components, the Hubble Space Telescope will cease scientific operations in 2008 instead of 2010. In January 2004, then-NASA Administrator Se...

D. Morgan

2006-01-01

254

Hubble Space Telescope on-Orbit Nih2 Battery Performance.  

National Technical Information Service (NTIS)

This paper summarizes the Hubble Space Telescope (HST) nickel-hydrogen (NiH2) battery performance from launch to the present time. Over the life of HST vehicle configuration, charge system degradation and failures together with thermal design limitations ...

S. J. Krol G. M. Rao

2002-01-01

255

UV Imaging of the Moon from the Hubble Space Telescope  

NASA Astrophysics Data System (ADS)

Hubble Space Telescope UV observations of three targets on the Moon have been successfully acquired (Apollo 15, Apollo 17, Aristarchus). These UV and Visible wavelength images demonstrate that lunar compositional mapping can be achieved via the HST's ACS instrument.

Garvin, J. B.; Robinson, M. S.; Hapke, B.; Bell, J. F., III; Skillman, D.; Ulmer, M.; Pieters, C.

2006-03-01

256

Carnegie Hubble Program: A Mid-infrared Calibration of the Hubble Constant  

NASA Astrophysics Data System (ADS)

Using a mid-infrared calibration of the Cepheid distance scale based on recent observations at 3.6 ?m with the Spitzer Space Telescope, we have obtained a new, high-accuracy calibration of the Hubble constant. We have established the mid-IR zero point of the Leavitt law (the Cepheid period-luminosity relation) using time-averaged 3.6 ?m data for 10 high-metallicity, Milky Way Cepheids having independently measured trigonometric parallaxes. We have adopted the slope of the PL relation using time-averaged 3.6 ?m data for 80 long-period Large Magellanic Cloud (LMC) Cepheids falling in the period range 0.8 < log(P) < 1.8. We find a new reddening-corrected distance to the LMC of 18.477 ± 0.033 (systematic) mag. We re-examine the systematic uncertainties in H 0, also taking into account new data over the past decade. In combination with the new Spitzer calibration, the systematic uncertainty in H 0 over that obtained by the Hubble Space Telescope Key Project has decreased by over a factor of three. Applying the Spitzer calibration to the Key Project sample, we find a value of H 0 = 74.3 with a systematic uncertainty of ±2.1 (systematic) km s-1 Mpc-1, corresponding to a 2.8% systematic uncertainty in the Hubble constant. This result, in combination with WMAP7 measurements of the cosmic microwave background anisotropies and assuming a flat universe, yields a value of the equation of state for dark energy, w 0 = -1.09 ± 0.10. Alternatively, relaxing the constraints on flatness and the numbers of relativistic species, and combining our results with those of WMAP7, Type Ia supernovae and baryon acoustic oscillations yield w 0 = -1.08 ± 0.10 and a value of N eff = 4.13 ± 0.67, mildly consistent with the existence of a fourth neutrino species.

Freedman, Wendy L.; Madore, Barry F.; Scowcroft, Victoria; Burns, Chris; Monson, Andy; Persson, S. Eric; Seibert, Mark; Rigby, Jane

2012-10-01

257

Covariance control design for Hubble Space Telescope  

NASA Astrophysics Data System (ADS)

To improve the response to unexpected thermally induced disturbances, two new controllers are designed for the Hubble Space Telescope (HST) using covariance control techniques. The first controller minimizes the required control effort subject to inequality constraints on the output covariance matrix. The second controller is designed to satisfy both output covariance constraints and controller covariance constraints. The importance of the controller covariance constraint is to properly scale the controller for digital implementation in the control computer using fixed-point arithmetic. We provide a technique to integrate modeling, control design, and signal processing (in HST's fixed-point control computer), since these problems are not separable. Covariance control can easily accommodate the roundoff error and computational time delay. Compared with the existing HST controller design, the results show that the required pointing error specifications can be achieved with 85% less control effort and that the error due to the finite-wordlength implementation of the controller can easily be included in the optimal control design process.

Zhu, Guoming; Grigoriadis, Karolos M.; Skelton, Robert E.

1995-03-01

258

Gravitational lensing and the Hubble Deep Field  

NASA Astrophysics Data System (ADS)

We calculate the expected number of multiply-imaged galaxies in the Hubble Deep Field (HDF), using photometric redshift information for galaxies with mI<27 that were detected in all four HDF passbands. A comparison of these expectations with the observed number of strongly lensed galaxies constrains the current value of ?m-??, where ?m is the mean mass density of the universe and ?? is the normalized cosmological constant. Based on current estimates of the HDF luminosity function and associated uncertainties in individual parameters, our 95% confidence lower limit on ?m-?? ranges between -0.44, if there are no strongly lensed galaxies in the HDF, and -0.73, if there are two strongly lensed galaxies in the HDF. If the only lensed galaxy in the HDF is the one presently viable candidate, then, in a flat universe (?m+??=1), ??<0.79 (95% C.L.). These limits are compatible with estimates based on high-redshift supernovae and with previous limits based on gravitational lensing.

Cooray, Asantha R.; Quashnock, Jean M.; Miller, M. Coleman

1999-04-01

259

A Hubble diagram of distant type IA supernovae  

Microsoft Academic Search

We have constructed Hubble diagrams in B and V for 13 Type Ia supernovae (SNe Ia) found in the course of the Calan\\/Tololo survey covering an unprecedented range in redshift (0.01 less than Z less than 0.1). As opposed to other published Hubble diagrams, these are solely based on light curves obtained with CCDs, which have been carefully reduced in

Mario Hamuy; M. M. Phillips; Jose Maza; Nicholas B. Suntzeff; R. A. Schommer; R. Aviles

1995-01-01

260

Studying Black Holes in the Internet with Hubble  

Microsoft Academic Search

We present Hubble, a system that operates contin- uously to find Internet reachability problems in which routes exist to a destination but packets are unable to reach the destination. Hubble monitors at a 15 minute granularity the data-path to prefixes that cover89%of the Internet's edge address space. Key enabling techniques include a hybrid passive\\/active monitoring approach and the synthesis of

Ethan Katz-bassett; Harsha V. Madhyastha; John P. John; Arvind Krishnamurthy; David Wetherall; Thomas E. Anderson

2008-01-01

261

A Proposed Revision of the Hubble Sequence for Elliptical Galaxies  

Microsoft Academic Search

The Hubble classification scheme has a well-known drawback for elliptical galaxies: the sequence E0--E6 correlates primarily with inclination and not with fundamental properties. In contrast, later-type galaxies are ordered by fundamental physical parameters. We propose to revise the Hubble sequence so that it orders ellipticals by isophote shape. Specifically, we suggest that the Im--spiral--S0 sequence be connected to disky ellipticals

John Kormendy; Ralf Bender

1996-01-01

262

Hubble-type outflows of the high-excitation poly-polar planetary nebula NGC 6302 - from expansion proper motions  

NASA Astrophysics Data System (ADS)

The outflowing proper motions of 15 knots in the dominant northwestern lobe of the high-excitation poly-polar planetary nebula NGC 6302 have been determined by comparing their positions relative to those of faint stars in an image taken at the San Pedro Martir Observatory in 2007 to those in a South African Astronomical Observatory archival plate obtained by Evans in 1956. The Hubble-type expansion of this lobe is now directly confirmed in a model-independent way from these measurements. Furthermore, an unambigous distance to NGC 6302 of 1.17 +/- 0.14 kpc is now determined. Also, all the velocity vectors of the 15 knots (and two others) point back to the central source. An eruptive event from within the central torus ~2200 yr previously must have created the high-speed lobes of NGC 6302.

Meaburn, J.; Lloyd, M.; Vaytet, N. M. H.; López, J. A.

2008-03-01

263

Novel optical designs for consumer astronomical telescopes and their application to professional imaging  

NASA Astrophysics Data System (ADS)

Since the launch of the Hubble Space Telescope there has been widespread popular interest in astronomy. A further series of events, most notably the recent Deep Impact mission and Mars oppositions have served to fuel further interest. As a result more and more amateurs are coming into astronomy as a practical hobby. At the same time more sophisticated optical equipment is becoming available as the price to performance ratio become more favourable. As a result larger and better optical telescopes are now in use by amateurs. We also have the explosive growth in digital imaging technologies. In addition to displacing photographic film as the preferred image capture modality it has made the capture of high quality astronomical imagery more accessible to a wider segment of the astronomy community. However, this customer requirement has also had an impact on telescope design. There has become a greater imperative for wide flat image fields in these telescopes to take advantage of the ongoing advances in CCD imaging technology. As a result of these market drivers designers of consumer astronomical telescopes are now producing state of the art designs that result in wide, flat fields with optimal spatial and chromatic aberrations. Whilst some of these designs are not scalable to the larger apertures required for professional ground and airborne telescope use there are some that are eminently suited to make this transition.

Wise, Peter; Hodgson, Alan

2006-07-01

264

The 6dF Galaxy Survey: baryon acoustic oscillations and the local Hubble constant  

NASA Astrophysics Data System (ADS)

We analyse the large-scale correlation function of the 6dF Galaxy Survey (6dFGS) and detect a baryon acoustic oscillation (BAO) signal at 105 h-1 Mpc. The 6dFGS BAO detection allows us to constrain the distance-redshift relation at zeff= 0.106. We achieve a distance measure of DV(zeff) = 457 ± 27 Mpc and a measurement of the distance ratio, rs(zd)/DV(zeff) = 0.336 ± 0.015 (4.5 per cent precision), where rs(zd) is the sound horizon at the drag epoch zd. The low-effective redshift of 6dFGS makes it a competitive and independent alternative to Cepheids and low-z supernovae in constraining the Hubble constant. We find a Hubble constant of H0= 67 ± 3.2 km s-1 Mpc-1 (4.8 per cent precision) that depends only on the Wilkinson Microwave Anisotropy Probe-7 (WMAP-7) calibration of the sound horizon and on the galaxy clustering in 6dFGS. Compared to earlier BAO studies at higher redshift, our analysis is less dependent on other cosmological parameters. The sensitivity to H0 can be used to break the degeneracy between the dark energy equation of state parameter w and H0 in the cosmic microwave background data. We determine that w=-0.97 ± 0.13, using only WMAP-7 and BAO data from both 6dFGS and Percival et al. (2010). We also discuss predictions for the large-scale correlation function of two future wide-angle surveys: the Wide field ASKAP L-band Legacy All-sky Blind surveY (WALLABY) blind H I survey (with the Australian Square Kilometre Array Pathfinder, ASKAP) and the proposed Transforming Astronomical Imaging surveys through Polychromatic Analysis of Nebulae (TAIPAN) all-southern-sky optical galaxy survey with the UK Schmidt Telescope. We find that both surveys are very likely to yield detections of the BAO peak, making WALLABY the first radio galaxy survey to do so. We also predict that TAIPAN has the potential to constrain the Hubble constant with 3 per cent precision.

Beutler, Florian; Blake, Chris; Colless, Matthew; Jones, D. Heath; Staveley-Smith, Lister; Campbell, Lachlan; Parker, Quentin; Saunders, Will; Watson, Fred

2011-10-01

265

Community College Class Devoted to Astronomical Research  

Microsoft Academic Search

A class at a small community college, Central Arizona College, was dedicated to astronomical research. Although hands-on research is usually reserved for professionals or graduate students, and occasionally individual undergraduate seniors, we decided to introduce community college students to science by devoting an entire class to research. Nine students were formed into three closely cooperating teams. The class as a

R. M. Genet; C. L. Genet

2002-01-01

266

Astronomical Photoelectric Photometry for Undergraduate Research  

Microsoft Academic Search

Many college physics departments would welcome the opportunity to initiate a modest research program which could involve their undergraduate students. Astronomical photoelectric photometry is a field in which it is possible to initiate a useful undergraduate oriented research program with relatively modest equipment, some of which can commonly be found in a college physics department. A sketch of the equipment

Albert D. Grauer

1974-01-01

267

Fags - a Fast Astronomical Grating Spectrometer  

NASA Astrophysics Data System (ADS)

A fast astronomical spectrometer is described using commercially available photographic lenses and a CCD detector. The size and weight of the instrument have been kept to a minimum to allow it to be used on telescopes as small as 0.6 m.

Denby, B.; Dalglish, R.; Meadows, V.; Taylor, K. N. R.

268

Short communications in the astronomical literature  

NASA Astrophysics Data System (ADS)

The tendency is noted for short, high-priority communications in the literature (Letters or Research Notes) to become longer with time. This trend occurs despite external controls (fixed page limits) and mimics the same trend noted for the astronomical literature in general (Abt 1981).

Harris, W. E.

1983-12-01

269

Analytic method for determining astronomical azimuths.  

National Technical Information Service (NTIS)

The analytic method for determining astronomical azimuths is a new means, put forward recently by the author, and a new theory as well. Suppose that near the diurnal apparent motion circle of the Polaris exist a fitting ellipse, with the north celestial p...

Jia Jingyun

1996-01-01

270

Infrared astronomical spectroscopy from high altitude aircraft  

Microsoft Academic Search

Two separate infrared astronomical observing programs are described which were carried out using telescopes mounted in aircraft flying above the tropopause. In the first program, the spectral reflectivity of the planet Mars was measured in the 2 micron to 4 micron wavelength region from the NASA Convair 990. The existence of a previously discovered broad and deep minimum in the

D. F. Schaack

1975-01-01

271

Hartung's Astronomical Objects for Southern Telescopes  

Microsoft Academic Search

Many of the most spectacular astronomical objects are found in the southern skies. With this up-to-date, superbly illustrated handbook, both the amateur with binoculars and the expert with a telescope can make discoveries about new and interesting objects. Professor E. J. Hartung first produced his comprehensive and highly respected guide in 1968. Now the book has been greatly expanded and

David Malin; David J. Frew

1995-01-01

272

Making films more efficient for astronomical photography  

Microsoft Academic Search

This paper examines the various methods by which photographic emulsions may be made to record faint deep-sky objects more efficiently. The effects of lowering emulsion temperature during exposure, and gas and liquid treatment prior to exposure, are discussed and examples are given from the author's own work. It is recommended that amateur astronomers who are seriously interested in deep-sky photography

C. R. Martys

1981-01-01

273

An Astronomer's View of Optical Turbulence  

NASA Astrophysics Data System (ADS)

Optical turbulence is a key determinant of an astronomical telescope science performance. Forecasting optical turbulence at altitude is thus of paramount importance for astronomy. And so are the understanding and management of ground layer and locally induced turbulence. This paper presents an astronomer's view of both the futility and the utility of various site characterization activities, of the challenges they pose and of dreams one has about understanding and forecasting site qualities. It is pointed out that, for likely suitable sites, the average integrated optical turbulence can be calculated to good accuracy by a simple model and that turbulence profiles differ less between sites that between nights or times at a given site. The challenges therefore stem from the temporal and spatial variability of the turbulence. This variability is illustrated and briefly discussed. Collaboration between astronomers and atmospheric physicists must hold the key to the astronomers' dream of knowing in detail what the optical turbulence at the site will be tomorrow night, or next week, and which science program will then make best use of the facility.

Racine, René

2009-09-01

274

An infrared hygrometer for astronomical site testing  

Microsoft Academic Search

This paper describes an i.r. hygrometer which measures the absolute water vapour content in the atmosphere. The instrument is easy to handle, it can be used with either the sun or the moon as a radiation source, and its design minimizes errors due to atmospheric aerosols. The instrument has already been used for astronomical site testing

E. Buescher; D. Lemke

1980-01-01

275

The Astronomical Orientation of Ancient Greek Temples  

Microsoft Academic Search

Despite its appearing to be a simple question to answer, there has been no consensus as to whether or not the alignments of ancient Greek temples reflect astronomical intentions. Here I present the results of a survey of archaic and classical Greek temples in Sicily and compare them with temples in Greece. Using a binomial test I show strong evidence

Alun M. Salt

2009-01-01

276

The CDS Reference Database for Astronomical Objects  

Microsoft Academic Search

Simbad is the reference database for identifi- cation and bibliography of astronomical objects. It con- tains identifications, 'basic data', bibliography, and se- lected observational measurements for several million as- tronomical objects. Simbad is developed and maintained by CDS, Stras- bourg. Building the database contents is achieved with the help of several contributing institutes. Scanning the bibli- ography is the result

Marc Wenger; Francois Ochsenbein; Daniel Egret; Pascal Dubois; Francois Bonnarel; Suzanne Borde; Francoise Genova; Gerard Jasniewicz; Suzanne Laloe; Soizick Lesteven; Richard Monier

277

The Sky Surveys with Astronomical Plate Archives  

NASA Astrophysics Data System (ADS)

The recent efforts to digitise plates in astronomical plate archives and to access these valuable and unique data by powerful computers and newly designed software enable to consider sky surveys based on these huge (there are almost 3 millions of astronomical archival plates at different observatories) database. I will review the recent status of astronomical plate collections as well as recent efforts to evaluate and scientifically exploit these data. The main advantage of the astronomical archival plate collections is the very large and unique time coverage which can span over more than 100 years and can achieve fine limiting magnitudes . As for scientific astrophysical applications, I will review astrophysical applications of these data and will show some selected examples. Since some parts of the sky are covered by very numerous and high-quality archival plates, there can be projects proposed based both on modern satellite data as well as on archival plate data. The optical identification of newly detected gamma-ray sources e.g. by the ESA INTEGRAL satellite can serve as an example, since most of these sources are located in regions either close to the Galactic centre or to the Galactic plane area which were densely covered in the past by several plate programs such as Franklin Adams Fields in Leiden proposed by Prof. Hertzsprung, or Sonneberg Field patrol proposed by Prof. Hoffmeister. These analyses require newly designed software whose examples will be also presented and discussed.

Hudec, R.; Basta, M.

2006-08-01

278

Professional Astronomers in Service to the AAVSO  

NASA Astrophysics Data System (ADS)

(Abstract only) Throughout its 100-year history, the American Association of Variable Star Observers (AAVSO) has welcomed professional astronomers to its membership ranks, and has encouraged their participation as organization leaders. The AAVSO has been fortunate to have over 60 distinguished professionals serve as officers (Directors, Presidents, Council), and as participants in its various scientific and organizational committees.

Saladyga, M.; Waagen, E. O.

2012-06-01

279

Inverse problems in astronomical adaptive optics  

Microsoft Academic Search

Adaptive optics (AO) is a technology used in ground-based astronomy to correct for the wavefront aberrations and loss of image quality caused by atmospheric turbulence. Provided some difficult technical problems can be overcome, AO will enable future astronomers to achieve nearly diffraction-limited performance with the extremely large telescopes that are currently under development, thereby greatly improving spatial resolution, spectral resolution

B L Ellerbroek; C R Vogel

2009-01-01

280

Astronomical Data Center Bulletin, volume 1, number 2  

NASA Astrophysics Data System (ADS)

Work in progress on astronomical catalogs is presented in 16 papers. Topics cover astronomical data center operations; automatic astronomical data retrieval at GSFC; interactive computer reference search of astronomical literature 1950-1976; formatting, checking, and documenting machine-readable catalogs; interactive catalog of UV, optical, and HI data for 201 Virgo cluster galaxies; machine-readable version of the general catalog of variable stars, third edition; galactic latitude and magnitude distribution of two astronomical catalogs; the catalog of open star clusters; infrared astronomical data base and catalog of infrared observations; the Air Force geophysics laboratory; revised magnetic tape of the N30 catalog of 5,268 standard stars; positional correlation of the two-micron sky survey and Smithsonian Astrophysical Observatory catalog sources; search capabilities for the catalog of stellar identifications (CSI) 1979 version; CSI statistics: blue magnitude versus spectral type; catalogs available from the Astronomical Data Center; and status report on machine-readable astronomical catalogs.

Nagy, T. A.; Warren, W. H., Jr.; Mead, J. M.

1981-07-01

281

SkyMaker: Astronomical Image Simulations Made Easy  

NASA Astrophysics Data System (ADS)

SkyMaker is a program that simulates astronomical images. It accepts object lists in ASCII generated by the Stuff program to produce realistic astronomical fields. SkyMaker is part of the EFIGI development project.

Bertin, Emmanuel; Fouqué, Pascal

2010-10-01

282

Recent Hubble Observations of Jupiter's Ring System  

NASA Astrophysics Data System (ADS)

The period December 2002 through February 2003 provided a rare opportunity to watch Jupiter sweep through its full range of Earth-based phase angles while the rings remained nearly edge-on to Earth. We used this period for a series of Jovian ring observations using the High Resolution Channel (HRC) of Hubble's new Advanced Camera for Surveys (ACS). Phase angles span 0.17o--10o. Our images showed the main ring, Adrastea and Metis with very high signal-to-noise ratios (SNR). Amalthea's gossamer ring was detected (and vertically resolved) in a small set of specially targeted images. Somewhat surprisingly, we have not yet been able to detect the halo in any of our images, perhaps because it is obscured by the scattered light from Jupiter's disk, positioned just 4'' outside the HRC's field of view. Preliminary results from this data set are as follows. (1) The ring is substantially less red than the moons, suggesting that fine dust represents a significant fraction of its backscattering intensity. (2) Neither the rings nor the embedded moons Metis and Adrastea have significant opposition surges. We were hoping to use the surge, which is characteristic of most macroscopic bodies but not dust, as an indicator of where any embedded ring parent bodies might reside. (3) Because our data are so sensitive to Metis (radius ˜ 20 km) and Adrastea ( ˜ 8 km), we believe that bodies as small as 3--4 km in radius should have been detected in the data. In an initial search, no additional bodies have been detected. (4) The Amalthea ring shows an enhancement in brightness in its outermost 15,000 km. This is consistent with what was seen in Galileo images at very high phase angles. Support for this work was provided by NASA through the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy under NASA contract NAS5-26555.

Showalter, M. R.; Burns, J. A.; de Pater, I.; Hamilton, D. P.; Horanyi, M.

2003-05-01

283

Sociological Profile of Astronomers in Spain  

NASA Astrophysics Data System (ADS)

In this paper the main findings are presented of a recent study made by a team of sociologists from the University of Granada on the professional astronomers currently working in Spain. Despite the peculiarities of this group - its youth, twentyfold increase in size over the last 20 years, and extremely high rate of specialization abroad - in comparison with other Spanish professionals, this is the first time that the sociological characteristics of the group have been studied discretely. The most significant results of the study are presented in the following sections. Section 1 gives a brief historical background of the development of Astronomy in Spain. Section 2 analyzes the socio-demographic profile of Spanish Astronomy professionals (sex, age, marital status, etc.). Sections 3-5 are devoted to the college education and study programs followed by Spanish astronomers, focusing on the features and evaluations of the training received, and pre- and postdoctoral study trips made to research centers abroad. The results for the latter clearly show the importance that Spanish astronomers place on having experience abroad. Special attention is paid to scientific papers published as a result of joint research projects carried out with colleagues from centers abroad as a result of these study trips. Section 6 describes the situation of Astronomy professionals within the Spanish job market, the different positions available and the time taken to find a job after graduation. Section 7 examines Astronomy as a discipline in Spain, including the astronomers' own opinions of the social status of the discipline within Spanish society. Particular attention is paid to how Spanish astronomers view the status of Astronomy in Spain in comparison with that of other European countries.

Iglesias de Ussel, Julio; Trinidad, Antonio; Ruiz, Diego; Battaner, Eduardo; Delgado, Antonio J.; Rodriguez-Espinosa, José M.; Salvador-Solé, Eduard; Torrelles, José M.

284

Sociological profile of astronomers in Spain.  

NASA Astrophysics Data System (ADS)

In this paper the main findings are presented of a recent study made by a team of sociologists from the University of Granada on the professional astronomers currently working in Spain. Despite the peculiarities of this group - its youth, twentyfold increase in size over the last 20 years, and extremely high rate of specialization abroad - in comparison with other Spanish professionals, this is the first time that the sociological characteristics of the group have been studied discretely. The most significant results of the study are presented in the following sections. Section 1 gives a brief historical background of the development of astronomy in Spain. Section 2 analyzes the socio-demographic profile of Spanish astronomy professionals (sex, age, marital status, etc.). Sections 3-5 are devoted to the college education and study programs followed by Spanish astronomers, focusing on the features and evaluations of the training received, and pre- and postdoctoral study trips made to research centers abroad. The results for the latter clearly show the importance that Spanish astronomers place on having experience abroad. Special attention is paid to scientific papers published as a result of joint research projects carried out with colleagues from centers abroad as a result of these study trips. Section 6 describes the situation of astronomy professionals within the Spanish job market, the different positions available and the time taken to find a job after graduation. Section 7 examines astronomy as a discipline in Spain, including the astronomers' own opinions of the social status of the discipline within Spanish society. Particular attention is paid to how Spanish astronomers view the status of astronomy in Spain in comparison with that of other European countries.

de Ussel, J. I.; Trinidad, A.; Ruíz, D.; Battaner, E.; Delgado, A. J.; Rodríguez-Espinosa, J. M.; Salvador-Solé, E.; Torrelles, J. M.

285

Biographial Encyclopedia of Astronomers-A status report  

Microsoft Academic Search

The Biographical Encyclopedia of Astronomers is nearing completion and should serve as a valuable resource for historians and astronomers alike. The work is expected to be published in two volumes in 2006, and will include approximately 1500 biographical sketches on astronomers from antiquity to modern times. This status report will summarize the project, the collective work of about 400 authors

T. R. Williams; T. A. Hockey

2004-01-01

286

The Astronomical Almanac 2006: Changes Resulting from IAU Resolutions  

Microsoft Academic Search

Over the last few decades, advances in the precision of astronomical and geophysical measurements along with improvements in the underlying theories have lead astronomers to realize that better models and computation methods -- and detailed specifications on how to apply them -- were necessary. This work culminated in several resolutions that were adopted by the International Astronomical Union (IAU) in

S. E. Urban; S. Bell; G. H. Kaplan; C. Y. Hohenkerk; S. G. Stewart; J. A. Bangert; J. L. Hilton

2005-01-01

287

Public Perception of Astronomers: Revered, Reviled and Ridiculed  

Microsoft Academic Search

Society's view of astronomers has changed over time and from culture to\\u000aculture. This review discusses some of the many ways that astronomers have been\\u000aperceived by their societies and suggests ways that astronomers can influence\\u000apublic perception of ourselves and our profession in the future.

Michael J. West

2009-01-01

288

Biographies and Portraits of British and Other Astronomers  

NASA Astrophysics Data System (ADS)

This paper originated as a document intended to serve as a general guide to the sources of biographies and portraits of astronomers for historians of astronomy and other researchers, particularly British astronomers. It was first compiled by the Librarian of the Royal Astronomical Society, Peter Hingley (1921-2012).

Hingley, Peter; Chibnall, Mary I.; Howarth, Ian; Lane, John; Mitton, Jacqueline; Penston, Margaret; Ridpath, Ian; Murdin, Paul

2013-01-01

289

American Astronomical Society Honors NRAO Scientist  

NASA Astrophysics Data System (ADS)

The American Astronomical Society (AAS) has awarded its prestigious George Van Biesbroeck Prize to Dr. Eric Greisen of the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico. The society cited Greisen's quarter-century as "principal architect and tireless custodian" of the Astronomical Image Processing System (AIPS), a massive software package used by astronomers around the world, as "an invaluable service to astronomy." Dr. Eric Greisen Dr. Eric Greisen CREDIT: NRAO/AUI/NSF (Click on image for larger version) The Van Biesbroeck Prize "honors a living individual for long-term extraordinary or unselfish service to astronomy, often beyond the requirements of his or her paid position." The AAS, with about 7,000 members, is the major organization of professional astronomers in North America. " The Very Large Array (VLA) is the most productive ground-based telescope in the history of astronomy, and most of the more than 10,000 observing projects on the VLA have depended upon the AIPS software to produce their scientific results," said Dr. James Ulvestad, NRAO's Director of New Mexico Operations. "This same software package also has been the principal tool for scientists using the Very Long Baseline Array and numerous other radio telescopes around the world," Ulvestad added. Greisen, who received a Ph.D in astronomy from the California Institute of Technology, joined the NRAO in 1972. He moved from the observatory's headquarters in Charlottesville, Virginia, to its Array Operations Center in Socorro in 2000. Greisen, who learned of the award in a telephone call from the AAS President, Dr. Robert Kirschner of Harvard University, said, "I'm pleased for the recognition of AIPS and also for the recognition of the contributions of radio astronomy to astronomy as a whole." He added that "it wasn't just me who did AIPS. There were many others." The AIPS software package grew out of the need for an efficient tool for producing images with the VLA, which was being built in the late 1970s. Work on the package began in 1978 in Charlottesville. Now including nearly a million lines of program code and almost a half-million lines of documentation, AIPS is used at more than 500 sites around the world. The package is a mainstay and a daily tool for most of the world's radio astronomers, and also has been used by scientists in such other fields as fluid-dynamics simulation and medical imaging. Over the years, Greisen and his colleagues at NRAO have revised the AIPS package numerous times and expanded its capabilities as new astronomical and computing hardware was developed. The software has been kept independent of specific computing hardware and operating systems, and so has been successfully used on a wide variety of computing equipment. "We are extremely proud of Eric's work and congratulate him on receiving this award," said NRAO Director Dr. Fred K.Y. Lo. "He has shown extraordinary dedication to making AIPS a valuable and effective tool for the world astronomical community, and this award is well-deserved recognition." The AAS citation reads, "The 2005 Van Biesbroeck Prize is awarded to Dr. Eric Greisen of NRAO for the initiation, development, and maintenance for twenty-five years of the Astronomical Image Processing System (AIPS). Virtually every VLA and VLBA program relies on AIPS for calibration and image reconstruction, and it has been exported to more than 500 sites worldwide. Greisen, as its principal architect and tireless custodian, has provided an invaluable service to astronomy. Moreover, AIPS represented a new paradigm for the processing of massive astronomical datasets, i.e., a comprehensive software package that was rigorously independent of particular operating systems, which supported portability and adaptability to evolving hardware designs. Beyond the call of duty, Greisen has generously responded to individual queries about the code from users at all levels, sometimes in real time at odd hours to support observ

2005-01-01

290

CARNEGIE HUBBLE PROGRAM: A MID-INFRARED CALIBRATION OF THE HUBBLE CONSTANT  

SciTech Connect

Using a mid-infrared calibration of the Cepheid distance scale based on recent observations at 3.6 {mu}m with the Spitzer Space Telescope, we have obtained a new, high-accuracy calibration of the Hubble constant. We have established the mid-IR zero point of the Leavitt law (the Cepheid period-luminosity relation) using time-averaged 3.6 {mu}m data for 10 high-metallicity, Milky Way Cepheids having independently measured trigonometric parallaxes. We have adopted the slope of the PL relation using time-averaged 3.6 {mu}m data for 80 long-period Large Magellanic Cloud (LMC) Cepheids falling in the period range 0.8 < log(P) < 1.8. We find a new reddening-corrected distance to the LMC of 18.477 {+-} 0.033 (systematic) mag. We re-examine the systematic uncertainties in H{sub 0}, also taking into account new data over the past decade. In combination with the new Spitzer calibration, the systematic uncertainty in H{sub 0} over that obtained by the Hubble Space Telescope Key Project has decreased by over a factor of three. Applying the Spitzer calibration to the Key Project sample, we find a value of H{sub 0} = 74.3 with a systematic uncertainty of {+-}2.1 (systematic) km s{sup -1} Mpc{sup -1}, corresponding to a 2.8% systematic uncertainty in the Hubble constant. This result, in combination with WMAP7 measurements of the cosmic microwave background anisotropies and assuming a flat universe, yields a value of the equation of state for dark energy, w{sub 0} = -1.09 {+-} 0.10. Alternatively, relaxing the constraints on flatness and the numbers of relativistic species, and combining our results with those of WMAP7, Type Ia supernovae and baryon acoustic oscillations yield w{sub 0} = -1.08 {+-} 0.10 and a value of N{sub eff} = 4.13 {+-} 0.67, mildly consistent with the existence of a fourth neutrino species.

Freedman, Wendy L.; Madore, Barry F.; Scowcroft, Victoria; Burns, Chris; Monson, Andy; Persson, S. Eric; Seibert, Mark [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 (United States); Rigby, Jane, E-mail: wendy@obs.carnegiescience.edu, E-mail: barry@obs.carnegiescience.edu, E-mail: vs@obs.carnegiescience.edu, E-mail: cburns@obs.carnegiescience.edu, E-mail: amonson@obs.carnegiescience.edu, E-mail: persson@obs.carnegiescience.edu, E-mail: mseibert@obs.carnegiescience.edu, E-mail: Jane.R.Rigby@nasa.gov [Observational Cosmology Lab, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-10-10

291

Astronomical dating in the 19th century  

NASA Astrophysics Data System (ADS)

Today astronomical tuning is widely accepted as numerical dating method after having revolutionised the age calibration of the geological archive and time scale over the last decades. However, its origin is not well known and tracing its roots is important especially from a science historic perspective. Astronomical tuning developed in consequence of the astronomical theory of the ice ages and was repeatedly used in the second half of the 19th century before the invention of radio-isotopic dating. Building upon earlier ideas of Joseph Adhémar, James Croll started to formulate his astronomical theory of the ice ages in 1864 according to which precession controlled ice ages occur alternatingly on both hemispheres at times of maximum eccentricity of the Earth's orbit. The publication of these ideas compelled Charles Lyell to revise his Principles of Geology and add Croll's theory, thus providing an alternative to his own geographical cause of the ice ages. Both Croll and Lyell initially tuned the last glacial epoch to the prominent eccentricity maximum 850,000 yr ago. This age was used as starting point by Lyell to calculate an age of 240 million years for the beginning of the Cambrium. But Croll soon revised the tuning to a much younger less prominent eccentricity maximum between 240,000 and 80,000 yr ago. In addition he tuned older glacial deposits of late Miocene and Eocene ages to eccentricity maxima around 800,000 and 2,800,000 yr ago. Archibald and James Geikie were the first to recognize interglacials during the last glacial epoch, as predicted by Croll's theory, and attempted to tune them to precession. Soon after Frank Taylor linked a series of 15 end-moraines left behind by the retreating ice sheet to precession to arrive at a possible age of 300,000 yr for the maximum glaciation. In a classic paper, Axel Blytt (1876) explained the scattered distribution of plant groups in Norway to precession induced alternating rainy and dry periods as recorded by the layering in Holocene peat bogs. He specifically linked the exceptionally wet Atlantic period to the prolonged precession minimum at 33,300 yr ago and further related basic stratigraphic alternations to precession induced climate change in general. Such a linkage was also proposed by Grove Karl Gilbert for cyclic alternations in the marine Cretaceous of North America. Extrapolating sedimentation rates, he arrived at an astronomical duration for part of the Cretaceous that was roughly as long as the final estimate of William Thomson for the age of the Earth. Assuming that orbital parameters directly affect sea level, Karl Mayer-Eymar and Blytt correlated the well known succession of Tertiary stages to precession and eccentricity, respectively. Remarkably, Blytt, like Croll before him, used very long-period cycles in eccentricity to establish and validate his tuning. Understandably these studies in the second half of the 19th century were largely deductive in nature and proved partly incorrect later. Nevertheless, this fascinating period marks a crucial phase in the development of the astronomical theory of the ice ages and climate, and in astronomical dating. It preceded the final inductive phase, which started with the recovery of deep-sea cores in 1947 and led to a spectacular revival of the astronomical theory, by a century. The first half of the 20th century can best be regarded as an intermediate phase, despite the significant progress made in both theoretical aspects and tuning.

Hilgen, Frederik J.

2010-01-01

292

Query driven visualization of astronomical catalogs  

NASA Astrophysics Data System (ADS)

Interactive visualization of astronomical catalogs requires novel techniques due to the huge volumes and complex structure of the data produced by existing and upcoming astronomical surveys. The creation as well as the disclosure of the catalogs can be handled by data pulling mechanisms (Buddelmeijer et al. 2011). These prevent unnecessary processing and facilitate data sharing by having users request the desired end products. In this work we present query driven visualization as a logical continuation of data pulling. Scientists can request catalogs in a declarative way and set process parameters directly from within the visualization. This results in profound interoperation between software with a high level of abstraction. New messages for the Simple Application Messaging Protocol are proposed to achieve this abstraction. Support for these messages are implemented in the Astro-WISE information system and in a set of demonstrational applications.

Buddelmeijer, Hugo; Valentijn, Edwin A.

2013-01-01

293

Astrophotonics: a new era for astronomical instruments.  

PubMed

Astrophotonics lies at the interface of astronomy and photonics. This burgeoning field has emerged over the past decade in response to the increasing demands of astronomical instrumentation. Early successes include: (i) planar waveguides to combine signals from widely spaced telescopes in stellar interferometry; (ii) frequency combs for ultra-high precision spectroscopy to detect planets around nearby stars; (iii) ultra-broadband fibre Bragg gratings to suppress unwanted background; (iv) photonic lanterns that allow single-mode behaviour within a multimode fibre; (v) planar waveguides to miniaturize astronomical spectrographs; (vi) large mode area fibres to generate artificial stars in the upper atmosphere for adaptive optics correction; (vii) liquid crystal polymers in optical vortex coronographs and adaptive optics systems. Astrophotonics, a field that has already created new photonic capabilities, is now extending its reach down to the Rayleigh scattering limit at ultraviolet wavelengths, and out to mid infrared wavelengths beyond 2500 nm. PMID:19189019

Bland-Hawthorn, Joss; Kern, Pierre

2009-02-01

294

Bad Pixel Modified Interpolation for Astronomical Images  

NASA Astrophysics Data System (ADS)

We present a new method of interpolation for the pixel brightness estimation in astronomical images. Our new method is simple and easily implementable. We show the comparison of this method with the widely used linear interpolation and other interpolation algorithms using 1000 astronomical images obtained from the Sloan Digital Sky Survey. The comparison shows that our method improves bad pixel brightness estimation with four times lower mean error than the presently most popular linear interpolation, and performs better than any other examined method. The presented idea is flexible and can be also applied to present and future interpolation methods. The proposed method is especially useful for large sky surveys image reduction but can be also applied to single image correction.

Popowicz, A.; Kurek, A. R.; Filus, Z.

2013-09-01

295

Recruitment and Retention of LGBTIQ Astronomers  

NASA Astrophysics Data System (ADS)

While lesbian, gay, bisexual, transgender, intersex, or questioning (LGBTIQ) astronomers face many of the same workplace challenges as women and racial/ethnic minorities, from implicit bias to overt discrimination, other challenges are unique to this group. An obvious example is the absence at many institutions of health insurance and other benefits for the same-sex domestic partners of their employees. More subtle is the psychological toll paid by LGBTIQ astronomers who remain "in the closet," self-censoring every statement about their personal lives. Paradoxically, the culture of the physical sciences, in which sexuality, gender identity, and gender expression are considered irrelevant, can discourage their discussion, further isolating LGBTIQ researchers. Addressing these challenges is not just a matter of fairness; it is an essential tool in the recruitment and retention of the brightest researchers and in assuring their productivity. We will discuss these issues and what individuals and departments can to make their institutions more welcoming to their LGBTIQ colleagues.

Dixon, William Van Dyke

2012-01-01

296

Isaac Newton and the astronomical refraction.  

PubMed

In a short interval toward the end of 1694, Isaac Newton developed two mathematical models for the theory of the astronomical refraction and calculated two refraction tables, but did not publish his theory. Much effort has been expended, starting with Biot in 1836, in the attempt to identify the methods and equations that Newton used. In contrast to previous work, a closed form solution is identified for the refraction integral that reproduces the table for his first model (in which density decays linearly with elevation). The parameters of his second model, which includes the exponential variation of pressure in an isothermal atmosphere, have also been identified by reproducing his results. The implication is clear that in each case Newton had derived exactly the correct equations for the astronomical refraction; furthermore, he was the first to do so. PMID:19037356

Lehn, Waldemar H

2008-12-01

297

New User Requirements for Astronomical Data Visualization  

NASA Astrophysics Data System (ADS)

The astronomical community has benefited greatly from the dramatic increase of speed and storage capacity of computers and the wide availability of high speed Internet access. Armed with the latest hardware, users have placed increased demands on astronomical data visualization software that no one could have imagined just a few years ago. Until recently, a typical FITS file was composed of a single image less than 100Mb in size. Now FITS files composed of mosaics images, multiple-extension FITS images, FITS data cubes, and RGB composite images are common. These FITS files now test the limits of hardware and operating systems with regard to file size and address space. And along with this explosion of new data file representations comes demands for more flexibility in visualization, support for external and remote analysis, and seamless Web integration. We will present a discussion of new user requirements and solutions we have encountered in development and support of SAOImage DS9.

Joye, W. A.; Mandel, E.

2004-07-01

298

Nicephoros Gregoras: the greatest Byzantine astronomer  

NASA Astrophysics Data System (ADS)

In the whole of Greece, no eminent astronomers appeared after the great Claudius Ptolemy (second century AD). For ten centuries after Ptolemy we can distinguish only one astronomer: Nicephoros Gregoras (1295 1360). The monk Nicephoros Gregoras is discussed together with his teacher, Theodoros Metochites, one of the most significant scholars of Byzantium. The literary work of Gregoras is especially important, while Byzantine astronomy owes indisputable progress to him. Gregoras was the first to propose, in 1324, a correction to the calculation of the date of Easter, and to the Julian calendar similar to that adopted later, in 1582, by Pope Gregory XIII. This proposition and, more obviously, his dispute with St Gregory Palamas created problems in the relationship between Gregoras and the Church, leading to the desecration of his corpse by a fanatical crowd.

Theodossiou, Efstratios Th.; Manimanis, Vassilios N.; Dimitrijevi?, Milan S.; Danezis, Emmanuel

2006-02-01

299

Physicists, Mathematicians and Astronomers- communists (Part 2)  

NASA Astrophysics Data System (ADS)

The second part is continuig the edition of communists (physicists, mathematicians, astronomers), which were not included in the reference books by Yu.A. Hramov, A. N. Bogoliubov, I.G. Kolchinskii et al.. The author is discussing here also the relation between business and Communist party, especially in the Post Soviet Russia. A discussion of the biographies of Soviet scientists included in the Britannica is given, as well as a list of Russian scientists included in the Oxford Dictionary of Physics is given. Another part of the paper is pointing out the defficiencies of the last edition of the Great Russian Encyclopedic Dictionary (Drofa Eds, Moscow, 2009) in what concerns physicists, mathematicians and astronomers. A great number of Nobel Prize Winners was ommited in the edition of 2009.

Gaina, Alex

300

The origins of Ptolemy's astronomical tables.  

NASA Astrophysics Data System (ADS)

Following the line set by his earlier book 'The crime of Claudius Ptolemy' the author discusses here the numerous astronomical tables in Ptolemy's work that have been calculated with the aid of trigonometric tables, as well as a few that are nonlinear but that do not involve trigonometry. The purpose in this study is to determine, if possible, whether Ptolemy calculated these tables or whether he copied them from now-lost original works. The conclusion isthat Ptolemy made few if any original contributions to astronomy, either observational or computational.Contents: 1. Introduction; thetable of chords. 2. The tables of the latitude and of gnomon shadows.3. Tables of the Sun. 4. Astronomical geography. 5. The tables of theMoon. 6. Eclipse tables. 7. Tables of the planets. 8. The empirical basis for Hipparchus's mean motions of the Moon. 9. Summary and conclusions.

Newton, R. R.

301

Astronomical Site Testing of the Antarctic Plateau  

NASA Astrophysics Data System (ADS)

We have assembled a team with expertise in astronomical site testing in the Antarctic and expertise in Antarctic meteorology, to answer the outstanding questions that must be answered before major facilities for optical and infrared astronomy can be deployed to the Antarctic plateau. Previous work has shown that the Antarctic Plateau is the best site on earth for many types of astronomical observation. The dry, tenuous and extremely cold air leads to considerable gains in sensitivity for the measurement of radiation fluxes incident on the earth from space across many wavebands. Optical turbulence in a boundary layer covering the plateau remains to be characterized, however. Understanding it is key to design of future telescopes or arrays of telescopes. Measurements should be made at a number of sites, including Dome A, Dome F, and a transantarctic mountain site.

Mould, J. R.; Mighell, K.; Merrill, M.; Lynds, R.; Tokovinin, A.; Travouillon, T.; Moore, A.; Pennypacker, C.; Wang, L.; Weidner, G.; Swain, M.; York, D.

2006-08-01

302

Encyclopedias of Astronomical Biographies - Status and Prospects --  

NASA Astrophysics Data System (ADS)

Simple requests for biographies of famous astronomers can easily be satisfied. Short accounts of their lives are to be found in many books and encyclopedias. However, most of these sources are very incomplete, i. e.\\ do not provide information on less famous persons, and are not up to scientific standards. The most comprehensive sources of scientific biographies, Poggendorffs Biographisch-Literarisches Handwoerterbuch and Dictionary of Scientific Biography, are also not complete, partly not up-to-date and for most users not easily accessible. The most recent and most comprehensive dictionary of astronomical biography, containing 500 short entries, was written in Russian. Although a lot of information on biographies is available in publications, these are spread over thousands of volumes. There is no bibliography of these papers and books. During the last three years, short biographies of astronomers were also published in the World Wide Web. Some of these are on a very high scientific level. The author's collection of links to such WWW pages (http://www.astro.uni-bonn.de/~pbrosche/hist\\_astr/ ha\\_pers.html}) contains currently several thousand entries for more than 1200 persons related to the history of astronomy. This electronic ``encyclopedia'' in distributed form is now the most comprehensive and concentrated source for astronomical biographies. However, there are several problems arising from the electronic form of publication and from the uncoordinated and not always qualified efforts of the authors. The paper will discuss proposals, plans and first results of filling the gaps and increasing the quality, as well as some principal problems of writing short biographies and making them available to the public.

Dick, W. R.

303

Automated object detection for astronomical images  

Microsoft Academic Search

Sponsored by the National Aeronautical Space Association (NASA), the Synergetic Education and Research in Enabling NASA-centered Academic Development of Engineers and Space Scientists (SERENADES) Laboratory was established at California State University, Los Angeles (CSULA). An important on-going research activity in this lab is to develop an easy-to-use image analysis software with the capability of automated object detection to facilitate astronomical

Sonny Orellana; Lei Zhao; Helen Boussalis; Charles Liu; Khosrow Rad; Jane Dong

2005-01-01

304

Astronomical Photography by Amateurs with Telescopes  

NASA Astrophysics Data System (ADS)

The modern amateur astronomer is capable of taking beautiful pictures of thenight sky, often with surprisingly humble equipment. One of the best ways toget started is to place a single-lens reflex (SLR) camera on a sturdy tripod,open the lens aperture as wide as possible and take a 10 min exposure(seeWIDE-FIELD ASTROPHOTOGRAPHY). This will recordthe stars as trails, because of the rotation of the ...

Szymanek, N.; Murdin, P.

2002-12-01

305

Preserving Dark Skies: Do Astronomers Care?  

NASA Astrophysics Data System (ADS)

Ground based telescopes are, even in this era of planetary missions and space telescopes, the dominant source of data on solar system objects. Yet many of the premier observing sites in the world are threatened by increasing artificial light that is scattered into the sky - light pollution. World class observing sites such as Mt. Wilson have long since lost the ability to do cutting edge faint object science and observatories in Southern Arizona have been recently threatened - the Canoa Ranch development being the most recent example. Yet there are actions that can be taken to preserve dark skies, not only for astronomy, but also for the benefit of all humanity. Lead by astronomers, effective outdoor lighting codes have been produced and adopted by many jurisdictional authorities. Advocacy organizations such as the International Dark-sky Association (IDA) distribute educational material on how to preserve dark skies through good outdoor lighting practices. Other institutions, such as the National Park Service, are realizing that dark skies are an integral part of the wilderness experience and are taking steps to preserve the quality of their skies. However, the primary beneficaries of dark sky preservation efforts, namely the ground based astronomical community, have largely failed to become involved in efforts to preserve dark skies. For example, only a few percent of the membership of the American Astronomical Society is active in light pollution work or is even a member of IDA. In this presentation, Iwe will outline what is being done locally to preserve dark skies througout the world. In addition, some observations on the level of support from the astronomical community will be offered.

Davis, D. R.; Crawford, D. L.

2001-12-01

306

Astronomical and space-based systems engineering  

Microsoft Academic Search

The Master's degree ``Outils et Systèmes de l'Astronomie et de l'Espace'' (OSAE, ``Astronomical and Space-based Systems Engineering'') is intended for students interested in Astronomy and Space technology. Students undergo a comprehensive training in partnership with international-level laboratories and with leading private companies. The degree provides physicists with a wide range of skills, appropriate for those whose intention is to participate

Benoît Mosser; Alain Abergel

2011-01-01

307

A new 10 micron astronomical polarimeter  

Microsoft Academic Search

A new design for an astronomical polarimeter optimized for use in the 8- to 13-micron spectral region based on an earlier visible wavelength instrument is described. The combination of a special infrared ZnSe birefringence modulator and a background-limited fast photoconductive detector permits carry-over of many of the digital signal processing advantages of the earlier instrument. Within a single measurement sequence,

P. A. Ekstrom; R. A. Stokes; G. M. Stokes; J. A. Hackwell

1981-01-01

308

Astronomers Find Planet with Similarities to Earth  

NSDL National Science Digital Library

Astronomers have found a new planet that is more like Earth than the other extrasolar planets found before, which were large and gaseous. This radio broadcast reports on this newly discovered planet, which appears to be small and rocky. The new terrestrial planet is extremely hot as it orbits very close to its star, Gliese 876. The clip is 1 minute and 58 seconds in length.

309

Astronomical Tiled Image Compression: How and Why  

NASA Astrophysics Data System (ADS)

A tsunami of astronomical data is fast approaching. New survey programs will dwarf any data sets that have come before. Observatories' data storage costs will threaten their budgets. Data transport latency and bandwidth will threaten not just budgets, but available technology and human patience. Under such circumstances, projects will increasingly rely on data compression as a technique necessary to meet requirements of acceptable throughput and affordable data handling.

Seaman, R.; Pence, W.; White, R.; Dickinson, M.; Valdes, F.; Zárate, N.

2007-10-01

310

Designing Models to Understand Astronomical Concepts1  

Microsoft Academic Search

The purpose of this study was to examine how designing three-dimensional (3-D) models of the SolarSystem supported student development of conceptual understandings of various astronomical phenomenathat required a change in frame of reference. In the course described in this study, students worked in teamsto design and construct 3-D models of the Solar System. Students designed and constructed their modelsusing software

Michael Barnett; Lisa Yamagata; Tom Keating; Sasha A. Barab; Kenneth E. Hay

311

Current Integrator for Astronomical Photoelectric Photometry  

Microsoft Academic Search

An integrator circuit is described, together with programmer and timer, which was constructed for measuring signal-current from a photomultiplier tube as used in astronomical photometry. At the end of a timed run, the voltage data are impressed upon a strip-chart pen recorder. The current-range of such instrument encompasses a span from 10?6 to 10?11 ampere, full scale, with stability and

Robert H. Weitbrecht

1957-01-01

312

The astronomical pulse of global extinction events.  

PubMed

The linkage between astronomical cycles and the periodicity of mass extinctions is reviewed and discussed. In particular, the apparent 26 million year cycle of global extinctions may be related to the motion of the solar system around the galaxy, especially perpendicular to the galactic plane. The potential relevance of Milankovitch cycles is also explored in the light of current evidence for the possible causes of extinction events over a geological timescale. PMID:16799743

Lewis, David F V; Dorne, Jean-Lou C M

2006-06-23

313

A website for astronomical news in Spanish  

NASA Astrophysics Data System (ADS)

Noticias del Cosmos is a collection of web pages within the Astronomical Observatory of the University of Valencia's website where we publish short daily summaries of astronomical press releases. Most, if not all of, the releases are originally written in English, and often Spanish readers may find them difficult to understand because not many people are familiar with the scientific language employed in these releases. Noticias del Cosmos has two principal aims. First, we want to communicate the latest astronomical news on a daily basis to a wide Spanish-speaking public who would otherwise not be able to read them because of the language barrier. Second, daily news can be used as a tool to introduce the astronomical topics of the school curriculum in a more immediate and relevant way. Most of the students at school have not yet reached a good enough level in their knowledge of English to fully understand a press release, and Noticias del Cosmos offers them and their teachers this news in their mother tongue. During the regular programme of school visits at the Observatory we use the news as a means of showing that there is still a lot to be discovered. So far the visits to the website have been growing steadily. Between June 2003 and June 2007 we had more than 30,000 visits (excluding 2006). More than 50% of the visits come from Spain, followed by visitors from South and Central America. The feedback we have received from teachers so far has been very positive, showing the usefulness of news items in the classroom when teaching astronomy.

Ortiz-Gil, A.

2008-06-01

314

AstroWeb -- Internet Resources for Astronomers  

NASA Astrophysics Data System (ADS)

AstroWeb is a World Wide Web (WWW) interface to a collection of Internet accessible resources aimed at the astronomical community. The collection currently contains more than 1000 WWW, Gopher, Wide Area Information System (WAIS), Telnet, and Anonymous FTP resources, and it is still growing. AstroWeb provides the additional value-added services: categorization of each resource; descriptive paragraphs for some resources; searchable index of all resource information; 3 times daily search for ``dead'' or ``unreliable'' resources.

Jackson, R. E.; Adorf, H.-M.; Egret, D.; Heck, A.; Koekemoer, A.; Murtagh, F.; Wells, D. C.

315

Astronomical data reduction in DATA-GRID  

NASA Astrophysics Data System (ADS)

The DRACO (Datagrid for Italian Research in Astrophysics and Coordination with the Virtual Observatory) project is meant to create a Grid distributed system of resources with multi-functionalities combined with the Virtual Obervatory approach. The final aim is the porting on DataGrid of all main astrophysical applications within a National calculation infrastructure. Partecipans to the DRACO project are the National Observatories of Rome, Trieste, Padua, Catania, Naples, Bologne and the University of study of Salern. An astronomical software package has been developed to make all main astronomical tools availables on Data Grid (Astrosoft_v1.0Jan2005, Gallozzi et al., 2005, ref. http://grid006.mporzio.astro.it) starting from the ESO-Scisoft package. This software package contains the ESO-MIDAS, IRAF, IDL, SEXTRACOTR, etc. Here we present a standard astronomical data reduction test performed with the ESO MIDAS component of the Astrosoft package. This data reduction test was submitted with a web Grid Portal developed within the same DRACO project. All tests and simulations were performed on the Gilda testbed.

Gallozzi, Stefano

316

Recent Astronomical Development in Asia Pacific Rim  

NASA Astrophysics Data System (ADS)

For over two decades The Pacific Rim Conference on Stellar Astrophysics series has been held exclusively at the Asian Rim. The primary reason is that the majority of nations in Asia are less developed in Astronomy than many countries on the American Rim. At time same time, many nations in Asia are less able to afford the costs of long distance travel for astronomical conferences. As a result Asia has had a hold on the Pacific Rim Conferences. Over the last few years new research institutes have been coming on board. The ones that have most visibly emerged are; National Astronomical Research Institute of Thailand, NARIT, The Astrophysical Research Center for the Structure and Evolution of the Cosmos, ARCSEC, and Kavli Institute of Astronomy and Astrophysics at Peking University, KIAA-PKU. It is interesting to note the development and structure of each is very different. So far they all appear to be working well. Hopefully they will provide a variety of models for astronomical institutes in developing nations of the region and perhaps beyond.

Leung, K.-C.

2009-08-01

317

The Future Astronomical Software Environment progress .  

NASA Astrophysics Data System (ADS)

The OPTICON working group 3.6 in collaboration with international partners and in coordination with the Virtual Observatory, has already identified the high level requirements and the main architectural concepts for a future software environment for astronomical data reduction and analysis (Future Astronomical Software Environment). A special attention has been payed to: a) scalability, to allow the reduction of huge data volumes exploiting the hardware and software parallel architecture, b) interoperability, in order to guarantee the interaction between software coming from different sources and make easy the access to the Virtual Observatory, c) and modularity, to separate the adopted software technology from the specific computational algorithm and allow an independent evolution of the two areas. The proposed concepts have been widely discussed and shared by the astronomical community; however a lot of work still remains to do, mainly: a) the definition of open standards, b) the verification of such standards thanks to at least one reference implementation and practical user cases, c) and the whole must be supported at least by the major international organizations that develop data reduction and analysis software. All this work has led up to the definition of a new proposal for FP7 within OPTICON (where ESO, INAF, LAM-OAMP and NRAO/NVO are actively involved) which we present describing the project in detail and adding a description of the European FASE prototype, developed by INAF-IASF Milano in collaboration with LAM-OAMP (Marseille).

Paioro, L.; Garilli, B.; Grosböl, P.; Tody, D.; Surace, C.; Fenouillet, T.; Franzetti, P.; Fumana, M.; Scodeggio, M.

318

Trials and tribulations of an amateur astronomer  

NASA Astrophysics Data System (ADS)

Trials and tribulations affect our everyday lives. If you happen to be an amateur astronomer, and live in New Zealand's largest city then there are a number of extra problems you'll find yourself having to deal with. I realise that amateur astronomers 10 to 15 years ago had the painstaking task of analysing data by hand, which, depending on the amount of data obtained, quite often took many hours and even days to complete. It was thought that this and other challenges were somewhat more demanding than there are today. With this in mind I ask myself, "could I be a lazy astronomer?" or "am I just lucky to be working in today's high tech world of CCD camera technology and computer controlled equipment?" All this new equipment appears to make the job simpler, but does it really? No matter how these questions are answered, we must all remember to keep problems in perspective as our fabulous technology evolves. The issues facing amateurs today are just as time consuming and difficult as those our counterparts faced in the past. The progression of time continues to throw new challenges our way and meeting them will always be an issue we will have to face.

McCormack, Jennie

2005-09-01

319

Increasing Astronomical Photographic Resolution by Convolution Matrices  

NASA Astrophysics Data System (ADS)

In digital astronomical image processing, distortion limits the quality of photometric data. Often, this precludes accurate and precise analysis of stars or planetary features imaged close to one another. This is a problem in particular for period analysis of binary stars and searching for planetary transits, due to the merging of nearby stars into the area of interest. I proposed a method which utilizes a pair of filters and pixel math to increase resolution, thereby improving astronomical image features and enabling more precise analysis thereof. Comparison of processed and unprocessed data was done by comparing signal to noise ratio and brightness profiles of each. All calculations were performed and results analyzed using Astronomical Image Processing for Windows (AIP4WIN) by Richard Berry. In many cases, previously unusable star profiles were resolved sufficiently to take photometric data from them, while those with low signal to noise ratios improved by a factor of two to three. These results suggest that the proposed method could be used to enable photometric analysis of previously un-usable data.

Nickel, Gerard

2012-03-01

320

Electron multiplication CCDs for astronomical applications  

NASA Astrophysics Data System (ADS)

Electron multiplication CCDs have been commercially available for a few years but have yet to make a wider impact in the astronomical community. They have specifically been designed to use an avalanche gain process during the serial charge transfer process to give large signal gain. In all other respects they are identical to the very latest generation of low-noise CCDs. They have been used with great success in “lucky” imaging, for adaptive optics systems and also in high-speed faint object spectroscopy science programs. Their sub-electron read noise makes them an obvious choice for any observation, which is normally detector read noise limited. I present a detailed summary of the typical performance and characteristics of these devices and compare and contrast them against standard low-noise astronomical CCDs. I also present modeled and real data for these detectors with particular regard to some of their lesser known issues such as clock-induced charge. Finally, I present results from real-world astronomical testing, which shows the superior performance of these devices.

Ives, Derek

2009-06-01

321

The Hubble Education Program's Tactile Astronomy: Making the Universe Touchable  

NASA Astrophysics Data System (ADS)

Tactile Astronomy supports the Hubble Education Program's efforts in bringing the wonders of the universe to everyone, regardless of their visual ability. This new section of the Amazing Space Website features "Images of the Month;" a collection of the latest Hubble images that can be printed in a tactile format. The images are specifically designed to be downloaded and printed on a thermal paper expansion machine, thus allowing the visually impaired to feel what they cannot see. In addition, there is a "special projects" section that currently features the limited-edition Tactile Carina Nebula booklet and accompanying materials, such as background text about the Carina Nebula and an audio tour. The opening of Tactile Astronomy is in celebration of Hubble's 20th anniversary and features the 20th anniversary image of a small portion of the Carina Nebula. New tactile images and additional projects will continue to be added to the site.

Eisenhamer, Bonnie; Mutchler, M.; Cordes, K.; Weaver, D.; Ryer, H.

2011-01-01

322

International Schools for Young Astronomers Teaching for Astronomy Development: two programmes of the International Astronomical Union  

NASA Astrophysics Data System (ADS)

This text outlines the main features of two educational programmes of the International Astronomical Union (IAU): the International Schools for Young Astronomers (ISYA) and the Teaching for Astronomy Development programme (TAD), developed since 1967. The main goal of the International Schools for Young Astronomers (ISYA) is to support astronomy (education and research) in developing countries in organizing a 3-week School for students with typically M.Sc. degrees. The context in which the ISYA were developed changed drastically during the last decade. From a time when access to large telescopes was difficult and mainly organized on a nation-basis, nowadays the archives of astronomical data have accumulated at the same time that many major telescope become accessible, and they are accessible from everywhere, the concept of virtual observatory reinforcing this access. A second programme of the IAU, Teaching for Astronomy Development (TAD), partially based on a School, but also of shorter duration (typically one week) has a complementary objective. It is dedicated to assist countries that have little or no astronomical activity, but that wish to enhance their astronomy education. The fast development of the TAD programme over the past years is emphasized.

Gerbaldi, Michèle; DeGreve, Jean-Pierre; Guinan, Edward

2011-06-01

323

RCT photometry of the Hubble Classical Cepheid V19 in M33: Evidence for the Cessation of Pulsations - A Case of Stellar Evolution in Real Time  

NASA Astrophysics Data System (ADS)

We report on our continuing efforts to monitor the photometric behavior of Hubble's Variable Star V19 in the Triangulum Spiral Galaxy M33. B,V photometry has been carried out of this unusual 18th mag (previous) Cepheid with the 1.3-m RCT (Robotically Controlled Telescope) at KPNO. With time-series photometry, with a dedicated robotic telescope, we can hope to solve the mystery of V19 and its unprecedented evolutionary behavior. In the influential work "A Spiral Nebula as a Stellar System: Messier 33" (Hubble 1926) Edwin Hubble determined the distance to M33 by using 35 Cepheids he discovered. One of those Cepheids was designated V19. At that time observations revealed V19 to have a 54.7-day period and B-band (converted from photographic magnitudes) light amplitude of 1.1-mag. Its mean B-magnitude was 19.6 /-0.2. V19 properties were consistent with the Period-Luminosity Law for M33 derived by Hubble at that time. Follow-up observations in 1996-1997 as part of the DIRECT Program (Macri et al. 2001), however, revealed large and surprising changes in the properties of V19. Its mean B-magnitude had risen to 19.05 /-0.05 and its amplitude had decreased to less than 0.1-mag. The DIRECT study thoroughly checked for possible misclassifications of the variable or contamination by nearby objects, and found none. For all intents and purposes, V19 is no longer a Classical Cepheid, or at least varying below the detectable levels of the photometry. The only other well-documented instance of Cepheid pulsations declining over time is in the case of Polaris - whose V-band amplitude decreased from just over 0.1-mag to below 0.03-mag over the course of a century (Engle et al 2004). Also, a study of the visual magnitudes of Polaris over the past two millennia has shown a possible increase in brightness of 1-mag over the past 1000 years. The changes observed for V19 are obviously on a much more dramatic scale. We discuss the properties of this unusual (former) Cepheid and discuss possible reasons for its apparent fast evolutionary changes. In this study we have combined the recent RCT CCD photometry with unpublished photometry secured a few years ago with the WIYN 3.5-m telescope as well as using the available photometry back to Hubble's original observations carried out during the mid-1920s. These data have been subjected to various period search routines to identify possible periods. We also discuss some possible scenarios to explain the strange behavior of the star. We gratefully acknowledge support from a NASA/HST grant and NSF/RUI grant AST-1009903. The RCT is operated by the RCT Consortium - a group of universities and research institutions who have assumed control of the 1.3-m (50-inch) telescope on Kitt Peak, Arizona. The Consortium members are Western Kentucky University, the Planetary Science Institute, South Carolina State University, and Villanova University.

Engle, Scott G.; Guinan, Edward F.; Macri, Lucas; Pellerin, Ann

2011-03-01

324

Hubble and Keck team up to find farthest known galaxy in the Universe  

NASA Astrophysics Data System (ADS)

Galaxy cluster Abell 2218 hi-res Size hi-res: 5212 Kb Credits: European Space Agency, NASA, J.-P. Kneib (Observatoire Midi-Pyrénées) and R. Ellis (Caltech) Close-up of the large galaxy cluster Abell 2218 This close-up of the large galaxy cluster Abell 2218 shows how this cluster acts as one of nature’s most powerful ‘gravitational telescopes’ and amplifies and stretches all galaxies lying behind the cluster core (seen as red, orange and blue arcs). Such natural gravitational ‘telescopes’ allow astronomers to see extremely distant and faint objects that could otherwise not be seen. A new galaxy (split into two ‘images’ marked with an ellipse and a circle) was detected in this image taken with the Advanced Camera for Surveys on board the NASA/ESA Hubble Space Telescope. The extremely faint galaxy is so far away that its visible light has been stretched into infrared wavelengths, making the observations particularly difficult. The galaxy may have set a new record in being the most distant known galaxy in the Universe. Located an estimated 13 billion light-years away (z~7), the object is being viewed at a time only 750 million years after the big bang, when the Universe was barely 5 percent of its current age. In the image the distant galaxy appears as multiple ‘images’, an arc (left) and a dot (right), as its light is forced along different paths through the cluster’s complex clumps of mass (the yellow galaxies) where the magnification is quite large. The colour of the different lensed galaxies in the image is a function of their distances and galaxy types. The orange arc is for instance an elliptical galaxy at moderate redshift (z=0.7) and the blue arcs are star forming galaxies at intermediate redshift (z between 1 and 2.5). An image of Abell 2218 hi-res Size hi-res: 29 563 Kb Credits: European Space Agency, NASA, J.-P. Kneib (Observatoire Midi-Pyrénées) and R. Ellis (Caltech) A ground-based wide-angle image of Abell 2218 This wide-angle image spans 0.4 by 0.4 degrees and was taken by the 12k camera on Canada-France-Hawaii Telescope on Mauna Kea, Hawaii, United States. The image is composited by three exposures through blue (B), red (R), and infrared (I) filters. The primeval galaxy was identified by combining the power of the NASA/ESA Hubble Space Telescope and CARA's W. M. Keck Telescopes on Mauna Kea in Hawaii. These great observatories got a boost from the added magnification of a natural ‘cosmic gravitational lens’ in space that further amplifies the brightness of the distant object. The newly discovered galaxy is likely to be a young galaxy shining during the end of the so-called "Dark Ages" - the period in cosmic history which ended with the first galaxies and quasars transforming opaque, molecular hydrogen into the transparent, ionized Universe we see today. The new galaxy was detected in a long exposure of the nearby cluster of galaxies Abell 2218, taken with the Advanced Camera for Surveys on board the Hubble Space Telescope. This cluster is so massive that the light of distant objects passing through the cluster actually bends and is amplified, much as a magnifying glass bends and magnifies objects seen through it. Such natural gravitational ‘telescopes’ allow astronomers to see extremely distant and faint objects that could otherwise not be seen. The extremely faint galaxy is so far away its visible light has been stretched into infrared wavelengths, making the observations particularly difficult. "As we were searching for distant galaxies magnified by Abell 2218, we detected a pair of strikingly similar images whose arrangement and colour indicate a very distant object," said astronomer Jean-Paul Kneib (Observatoire Midi-Pyrénées and California Institute of Technology), who is lead author reporting the discovery in a forthcoming article in the Astrophysical Journal. Analysis of a sequence of Hubble images indicate the object lies between a redshift of 6.6 and 7.1, making it the most distant source currently known. However, long exposures in the optical and

2004-02-01

325

The Hubble Deep Field: Observations, Data Reduction, and Galaxy Photometry  

Microsoft Academic Search

The Hubble Deep Field (HDF) is a Director's Discretionary program on HST in Cycle 5 to image an undistinguished field at high Galactic latitude in four passbands as deeply as reasonably possible. These images provide the most detailed view to date of distant field galaxies and are likely to be important for a wide range of studies in galaxy evolution

Robert E. Williams; Brett Blacker; Mark Dickinson; W. Van Dyke Dixon; Henry C. Ferguson; Andrew S. Fruchter; Mauro Giavalisco; Ronald L. Gilliland; Inge Heyer; Rocio Katsanis; Zolt Levay; Ray A. Lucas; Douglas B. McElroy; Larry Petro; Marc Postman; Hans-Martin Adorf; Richard Hook

1996-01-01

326

Space Science: Status of the Hubble Space Telescope Program.  

National Technical Information Service (NTIS)

The current status of the NASA's Hubble Space Telescope (HST) program is reviewed. The following questions are addressed: (1) what is the current status of the program with respect to cost, schedule, and performance; (2) what is the role of the Space Tele...

1988-01-01

327

Widefield camera 3 for the Hubble Space Telescope  

Microsoft Academic Search

In June 1997, NASA made the decision to extend the end of the Hubble Space Telescope (HST) mission from 2005 until 2010. As a result, the age of the instruments on board the HST became a consideration. After careful study, NASA decided to ensure the imaging capabilities of the HST by replacing the Wide Field Planetary Camera 2 with a

Edward S. Cheng; Robert J. Hill; John W. MacKenty; Laura Cawley; P. Knezek; Ray E. Kutina; Casey M. Lisse; Olivia L. Lupie; Massimo Robberto; Massimo Stiavelli; Robert W. O'Connell; Bruce Balick; H. Bond; Daniela Calzetti; M. Carollo; Mike Disney; Mike Dopita; J. Frogel; Donald N. Hall; J. Hester; J. Holtzman; Gerard A. Luppino; P. McCarthy; Francesco Paresce; Abhijit Saha; J. Silk; John T. Trauger; A. Walker; B. Whitmore; R. Windhorst; Erick T. Young

2000-01-01

328

Artificial intelligence scheduling for NASA's Hubble Space Telescope  

Microsoft Academic Search

An artificial intelligence (AI) system called Spike has been implemented for scheduling observations with NASA's Hubble Space Telescope. The system incorporates innovative methodologies for representing and reasoning with scheduling constraints and preferences and for conducting scheduling search. For the former, a combination of constraint satisfaction techniques and weight-of evidence combination has been devised to propagate temporal constraints and preferences. For

Mark D. Johnston; Glenn Miller

1990-01-01

329

Exploring the universe with the Hubble Space Telescope  

NASA Astrophysics Data System (ADS)

A general overview is given of the operations, engineering challenges, and components of the Hubble Space Telescope. Deployment, checkout and servicing in space are discussed. The optical telescope assembly, focal plane scientific instruments, wide field/planetary camera, faint object spectrograph, faint object camera, Goddard high resolution spectrograph, high speed photometer, fine guidance sensors, second generation technology, and support systems and services are reviewed.

330

Elliptical galaxies and non-uniformities in the Hubble flow  

Microsoft Academic Search

Spectroscopic and photometric data have been obtained for 400 elliptical galaxies that permit distances to individual galaxies to be predicted with accuracies of + or - 23 percent. Systematic velocities relative to a smooth Hubble flow are observed that are most straightforwardly interpreted as a bulk motion of approximately 700 km\\/s towards I = 299 deg, b = +1 deg

David Burstein; Roger L. Davies; Alan Dressler; S. M. Faber; Donald Lynden-Bell

1986-01-01

331

Constraining Galaxy Evolution With Hubble's Next Generation Spectral Library  

NASA Astrophysics Data System (ADS)

We present Hubble's Next Generation Spectral Library, a library of UV-optical spectra (0.2-1.0 ?) of 378 stars. We show that the mid-UV spectrum can be used to constrain the ages and metallicities of high-redshift galaxies presently being observed with large, ground-based telescopes.

Heap, S.; Lindler, D. J.

2009-03-01

332

Spectacles in Space: A Museum of the Hubble Telescope  

ERIC Educational Resources Information Center

|When the space shuttle "Columbia" was "lost entering the Earth's atmosphere," third graders at the Lamplighter School in Texas became curious about space travel. Using topics of interest and brainstorming exercises based on a presentation by Elaine Scott, author of "Adventures in Space: The Flight to Fix the Hubble," the author and her colleagues…

Vermillion, Patricia

2004-01-01

333

Geologic Mapping of Vesta from 1994 Hubble Space Telescope Images  

Microsoft Academic Search

We utilize the 56 images of Asteroid 4 Vesta obtained through four mineralogically diagnostic filters by the Hubble Space Telescope (Zellner et al. 1997, Icarus) to construct a geologic map. Vesta's surface is found to be geologically diverse and to be dichotomous at a hemispheric scale. The eastern hemisphere (longitude definition from Thomas et al. 1997, Icarus) is dominated by

Richard P. Binzel; Michael J. Gaffey; Peter C. Thomas; Benjamin H. Zellner; Alex D. Storrs; Eddie N. Wells

1997-01-01

334

Astronomers Gain Clues About Fundamental Physics  

NASA Astrophysics Data System (ADS)

An international team of astronomers has looked at something very big -- a distant galaxy -- to study the behavior of things very small -- atoms and molecules -- to gain vital clues about the fundamental nature of our entire Universe. The team used the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) to test whether the laws of nature have changed over vast spans of cosmic time. The Green Bank Telescope The Robert C. Byrd Green Bank Telescope CREDIT: NRAO/AUI/NSF (Click on image for GBT gallery) "The fundamental constants of physics are expected to remain fixed across space and time; that's why they're called constants! Now, however, new theoretical models for the basic structure of matter indicate that they may change. We're testing these predictions." said Nissim Kanekar, an astronomer at the National Radio Astronomy Observatory (NRAO), in Socorro, New Mexico. So far, the scientists' measurements show no change in the constants. "We've put the most stringent limits yet on some changes in these constants, but that's not the end of the story," said Christopher Carilli, another NRAO astronomer. "This is the exciting frontier where astronomy meets particle physics," Carilli explained. The research can help answer fundamental questions about whether the basic components of matter are tiny particles or tiny vibrating strings, how many dimensions the Universe has, and the nature of "dark energy." The astronomers were looking for changes in two quantities: the ratio of the masses of the electron and the proton, and a number physicists call the fine structure constant, a combination of the electron charge, the speed of light and the Planck constant. These values, considered fundamental physical constants, once were "taken as time independent, with values given once and forever" said German particle physicist Christof Wetterich. However, Wetterich explained, "the viewpoint of modern particle theory has changed in recent years," with ideas such as superstring theory and extra dimensions in spacetime calling for the "constants" to change over time, he said. The astronomers used the GBT to detect and study radio emissions at four specific frequencies between 1612 MHz and 1720 MHz coming from hydroxyl (OH) molecules in a galaxy more than 6 billion light-years from Earth, seen as it was at roughly half the Universe's current age. Each of the four frequencies represents a specific change in the energy level of the molecule. The exact frequency emitted or absorbed when the molecule undergoes a transition from one energy level to another depends on the values of the fundamental physical constants. However, each of the four frequencies studied in the OH molecule will react differently to a change in the constants. That difference is what the astronomers sought to detect using the GBT, which, Kanekar explained, is the ideal telescope for this work because of its technical capabilities and its location in the National Radio Quiet Zone, where radio interference is at a minimum. "We can place very tight limits on changes in the physical constants by studying the behavior of these OH molecules at a time when the Universe was only about half its current age, and comparing this result to how the molecules behave today in the laboratory," said Karl Menten of the Max-Planck Institute for Radioastronomy in Germany. Wetterich, a theorist, welcomes the new capability, saying the observational method "seems very promising to obtain perhaps the most accurate values for such possible time changes of the constants." He pointed out that, while some theoretical models call for the constants to change only in the early moments after the Big Bang, models of the recently-discovered, mysterious "dark energy" that seems to be accelerating the Universe's expansion call for changes "even in the last couple of billion years." "Only observations can tell," he said. This research ties together the theoretical and observation

2005-12-01

335

How Astronomers Can Help Prepare Future Teachers  

NASA Astrophysics Data System (ADS)

Classroom teachers are expected to teach a variety of astronomical topics, yet research indicates that most undergraduates do not have a scientific understanding of these topics, and there is widespread misunderstanding as to the nature of science. How can astronomers help to prepare the next generation of teachers in space science? Our group has met with teacher educators from both science and education departments, and conducted a survey to better understand the role and needs for astronomy in teacher pre-service. We will share the current research and the results of our own survey of teacher educators, and some of the models and suggestions that the members of the NASA Science Mission Directorate’s Pre-Service Education Working Group (http://www.lpi.usra.edu/education/score/pre_service.shtml) have discovered. Research has shown that effective teaching practices need to be modeled--future teachers need to be taught a subject the way they will be teaching it in their classrooms. Our survey of teacher educators (from science and education departments at a variety of colleges across the US) suggests educators are concerned that today's future teachers are not taught science in college as inquiry-based, with activities that model the nature of investigation. The survey also indicated that future elementary teachers often have a fear or dislike of science, and do not understand the nature of science, and that students do not have enough breadth in science subjects. Our group's meetings and discussions have discerned a variety of opportunities for astronomers to effect change in the future classroom teacher. These include changing the way that classes are taught, increasing opportunities for future teachers (in addition to future scientists) to have true scientific research experiences, creating scientist-education partnerships to improve science pre-service education, and establishing programs with scientists as mentors to future teachers.

Shupla, Christine; Ruberg, L.; Slater, T. F.; Schultz, G.

2006-12-01

336

A Lead Astronomical Neutrino Detector: LAND  

NASA Astrophysics Data System (ADS)

The development of a sensitive detector for neutrinos of astronomical origin (simply called astronomical neutrinos hereafter) would make possible detailed investigation of supernovae (SN) and open the way for the discovery of new astronomical phenomena. The neutrino weak interaction cross section at energies less than 100 MeV increases with Z due to correlated nucleon effects and the nuclear Coulomb factor (Fermi function). Therefore neutrino detection based on high Z materials will give the largest possible cross sections and best possible neutrino detection efficiency. This physics argument motivated us to study lead as a detector of SN. The neutrino cross section for neutron production on lead through the reaction Pb( ? e,?,?, ln)X is ? 10 -40 cm 2, for energies up to 50 MeV, where X refers to Pb, Bi or Tl, the product nuclei of the reactions, l refers to the scattered lepton, and n refers to neutrons. Neutron production will occur for all types of neutrinos and the neutrons can be detected easily and efficiently. The detector is uniquely sensitive to all neutrinos but #x003BD; e. We show that a SN at the centre of the galaxy produces about 1000 neutrons in a 1 kiloton detector. This large number will make it possible to measure the mass of ? ? and ? ? neutrinos between 10 and 100 eV with a precision of 10 eV. Further, we describe a possible detector in which one also detects the associated electromagnetic energy in coincidence with the neutrons. The coincidence makes this detector essentially background free. It is possible to expand such a detector to a size which will reach SN well beyond our galaxy. We calculate the ?-Pb cross section, discuss the design, neutrino mass resolution, neutron detection efficiency and signal to noise ratio aspects of these detectors.

Hargrove, C. K.; Batkin, I.; Sundaresan, M. K.; Dubeau, J.

1996-08-01

337

Is the Astronomical Literature Still Expanding Exponentially?  

NASA Astrophysics Data System (ADS)

Have the recent reductions in funding for astronomy resulted in a significant decrease in the exponential growth of our astronomical publications? I studied the growth of five American and European journals (A&A, AJ, ApJ, MNRAS, and PASP) that publish papers on a broad range of astronomical topics. For each, I counted the numbers of normalized pages and papers published at 10 intervals in 1960-1996. The average numbers of pages showed an exponential increase of 11% per year before the mid-1970s and 6% per year thereafter. The average number of papers increased exponentially by 9% before the mid-1970s and by 4% per year thereafter. The difference between these two sets of numbers is caused by an increase in average paper lengths from six normalized pages in 1960 to a constant 12 pages per paper during the last decade. Thus, the average paper lengths have asymptotically reached a constant value. However, there is no sign of a leveling off in the growth of our literature. The number of different authors also increased steadily. Over the past 36 years there have been few systematic shifts from one journal to another, implying that few authors have changed their habitual choices of journals. The numbers of papers in the three American journals has been directly proportional to the numbers of AAS members at 0.41 papers per year per member during the past 36 years. Therefore, the growth in our numbers of papers is entirely due to the growth in the numbers of astronomers, and the additional growth in pages is due to the growth in paper lengths.

Abt, Helmut A.

1998-02-01

338

Community College Class Devoted to Astronomical Research  

NASA Astrophysics Data System (ADS)

A class at a small community college, Central Arizona College, was dedicated to astronomical research. Although hands-on research is usually reserved for professionals or graduate students, and occasionally individual undergraduate seniors, we decided to introduce community college students to science by devoting an entire class to research. Nine students were formed into three closely cooperating teams. The class as a whole decided that all three teams would observe Cepheid stars photometrically using a robotic telescope at the Fairborn Observatory. Speaker-phone conference calls were made to Kenneth E. Kissell for help on Cepheid selection, Michael A. Seeds for instructions on the use of the Phoenix-10 robotic telescope, and Douglas S. Hall for assitance in selecting appropriate comparison and check stars. The students obtained critical references on past observations from Konkoly Observatory via airmail. They spent several long night sessions at our apartment compiling the data, making phase calculations, and creating graphs. Finally, the students wrote up their results for publication in a forthcoming special issue of the international journal on stellar photometry, the IAPPP Communication. We concluded that conducting team research is an excellent way to introduce community college students to science, that a class devoted to cooperation as opposed to competition was refreshing, and that group student conference calls with working astronomers were inspiring. A semester, however, is a rather short time to initiate and complete research projects. The students were Sally Baldwin, Cory Bushnell, Bryan Dehart, Pamela Frantz, Carl Fugate, Mike Grill, Jessica Harger, Klay Lapa, and Diane Wiseman. We are pleased to acknowledge the assistance provided by the astronomers mentioned above, James Stuckey (Campus Dean), and our Union Institute and University doctoral committee members Florence Pittman Matusky, Donald S. Hayes, and Karen S. Grove.

Genet, R. M.; Genet, C. L.

2002-05-01

339

Expansion of The Astronomical Almanac Online Website  

NASA Astrophysics Data System (ADS)

The Astronomical Almanac (AsA) Online website (http://asa.usno.navy.mil/ and http://asa.hmnao.com/), a joint project between the Nautical Almanac Office (NAO) at the US Naval Observatory and Her Majesty's Nautical Almanac Office (HMNAO) at the UK Hydrographic Office, began as a supplement to the printed Astronomical Almanac. The original intent of the AsA Online was to provide data in text form for machine parsing, datasets no longer published in the book but still needed by some users, a list of errata as they become known, and a means for user feedback. For the past few years we have looked at how to improve the AsA Online by presenting additional data with methods not available in a printed book. Starting with the proof-of-concept observatory search--designed to add a dynamic element to the data from the observatory section while still maintaining the look of printed pages in the AsA--we have added: maps for lunar occultations of the planets, many minor planets, and bright stars (supplementing the Phenomena section); a table on the main page of the website that presents entries from the Diary of Phenomena for two weeks into the future; a utility for finding the geocentric coordinates of the planets (supplementing Section E); searches for some tables found in Section H (Stars), allowing users to filter the data and print a subset of the entries for ease-of-use; and a Delta T: Past, Present and Future feature updated multiple times per year. In the future, we plan to increase the amount of information on the AsA Online by adding more filterable datasets from the book, new ways of visualizing information, and options to download data in machine-friendly XML, while still maintaining the website as a complement to the printed Astronomical Almanac.

Barron, Eric G.; Bell, S. A.; Hohenkerk, C. Y.; Stewart, S. G.; Urban, S. E.

2010-01-01

340

The Astronomical Orientation of Ancient Greek Temples  

PubMed Central

Despite its appearing to be a simple question to answer, there has been no consensus as to whether or not the alignments of ancient Greek temples reflect astronomical intentions. Here I present the results of a survey of archaic and classical Greek temples in Sicily and compare them with temples in Greece. Using a binomial test I show strong evidence that there is a preference for solar orientations. I then speculate that differences in alignment patterns between Sicily and Greece reflect differing pressures in the expression of ethnic identity.

Salt, Alun M.

2009-01-01

341

The astronomical orientation of ancient Greek temples.  

PubMed

Despite its appearing to be a simple question to answer, there has been no consensus as to whether or not the alignments of ancient Greek temples reflect astronomical intentions. Here I present the results of a survey of archaic and classical Greek temples in Sicily and compare them with temples in Greece. Using a binomial test I show strong evidence that there is a preference for solar orientations. I then speculate that differences in alignment patterns between Sicily and Greece reflect differing pressures in the expression of ethnic identity. PMID:19936239

Salt, Alun M

2009-11-19

342

Astronomical Verification of ALMA Array Elements  

NASA Astrophysics Data System (ADS)

The Atacama Large Millimeter/submillimeter Array (ALMA) will consist of at least 54 twelve-meter and 12 seven-meter antennas operating as an aperture synthesis array in the (sub)millimeter wavelength range. The ALMA System Integration Science Team (SIST) verifies and characterizes the astronomical performance of the ALMA array elements as single dish and interferometric systems before being accepted for array commissioning. These activities occur both at the Operations Support Facility (OSF; just below 3000 m elevation) and at the Array Operations Site (AOS) at 5000 m.

Asayama, S.; Knee, L. B. G.; Calisse, P. G.; Colque, J. P.; López, C.; Nakos, T.; Phillips, N. M.; Plarre, K. H.; Radiszcz, M. C.; Siringo, G.; Yatagai, H.

2013-10-01

343

Anglo-Australian Observatory Astronomical Images  

NSDL National Science Digital Library

David Malin, Adjunct Professor of Scientific Photography at Royal Melbourne Institute of Technology (RMIT), has created this "gateway to a unique collection of wide-field astronomical photographs." These awe-striking photographs were mostly taken with the telescopes of the Anglo-Australian Observatory and include photos of galaxies, emission and reflection nebulae, supernovae, star clusters, messier objects, and more. Underneath each picture is a brief description, along with links to other related images. Users may scan the images by object type, by telescope type, or by the portfolio pages of thumbnail pictures (a slightly slower process).

Malin, David.

344

Information Mining in Astronomical Literature with Tetralogie  

NASA Astrophysics Data System (ADS)

A tool derived for the technological watch (\\htmladdnormallinkfoot{Tetralogie}{http://atlas.irit.fr}) is applied to a dataset of three consecutive years of article abstracts published in the European Journal {\\it Astronomy and Astrophysics}. This tool is based on a two step approach: first, a pretreatment step that extracts elementary items from the raw information (keywords, authors, year of publication, etc.); second, a mining step that analyses the extracted information using statistical methods. It is shown that this approach allows one to qualify and visualize some major trends characterizing the current astronomical literature: multi-author collaborative work, the impact of observational projects and thematic maps of publishing authors.

Egret, D.; Mothe, J.; Dkaki, T.; Dousset, B.

345

Astronomical coordinates at the Parkes radio telescope  

NASA Astrophysics Data System (ADS)

The design and operation of the control system for the Parkes radio telescope are described. A coordinate transformation computer is utilized for transforming position requests into commands for the telescope drive; a diagram of the computer is provided. The coordinate transform techniques employed by the computer to transform position requests are discussed. The new control system allows for scanning the telescope in any astronomical coordinate system, the definition and use of beams offset in azimuth and elevation from the telescope's optical axis, and the definition of arbitrary coordinate frames which may move with respect to standard reference frames.

McConnell, D.

346

Astronomical analysis of the taosi observatory site  

NASA Astrophysics Data System (ADS)

An ancient observatory was unearthed recently at Taosi site. This paper discussed the figure of the relic, analyzed the relationship between the 12 backsights and calendar date using astronomical method, and compared the simulated observation with theoretic computation. The investigation shows that backsight E2---E12 indicated the directions of sunrise in the whole year, which were roughly equally distributed and offered an unequal calendar system. The backsight E1 indicated the south-end of the moonrise, giving a time symbol of 18---19 years. This building must be a complex of solar observation, time service, solar worship, and sacrificial ritual

Liu, C. Y.

2009-01-01

347

Illinois­—Where Astronomical Photometry Grew Up  

NASA Astrophysics Data System (ADS)

In 1903 Dr. Joel Stebbins joined the University of Illinois faculty as an astronomy instructor and Director of the University of Illinois Observatory. In 1905 he and F. C. Brown began experimenting with selenium sell photometry and developed the equipment and many of the photometric practices used then. Those practices formed the foundation on which present day photometry processes are based. This paper will trace the history of Stebbins’ career and his development of photoelectric photometry from 1903 to 1922. This story explains how Stebbins’ wife, May, caused a change in astronomical observing that continues today.

Beaman, B. B.; Svec, M. T.

2012-06-01

348

Atomic collisions in solids: Astronomical applications  

NASA Astrophysics Data System (ADS)

Airless bodies in space are subject to irradiation with energetic atomic particles, which generate atmospheres by sputtering and alter the surface composition. Astronomical observations with telescopes and space probes continuously provide new data that require new laboratory experiments for their interpretation. Many of these experiments also serve to expand the current frontier of atomic collisions in solids by discovering previously unknown phenomena. Some of the experimental techniques used in these experiments could find applications in other areas of atomic collisions in solids. We present results from our current experimental research program on sputtering and surface modification of ices and minerals and point out opportunities for research in this area.

Baragiola, R. A.; Atteberry, C. L.; Dukes, C. A.; Famá, M.; Teolis, B. D.

2002-06-01

349

Multilayer coatings for astronomical telescope mirrors  

NASA Astrophysics Data System (ADS)

Silver-based high-reflectance coatings that can withstand the humid and polluted conditions common in the open air have been developed for astronomical telescope optics. The successful designs incorporate a silver reflective layer with a copper underlayer and a stack of dielectric overlayers. Prototypes have been deposited and tested in a controlled environmental chamber and under true operating conditions on Kitt Peak in Arizona. The improved durability, which is due to the copper underlayer, has been investigated with analytical techniques, including Rutherford backscattering.

Song, D. Y.; MacLeod, H. A.

350

Hubble flow variance and the cosmic rest frame  

NASA Astrophysics Data System (ADS)

We characterize the radial and angular variance of the Hubble flow in the composite sample of 4534 galaxies, on scales in which much of the flow is in the nonlinear regime. With no cosmological assumptions other than the existence of a suitably averaged linear Hubble law, we find with decisive Bayesian evidence (ln?B?5) that the Hubble constant, when averaged in independent spherical shells, is closer to its asymptotic value when referred to the rest frame of the Local Group (LG), rather than the standard rest frame of the cosmic microwave background (CMB). An exception occurs for radial shells in the range 40h-1–60h-1Mpc. Angular averages reveal a dipole structure in the Hubble flow, whose amplitude changes markedly over the range 32h-1–62h-1Mpc. Whereas the LG frame dipole is initially constant and then decreases significantly, the CMB frame dipole initially decreases but then increases. The map of angular Hubble flow variation in the LG rest frame is found to coincide with that of the residual CMB temperature dipole, with correlation coefficient -0.92. These results are difficult to reconcile with the standard kinematic interpretation of the motion of the Local Group in response to the clustering dipole, but are consistent with a foreground nonkinematic anisotropy in the distance-redshift relation of 0.5% on scales up to 65h-1Mpc. Effectively, the differential expansion of space produced by nearby nonlinear structures of local voids and denser walls and filaments cannot be reduced to a local boost. This hypothesis suggests a reinterpretation of bulk flows, which may potentially impact on calibration of supernova distances, anomalies associated with large angles in the CMB anisotropy spectrum, and the dark flow inferred from the kinematic Sunyaev-Zel’dovich effect. It is consistent with recent studies that find evidence for a nonkinematic dipole in the distribution of distant radio sources.

Wiltshire, David L.; Smale, Peter R.; Mattsson, Teppo; Watkins, Richard

2013-10-01

351

The cosmic age crisis and the Hubble constant in a non-expanding universe  

NASA Astrophysics Data System (ADS)

The present paper outlines a cosmological paradigm based upon Dirac’s large number hypothesis and continual creation of matter in a closed static (nonexpanding) universe. The cosmological redshift is caused by the tired-light phenomenon originally proposed by Zwicky. It is shown that the tired-light cosmology together with continual matter creation has a universal Hubble constant H 0=(512 ? 2/3)1/6( GC 0)1/3 fixed by the universal rate C 0 of matter creation, where G is Newton’s gravitational constant. It is also shown that a closed static universe has a finite age ? 0=(243 ? 5/8 GC 0)1/3 also fixed by the universal rate of matter creation. The invariant relationship H 0 ? 0=3 ? 261/2 shows that a closed static universe is much older (?one trillion years) than any expanding universe model based upon Big-Bang cosmology. It is this property of a static universe that resolves any cosmic age crisis provided that galaxy formation in the universe is a continual recurring process. Application of Dirac’s large number hypothesis gives a matter creation rate C 0=4.6×10-48 gm cm-3 s-1 depending only on the fundamental constants of nature. Hence, the model shows that a closed static universe has a Hubble constant H 0=70 km s-1 Mpc-1 in good agreement with recent astronomical determinations of H 0. By using the above numerical value for H 0 together with observational data for elongated cellular-wall structures containing superclusters of galaxies, it is shown that the elongated cellular-wall configurations observed in the real universe are at least one hundred billion years old. Application of the microscopic laws of physics to the large-scale macroscopic universe leads to a static eternal cosmos endowed with a matter-antimatter symmetry. It is proposed that the matter-antimatter asymmetry is continuously created by particle-antiparticle pair annihilation occurring in episodic cosmological gamma-ray bursts observed in the real universe.

Sorrell, Wilfred H.

2008-09-01

352

Enhanced management of personal astronomical data with FITSManager  

NASA Astrophysics Data System (ADS)

Although the roles of data centers and computing centers are becoming more and more important, and on-line research is becoming the mainstream for astronomy, individual research based on locally hosted data is still very common. With the increase of personal storage capacity, it is easy to find hundreds to thousands of FITS files in the personal computer of an astrophysicist. Because Flexible Image Transport System (FITS) is a professional data format initiated by astronomers and used mainly in the small community, data management toolkits for FITS files are very few. Astronomers need a powerful tool to help them manage their local astronomical data. Although Virtual Observatory (VO) is a network oriented astronomical research environment, its applications and related technologies provide useful solutions to enhance the management and utilization of astronomical data hosted in an astronomer's personal computer. FITSManager is such a tool to provide astronomers an efficient management and utilization of their local data, bringing VO to astronomers in a seamless and transparent way. FITSManager provides fruitful functions for FITS file management, like thumbnail, preview, type dependent icons, header keyword indexing and search, collaborated working with other tools and on-line services, and so on. The development of the FITSManager is an effort to fill the gap between management and analysis of astronomical data.

Cui, Chenzhou; Fan, Dongwei; Zhao, Yongheng; Kembhavi, Ajit; He, Boliang; Cao, Zihuang; Li, Jian; Nandrekar, Deoyani

2012-02-01

353

Automated system and method for processing of astronomical images  

US Patent & Trademark Office Database

This invention encompasses near-real-time processing of astronomical images for viewing on a computer. This image processing method is preferably integrated with the control of an astronomical observatory. The subject invention thus includes an Internet-based system that provides a virtual experience of an astronomical observatory. The subject invention preferably uses an unmanned astronomical observatory to observe galaxies, nebulae, stars, etc. The observatory produces color images suitable for viewing on a computer monitor. These images are delivered to users across the Internet using web browser-based software.

2007-03-20

354

The First Astronomical Observatory in Cluj-Napoca  

NASA Astrophysics Data System (ADS)

One of the most important cities of Romania is Cluj-Napoca (Kolozsvár, Klausenburg). This is a traditional center of education, with many universities and high schools. From the second half of the 18th century the University of Cluj has its own Astronomical Observatory, serving for didactical activities and scientific researches. The famous astronomer Maximillian Hell was one of those Jesuits who put the base of this Astronomical Observatory. Our purpose is to offer a short history of the beginnings of this Astronomical Observatory.

Szenkovits, Ferenc

2008-09-01

355

Astronomical Alignments in a Neolithic Chinese Site?  

NASA Astrophysics Data System (ADS)

In the Manchurian province of Liaoning, near 41N19' and 119E30', exist ruins of a middle Neolithic society (2500 to 4000 BC) known as the Hongshan culture. This location, called Niuheliang, is comprised of 16 locations with monumental structures scattered over 80 square kilometers of hills. Most are stone burial structures that contain jade artifacts implying wealth and power. One structure is unique in being unusually shaped and containing oversized effigies of goddess figures. This structure also has a commanding view of the surrounding landscape. The presence of decorated pottery, jade and worked copper suggests the Hongshan people were sophisticated artisans and engaged in long-distance trading. During 1997, we've conducted a course at Denver as part of our Core Curriculum program for upper division students, that has examined the astronomical and cultural aspects of the Niuheliang site, to attempt to determine whether these contemporaries of the builders of Stonehenge may have included astronomical alignments into their constructions. The preliminary result of our studies suggests that certain monuments have potential for lunar standstill observation from the "goddess temple". For updates on these results, please see our website: www.du.edu/ rstencel/core2103.html.

Nelson, S.; Stencel, R. E.

1997-12-01

356

Astronomical Parallax 2D JS Model  

NSDL National Science Digital Library

The Astronomical Parallax 2D Javascript Model illustrates This simulation illustrates the phenomenon of parallax in astronomy. Parallax is the apparent displacement of an object relative to the background that is caused by the motion of the observer (rather than the motion of the object itself, or of the background). This simulation illustrates the parallax of an object in space that results from the Earth's rotational or orbital motions. The simulation has two different modes. The default is an Earth Rotation Mode. In this mode the simulation illustrates the parallax caused by Earth's rotation on its axis. The other mode for the simulation is Earth Orbit Mode. In this mode the simulation illustrates the parallax caused by Earth's orbit around the Sun. Now the observer moves along Earth's orbital path (shown as a blue circle with the orange Sun in the center). The bottom window shows the apparent motion of the object being observed. The Astronomical Parallax 2D JS Model was developed using the Easy Java Simulations (EJS) version 5. It is distributed as a ready-to-run html page and requires only a browser with JavaScript support.

Timberlake, Todd; Belloni, Mario

2013-09-03

357

Automated object detection for astronomical images  

NASA Astrophysics Data System (ADS)

Sponsored by the National Aeronautical Space Association (NASA), the Synergetic Education and Research in Enabling NASA-centered Academic Development of Engineers and Space Scientists (SERENADES) Laboratory was established at California State University, Los Angeles (CSULA). An important on-going research activity in this lab is to develop an easy-to-use image analysis software with the capability of automated object detection to facilitate astronomical research. This paper presented a fast object detection algorithm based on the characteristics of astronomical images. This algorithm consists of three steps. First, the foreground and background are separated using histogram-based approach. Second, connectivity analysis is conducted to extract individual object. The final step is post processing which refines the detection results. To improve the detection accuracy when some objects are blocked by clouds, top-hat transform is employed to split the sky into cloudy region and non-cloudy region. A multi-level thresholding algorithm is developed to select the optimal threshold for different regions. Experimental results show that our proposed approach can successfully detect the blocked objects by clouds.

Orellana, Sonny; Zhao, Lei; Boussalis, Helen; Liu, Charles; Rad, Khosrow; Dong, Jane

2005-10-01

358

Recent advances in astronomical adaptive optics.  

PubMed

The imaging performance of large ground-based astronomical telescopes is compromised by dynamic wavefront aberration caused by atmospheric turbulence. Techniques to measure and correct the aberration in real time, collectively called adaptive optics (AO), have been developed over the past half century, but it is only within the past decade that the delivery of diffraction-limited image quality at near- and mid-infrared wavelengths at many of the world's biggest telescopes has become routine. Exploitation of this new capability has led to a number of ground-breaking astronomical results, which has in turn spurred the continued development of AO to address ever more technical challenges that limit its scientific applicability. I review the present state of the art, highlight a number of noteworthy scientific results, and outline several ongoing experiments designed to broaden the scope of observations that can be undertaken with AO. In particular, I explore the significant advances required in AO technology to satisfy the needs for a new generation of extremely large telescopes of diameter 25 m and larger that are now being designed. PMID:20517357

Hart, Michael

2010-06-01

359

Astronomers Discover Spectacular Structure in Distant Galaxy  

NASA Astrophysics Data System (ADS)

Researchers using the National Science Foundation's Very Large Array (VLA) radio telescope have imaged a "spectacular and complex structure" in a galaxy 50 million light-years away. Their work both resolves a decades-old observational mystery and revises current theories about the origin of X-ray emission coming from gas surrounding the galaxy. The new VLA image is of the galaxy M87, which harbors at its core a supermassive black hole spewing out jets of subatomic particles at nearly the speed of light and also is the central galaxy of the Virgo Cluster of galaxies. The VLA image is the first to show detail of a larger structure that originally was detected by radio astronomers more than a half-century ago. Analysis of the new image indicates that astronomers will have to revise their ideas about the physics of what causes X-ray emission in the cores of many galaxy clusters. Frazer Owen of the National Radio Astronomy Observatory (NRAO) in Socorro, NM; Jean Eilek of the New Mexico Institute of Mining and Technology (NM Tech) in Socorro, NM; and Namir Kassim of the Naval Research Laboratory in Washington, DC, announced their discovery at the American Astronomical Society's meeting today in Austin, TX. The new observations show two large, bubble-like lobes, more than 200,000 light-years across, that emit radio waves. These lobes, which are intricately detailed, apparently are powered by gravitational energy released from the black hole at the galaxy's center. "We think that material is flowing outward from the galaxy's core into these large, bright, radio-emitting 'bubbles,'" Owen said. The newly-discovered "bubbles" sit inside a region of the galaxy known to be emitting X-rays. Theorists have speculated that this X-ray emission arises when gas that originally was part of the Virgo Cluster of galaxies, cools and falls inwards onto M87 itself, at the center of the cluster. Such "cooling flows" are commonly thought to be responsible for strong X-ray emission in many galaxy clusters. "The new structures that we found in M87 show that the story is much more complicated," Eilek said. "What we know about radio jets suggests that the energy being pumped into this region from the galaxy's central black hole exceeds the energy being lost in the X-ray emission. This system is more like a heating flow than a cooling flow. We're going to have to revise our ideas about the physics of what's going on in regions like this." M87, discovered by the French astronomer Charles Messier in 1781, is the strongest radio-emitting object in the constellation Virgo. Its jet was described by Lick Observatory astronomer Heber Curtis in 1918 as "a curious straight ray ... apparently connected with the nucleus by a thin line of matter." In 1954, Walter Baade reported that the jet's light is strongly polarized. M87's X-ray emission was discovered in 1966. M87 is the largest of the thousands of galaxies in the Virgo Cluster. The Local Group of galaxies, of which our own Milky Way is one, is part of the Virgo Cluster's outskirts. The galaxy's radio emissions first were observed by Australian astronomers in 1947, but the radio telescopes of that time were unable to discern much detail. They could, however, show that there is a structure more than 100,000 light-years across. Subsequent radio images, particularly those made using the sharp radio "vision" of the VLA, were primarily aimed at studying the inner 10,000 light-years or so, and showed great detail in the galaxy's jet. Astronomers even have followed the motions of concentrations of material within the jet over time. These observations, however, did not show much about the larger structure that was seen by earlier radio astronomers, leaving its details largely a mystery. Radio Images of M87 at Vastly Different Size Scales The mystery was solved by using the VLA to observe at longer radio wavelengths, thus revealing larger-scale structures. The processing speeds of modern computers and recently-developed imaging techniques

1999-01-01

360

Monitoring greenhouse gases with astronomical observations  

NASA Astrophysics Data System (ADS)

Modern telescopes are equipped with high-precision multi-mode spectrographs. To obtain proper calibration, astronomers observe the plain night sky and specific telluric standard stars (TS stars) to estimate the influence of the Earth atmosphere on astronomical observations. TS stars are usually white dwarfs, as their spectra are not time dependent and hardly contain any spectral features. Since the atmospheric emission in the thermal infrared and the absorption of stellar radiation reflect molecular abundances in the lower atmosphere, plain night sky and TS spectra can be used to obtain column densities of greenhouse gases. We present a method for determining this, incorporating the radiative transfer code LBLRTM and the HITRAN database. We fit specific molecular absorption and emission features by varying the corresponding abundance profiles iteratively implementing a Levenberg-Marquardt ?2 minimisation algorithm. This method was originally developed to estimate the amount of precipitable water vapour, which strongly influences infrared observations, above the observing site of the ESO Very Large Telescope, Cerro Paranal. We are currently in the process of extending this procedure to other greenhouse gases. As plain sky and TS stars are observed several times per night these spectra can be used to monitor molecular column densities on a long term basis.

Kausch, W.; Noll, S.; Barden, M.; Smette, A.; Szyszka, C.; Jones, A.; Kimeswenger, S.; Sana, H.; Horst, H.

2012-04-01

361

Monitoring greenhouse gases with astronomical observations  

NASA Astrophysics Data System (ADS)

Modern telescopes are equipped with high-precision multi-mode spectrographs. To obtain proper calibration, astronomers observe the plain night sky and specific telluric standard stars (TS stars) to estimate the influence of the Earth atmosphere on astronomical observations. TS stars are usually white dwarfs, as their spectra are not time dependent and hardly contain any spectral features. Since the atmospheric emission in the thermal infrared and the absorption of stellar radiation reflect molecular abundances in the lower atmosphere, plain night sky and TS spectra can be used to obtain column densities of greenhouse gases. We present a method for determining this, incorporating the radiative transfer code LBLRTM and the HITRAN database. We fit specific molecular absorption and emission features by varying the corresponding abundance profiles iteratively implementing a Levenberg-Marquardt ?^2 minimisation algorithm. This method was originally developed to estimate the amount of precipitable water vapour, which strongly influences infrared observations, above the observing site of the ESO Very Large Telescope, Cerro Paranal. We are currently in the process of extending this procedure to other greenhouse gases. As plain sky and TS stars are observed several times per night these spectra can be used to monitor molecular column densities on a long term basis.

Kausch, W.; Noll, S.; Barden, M.; Smette, A.; Szyszka, C.; Jones, A. M.; Kimeswenger, S.; Sana, H.; Horst, H.

2012-04-01

362

A Relationship Worth Cultivating: Astronomers and Planateria  

NASA Astrophysics Data System (ADS)

There is a growing need for research scientists to bring their expertise and their interest to the larger community, both through formal (classroom) activities and through informal (i.e. museum) activities. Astronomy has a powerful ally which is not available to most sciences -- the planetarium community. There are approximlatey 1000 planetaria in this country, including major planetaria in urban areas (e.g. Buhl Planetarium of Pittsburgh) and smaller planetaria in more urban areas (e.g. Loras College Planetarium of Dubuque Iowa). They serve a wide and diverse audience, and provide a grass roots network that is very receptive to astronomical results. The planetaria bring the wider public as well as the classroom into the world of astronomy. It serves the astronomers well to think about how to best support this very effective network. In this talk I will discuss the program being developed by STScI to provide systematic and cost effective communication between the HST observers and the planetarium community.

Kinney, A. L.

1995-05-01

363

Bayesian fusion of hyperspectral astronomical images  

NASA Astrophysics Data System (ADS)

The new integral-field spectrograph MUSE will acquire hyperspectral images of the deep sky, requiring huge amounts of raw data to be processed, posing a challenge to modern algorithms and technologies. In order to achieve the required sensitivity to observe very faint objects, many observations need to be reconstructed and co-added into a single data cube. In this paper, we propose a new fusion method to combine all raw observations while removing most of the instrumental and observational artifacts such as blur or cosmic rays. Thus, the results can be accurately and consistently analyzed by astronomers. We use a Bayesian framework allowing for optimal data fusion and uncertainty estimation. The knowledge of the instrument allows to write the direct problem (data acquisition on the detector matrix) and then to invert it through Bayesian inference, assuming a smoothness prior for the data cube to be reconstructed. Compared to existing methods, the originality of the new technique is in the propagation of errors throughout the fusion pipeline and the ability to deal with various acquisition parameters for each input image. For this paper, we focus on small-size, simulated astronomical observations with varying parameters to validate the image formation model, the reconstruction algorithm and the predicted uncertainties.

Jalobeanu, André; Petremand, Matthieu; Collet, Christophe

2011-03-01

364

Young Astronomers and Astronomy teaching in Moldavia  

NASA Astrophysics Data System (ADS)

Curricular Astronomy is taught in Moldavia , except Transnistria and Gagauzia, in the final (11th class) of the secondary schools and gymnasiums, and in the 12th class of the lyceums. The program takes 35 academic hours. The basic book is by Vorontsov-Veliaminov, used in the former USSR, but the Romanian one is also used, in spite of many criticisms addressed to both by our astronomy teachers. In Transinstria (on the left of the Dniester river)astronomy is taught 17 hours. Extracurricular activities develop at the Real Lyceum, where students and amateur astronomers carry out regular observations. Particularly, photographs of the comet Hale-Bopp have been realized using a Cassegrain 450 mm telescope by young astronomers under supervision of S. Luca and D. Gorodetzky (Gorodetchi). Except the telescope from the Real Lyceum other few telescopes are in construction. Unfortunately, no planetarium exists now in Chisinau, since the old one was returned to church. Astronomy courses are taught at the physical and mathematical departments of the Pedagogical University, Transnistrian Moldavian University in Tiraspol and the State University of |Moldavia. Many efforts were made by the State University lecturers and scientists to popularize Astronomy and Astrophysics in the books and in the press, at the radio and TV. No astronomy is taught at the Gagauzian National University in Comrat. No astronomiucal departments exist in Universities of |Moldavia.

Gaina, Alex

1998-09-01

365

Database-Driven Analyses of Astronomical Spectra  

NASA Astrophysics Data System (ADS)

Spectroscopy is one of the most powerful tools to study the physical properties and chemical composition of very diverse astrophysical environments. In principle, each nuclide has a unique set of spectral features; thus, establishing the presence of a specific material at astronomical distances requires no more than finding a laboratory spectrum of the right material that perfectly matches the astronomical observations. Once the presence of a substance is established, a careful analysis of the observational characteristics (wavelengths or frequencies, intensities, and line profiles) allows one to determine many physical parameters of the environment in which the substance resides, such as temperature, density, velocity, and so on. Because of this great diagnostic potential, ground-based and space-borne astronomical observatories often include instruments to carry out spectroscopic analyses of various celestial objects and events. Of particular interest is molecular spectroscopy at infrared wavelengths. From the spectroscopic point of view, molecules differ from atoms in their ability to vibrate and rotate, and quantum physics inevitably causes those motions to be quantized. The energies required to excite vibrations or rotations are such that vibrational transitions generally occur at infrared wavelengths, whereas pure rotational transitions typically occur at sub-mm wavelengths. Molecular vibration and rotation are coupled though, and thus at infrared wavelengths, one commonly observes a multitude of ro-vibrational transitions (see Figure 13.1). At lower spectral resolution, all transitions blend into one broad ro-vibrational molecular band. The isotope. Molecular spectroscopy thus allows us to see a difference of one neutron in an atomic nucleus that is located at astronomical distances! Since the detection of the first interstellar molecules (the CH [21] and CN [14] radicals), more than 150 species have been detected in space, ranging in size from diatomic species to the fullerene species C60 and C70 [4]. Given the large number and variety of molecules detected in space, molecular infrared spectroscopy can be used to study pretty much any astrophysical environment that is not too energetic to dissociate the molecules. At the lowest energies, it is interesting to note that molecules such as CN have been used to measure the temperature of the Cosmic Microwave Background (see e.g., Ref. 15). The great diagnostic potential of infrared molecular spectroscopy comes at a price though. Extracting the physical parameters from the observations requires expertise in knowing how various physical processes and instrumental characteristics play together in producing the observed spectra. In addition to the astronomical aspects, this often includes interpreting and understanding the limitations of laboratory data and quantum-chemical calculations; the study of the interaction of matter with radiation at microscopic scales (called radiative transfer, akin to ray tracing) and the effects of observing (e.g., smoothing and resampling) on the resulting spectra and possible instrumental effects (e.g., fringes). All this is not trivial. To make matters worse, observational spectra often contain many components, and might include spectral contributions stemming from very different physical conditions. Fully analyzing such observations is thus a time-consuming task that requires mastery of several techniques. And with ever-increasing rates of observational data acquisition, it seems clear that in the near future, some form of automation is required to handle the data stream. It is thus appealing to consider what part of such analyses could be done without too much human intervention. Two different aspects can be separated: the first step involves simply identifying the molecular species present in the observations. Once the molecular inventory is known, we can try to extract the physical parameters from the observed spectral properties. For both steps, good databases of molecular spectroscopic information is vital; the second step furthermor

Cami, Jan

2012-03-01

366

Heavens Open Up for UK Astronomers  

NASA Astrophysics Data System (ADS)

A significant milestone for British and European science occurred today (July 8, 2002) when the Council of the European Southern Observatory (ESO) met in London. At this historical meeting, the United Kingdom was formally welcomed into ESO by the nine other member states. The UK, one of the leading nations in astronomical research, now joins one of the world's major astronomical organisations. UK astronomers will now be able to use the four 8.2-metre and several 1.8-metre telescopes that comprise the Very Large Telescope (VLT) facility located at the Paranal Observatory in the northern part of the Atacama desert in Chile, as well as two 4-m class telescopes and several smaller ones at the ESO La Silla Observatory further south. The UK will also benefit from increased involvement in the design and construction of the Atacama Large Millimetre Array (ALMA), a network of 64 twelve-metre telescopes also sited in Chile, and play a defining role in ESO's 100-metre Overwhelmingly Large Telescope (OWL). Sir Martin Rees , The Astronomer Royal, said, "Joining ESO is good for UK science, and I think good for Europe as well. It offers us access to the VLT's 8-m class telescopes and restores the UK's full competitiveness in optical astronomy. We're now guaranteed full involvement in ALMA and in the next generation of giant optical instruments - projects that will be at the forefront of the research in the next decade and beyond. Moreover, our commitment to ESO should enhance its chances of forging ahead of the US in these technically challenging and high profile scientific projects. UK membership of ESO is a significant and welcome outcome of this government's increasing investment in science". Prof. Ian Halliday , Chief Executive of the Particle Physics and Astronomy Research Council (PPARC), the UK's strategic science investment agency said, "The United Kingdom already participates in Europe's flagship particle physics research and the space science research programmes through membership of CERN and the European Space Agency. Both of which provide UK scientists with access to world-class facilities that, on a national basis alone, we could not begin to consider. Joining ESO consolidates this strategy for UK astronomers and redresses the balance of UK ground based facilities compared to other European countries, Japan and the US." The ESO Director General, Dr. Catherine Cesarsky , is "delighted that the UK has joined our organisation. When ESO was created nearly 40 years ago, the UK was planning for its own facilities and decided not to join. However, the impressive scientific and technological advances since then, coupled with ESO's 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." Ian Halliday added,"Membership of ESO will ensure that UK astronomy remains at the cutting edge of scientific research and discovery, whilst playing an integral role in developing the next generation of ground based facilities. This strategy also endorses the recommendations of the 'International Perceptions of UK Research in Physics and Astronomy', an independent review which recommended joining ESO". Note [1]: Both PPARC and ESO issue co-ordinated releases regarding UK accession to The European Southern Observatory today. The PPARC release can be accessed at: www.pparc.ac.uk/.

2002-07-01

367

Verification of the performance of large space-based astronomical observatories: AXAF experience and SIM approaches  

NASA Astrophysics Data System (ADS)

NASA's Search for Origins calls for ambitious astronomical mission to identify Earth-like planets orbiting neighboring stars and observe the formation of the earliest galaxies. These goals demand large, high performance optical systems integrated within precise and stable structures.One of the greatest challenges in developing origins mission is verifying astronomical performance prior to launch. The optical systems for these missions may require dimensions of meters or tens of meters making it extremely unlikely that they can undergo a full scale environmental simulation in their flight configuration. A similar challenge was encountered in the development of the AXAF mission, which combined difficult optical performance requirements with equally daunting cost and schedule constraints. This task was faced by NASA's Marshall Space Flight Center, the Smithsonian Astrophysical Observatory and an industry team led by TRW. Even before the discovery of spherical aberration on the primary mirror of the Hubble Space Telescope, the AXAF project planned for an extensive series of investments in optical testbeds, simulations, and selective testing of mission-critical subsystems. Planned as the first Origins mission, the Space Interferometry Mission will make microarcsecond astrometric measurements with optics deployed along a ten meter baseline precision structure. SIM lends itself to the same performance verification approach as that taken by the TRW Team on AXAF. Verification approaches for SIM will involve testing these subsystems specifically required for microarcsecond performance in a manageable configuration and relying on analyses and individual component testing to characterize the entire flight configuration system. This paper presented the experience gained from AXAF and outlines a strategy to be used in developing the testing approach for SIM.

Moses, Stewart L.; Iwens, Ralph P.; Grimm, Gary

1998-08-01

368

Star Forming Regions and the IMF Along the Hubble Sequence  

NASA Astrophysics Data System (ADS)

This thesis examines the properties of star forming regions in galaxies across the Hubble sequence. It focuses on the stellar populations of giant extragalactic H scII regions and OB associations, addressing in particular the question of Initial Mass Function (IMF) variations with metallicity and/or galaxy morphology. This work is composed of three main sections: (a) 3650-10,000 A spectroscopy of nearly 100 H scII regions in 20 spiral galaxies (Sa through Sm). Two indicators of the ionizing cluster effective temperature (T*) are analyzed: the intensity of the He I ?5876 line, and the 'radiation softness' parameter ?=(O+/O++)/(S+/S++). The interpretation of the data relies on CLOUDY photoionization models. A positive T* gradient of 7000-8000 K is found between 2 Zsolar and 0.2 Zsolar. The diagnostic diagrams and the T* - metallicity relation are consistent with an upper mass limit of the IMF of ~100 Msolar and an age of ~1 Myr, irrespective of chemical abundance or Hubble type. (b) An investigation of extragalactic OB associations, based on Hubble Space Telescope images. The size distribution of the associations (found with an automated search algorithm) is similar in all galaxies examined, with a mean size around 80 pc. An indication is found that the average number of bright blue stars depends on the parent galaxy Hubble type. The upper stellar V luminosity function is comparable among galaxies, with slope dlog N/dMV=0.61±0.03. A few star cluster candidates are identified. (c) UBVR and H? photometry of 266 H scII regions in 10 spiral galaxies (Sa through Sd). The H? equivalent width is independent of Hubble type. The continuum and H? luminosity functions show similar trends, namely a steeper slope and a smaller characteristic luminosity for early-type galaxies. These results lead to the conclusion that changes in the properties of H scII regions and associations along the Hubble sequence are most likely due to variations in the number of stars per star forming region and in the number of regions per unit area, rather than the mass function.

Bresolin, Fabio

369

The lamps of Atlantis: an astronomical detective story  

NASA Astrophysics Data System (ADS)

The origin of the stellar constellations familiar to western astronomers from ancient times is discussed using astronomical, literary, and archaeological evidence. The precession of the equinoxes, the zone of avoidance and the orientation of the constellations, and early Greek and Minoan astronomy are considered.

Roy, Archie E.

1986-11-01

370

William Andrews, a 19th century amateur astronomer  

Microsoft Academic Search

William Andrews (1835 - 1914) lived and worked for most of his life in Coventry in the silk weaving industry. He kept a diary from 1850 onwards, in which he records his astronomical observations made either with the naked eye or by using a small telescope. As far as is known, he never made contact with any other astronomers and

H. Miles

1988-01-01

371

Purple Mountain Observatory Astronomical Data Reduction and Analysis Facility.  

NASA Astrophysics Data System (ADS)

A short description of Purple Mountain Observatory Astronomical Data Reduction and Analysis Facility is presented. It consists of PDS 1010M microdensitometer, PDP-11/34A minicomputer and Comtal/Grinnell image processing subsystem. The minicomputer-based Tololo-Vienna Interactive Astronomical Image Processing Software System runs on it.

Zhang, Y.-Y.; Sheng, C.-J.; Chen, Y.-L.; An, X.-L.; Fang, H.; Su, H.-J.; Han, H.-Y.

372

Neural net aided detection of astronomical periodicities in geologic records  

Microsoft Academic Search

Astronomically controlled variations in the Earth's climate induce cyclic trends in the sedimentary process and record (Milankovitch periodicity). One of the main difficulties to be solved in order to choose among the registered periodicities is the conversion from the spatial (i.e. recurrent variations along the stratal sequences) to the temporal domains of the astronomically induced frequencies present in the rock

M. Brescia; B. D'Argenio; V. Ferreri; G. Longo; N. Pelosi; S. Rampone; R. Tagliaferri

1996-01-01

373

Daytime School Guided Visits to an Astronomical Observatory in Brazil  

ERIC Educational Resources Information Center

|This article analyzes the activity "Daytime School Guided Visits" at an astronomical observatory in Brazil with pupils from primary school. The adopted research methodology relied on questionnaire applications and semistructured interviews. The objectives were to identify the influences of the visits on learning of astronomical concepts and on…

Colombo, Pedro Donizete, Jr.; Silva, Cibelle Celestino; Aroca, Silvia Calbo

2010-01-01

374

Buenaventura Suárez SJ: the pioneer astronomer of Paraguay  

NASA Astrophysics Data System (ADS)

Father Suärez was a self-made astronomer in colonial Paraguay during the first half of eighteenth century. He constructed some scientific instruments, obtained data from his own astronomical observations, and made his own computations. He wrote to other scientists around the world, and published a book, Lunario de un Siglo, which was well received in Europe. Copies of this work are elusive today.

Troche-Boggino, Alexis E.

2000-12-01

375

The lamps of Atlantis: an astronomical detective story  

Microsoft Academic Search

The origin of the stellar constellations familiar to western astronomers from ancient times is discussed using astronomical, literary, and archaeological evidence. The precession of the equinoxes, the zone of avoidance and the orientation of the constellations, and early Greek and Minoan astronomy are considered.

Archie E. Roy

1986-01-01

376

The Persian-Toledan Astronomical Connection and the European Renaissance  

Microsoft Academic Search

This paper aims at presenting a brief overview of astronomical exchanges between the Eastern and Western parts of the Islamic world from the 8th to 14th century. These cultural interactions were in fact vaster involving Persian, Indian, Greek, and Chinese traditions. I will particularly focus on some interesting relations between the Persian astronomical heritage and the Andalusian (Spanish) achievements in

M. Heydari-Malayeri

2007-01-01

377

Software Package for Preparing and Processing of an Astronomical Observation  

NASA Astrophysics Data System (ADS)

This paper presents an astronomical software package which draws celestial charts. It was conceived taking into account the technical possibilities available for the Romanian astronomers and the actual trend of the observational astronomy. The software package, now to its third version, comes to decrease the time to prepare an observation and to perform accurate charts for searching and identification.

Vaduvescu, Ovidiu; Birlan, Mirel

378

Observing techniques for astronomical laser guide star adaptive optics  

SciTech Connect

We discuss astronomical observing requirements and their implementation using sodium-layer laser guide star adaptive optics. Specific issues requiring implementation include the ability to place the astronomical object at different locations within the field of view; reliable subtraction of Rayleigh-scattered light; efficient focusing; and stable point-spread-function characterization.

Max, C.E.; Macintosh, B.; Olivier, S.S.; Gavel, D.T.; Friedman, H.W.

1998-05-01

379

The Astronomical Array Control & Acquisition System at NAOC  

Microsoft Academic Search

The Astronomical Array Control & Acquisition System (AACAS) has been completed at the Research Labs for Astronomy of the National Astronomical Observatories of China (NAOC). Ethernet network is used for interface, ensuring that the AACAS can be accessed and controlled around the globe. Various CCD chips, e.g. e2v, Kodak, SITE, Fairchild, etc., can be controlled by the AACAS in many

Zhaowang Zhao; Binxun Ye

2006-01-01

380

Large-scale bulk motions complicate the Hubble diagram  

SciTech Connect

We investigate the extent to which correlated distortions of the luminosity distance-redshift relation due to large-scale bulk flows limit the precision with which cosmological parameters can be measured. In particular, peculiar velocities of type 1a supernovae at low redshifts, z<0.2, may prevent a sufficient calibration of the Hubble diagram necessary to measure the dark energy equation of state to better than 10%, and diminish the resolution of the equation of state time-derivative projected for planned surveys. We consider similar distortions of the angular-diameter distance, as well as the Hubble constant. We show that the measurement of correlations in the large-scale bulk flow at low redshifts using these distance indicators may be possible with a cumulative signal-to-noise ratio of order 7 in a survey of 300 type 1a supernovae spread over 20 000 square degrees.

Cooray, Asantha [Center for Cosmology, Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Caldwell, Robert R. [Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratory, Hanover, New Hampshire 03755 (United States)

2006-05-15

381

Mega-masers, Dark Energy and the Hubble Constant  

ScienceCinema

Powerful water maser emission (water mega-masers) can be found in accretion disks in the nuclei of some galaxies. Besides providing a measure of the mass at the nucleus, such mega-masers can be used to determine the distance to the host galaxy, based on a kinematic model. We will explain the importance of determining the Hubble Constant to high accuracy for constraining the equation of state of Dark Energy and describe the Mega-maser Cosmology Project that has the goal of determining the Hubble Constant to better than 3%. Time permitting, we will also present the scientific capabilities of the current and future NRAO facilities: ALMA, EVLA, VLBA and GBT, for addressing key astrophysical problems

382

Generalized holographic dark energy model in the Hubble length  

NASA Astrophysics Data System (ADS)

We generalize the holographic dark energy model described in Hubble length IR cutoff by assuming a slowly time varying function for holographic parameter c 2. We calculate the evolution of EoS parameter and the deceleration parameter as well as the evolution of dark energy density parameter of the model in flat FRW universe. We show that in this model the phantom line is crossed from quintessence regime to phantom regime which is in agreement with observation. The evolution of deceleration parameter of the model indicates the transition from decelerated to accelerated expansion consistently with observation. Eventually, we show that the holographic dark energy model with Hubble horizon IR cutoff can interpret the pressureless dark matter era at the early time and dark energy dominated phase later. The singularity of the model is also calculated.

Malekjani, Mohammad

2013-10-01

383

PyEphem: Astronomical Ephemeris for Python  

NASA Astrophysics Data System (ADS)

PyEphem provides scientific-grade astronomical computations for the Python programming language. Given a date and location on the Earth’s surface, it can compute the positions of the Sun and Moon, of the planets and their moons, and of any asteroids, comets, or earth satellites whose orbital elements the user can provide. Additional functions are provided to compute the angular separation between two objects in the sky, to determine the constellation in which an object lies, and to find the times at which an object rises, transits, and sets on a particular day.The numerical routines that lie behind PyEphem are those from the wonderful XEphem astronomy application, whose author, Elwood Downey, generously gave permission for us to use them as the basis for PyEphem.

Rhodes, Brandon Craig

2011-12-01

384

Teachers' Domain: Astronomical Images in Different Wavelengths  

NSDL National Science Digital Library

This item is an interactive set of astronomical images produced from four types of telescopes: radio, infrared, x-ray, and visible-light. Image sets include the Milky Way, the crab nebula, a supernova, and the most luminous star in our galaxy. The organization of the images allows students to easily compare how the various telescopes detect different wavelengths of electromagnetic radiation. This collection was produced especially for Teachers' Domain, and includes background information, questions for classroom discussion, and content standards. Teachers' Domain is an NSF-funded pathway of the National Science Digital Library (NSDL). It is a growing collection of more than 1,000 free educational resources compiled by researchers and experienced teachers to promote the use of digital resources in the classroom.

2009-06-18

385

Common Astronomical Software Environment for Data Analysis  

NASA Astrophysics Data System (ADS)

The general user support for many traditional data processing systems (e.g. IRAF, Starlink, and MIDAS) has been significantly reduced in recent years. Further, much of the current efforts in the area of data processing is related to special purpose packages for specific project. This emphasizes the need for planning in the area of common data processing software to ensure that new applications can be shared, general support provided and new technologies (such as VO, Grid) utilized. The OPTICON Network 3.6 and NVO have started a discussion on the high-level requirements and architectural concepts for a common software environment for astronomical data analysis and processing. The BoF was convened to summarize the current status and discuss the developments in a broader community.

Grosbøl, P.; Tody, D.

2006-07-01

386

Measuring Terrestrial Ozone from Historic Astronomical Spectra  

NASA Astrophysics Data System (ADS)

``Ozone'' is a sensitive topic that arouses interest everywhere. Its presence in the stratosphere affects us all, and its threatened reduction would have such dire consequences that it energizes international campaigns, influences the thinking of governments, and activates substantial alterations in the accustomed habits of millions throughout the world. However, the properties of ozone are not that well known by most people (what is ``known'' about ozone has generally been relayed through various media channels), while the actual facts concerning its concentration and in particular its reduction require sophisticated scientific measurements that are only accessible to a few and are limited by data that have not always been as plentiful as they are nowadays. This paper describes a new initiative to examine overlooked but potentially informative ozone data from last century's astronomical records.

Griffin, Elizabeth

2009-01-01

387

Astronomical results from the PRONAOS experiment  

NASA Astrophysics Data System (ADS)

The high sensitivity sub-millimetre observations performed with the French balloon-borne experiment PRONAOS have brought exciting and sometimes unexpected new astronomical results. In particular, they have lead to the first detection of the Sunyaev-Zel'dovich effect in its positive part, toward the galaxy cluster A2163. They also have revealed the existence of cold condensations in different sites of star forming regions and toward thin dust clouds at high galactic latitude. This cannot be explained by the standard dust models currently used and could be interpreted as the existence of fractal dust aggregates. The PRONAOS observations have also evidenced a significant correlation between the dust equilibrium temperature and the spectral emissivity index, which may reflect new quantum processes within the grains specific to low temperatures. These results have raised a number of new questions which will be addressed using future balloon-borne projects such as ELISA and the space mission Planck and Herschel.

Bernard, J.-Ph.; Dupac, X.; Giard, M.; Lamarre, J. M.; Mény, C.; Pajot, F.; Ristorcelli, I.; Stepnik, B.; Torre, J. P.

2001-08-01

388

Large-area astronomical Surveys and Catalogs  

NASA Astrophysics Data System (ADS)

We review the status of all-sky and large astronomical surveys and their catalogued data over the whole range of electromagnetic spectrum, from gamma-ray to radio, such as ROSAT in X-ray, GALEX in UV, SDSS and several POSS1/2 based catalogs (APM, MAPS, USNO, GSC) in optical, 2MASS and WISE in NIR, IRAS and AKARI in MIR/FIR, NVSS and FIRST in radio and many others, as well as most important surveys giving optical images (DSS, SDSS), variability (GCVS, NSVS, ASAS) and spectroscopic (FBS, SBS, HQS, HES, SDSS) data. An overall understanding of coverage along the whole wavelength range and comparisons between various surveys are given: galaxy redshift surveys, QSO, radio, Galactic structure, and Dark Energy surveys.

Mickaelian, A. M.

2012-05-01

389

Astronomical Data Analysis on Graphics Cards  

NASA Astrophysics Data System (ADS)

Increasing detector sizes and advanced algorithms make astronomical data analysis tasks computationally demanding. Tools are therefore needed that simplify the development of parallel data analysis algorithms. Modern graphics cards offer a large amount of processing power at low cost and therefore have the potential to benefit these analyzes. However, the massively parallel nature of these devices makes them difficult to develop for. In this talk, we present a library of general purpose vector operations that can run on graphics cards. Bindings to widely used data analysis tools, including IDL and Matlab are provided, enabling scientists to take advantage of the enhanced processing power from within a familiar environment. We will present the programming interface and performance results for example applications.

Messmer, Peter; Mullowney, Paul; Galloy, Michael; Fillmore, David; Granger, Brian; Amyx, Keegan; Fillmore, David

2008-04-01

390

Simon Newcomb: America's Unofficial Astronomer Royal  

NASA Astrophysics Data System (ADS)

Bill Carter and Merri Sue Carter Mantazas; xiii + 213 pp.; ISBN 1-59113-803-5 2006; $26.95 This book introduced me to a commanding figure in American science from the late nineteenth century: Simon Newcomb. Newcomb has been called the nineteenth-century equivalent of Carl Sagan and Albert Einstein. He rose from humble beginnings to be the preeminent American astronomer of his generation. He made basic, far-reaching, and enduring contributions to positional astronomy and planetary dynamics. On the more practical side, he determined a remarkably accurate value for the velocity of light, one within 0.01% of the value accepted today. His work provided an experimental grounding for the special and general theories of relativity to be formulated by Einstein in the coming twentieth century.

Graham, John

2007-10-01

391

Kepler's Ellipse and Jewish Astronomical Tradition  

NASA Astrophysics Data System (ADS)

Analysis of the medieval Jewish texts related to astronomy is given and three different Jewish accounts of Creation are turned into strict astronomical statements about relative positions of the equinoxes and the Apse line. An important hint comes from the solution of a mathematical problem related to the Earth's orbital motion: from the known length of any of the four seasons of a certain year, find the position of the equinoxes on the Kepler's ellipse in the same year. After this all the accounts recognized as post-Ptolemaic and composed after the treatise "On the Solar Year" by Thabit ibn-Qurra appeared. A historical reconstruction is attempted. The account mentioned by al-Biruni and the so-called ``Tekufa of Shmuel'' are dated around the year 870 while the account mentioned in ``Seder Olam'' is dated in between the years 990-1065.

Belenkiy, Ari

392

Integral Programme of Basic Astronomic Literacy Development  

NASA Astrophysics Data System (ADS)

We discuss the development and optimization of an ongoing educational project involving the whole population of the province of San Luis, Argentina. The core of the project includes activities and resources that capture formal curricular aspects directed towards all levels of teaching. The educational activities related to this project have been benefited by the acquisition of two planetariums made in Argentina, a MEADE 16'' telescope to be operated by remote control from any school-room in San Luis, and a naked-eye observatory with more than 30 pre-telescopic instruments, and other didactic tools specially designed for the teaching of Astronomy. Furthermore, an Internet site to upload all the astronomical activities suggested that has been developed along with a number of didactic and general-interest publications.

Tignanelli, H.

2009-05-01

393

Cepheid calibration of Type Ia supernovae and the Hubble constant  

Microsoft Academic Search

We investigate how a different calibration of the Cepheid period-luminosity (PL) relation, taking into account metallicity corrections, affects the absolute magnitude calibration of Type Ia supernovae (SNe Ia) and, in turn, the determination of the Hubble constant H0. We use SN Ia light curves from the literature and previously unpublished data to establish the MB-Deltam15(B) relation, and calibrate the zero

G. Altavilla; G. Fiorentino; M. Marconi; I. Musella; E. Cappellaro; R. Barbon; S. Benetti; A. Pastorello; M. Riello; M. Turatto; L. Zampieri

2004-01-01

394

Hubble Space Telescope - Dawn of the ERA of serviceable spacecraft  

NASA Astrophysics Data System (ADS)

The Hubble Space Telescope, scheduled for launch in late 1988, is designed to include on-orbit servicing as an integral part of its operational plan. Here, the design philosophy of the Space Telescope and the lessons learned are explored insofar as they can be applied to the design of future serviceable spacecraft. In particular, attention is given to the use of orbital replaceable units, redundancy, environmental considerations, workspace accessibility, and standardization of the design of mechanical fasteners.

Wickman, L. A.

1986-10-01

395

Hubble Space Telescope: the new telemetry archiving system  

Microsoft Academic Search

The Hubble Space Telescope (HST), the first of NASA's Great Observatories, was launched on April 24, 1990. The HST was designed for a minimum fifteen-year mission with on-orbit servicing by the Space Shuttle System planned at approximately three-year intervals. Major changes to the HST ground system have been implemented for the third servicing mission in December 1999. The primary objectives

Manfred P. Miebach

2000-01-01

396

Hubble Space Telescope Observations of the Windblown Nebula NGC 7635  

Microsoft Academic Search

We present Hubble Space Telescope observations of the northern part of NGC 7635, a circular shell around the O6.5 IIIf star BD +60°2522. The nebula, which lies within the large emission-line region S162, is notable not only for its symmetric shell, but also for a complex of ``cometary'' knots close to the central star. Our observations include spectra taken with

Brian D. Moore; Donald K. Walter; J. Jeff Hester; Paul A. Scowen; Reginald J. Dufour; Brent A. Buckalew

2002-01-01

397

Space Science: Status of the Hubble Space Telescope Program  

NASA Astrophysics Data System (ADS)

The current status of the NASA's Hubble Space Telescope (HST) program is reviewed. The following questions are addressed: (1) what is the current status of the program with respect to cost, schedule, and performance; (2) what is the role of the Space Telescope Institute; and (3) what are NASA's plans for providing on-orbit maintenance to the space telescope. The objectives, scope, and methodology are discussed and summarized.

1988-05-01

398

Resolving Sirius-like binaries with the Hubble Space Telescope  

Microsoft Academic Search

We present initial results from a Hubble Space Telescope ultraviolet imaging\\u000asurvey of stars known to have hot white-dwarf companions which are unresolved\\u000afrom the ground. The hot companions, discovered through their EUV or UV\\u000aemission, are hidden by the overwhelming brightnesses of the primary stars at\\u000avisible wavelengths. Out of 17 targets observed, we have resolved eight of them

M. A. Barstow; Howard E. Bond; M. R. Burleigh; Jay Holberg

2000-01-01

399

Hubble Space Telescope Beryllium Abundances in the alpha Centauri System  

Microsoft Academic Search

High signal-to-noise ratio Hubble Space Telescope Goddard High-Resolution Spectrograph spectra of alpha Centauri A (spectral type G2 V) and alpha Centauri B (spectral type K1 V) have been analyzed in the Be II lambda 3130 spectral region. Both stars offer an excellent opportunity for testing predictions of 9Be destruction since they are nearby, have a well-determined orbit and parallax, and

F. Primas; D. K. Duncan; M. H. Pinsonneault; Constantine P. Deliyannis; J. A. Thorburn

1997-01-01

400

Atomic and Molecular Aspects of Astronomical Spectra  

NASA Astrophysics Data System (ADS)

In the first section we present the atomic part where a C2+ atomic target was prepared and used to generate theoretical data to investigate recombination lines arising from electron-ion collisions in thin plasma. R-matrix method was used to describe the C2+ plus electron system. Theoretical data concerning bound and autoionizing states were generated in the intermediate-coupling approximation. The data were used to generate dielectronic recombination data for C+ which include transition lines, oscillator strengths, radiative transition probabilities, emissivities and dielectronic recombination coefficients. The data were cast in a line list containing 6187 optically-allowed transitions which include many C II lines observed in astronomical spectra. This line list was used to analyze the spectra from a number of astronomical objects, mainly planetary nebulae, and identify their electron temperature. The electron temperature investigation was also extended to include free electron energy analysis to investigate the long-standing problem of discrepancy between the results of recombination and forbidden lines analysis and its possible connection to the electron distribution. In the second section we present the results of our molecular investigation; the generation of a comprehensive, calculated line list of frequencies and transition probabilities for H2D+. The line list contains over 22 million rotational-vibrational transitions occurring between more than 33 thousand energy levels and covers frequencies up to 18500 cm-1. About 15% of these levels are fully assigned with approximate rotational and vibrational quantum numbers. A temperature-dependent partition function and cooling function are presented. Temperature-dependent synthetic spectra for the temperatures T=100, 500, 1000 and 2000 K in the frequency range 0-10000 cm-1 were also generated and presented graphically.

Sochi, Taha

2012-11-01

401

Compression and Progressive Transmission of Astronomical Images  

NASA Astrophysics Data System (ADS)

An image compression algorithm has been developed that is well-suited to astronomical images. The method has 3 steps: an intensity mapping to generate an image that has roughly constant noise in each pixel, an orthonormal wavelet transform, and quadtree coding of the bit-planes of the wavelet coefficients. The quadtree values may be further compressed by any standard compression technique, such as Huffman or arithmetic coding. If the 2-dimensional Haar transform is used, the calculations can be carried out using integer arithmetic, and the method can be used for both lossy and lossless compression. The Haar transform basis functions are well-suited to most astronomical images because they are highly localized. The performance of the algorithm using smoother, longer range wavelets has also been explored; they can give slightly better lossy compression at the cost of an increase in artifacts around point sources, but they are not effective for lossless compression using this scheme. The algorithm using Haar transforms is being used for compression of the STScI Digitized Sky Survey now being distributed on CD-ROMs. This technique has been used as the basis of a progressive image transmission system that can be used for either remote observing or access to remote image archives. After less than 1% of the data have been received, the image is visually similar to the original, so it is possible to assess the quality of images very quickly. If necessary, the entire compressed data set can be sent so that the original image is recovered exactly. J. Percival describes the remote observing system in an accompanying paper.

White, R. L.; Percival, J. W.

1994-12-01

402

Flexion measurement in simulations of Hubble Space Telescope data  

NASA Astrophysics Data System (ADS)

We present a simulation analysis of weak gravitational lensing flexion and shear measurement using shapelet decomposition, and identify differences between flexion and shear measurement noise in deep survey data. Taking models of galaxies from the Hubble Space Telescope Ultra Deep Field (HUDF) and applying a correction for the HUDF point spread function, we generate lensed simulations of deep, optical imaging data from Hubble's Advanced Camera for Surveys, with realistic galaxy morphologies. We find that flexion and shear estimates differ in our measurement pipeline: whereas intrinsic galaxy shape is typically the dominant contribution to noise in shear estimates, pixel noise due to finite photon counts and detector read noise is a major contributor to uncertainty in flexion estimates, across a broad range of galaxy signal-to-noise. This pixel noise also increases more rapidly as galaxy signal-to-noise decreases than is found for shear estimates. We provide simple power-law fitting functions for this behaviour, for both flexion and shear, allowing the effect to be properly accounted for in future forecasts for flexion measurement. Using the simulations, we also quantify the systematic biases of our shapelet flexion and shear measurement pipeline for deep Hubble data sets such as Galaxy Evolution from Morphology and SEDs, Space Telescope A901/902 Galaxy Evolution Survey or Cosmic Evolution Survey. Flexion measurement biases are found to be significant but consistent with previous studies.

Rowe, Barnaby; Bacon, David; Massey, Richard; Heymans, Catherine; Häußler, Boris; Taylor, Andy; Rhodes, Jason; Mellier, Yannick

2013-10-01

403

GRB Hubble diagram and constraints on a ?(t) CDM model  

NASA Astrophysics Data System (ADS)

In previous papers, a cosmological model with constant rate particle creation and vacuum term decaying linearly with the Hubble parameter was shown to lead to a good concordance when tested against precise observations: the position of the first peak in the spectrum of anisotropies of the cosmic microwave background (CMB), the Hubble diagram for Type Ia supernovae (SNe Ia), the distribution of large-scale structures and the distance to the baryonic acoustic oscillations (BAO). That model has the same number of parameters as the spatially flat standard model and seems to alleviate some observational/theoretical tensions appearing in the latter. In this paper, we complement those tests with 109 gamma-ray bursts (GRBs), 59 of them with redshifts above z = 1.4, which permits to extend the Hubble diagram to redshifts up to z ? 8. For the calibration of the 50 GRBs with z < 1.4, we use the 288 supernovae of the Sloan Digital Sky Survey project, calibrated with the MLCS2k2 fitter, less model-dependent than other samples like Union2. Our results show a good concordance with the previous tests and, again, less tensions between SNe Ia and GRB best fits as compared to the standard model.

Velten, H.; Montiel, A.; Carneiro, S.

2013-06-01

404

The Hubble Space Telescope Education and Outreach Program  

NASA Astrophysics Data System (ADS)

One of the three central missions of NASA's vision is to ``inspire the next generation of explorers... as only NASA can." Recognizing this, NASA has charged the Space Telescope Science Institute (STScI) with sharing the amazing discoveries of the Hubble Space Telescope with the public. By co-locating a significant outreach effort at the site of a major scientific institution, education and public outreach have become essential parts of the overall research enterprise at STScI To carry out NASA's commission STScI has developed a multitude of products, programs and initiatives which have capitalized on the intense interest in Hubble to inform, educate and to inspire. Key elements of our program include the active participation of research scientists in every aspect of outreach, the full integration of public affairs with educational activities and developing partnerships with a variety of organizations to reach a wide audience. Our presentation will characterize the scientific rationale for our program, summarize its highlights, and discuss metrics we use to measure our success. Finally we will describe our plans for the future and show how we intend to keep Hubble science in the public eye.

Beckwith, S. V. W.; Griffin, I. P.

2003-12-01

405

The Victorian Amateur Astronomer: Independent Astronomical Research in Britain 1820-1920  

NASA Astrophysics Data System (ADS)

This is the first book to look in detail at amateur astronomy in Victorian Britain. It deals with the technical issues that were active in Victorian astronomy, and reviews the problems of finance, patronage and the dissemination of scientific ideas. It also examines the relationship between the amateur and professional in Britain. It contains a wealth of previously unpublished biographical and anecdotal material, and an extended bibliography with notes incorporating much new scholarship. In The Victorian Amateur Astronomer, Allan Chapman shows that while on the continent astronomical research was lavishly supported by the state, in Britain such research was paid for out of the pockets of highly educated, wealthy gentlemen the so-called Grand Amateurs . It was these powerful individuals who commissioned the telescopes, built the observatories, ran the learned societies, and often stole discoveries from their state-employed colleagues abroad. In addition to the Grand Amateurs , Victorian Britain also contained many self-taught amateurs. Although they belonged to no learned societies, these people provide a barometer of the popularity of astronomy in that age. In the late 19th century, the comfortable middle classes clergymen, lawyers, physicians and retired military officers took to astronomy as a serious hobby. They formed societies which focused on observation, lectures and discussions, and it was through this medium that women first came to play a significant role in British astronomy. Readership: Undergraduate and postgraduate students studying the history of science or humanities, professional historians of science, engineering and technology, particularly those with an interest in astronomy, the development of astronomical ideas, scientific instrument makers, and amateur astronomers.

Chapman, Allan

1999-01-01

406

An Empirical Explanation of the Anomalous Increases in the Astronomical Unit and the Lunar Eccentricity  

NASA Astrophysics Data System (ADS)

The subject of this paper is the empirically determined anomalous secular increases of the astronomical unit, of the order of some cm yr-1, and of the eccentricity of the lunar orbit, of the order of 10-12 yr-1. The aim is to find an empirical explanation of both anomalies as far as their orders of magnitude are concerned. The methods employed are working out perturbatively with the Gauss equations the secular effects on the semi-major axis a and the eccentricity e of a test particle orbiting a central body acted upon by a small anomalous radial acceleration A proportional to the radial velocity vr of the particle-body relative motion. The results show that non-vanishing secular variations \\left\\langle \\dot{a}\\right\\rangle and lang?rang occur. If the magnitude of the coefficient of proportionality of the extra-acceleration is of the same order of magnitude as the Hubble parameter H 0 = 7.47 × 10-11 yr-1 at the present epoch, they are able to explain both astrometric anomalies without contradicting other existing observational determinations for the Moon and the other planets of the solar system. Finally, it is concluded that the extra-acceleration might be of cosmological origin, provided that the relative radial particle-body motion is accounted for in addition to that due to the cosmological expansion only. Further data analyses should confirm or disprove the existence of both astrometric anomalies as genuine physical phenomena.

Iorio, L.

2011-09-01

407

"Movie Star" Acting Strangely, Radio Astronomers Find  

NASA Astrophysics Data System (ADS)

Astronomers have used the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope to make the first-ever time-lapse "movie" showing details of gas motions around a star other than our Sun. The study, the largest observational project yet undertaken using Very Long Baseline Interferometry, has produced surprising results that indicate scientists do not fully understand stellar atmospheres. The "movie" shows that the atmosphere of a pulsating star more than 1,000 light-years away continues to expand during a part of the star's pulsation period in which astronomers expected it to start contracting. Philip Diamond and Athol Kemball, of the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, announced their findings at the American Astronomical Society's meeting in Austin, TX, today. "The continued expansion we're seeing contradicts current theoretical models for how these stars work," Diamond said. "The models have assumed spherical symmetry in the star's atmosphere, and our movie shows that this is not the case. Such models suggest that a shock wave passes outward from the star. Once it's passed, then the atmosphere should begin to contract because of the star's gravity. We've long passed that point and the contraction has not begun." The time-lapse images show that the gas motions are not uniform around the star. Most of the motion is that of gas moving directly outward from the star's surface. However, in about one-fourth of the ring, there are peculiar motions that do not fit this pattern. The scientists speculate that the rate of mass loss may not be the same from all parts of the star's surface. "A similar star behaved as predicted when studied a few years ago, so we're left to wonder what's different about this one," Diamond said. "Right now, we think that different rates of mass loss in the two stars may be the cause of the difference. This star is losing mass at 100 times the rate of the star in the earlier study." "This is the first time anyone has been able to follow the motions of gas in the atmosphere of any star other than the sun. Our results raise a lot of questions that we can't answer yet, but this will give the theorists new information to work with," said Diamond. The star, called TX Cam, in the constellation Camelopardalis, is a variable star whose brightness changes regularly over a period of 557 days. In 1997, the NRAO astronomers began a series of observations aimed at tracking gas motions in the star's outer atmosphere through a full pulsation cycle. Observing with the VLBA every two weeks, they now have accumulated 37 separate images, which they combined to make the "movie." They were able to measure the gas motions because one of the gases in the star's atmosphere, Silicon Monoxide (SiO), can act as a natural amplifier of radio signals. Such cosmic masers amplify radio emission similar to the way that a laser amplifies light emission. Regions where this maser activity occurs appear as bright spots on radio telescope images when the telescope's receivers are tuned to the specific frequency emitted by the masers. With the extremely high resolving power, or ability to see detail, of the VLBA, the astronomers were able to follow the motions of individual maser regions within the star's atmosphere. These served as tracers of overall gas motions. "Such a study only became possible when the VLBA became operational, and with the availability of computers able to handle the quantity of data produced," Kemball said. The SiO maser regions appear to form a ring around the star. The ring's diameter is greater than the distance from the Sun to Saturn, and has expanded from 10 to 20 percent over the course of the VLBA observations. "The continued expansion was our first surprise, but we've only scratched the surface of the immense amount of data our observations have produced," Diamond said. "Since we think that magnetic fields are playing a large role in how this gas beha

1999-01-01

408

"Microquasar" Discoveries Win Prize for Astronomers  

NASA Astrophysics Data System (ADS)

The discovery of "microquasars" within our own Milky Way Galaxy has won two astronomers a prize from the High Energy Astrophysics Division of the American Astronomical Society. Felix Mirabel of the Center for Studies at Saclay, France, and Luis Rodriguez of the Institute of Astronomy at the National Autonomous University in Mexico City, were awarded the Bruno Rossi Prize at the American Astronomical Society meeting in Toronto, Ontario, today. The two researchers, who have collaborated for more than 15 years, used an orbiting X-Ray observatory and the National Science Foundation's Very Large Array (VLA) radio telescope to discover the extremely energetic microquasars. Microquasars are thought to be binary-star systems with one of the stars either a superdense neutron star or a black hole. They emit X-rays and eject jets of subatomic particles at speeds approaching that of light. Though the neutron stars or black holes in microquasars are only a few times the mass of the sun, the phenomena associated with them, such as the jets, are similar to those seen in active galaxies and quasars, believed to be powered by the gravitational energy of black holes with millions of times the mass of the sun. As such, the microquasars provide much closer "laboratories" for study of these phenomena, which remain poorly understood. The Rossi Prize is awarded for "a significant contribution to high energy astrophysics, with particular emphasis on recent work," according to the High Energy Astrophysics Division. Mirabel and Rodriguez began the research that led to the microquasar discoveries in 1990. Using the French-Russian SIGMA- GRANAT X-Ray satellite, they discovered a microquasar near the Milky Way's center in 1992. With the VLA, they found radio emission from this object. In 1992, using the same satellite, they discovered a similar object, called GRS 1915+105. In 1994, that object experienced an outburst that made it bright enough at radio wavelengths to observe with the VLA. Observing it at frequent intervals with the VLA, the researchers discovered that "blobs" in its radio jets were traveling at speeds apparently greater than that of light. Correcting for relativistic effects, they calculated that the material in the jets was actually moving at 92 percent of light speed. This was the first object found in our own Galaxy that displayed such apparent "superluminal" speed. A time series of radio images showing the motion of the blobs appeared on the cover of the scientific journal Nature for September 1, 1994. At the time, Mirabel and Rodriguez' work on GRS 1915+105 was called "one of the most valuable results of more than a decade and a half of observations at the VLA," by Miller Goss, assistant director of the National Radio Astronomy Observatory for VLA/VLBA observations. Another microquasar discovered in 1994 also showed apparent superluminal motion. Since these discoveries, the microquasars have been the targets of intense observational programs, as researchers seek to learn just how the gravitation of superdense objects can power the generation of relativistic jets and other energetic phenomena. The VLA is one of the instruments of the National Radio Astronomy Observatory, a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

409

NRAO Astronomer Wins Prestigious Guggenheim Fellowship  

NASA Astrophysics Data System (ADS)

Dr. Dale Frail, an astronomer at the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, has been awarded a prestigious Guggenheim Fellowship, according to the John Simon Guggenheim Memorial Foundation. The Guggenheim Foundation describes its fellowships as "mid-career" awards "intended for men and women who have already demonstrated exceptional capacity for productive scholarship or exceptional creative ability in the arts." Frail, 48, has worked at the NRAO for more than 20 years, first as a postdoctoral fellow, and then as a staff scientist. He received his bachelor's degree in physics from Acadia University in Nova Scotia, and his Ph.D in astronomy from the University of Toronto. Frail is best known for his landmark contributions to the understanding of gamma ray bursts, making critical measurements that provided key insights into the mechanisms of these superenergetic and once-mysterious explosions. He also has made important contributions to the understanding of other astronomical phenomena, including pulsars and their neighborhoods, supernova remnants, and magnetars. In 1992, he was the co-discoverer, with Alex Wolszczan, of the first planets outside our own solar system. "We congratulate Dale on this well-deserved honor that recognizes not only his past achievements but also his potential for exciting scientific work in the future," said Dr. Fred K.Y. Lo, NRAO Director. "We're very proud to see one of our scientists receive such a great honor," Lo added. Frail is one of 180 recipients of this year's Guggenheim Fellowships, chosen from some 3,000 applicants. The fellowships were established in 1925 and past recipients include photographer Ansel Adams, author Saul Bellow, former Secretary of State Henry Kissinger, and chemist Linus Pauling. 102 Guggenheim Fellows have subsequently won Nobel Prizes, and others have received Pulitzer Prizes and other honors. As a Guggenheim Fellow, Frail intends to intensify his research in the areas of pulsars, cosmology, and gamma ray bursts, using the new and dramatically-improved capabilities of the Very Large Array (VLA) to advance the frontiers of knowledge. "I like to work at the limits of technology, and the new capabilities of the VLA are providing opportunities of the kind that come along only once in a generation," Frail said.

2010-04-01

410

Astronomical Calendar Cluj-Napoca 2003 (July - December)  

NASA Astrophysics Data System (ADS)

The content of the calendar is as follows: Astronomical constants; Constelations;Guide of use; Calendar for Cluj Napoca which includes: Sunrise, The transit of the Sun, Sunset for the Sun and for the Moon; The Julian Date; Twilights Civil, Nautical and Astronomic Maps of the sky and phenomena with explanations; General data concerning the Sun, Moon and planets; Meteors and Meteors flows; Eclipses and ocultations; Time and Time scales; The magnitude of the stars; Distances on the sky, Galaxies; Astronomical Phenomena during 2003-2010. Bibliography 15 titles.

Turcu, Vlad; Csillik, Iharka; Moldovan, Dan

411

IYA2009 Asks a Better Astronomical Education in Europe  

NASA Astrophysics Data System (ADS)

The world will soon celebrate the International Year of Astronomy; however, after 400 years of modern astronomy, we are faced with a paradox: whilst science and technique keep making huge progress, children in school learn less and less about the universe. Therefore, we intend to explore some possible teaching strategies in countries where at present astronomy is not part of the curriculum. These include local school TV-networks, conferences, talks and lectures, leaflets, meetings with experts, mass media, museums, planetaria, amateur astronomers, presentation of different astronomical phenomena for education (eclipses, comets etc). We also intend to suggest how astronomers could get the support of IAU Commission 46.

Stavinschi, Magda

2007-08-01

412

U.S. Naval Observatory Astronomical Applications Department  

NSDL National Science Digital Library

The Astronomical Applications Department of the United States Naval Observatory (USNO) provides access to astronomical data, including sun- and moonrise and set times, moon phases, solar and lunar eclipses, seasons, positions of solar system objects, and others. The publications page provides access to annual astronomical and navigational almanacs, USNO special publications, USNO technical reports, and related publications by other institutions. There are also links to obtain software such as the Multiyear Interactive Computer Almanac (MICA) and Naval Observatory Vector Astrometry Subroutines (NOVAS), software products from related organizations, and discontinued USNO software.

413

Event Discovery in Astronomical Time Series  

NASA Astrophysics Data System (ADS)

The discovery of events in astronomical time series data is a non-trival problem. Existing methods address the problem by requiring a fixed-sized sliding window which, given the varying lengths of events and sampling rates, could overlook important events. In this work, we develop probability models for finding the significance of an arbitrary-sized sliding window, and use these probabilities to find areas of significance. In addition, we present our analyses of major surveys archived at the Time Series Center, part of the Initiative in Innovative Computing at Harvard University. We applied our method to the time series data in order to discover events such as microlensing or any non-periodic events in the MACHO, OGLE and TAOS surveys. The analysis shows that the method is an effective tool for filtering out nearly 99% of noisy and uninteresting time series from a large set of data, but still provides full recovery of all known variable events (microlensing, blue star events, supernovae etc.). Furthermore, due to its efficiency, this method can be performed on-the-fly and will be used to analyze upcoming surveys, such as Pan-STARRS.

Preston, D.; Protopapas, P.; Brodley, C.

2009-09-01

414

Automatic processing method for astronomical CCD images  

NASA Astrophysics Data System (ADS)

Since several hundreds of CCD images are obtained with the CCD camera in the Lower Latitude Meridian Circle (LLMC) every observational night, it is essential to adopt an automatic processing method to find the initial position of each object in these images, to center the object detected and to calculate its magnitude. In this paper several existing automatic search algorithms searching for objects in astronomical CCD images are reviewed. Our automatic searching algorithm is described, which include 5 steps: background calculating, filtering, object detecting and identifying, and defect eliminating. Then several existing two-dimensional centering algorithms are also reviewed, and our modified two-dimensional moment algorithm and an empirical formula for the centering threshold are presented. An algorithm for determining the magnitudes of objects is also presented in the paper. All these algorithms are programmed with VC++ programming language. In the last our method is tested with CCD images from the 1m RCC telescope in Yunnan Observatory, and some primary results are also given.

Li, Binhua; Yang, Lei; Mao, Wei

2002-12-01

415

Taking the Observatory to the Astronomer  

NASA Astrophysics Data System (ADS)

Since 1992, Software Bisque's Remote Astronomy Software has been used by the Mt. Wilson Institute to allow interactive control of a 24" telescope and digital camera via modem. Software Bisque now introduces a comparable, relatively low-cost observatory system that allows powerful, yet "user-friendly" telescope and CCD camera control via the Internet. Utilizing software developed for the Windows 95/NT operating systems, the system offers point-and-click access to comprehensive celestial databases, extremely accurate telescope pointing, rapid download of digital CCD images by one or many users and flexible image processing software for data reduction and analysis. Our presentation will describe how the power of the personal computer has been leveraged to provide professional-level tools to the amateur astronomer, and include a description of this system's software and hardware components. The system software includes TheSky Astronomy Software?, CCDSoft CCD Astronomy Software?, TPoint Telescope Pointing Analysis System? software, Orchestrate? and, optionally, the RealSky CDs. The system hardware includes the Paramount GT-1100? Robotic Telescope Mount, as well as third party CCD cameras, focusers and optical tube assemblies.

Bisque, T. M.

1997-05-01

416

An Early Astronomical Observation by John Goodricke  

NASA Astrophysics Data System (ADS)

John Goodricke (1764-1786) is one of the most intriguing and enigmatic figures in the history of astronomy. Deaf from the age of five, his observations of the light variation of Algol brought him acclaim and the Copley Medal of the Royal Society by the age of nineteen. Together with his neighbor, mentor, and distant relative Edward Pigott, he went on to discover and quantify the light variations of other stars, including Delta Cephei. Goodricke's careful accounts of his observations, and their accuracy, remain a model of clear scientific thinking and reporting. His final derived value for the time between eclipse minima for Algol, for example, is within eight seconds of the modern value. Goodricke's astronomical observing career is generally thought to have begun with his return to his family home in York in 1781 at the age of seventeen. His school mathematics notebook and workbook from the Warrington Academy, however, contains a detailed drawing of the sky which suggest that he was already a knowledgable observer by the age of fifteen. This drawing is presented and interpreted.

French, Linda M.

2009-12-01

417

Infrared astronomical spectroscopy with a noncryogenic spectrograph  

NASA Astrophysics Data System (ADS)

Large astronomical spectrographs designed for use in the visible for use in the visible can operate efficiently well beyond the long wavelength cutoff of CCD detectors. Given the expense and complexity of constructing IR-optimized high resolution or multi-object spectrographs, it is prudent to explore the range of scientific programs possible utilizing modern near-IR arrays at the focal plane of historically visible wavelength instruments. For the past three years, we have used the NICMASS camera, a 256 by 256 HgCdTe imager developed at the University of Massachusetts, at the camera 5 focus of the Coude Feed Spectrograph on Kitt Peak for moderate and high resolution IR spectroscopy in the 1-1.8 micrometers range. This configuration has been used at a spectral resolution 7200 using a 316 1/mm grating an extremely stable platform permitting radial velocity determinations to better than 1 km-s (superscript -1). We will discuss some scientific results obtained with this novel configuration and the performance limitations imposed by the ambient temperature spectrograph beyond a wavelength of 1 micrometers . We also discuss plans to evaluate the suitability of NICMASS for multi- object near-IR spectroscopy on the Hydra Bench Spectrograph at the WIYN telescope on Kitt Peak.

Joyce, Richard R.; Hinkle, Kenneth H.; Meyer, Michael R.; Skrutskie, Michael F.

1998-08-01

418

Hydrated Minerals on Asteroids: The Astronomical Record  

NASA Astrophysics Data System (ADS)

Knowledge of the hydrated mineral inventory on the asteroids is important for deducing the origin of Earth's water, interpreting the meteorite record, and unraveling the processes occurring during the earliest times in solar system history. Reflectance spectroscopy shows absorption features in both the 0.6-0.8 and 2.5-3.5 micrometers regions, which are diagnostic of or associated with hydrated minerals. Observations in those regions show that hydrated minerals are common in the mid-asteroid belt, and can be found in unexpected spectral groupings, as well. Asteroid groups formerly associated with mineralogies assumed to have high temperature formation, such as M- and E-class asteroids, have been observed to have hydration features in their reflectance spectra. Some asteroids have apparently been heated to several hundred degrees Celsius, enough to destroy some fraction of their phyllosilicates. Others have rotational variation suggesting that heating was uneven. We summarize this work, and present the astronomical evidence for water- and hydroxyl-bearing minerals on asteroids.

Rivkin, A. S.; Howell, E. S.; Vilas, F.; Lebofsky, L. A.

2002-03-01

419

Electronic Publishing and The American Astronomical Society  

NASA Astrophysics Data System (ADS)

Electronic Publishing has created, and will continue to create, new opportunities and challenges for representing scientific work in new media and formats. The AAS will position itself to take advantage of these, both for newly created works and for improved representation of works already published. It is the view of the AAS that we hold the works that we publish in trust for our community and are obligated to protect the integrity of these works and to assure that they continue to be available to the research community. Assignment of copyright to the AAS by the author plays a central role in the preservation of the integrity and accessability of the literature published by the American Astronomical Society. In return for such assignment the AAS allows the author to freely use the work for his/her own purpose and to control the grant of permission to third parties to use such materials. The AAS retains the right to republish the work in whatever format or medium, and to retain the rights after the author's death. Specific advantages to this approach include: Assurance of the continued availability of the materials to the research and educational communities; A guarantee of the intellectual integrity of the materials in the archive; Stimulation of the development of new means of presentation or of access to the archival literature; and Provision of a uniformity of treatment for copyright issues and to relieve the individual authors of much of the administrative work.

Milkey, R. W.

1999-12-01

420

An Astronomical Life Salted by Pure Chance  

NASA Astrophysics Data System (ADS)

My childhood upbringing in no way suggested that I would become an astronomer, but accidents of fate pushed me in the direction of science, and I have benefited greatly from being in the right place at the right time. I grew up in Seattle, earned B.S. and M.S. degrees in mathematics at the University of Washington, and eventually a Ph.D. in astronomy from the University of California, Berkeley. I was a postdoc at the Mt. Wilson Observatory, an assistant professor at Indiana University, later the Yerkes Observatory (University of Chicago), and still later I became a staff member of the Mt. Wilson and Palomar Observatories. After several years, I returned to the University of California, this time with the Lick Observatory staff at its new academic home on the Santa Cruz campus, where I have been ever since. My research has focused on the relation of Cepheids and RR Lyrae stars to problems of Galactic structure, the binary nature of cataclysmic variables, the decay of angular momentum of solar type stars, and the chemical history of the Galaxy as revealed by the abundances of very old stars in globular clusters and the Galactic halo field. None of this work would have been possible without the help of excellent teachers and mentors, great colleagues, and superb postdocs and graduate students. Most of all, I am grateful for the educational opportunities afforded me by state-supported public Universities.

Kraft, Robert P.

2009-09-01

421

Astronomical Point Sources of Underground Muons  

NASA Astrophysics Data System (ADS)

The Soudan 2 detector has been in routine operation since June 1988, and at least 25% of the full 16m x 8m x 5m detector has been in place since January 1989. In this thesis, the underground muon data from the Soudan 2 detector for the period January 21, 1989 through July 31, 1990 are studied for indications of excess emission from four potential astronomical sources. Signals are claimed at about the 85% confidence level for PSR1957 + 20 near the L4 stable Lagrange point and X2127 + 11 near the phase of the 150s 1988 X-ray burst. In addition, a signal is indicated at the 87% confidence level for Cygnus X-3 during a 111 day period during the 1989 radio burst. Despite the low significance of these reports, they are notable because the signals are in phase regions of a priori interest. Using this fact boosts the confidence levels to greater than 95%. In addition, a 90% flux limit is calculated to be 2.1 times rm 10^{-11}s^{-1}cm ^{-2} for events from Cygnus X -3 during the period of the data set. This is compared to the flux reported from other underground experiments.

Lowe, Mark Joseph

422

The Taiwan Extragalactic Astronomical Data Center  

NASA Astrophysics Data System (ADS)

Founded in 2010, the Taiwan Extragalactic Astronomical Data Center (TWEA-DC) has for its goal to provide access to large amount of data for the Taiwanese and International community, focusing its efforts on Extragalactic science. In continuation with individual efforts in Taiwan over the past few years, this is the first stepping-stone towards the building of a National Virtual Observatory. Taking advantage of our own fast indexing algorithm (BLINK), based on a octahedral meshing of the sky coupled with a very fast kd-tree and a clever parallelization amongst available resources, TWEA-DC will provide, from spring 2013, a service of “on-the-fly” matching, between on-site and user-based catalogs. We will also offer access to public and private raw and reducible data available to the Taiwanese community. Finally, we are developing high-end on-line analysis tools, such as an automated photometric redshifts and SED fitting code (APz), and an automated groups and clusters finder (APFoF).

Foucaud, S.; Hashimoto, Y.; Tsai, M.-F.; Kamennoff, N.; TWEA-DC Team

2013-10-01

423

Widefield camera 3 for the Hubble Space Telescope  

NASA Astrophysics Data System (ADS)

In June 1997, NASA made the decision to extend the end of the Hubble Space Telescope (HST) mission from 2005 until 2010. As a result, the age of the instruments on board the HST became a consideration. After careful study, NASA decided to ensure the imaging capabilities of the HST by replacing the Wide Field Planetary Camera 2 with a low-cost facility instrument, the Wide Field Camera 3. This paper provides an overview of the scientific goals and capabilities of the instrument.

Cheng, Edward S.; Hill, Robert J.; MacKenty, John W.; Cawley, Laura; Knezek, P.; Kutina, Ray E.; Lisse, Casey M.; Lupie, Olivia L.; Robberto, Massimo; Stiavelli, Massimo; O'Connell, Robert W.; Balick, Bruce; Bond, H.; Calzetti, Daniela; Carollo, M.; Disney, Mike; Dopita, Mike; Frogel, J.; Hall, Donald N.; Hester, J.; Holtzman, J.; Luppino, Gerard A.; McCarthy, P.; Paresce, Francesco; Saha, Abhijit; Silk, J.; Trauger, John T.; Walker, A.; Whitmore, B.; Windhorst, R.; Young, Erick T.

2000-07-01

424

Atmospheric Parameters of Stars in Hubble's Next Generation Spectral Library  

NASA Astrophysics Data System (ADS)

Hubble's Next Generation Spectral Library (NGSL) consists of R˜1000 spectra of 374 stars of assorted temperature, gravity, and metallicity. We have determined the atmospheric and fundamental parameters of most of the stars from the NGSL spectra themselves via full-spectrum fitting of model spectra to the observed (extinction-corrected) spectrum over the full wavelength range, 0.2-1.0 ?. We present our preliminary results with a comparison with parameters culled from the literature and parameters derived from NGSL by other means.

Heap, S. R.; Lindler, D.

2011-12-01

425

Press briefing: Science with the Hubble Space Telescope  

NASA Astrophysics Data System (ADS)

From 4 to 9 December 1995, about three hundred scientists from around the world will gather for a conference in Paris to present and discuss the most exciting discoveries that they are making in observing planets, stars, nebulae, galaxies and distant quasars with the unprecedented clear focus of the Hubble Space Telescope. A special session of the conference (Saturday 9 December) has been arranged to discuss ways for bringing these new results into the classroom and to the general public. At the start of the conference, some of the most distinguished participants will present to the media their views on the impact that this new data is having on our understanding of the universe. A press release concerning the discovery of a new black hole in a galaxy will be distributed and commented on by the author. Photographic material and narrative description will be included in the press kit that will be distributed. Media representatives are invited to attend the press briefing on Monday 4 December at ESA Headquarters (programme attached), and are kindly requested to fill in and return the attached registration form preferably by fax to the Public Relations Division (Fax. +33 1 53 69 76 90). Later that same day, at 19:00 hours, in Room XII at UNESCO (7 place de Fontenoy, 75007 Paris), Professor Roger Bonnet, the Director of the ESA Science Programme and Dr. Duccio Macchetto, Associate Director for scientific programs at the Space Telescope Science Institute in Baltimore, will present an overview of ESA's science programmes and the exciting results obtained by the Hubble Space Telescope. This public event is free and no pre- registration is needed in order to attend.. (*) a project of international cooperation between NASA and ESA. Science with the Hubble Space Telescope Press Briefing Monday 4 December 1995 09:45 - 13:00 hrs European Space Agency Headquarters 8-10 rue Mario Nikis Paris Room A 09:45 hrs Arrival. 10:00- 10:15 hrs Overview, European Space Agency science programme. Prof. Roger Bonnet, ESA science programmes director. 10:15- 10:30 hrs Overview, Hubble Space Telescope Program. Dr. John Campbell, Director of Flight Projects, NASA Goddard Space Flight Center. 10:40- 11:00 hrs The age of the universe. Prof. Gustav Tamman, Institute of Astronomy, University of Basel, Switzerland. 11:00- 11:20 hrs Distant galaxies and quasars. Prof. Malcolm Longhair, Mullard Radio Astronomy Observatory, Cambridge, England. Supernovae. Prof. Robert Kirshner, Harvard University, Cambridge, Massachussets. Special press announcement. A black hole in Galaxy NGC 4261. Prof. Holland Ford, John Hopkins University, Baltimore, Maryland.

1995-11-01