Sample records for astronomer edwin hubble

  1. Edwin Hubble, The Discoverer of the Big Bang Universe

    Microsoft Academic Search

    Alexander S. Sharov; Igor D. Novikov

    1993-01-01

    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

  2. Edwin Hubble. Mariner of the nebulae.

    NASA Astrophysics Data System (ADS)

    Christianson, G. E.

    This biography of Edwin Hubble has been acclaimed by professionals and laymen alike. It is both the biography of an extraordinary human being and the story of the greatest quest in the history of astronomy since the Copernican revolution. Born in 1889 and reared in the village of Marshfield, Missouri, Edwin Powell Hubble became one of the towering figures in 20th century science. Hubble worked with the great 100 inch Hooker telescope at California's Mount Wilson Observatory and made a series of discoveries that revolutionized humanity's vision of the cosmos. In 1923 he was able to confirm the existence of other nebulae beyond our own Milky Way. By the end of the decade, he had proven that the universe is expanding, thus laying the very cornerstone of the "Big Bang" theory of creation. It was Hubble who developed the elegant scheme by which the galaxies are classified as ellipticals and spirals, and it was Hubble who first provided reliable evidence that the universe is homogeneous, the same in all directions as far as the telescope can see.

  3. Astronomers Track Down Asteroids in Hubble Archive

    NSDL National Science Digital Library

    1998-01-01

    This site provides information related to the recently discovered asteroid 1997XF11. The Space Science Telescope Institute site has begun to document how astronomers are using photos from the Hubble Space Telescope to find asteroids; over 100 small asteroids have so far been found, of which captioned examples of four (in various formats) are now available.

  4. The Animated Story of Edwin Hubble and the Discovery of the Structure of the Universe

    NASA Astrophysics Data System (ADS)

    Longson, Tony; Armitage, P.; Chu, Y.; Dzhambazyan, G.; Bayindir, H.; Park, D.; Yefimenko, J.; Simonian, V.; Levitin, S.; Sullivan, A.; Shitanishi, J.; Wells, D.; Wong, F.; Kang, E. Y. E.; Mijic, M.; State LA SciVi Project, Cal

    2009-05-01

    The turning point in our understanding of the Universe was when Edwin Hubble determined the distances to nearby galaxies and showed conclusively that they are islands of stars separate from our own. Our computer animation explains the key moments of that story: the puzzle about the nature of galaxies, the decisive role and the power of the Hooker telescope at the Mt. Wilson Observatory, the discovery and use of Cepheids in the Andromeda galaxy, and the subsequent interpretation of results as this new paradigm of the universe filled with islands of stars was established. The animation can be used as educational material in classroom or in any public education setting

  5. Dismantling Hubble's Legacy?

    NASA Astrophysics Data System (ADS)

    Way, M. J.

    2013-04-01

    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.

  6. European astronomers' successes with the Hubble Space Telescope*

    NASA Astrophysics Data System (ADS)

    1997-02-01

    [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

  7. Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    The Space Telescope, scheduled for launch aboard the Space Shuttle in 1986, has been renamed the Edwin P. Hubble Space Telescope, the National Aeronautics and Space Administration (NASA) announced. The orbiting optical astronomical observatory will carry a 2.4-m mirror and five scientific instruments that will be able to look into space 7 times farther than any ground-based observatory; NASA expects the resolution of the resulting images to be 10-20 times better than images from ground-based instruments.Hubble probably is best known for his discovery, with colleague Milton Humason, that the universe is expanding. Hubble confirmed that the faint, spiral nebulae viewed through the Mount Wilson Observatory's Hooker Telescope were distant systems receding from us at velocities proportional to their distances. Hubble was a staff member at Carnegie Institution's Mount Wilson Observatory near Pasadena, Calif., from 1919 until his death in 1953.

  8. Hubble Space Telescope-Illustration

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This is a cutaway illustration of the Hubble Space Telescope (HST) with callouts. The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  9. Hubble Space Telescope-Illustration

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This illustration depicts a side view of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  10. Astronomers in the Chemist's War

    NASA Astrophysics Data System (ADS)

    Trimble, Virginia L.

    2012-01-01

    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.

  11. Hubble's diagram and cosmic expansion

    PubMed Central

    Kirshner, Robert P.

    2004-01-01

    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

  12. External Resource: Hubble Deep Space Field Academy

    NSDL National Science Digital Library

    1900-01-01

    This Space Telescope Science Institute web page contains resources for students to 'walk' in the footsteps of astronomers as they explore the farthest regions of the known universe. Using astronomers' methods, students will observe the Hubble Deep Field

  13. Hubble and Shapley - Two Early Giants of Observational Cosmology

    NASA Astrophysics Data System (ADS)

    van den Bergh, Sidney

    2011-12-01

    Observational cosmology of the first decades of the Twentieth Century was dominated by two giants: Edwin Hubble and Harlow Shapley. Hubble's major contributions were to the study and classification of individual galaxies with large telescopes, whereas Shapley is best remembered for his work on groups and clusters of galaxies using telescopes of more modest aperture.

  14. Edwin W. Lewis, Jr.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Edwin W. Lewis Jr. is a research pilot in the Airborne Science program, Flight Crew Branch, Dryden Flight Research Center, Edwards, California. He currently flies the DC-8, F/A-18, Lear Jet 24, King Air, and T-34C in support of Dryden's flight operations and is mentor pilot for the King Air and the Lear Jet. Prior to accepting this assignment Lewis was a pilot for eight years at NASA's Ames Research Center, Moffett Field, California, flying 10 different aircraft - C-130B, DC-8-72, UH-1, SH-3, King Air, Lear 24, T-38A, T-39G and YO-3A - in support of NASA flight missions. Lewis also flew the Kuiper Airborne Observatory (a modified civilian version of the Lockheed C-141 Starlifter). He was project pilot for Ames' 747 and T-38 programs. Lewis was born in New York City on May 19, 1936, and began flight training as a Civil Air Patrol cadet in 1951, ultimately earning his commercial pilot's certificate in 1958. He received a bachelor of arts degree in biology from Hobart College, Geneva, N.Y., and entered the U.S. Air Force through the Reserve Officer Training Corps. Following pilot training he was assigned to Moody Air Force Base, Ga., as an instructor pilot, for both the T-33 and T-37 aircraft. He served in Vietnam in 1965 and 1966, where he was a forward air controller, instructor and standardization/evaluation pilot, flying more than 1,000 hours in the O-1 'Bird Dog.' Lewis separated from the regular Air Force and joined Pan American World Airways and the 129th Air Commando Group, California Air National Guard (ANG) based in Hayward, California. During his 18-year career with the California ANG he flew the U-6, U-10, C-119, HC-130 aircraft and the HH-3 helicopter. He retired as commander, 129th Air Rescue and Recovery Group, a composite combat rescue group, in the grade of colonel. During his 22 years as an airline pilot, he flew the Boeing 707, 727 and 747. He took early retirement from Pan American in 1989 to become a pilot with NASA.

  15. Hubble: 20 Years of Discovery - Duration: 15 minutes.

    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 ...

  16. Hubble Space Telescope Deep Field Lesson Package

    NSDL National Science Digital Library

    1997-01-01

    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.

  17. Planets in a Sandbox: Hubble's Renaissance of Debris

    E-print Network

    Kalas, Paul G.

    Planets in a Sandbox: Hubble's Renaissance of Debris Disk Imaging Paul Kalas Taken from: Hubble. Planets in a Sandbox: Hubble's Renaissance of Debris Disk Imaging Paul Kalas Conduct a search for "false) When NASA launched the Infrared Astronomical Satellite (IRAS) in 1983, a renaissance began. Starting

  18. Edwin O. Reischauer Institute of Japanese Studies Harvard University

    E-print Network

    Wolfe, Patrick J.

    Edwin O. Reischauer Institute of Japanese Studies Harvard University 2006-2008 Biennial Report #12;Edwin O. Reischauer Institute of Japanese Studies Harvard University Center for Government.495.3220 Fax 617.496.8083 Email rijs@fas.harvard.edu Website http://www.fas.harvard.edu/~rijs/ The Edwin O

  19. HUBBLE REVEALS 'BACKWARDS' SPIRAL GALAXY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Astronomers have found a spiral galaxy that may be spinning to the beat of a different cosmic drummer. To the surprise of astronomers, the galaxy, called NGC 4622, appears to be rotating in the opposite direction to what they expected. Pictures by NASA's Hubble Space Telescope helped astronomers determine that the galaxy may be spinning clockwise by showing which side of the galaxy is closer to Earth. A Hubble telescope photo of the oddball galaxy is this month's Hubble Heritage offering. The image shows NGC 4622 and its outer pair of winding arms full of new stars [shown in blue]. Astronomers are puzzled by the clockwise rotation because of the direction the outer spiral arms are pointing. Most spiral galaxies have arms of gas and stars that trail behind as they turn. But this galaxy has two 'leading' outer arms that point toward the direction of the galaxy's clockwise rotation. To add to the conundrum, NGC 4622 also has a 'trailing' inner arm that is wrapped around the galaxy in the opposite direction it is rotating. Based on galaxy simulations, a team of astronomers had expected that the galaxy was turning counterclockwise. NGC 4622 is a rare example of a spiral galaxy with arms pointing in opposite directions. What caused this galaxy to behave differently from most galaxies? Astronomers suspect that NGC 4622 interacted with another galaxy. Its two outer arms are lopsided, meaning that something disturbed it. The new Hubble image suggests that NGC 4622 consumed a small companion galaxy. The galaxy's core provides new evidence for a merger between NGC 4622 and a smaller galaxy. This information could be the key to understanding the unusual leading arms. Galaxies, which consist of stars, gas, and dust, rotate very slowly. Our Sun, one of many stars in our Milky Way Galaxy, completes a circuit around the Milky Way every 250 million years. NGC 4622 resides 111 million light-years away in the constellation Centaurus. The pictures were taken in May 2001 with Hubble's Wide Field Planetary Camera 2. The science team, consisting of Ron Buta and Gene Byrd from the University of Alabama, Tuscaloosa, and Tarsh Freeman of Bevill State Community College in Alabama, observed NGC 4622 in ultraviolet, infrared, and blue and green filters. Their composite image and science findings were presented at the meeting of the American Astronomical Society in January of 2002. Image Credit: NASA and the Hubble Heritage Team (STScI/AURA) Acknowledgment: Dr. Ron Buta (U. Alabama), Dr. Gene Byrd (U. Alabama) and Tarsh Freeman (Bevill State Community College)

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

    NASA Astrophysics Data System (ADS)

    Soderblom, D. R.

    2012-06-01

    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.

  1. Edwin M. McMillan, A biographical sketch

    SciTech Connect

    Lofgren, E.J.

    1994-07-01

    Edwin M. McMillan was one of the great scientists of the middle years of this century. He made notable contributions to nuclear, and particle physics, the chemistry of transuranic elements, and accelerator physics.

  2. Hubble's new view of the cosmos

    PubMed

    Villard, R

    1996-05-01

    Since the December 1993 repair of NASA's Hubble Space Telescope's (HST) optics by the crew of the Space Shuttle Endeavour, the rapid-fire scientific achievements have brought a new era of discovery to the field of astronomy. Hubble has confirmed some astronomical theories, challenged others, and often come up with complete surprises. Some images are so unexpected that astronomers have to develop new theories to explain what they are seeing. The HST has detected galaxies out to the visible horizon of the cosmos, and has made an attempt at pinning down the universe's expansion rate. Both of these key research areas should ultimately yield answers to age-old questions: What has happened since the beginning of time, and will the universe go on forever? PMID:11538725

  3. Official Portrait of Astronaut Edwin E. Aldrin

    NASA Technical Reports Server (NTRS)

    1967-01-01

    This is the official NASA portrait of astronaut Edwin E. (Buzz) Aldrin. Prior to joining NASA, Aldrin flew 66 combat missions in F-86s while on duty in Korea. At Nellis Air Force Base, Nevada, he served as an aerial gunnery instructor. Following his assignment as aide to the dean of faculty at the Air Force Academy, Aldrin flew F-100s as a flight commander at Bitburg, Germany. Aldrin was one of the third group of astronauts named by NASA in October 1963 and has logged 289 hours and 53 minutes in space, of which, 7 hours and 52 minutes were spent in Extra Vehicular Activity (EVA). On November 11, 1966, he launched into space aboard the Gemini 12 spacecraft on a 4-day flight, which brought the Gemini program to a successful close. During that mission, Aldrin established a new record for EVA, spending 5-1/2 hours outside the spacecraft. July 16-24, 1969, Aldrin served as lunar module pilot for Apollo 11, the first manned lunar landing mission. Aldrin followed Neil Armstrong onto the lunar surface on July 20, 1969, completing a 2-hour and 15 minute lunar EVA. Aldrin resigned from NASA in July 1971.

  4. Hubble Space Telescope Image

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This deepest-ever view of the universe unveils myriad galaxies back to the begirning of time. Several hundred, never-before-seen, galaxies are visible in this view of the universe, called Hubble Deep Field (HDF). Besides the classical spiral and elliptical shaped galaxies, there is a bewildering variety of other galaxy shapes and colors that are important clues to understanding the evolution of the universe. Some of the galaxies may have formed less than one-billion years after the Big Bang. The image was assembled from many separate exposures with the Wide Field/Planetary Camera 2 (WF/PC2), for ten consecutive days between December 18, 1995 and December 28, 1995. This true-color view was assembled from separate images taken with blue, red, and infrared light. By combining these separate images into a single color picture, astronomers will be able to infer, at least statistically, the distance, age, and composition of galaxies in the field. Blue objects contain young stars and/or are relatively close, while redder objects contain older stellar populations and/or are farther away.

  5. Astronomical masers

    Microsoft Academic Search

    Moshe Elitzur

    1992-01-01

    The present treatment of astronomical masers discusses their thermodynamic equilibrium and matter-line radiation interaction, the OH, H2O, and SiO maser molecules, general properties of saturated masers, spherical and filamentary masers, and fully resolved Zeeman patterns and overlapping Zeeman components. Also considered are pumping effects, the stellar environment of astronomical masers, the relationship of astronomical masers to the stellar wing and

  6. HUBBLE'S INFRARED GALAXY GALLERY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Astronomers have used the NASA Hubble Space Telescope to produce an infrared 'photo essay' of spiral galaxies. By penetrating the dust clouds swirling around the centers of these galaxies, the telescope's infrared vision is offering fresh views of star birth. These six images, taken with the Near Infrared Camera and Multi-Object Spectrometer, showcase different views of spiral galaxies, from a face-on image of an entire galaxy to a close-up of a core. The top row shows spirals at diverse angles, from face-on, (left); to slightly tilted, (center); to edge-on, (right). The bottom row shows close-ups of the hubs of three galaxies. In these images, red corresponds to glowing hydrogen, the raw material for star birth. The red knots outlining the curving spiral arms in NGC 5653 and NGC 3593, for example, pinpoint rich star-forming regions where the surrounding hydrogen gas is heated by intense ultraviolet radiation from young, massive stars. In visible light, many of these regions can be hidden from view by the clouds of gas and dust in which they were born. The glowing hydrogen found inside the cores of these galaxies, as in NGC 6946, may be due to star birth; radiation from active galactic nuclei (AGN), which are powered by massive black holes; or a combination of both. White is light from middle-age stars. Clusters of stars appear as white dots, as in NGC 2903. The galaxy cores are mostly white because of their dense concentration of stars. The dark material seen in these images is dust. These galaxies are part of a Hubble census of about 100 spiral galaxies. Astronomers at Space Telescope Science Institute took these images to fill gaps in the scheduling of a campaign using the NICMOS-3 camera. The data were non-proprietary, and were made available to the entire astronomical community. Filters: Three filters were used: red, blue, and green. Red represents emission at the Paschen Alpha line (light from glowing hydrogen) at a wavelength of 1.87 microns. Blue shows the galaxies in near-infrared light, measured between 1.4 and 1.8 microns (H-band emission). Green is a mixture of the two. Distance of galaxies from Earth: NGC 5653 - 161 million light-years; NGC 3593 - 28 million light-years; NGC 891 - 24 million light-years; NGC 4826 - 19 million light-years; NGC 2903 - 25 million light-years; and NGC 6946 - 20 million light-years. Credits: Torsten Boeker, Space Telescope Science Institute, and NASA NOTE TO EDITORS: Image files and photo caption are available on the Internet at: http://oposite.stsci.edu/pubinfo/pr/1999/10 or via links in http://oposite.stsci.edu/pubinfo/latest.html and http://oposite.stsci.edu/pubinfo/pictures.html Higher resolution digital versions of (300 dpi JPEG and TIFF) of the release photo are available at: http://oposite.stsci.edu/pubinfo/pr/1999/10/extra-photos.html STScI press releases and other information are available automatically by sending an Internet electronic mail message to pio-request@stsci.edu. In the body of the message (not the subject line) users should type the word 'subscribe' (don't use quotes). The system will respond with a confirmation of the subscription, and users will receive new press releases as they are issued. To unsubscribe, send mail to pio-request@stsci.edu. Leave the subject line blank, and type 'unsubscribe' (don't use quotes) in the body of the message.

  7. Astronomical masers

    NASA Technical Reports Server (NTRS)

    Elitzur, Moshe

    1992-01-01

    Recent research related to astronomical masers is reviewed. First, attention is given to phenomenology, including observations and modeling of galactic and extragalactic maser sources. The discussion then focuses on the developments concerning the physical properties of maser radiation. Finally, the use of masers as general tools for the study of astronomical environments where the radiation is produced and where it propagates, is discussed.

  8. GORDON EDWIN DICKERSON, 1912 - 2000: A BRIEF BIOGRAPHY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gordon Edwin Dickerson was an international leader for most of the 20th Century in the field of quantitative animal breeding and genetics. This short biography sketches Gordon's personal, academic and scientific paths which are naturally intertwined. The sketch begins with his birth in Lagrande, Ore...

  9. Epic --A Library for Generating Compilers Edwin Brady

    E-print Network

    Brady, Edwin

    Epic -- A Library for Generating Compilers Edwin Brady University of St Andrews, KY16 9SX, Scotland. Epic is a compiled functional language which exposes functional compi- lation techniques to a language implementor, with a Haskell API. In this paper we describe Epic and outline how it may be used to implement

  10. Spatially Disaggregated Real Estate Indices Edwin S. Iversen, Jr.

    E-print Network

    West, Mike

    residential real estate market. Results are compared to those obtained using competing spatial models. KEY markets, real estate markets can prove to be rather volatile. Following real gains of about 17% per yearSpatially Disaggregated Real Estate Indices Edwin S. Iversen, Jr. A spatial--temporal Markov random

  11. HUBBLE PINPOINTS WHITE DWARFS IN GLOBULAR CLUSTER

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Peering deep inside a cluster of several hundred thousand stars, NASA's Hubble Space Telescope uncovered the oldest burned-out stars in our Milky Way Galaxy. Located in the globular cluster M4, these small, dying stars - called white dwarfs - are giving astronomers a fresh reading on one of the biggest questions in astronomy: How old is the universe? The ancient white dwarfs in M4 are about 12 to 13 billion years old. After accounting for the time it took the cluster to form after the big bang, astronomers found that the age of the white dwarfs agrees with previous estimates for the universe's age. In the top panel, a ground-based observatory snapped a panoramic view of the entire cluster, which contains several hundred thousand stars within a volume of 10 to 30 light-years across. The Kitt Peak National Observatory's 0.9-meter telescope took this picture in March 1995. The box at left indicates the region observed by the Hubble telescope. The Hubble telescope studied a small region of the cluster. A section of that region is seen in the picture at bottom left. A sampling of an even smaller region is shown at bottom right. This region is only about one light-year across. In this smaller region, Hubble pinpointed a number of faint white dwarfs. The blue circles pinpoint the dwarfs. It took nearly eight days of exposure time over a 67-day period to find these extremely faint stars. Globular clusters are among the oldest clusters of stars in the universe. The faintest and coolest white dwarfs within globular clusters can yield a globular cluster's age. Earlier Hubble observations showed that the first stars formed less than 1 billion years after the universe's birth in the big bang. So, finding the oldest stars puts astronomers within arm's reach of the universe's age. M4 is 7,000 light-years away in the constellation Scorpius. Hubble's Wide Field and Planetary Camera 2 made the observations from January through April 2001. These optical observations were combined to create the above images. Spectral data were also taken. Credit for Hubble telescope photos: NASA and H. Richer (University of British Columbia) Credit for ground-based photo: NOAO/AURA/NSF

  12. Chandra Independently Determines Hubble Constant

    NASA Astrophysics Data System (ADS)

    2006-08-01

    A critically important number that specifies the expansion rate of the Universe, the so-called Hubble constant, has been independently determined using NASA's Chandra X-ray Observatory. This new value matches recent measurements using other methods and extends their validity to greater distances, thus allowing astronomers to probe earlier epochs in the evolution of the Universe. "The reason this result is so significant is that we need the Hubble constant to tell us the size of the Universe, its age, and how much matter it contains," said Max Bonamente from the University of Alabama in Huntsville and NASA's Marshall Space Flight Center (MSFC) in Huntsville, Ala., lead author on the paper describing the results. "Astronomers absolutely need to trust this number because we use it for countless calculations." Illustration of Sunyaev-Zeldovich Effect Illustration of Sunyaev-Zeldovich Effect The Hubble constant is calculated by measuring the speed at which objects are moving away from us and dividing by their distance. Most of the previous attempts to determine the Hubble constant have involved using a multi-step, or distance ladder, approach in which the distance to nearby galaxies is used as the basis for determining greater distances. The most common approach has been to use a well-studied type of pulsating star known as a Cepheid variable, in conjunction with more distant supernovae to trace distances across the Universe. Scientists using this method and observations from the Hubble Space Telescope were able to measure the Hubble constant to within 10%. However, only independent checks would give them the confidence they desired, considering that much of our understanding of the Universe hangs in the balance. Chandra X-ray Image of MACS J1149.5+223 Chandra X-ray Image of MACS J1149.5+223 By combining X-ray data from Chandra with radio observations of galaxy clusters, the team determined the distances to 38 galaxy clusters ranging from 1.4 billion to 9.3 billion light years from Earth. These results do not rely on the traditional distance ladder. Bonamente and his colleagues find the Hubble constant to be 77 kilometers per second per megaparsec (a megaparsec is equal to 3.26 million light years), with an uncertainty of about 15%. This result agrees with the values determined using other techniques. The Hubble constant had previously been found to be 72, give or take 8, kilometers per second per megaparsec based on Hubble Space Telescope observations. The new Chandra result is important because it offers the independent confirmation that scientists have been seeking and fixes the age of the Universe between 12 and 14 billion years. Chandra X-ray Image of CL J1226.9+3332 Chandra X-ray Image of CL J1226.9+3332 "These new results are entirely independent of all previous methods of measuring the Hubble constant," said team member Marshall Joy also of MSFC. The astronomers used a phenomenon known as the Sunyaev-Zeldovich effect, where photons in the cosmic microwave background (CMB) interact with electrons in the hot gas that pervades the enormous galaxy clusters. The photons acquire energy from this interaction, which distorts the signal from the microwave background in the direction of the clusters. The magnitude of this distortion depends on the density and temperature of the hot electrons and the physical size of the cluster. Using radio telescopes to measure the distortion of the microwave background and Chandra to measure the properties of the hot gas, the physical size of the cluster can be determined. From this physical size and a simple measurement of the angle subtended by the cluster, the rules of geometry can be used to derive its distance. The Hubble constant is determined by dividing previously measured cluster speeds by these newly derived distances. Chandra X-ray Image of Abell 1689 Chandra X-ray Image of Abell 1689 This project was championed by Chandra's telescope mirror designer, Leon Van Speybroeck, who passed away in 2002. The foundation was laid when team members John Carlstrom

  13. Determination of the Hubble constant

    PubMed Central

    Freedman, Wendy L.; Feng, Long Long

    1999-01-01

    Establishing accurate extragalactic distances has provided an immense challenge to astronomers since the 1920s. The situation has improved dramatically as better detectors have become available, and as several new, promising techniques have been developed. For the first time in the history of this difficult field, relative distances to galaxies are being compared on a case-by-case basis, and their quantitative agreement is being established. New instrumentation, the development of new techniques for measuring distances, and recent measurements with the Hubble Space telescope all have resulted in new distances to galaxies with precision at the ±5–20% level. The current statistical uncertainty in some methods for measuring H0 is now only a few percent; with systematic errors, the total uncertainty is approaching ±10%. Hence, the historical factor-of-two uncertainty in the value of the H0 is now behind us. PMID:10500124

  14. HUBBLE FINDS NEW DARK SPOT ON NEPTUNE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's Hubble Space Telescope has discovered a new great dark spot, located in the northern hemisphere of the planet Neptune. Because the planet's northern hemisphere is now tilted away from Earth, the new feature appears near the limb of the planet. The spot is a near mirror-image to a similar southern hemisphere dark spot that was discovered in 1989 by the Voyager 2 probe. In 1994, Hubble showed that the southern dark spot had disappeared. Like its predecessor, the new spot has high altitude clouds along its edge, caused by gasses that have been pushed to higher altitudes where they cool to form methane ice crystal clouds. The dark spot may be a zone of clear gas that is a window to a cloud deck lower in the atmosphere. Planetary scientists don t know how long lived this new feature might be. Hubble's high resolution will allow astronomers to follow the spot's evolution and other unexpected changes in Neptune's dynamic atmosphere. The image was taken on November 2, 1994 with Hubble's Wide Field Planetary Camera 2, when Neptune was 2.8 billion miles (4.5 billion kilometers) from Earth. Hubble can resolve features as small as 625 miles (1,000 kilometers) across in Neptune's cloud tops. Credit: H. Hammel (Massachusetts Institute of Technology) and NASA

  15. HUBBLE HERITAGE PROJECT'S FIRST ANNIVERSARY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NGC 2440 is another planetary nebula ejected by a dying star, but it has a much more chaotic structure than NGC 2346. The central star of NGC 2440 is one of the hottest known, with a surface temperature near 200,000 degrees Celsius. The complex structure of the surrounding nebula suggests to some astronomers that there have been periodic oppositely directed outflows from the central star, somewhat similar to that in NGC 2346, but in the case of NGC 2440 these outflows have been episodic, and in different directions during each episode. The nebula is also rich in clouds of dust, some of which form long, dark streaks pointing away from the central star. In addition to the bright nebula, which glows because of fluorescence due to ultraviolet radiation from the hot star, NGC 2440 is surrounded by a much larger cloud of cooler gas which is invisible in ordinary light but can be detected with infrared telescopes. NGC 2440 lies about 4,000 light-years from Earth in the direction of the constellation Puppis. The Hubble Heritage team made this image from observations of NGC 2440 acquired by Howard Bond (STScI) and Robin Ciardullo (Penn State). Image Credit: NASA/The Hubble Heritage Team (AURA/STScI).

  16. STS-31: Hubble HST Science

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The primary objective of STS-31 was to deploy the Hubble Space Telescope(HST). This videotape presents a press briefing about the scientific goals of the HST program. The panel members were Dr. Weiler, HST program scientist; Dr. Boggess from NASA Goddard, the Center managing the HST Program; and Dr. Bahcall, President Elect of the American Astronomical Union. Dr. Weiler opened the panel discussion by introducing other HST scientists who were in the audience. Dr. Bahcall explained the four major areas that astronomers hope to better understand using the HST data: (1) The size and age of the universe; (2) quasars as flashlights to understanding other features of the universe; (3) planets around other stars; and (4) weather on the other planets of our Solar System. Other areas in which he hopes to have some understanding are galaxies under quasars, black holes, and missing matter. After his remarks, Dr. Bahcall presented a plaque to Charles Pellerin, who helped initiate the series of astrophysics telescopes. The HST is the first of these "Great Observatories". After the presentation, questions from the press were answered.

  17. HUBBLE CAPTURES DETAILED IMAGE OF URANUS' ATMOSPHERE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Hubble Space Telescope has peered deep into Uranus' atmosphere to see clear and hazy layers created by a mixture of gases. Using infrared filters, Hubble captured detailed features of three layers of Uranus' atmosphere. Hubble's images are different from the ones taken by the Voyager 2 spacecraft, which flew by Uranus 10 years ago. Those images - not taken in infrared light - showed a greenish-blue disk with very little detail. The infrared image allows astronomers to probe the structure of Uranus' atmosphere, which consists of mostly hydrogen with traces of methane. The red around the planet's edge represents a very thin haze at a high altitude. The haze is so thin that it can only be seen by looking at the edges of the disk, and is similar to looking at the edge of a soap bubble. The yellow near the bottom of Uranus is another hazy layer. The deepest layer, the blue near the top of Uranus, shows a clearer atmosphere. Image processing has been used to brighten the rings around Uranus so that astronomers can study their structure. In reality, the rings are as dark as black lava or charcoal. This false color picture was assembled from several exposures taken July 3, 1995 by the Wide Field Planetary Camera-2. CREDIT: Erich Karkoschka (University of Arizona Lunar and Planetary Lab) and NASA

  18. HUBBLE: ON THE ASTEROID TRAIL

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Astronomers Karl Stapelfeldt and Robin Evans have tracked down about 100 small asteroids by hunting through more than 28,000 archival images taken by the Hubble Space Telescope's Wide Field and Planetary Camera 2. Here is a sample of what they have found: four archival images that show the curved trails left by asteroids. [Top left]: Hubble captured a bright asteroid, with a visual magnitude of 18.7, roaming in the constellation Centaurus. Background stars are shown in white, while the asteroid trail is depicted in blue at top center. The trail has a length of 19 arc seconds. This asteroid has a diameter of one and one-quarter miles (2 kilometers), and was located 87 million miles from Earth and 156 million miles from the sun. Numerous orange and blue specks in this image and the following two images were created by cosmic rays, energetic subatomic particles that struck the camera's detector. [Top right]: Here is an asteroid with a visual magnitude of 21.8 passing a galaxy in the constellation Leo. The trail is seen in two consecutive exposures, the first shown in blue and the second in red. This asteroid has a diameter of half a mile (0.8 kilometers), and was located 188 million miles from Earth and 233 million miles from the sun. [Lower left]: This asteroid in the constellation Taurus has a visual magnitude of 23, and is one of the faintest seen so far in the Hubble archive. It moves from upper right to lower left in two consecutive exposures; the first trail is shown in blue and the second in red. Because of the asteroid's relatively straight trail, astronomers could not accurately determine its distance. The estimated diameter is half a mile (0.8 kilometers) at an Earth distance of 205 million miles and a sun distance of 298 million miles. [Lower right]: This is a broken asteroid trail crossing the outer regions of galaxy NGC 4548 in Coma Berenices. Five trail segments (shown in white) were extracted from individual exposures and added to a cleaned color image of the galaxy. The asteroid enters the image at top center and moves down toward the lower left. Large gaps in the trail occur because the telescope is orbiting the Earth and cannot continuously observe the galaxy. This asteroid has a visual magnitude of 20.8, a diameter of one mile (1.6 kilometers), and was seen at a distance of 254 million miles from Earth and 292 million miles from the sun. Credit: R. Evans and K. Stapelfeldt (Jet Propulsion Laboratory) and NASA

  19. Astronomer's Proposal Tool

    NASA Technical Reports Server (NTRS)

    Krueger, Tony

    2005-01-01

    Astronomer's Proposal Tool (APT) is a computer program that assists astronomers in preparing their Phase 1 and Phase 2 Hubble Space Telescope science programs. APT is a successor to the Remote Proposal Submission System 2 (RPS2) program, which has been rendered obsolete by more recent advances in computer software and hardware. APT exploits advances associated with widespread use of the Internet, multiplatform visual development software tools, and overall increases in the power of desktop computer hardware, all in such a way as to make the preparation and submission of proposals more intuitive and make observatory operations less cumbersome. APT provides documentation and help that are friendly, up to date, and easily accessible to users of varying levels of expertise, while defining an extensible framework that is responsive to changes in both technology and observatory operations. APT consists of two major components: (1) a set of software tools that are intuitive, visual, and responsive and (2) an integrated software environment that unifies all the tools and makes them interoperable. The APT tools include the Visual Target Tuner, Proposal Editor, Exposure Planner, Bright Object Checker, and Visit Planner.

  20. New Hubble Servicing Mission to upgrade instruments

    NASA Astrophysics Data System (ADS)

    2006-10-01

    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.

  1. Hubble Finds New Dark Spot on Neptune

    NASA Technical Reports Server (NTRS)

    1995-01-01

    NASA's Hubble Space Telescope has discovered a new great dark spot, located in the northern hemisphere of the planet Neptune. Because the planet's northern hemisphere is now tilted away from Earth, the new feature appears near the limb of the planet.

    The spot is a near mirror-image to a similar southern hemisphere dark spot that was discovered in 1989 by the Voyager 2 probe. In 1994, Hubble showed that the southern dark spot had disappeared.

    Like its predecessor, the new spot has high altitude clouds along its edge, caused by gasses that have been pushed to higher altitudes where they cool to form methane ice crystal clouds. The dark spot may be a zone of clear gas that is a window to a cloud deck lower in the atmosphere.

    Planetary scientists don t know how long lived this new feature might be. Hubble's high resolution will allow astronomers to follow the spot's evolution and other unexpected changes in Neptune's dynamic atmosphere.

    The image was taken on November 2, 1994 with Hubble's Wide Field Planetary Camera 2, when Neptune was 2.8 billion miles (4.5 billion kilometers) from Earth. Hubble can resolve features as small as 625 miles (1,000 kilometers) across in Neptune's cloud tops.

    The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  2. Hubble Captures Detailed Image of Uranus' Atmosphere

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Hubble Space Telescope has peered deep into Uranus' atmosphere to see clear and hazy layers created by a mixture of gases. Using infrared filters, Hubble captured detailed features of three layers of Uranus' atmosphere.

    Hubble's images are different from the ones taken by the Voyager 2 spacecraft, which flew by Uranus 10 years ago. Those images - not taken in infrared light - showed a greenish-blue disk with very little detail.

    The infrared image allows astronomers to probe the structure of Uranus' atmosphere, which consists of mostly hydrogen with traces of methane. The red around the planet's edge represents a very thin haze at a high altitude. The haze is so thin that it can only be seen by looking at the edges of the disk, and is similar to looking at the edge of a soap bubble. The yellow near the bottom of Uranus is another hazy layer. The deepest layer, the blue near the top of Uranus, shows a clearer atmosphere.

    Image processing has been used to brighten the rings around Uranus so that astronomers can study their structure. In reality, the rings are as dark as black lava or charcoal.

    This false color picture was assembled from several exposures taken July 3, 1995 by the Wide Field Planetary Camera-2.

    The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  3. The Hubble Tarantula Treasury Project

    NASA Astrophysics Data System (ADS)

    Sabbi, Elena; Lennon, D. J.; Anderson, J.; Van Der Marel, R. P.; Aloisi, A.; Boyer, M. L.; Cignoni, M.; De Marchi, G.; de Mink, S. E.; Evans, C. J.; Gallagher, J. S.; Gordon, K. D.; Gouliermis, D.; Grebel, E.; Koekemoer, A. M.; Larsen, S. S.; Panagia, N.; Ryon, J. E.; Smith, L. J.; Tosi, M.; Zaritsky, D. F.

    2014-01-01

    The Tarantula Nebula (a.k.a. 30 Doradus) in the Large Magellanic Cloud is one of the most famous objects in astronomy, with first astronomical references being more than 150 years old. Today the Tarantula Nebula and its ionizing cluster R136 are considered one of the few known starburst regions in the Local Group and an ideal test bed to investigate the temporal and spatial evolution of a prototypical starburst on a sub-cluster scale. The Hubble Tarantula Treasury Project (HTTP) is a panchromatic imaging survey of the stellar populations and ionized gas in the Tarantula Nebula that reaches into the sub-solar mass regime (<0.5 M?). HTTP utilizes the capability of the Hubble Space Telescope to operate the Advanced Camera for Surveys and the Wide Field Camera 3 in parallel to study this remarkable region in the near-ultraviolet, optical, and near-infrared spectral regions, including narrow-band H? images. The program was awarded 60 orbits of HST time and is built on the existing 30 orbits monochromatic proper motion program GO-12499 (PI Lennon). The combination of all these bands provides a unique view of the region: the resulting maps of the Tarantula’s stellar content provide the basis for investigations of star formation in an environment resembling the extreme conditions found in starburst galaxies and in the early universe. At the same time access to detailed properties of individual stars allows us to begin to reconstruct the temporal and spatial evolution of the Tarantula Nebula over space and time on a sub-parsec scale. We will deliver high-level data products (i.e. star and cluster catalogs, co-registered stacked images). HTTP will become the definitive catalog of the field, and have lasting value for future. HTTP also has an educational and public outreach component aimed to stimulate interest in STEM disciplines among people with visual impairments. “Reach for the Stars: Touch, Look, Listen, Learn” is a free eBook that explains how stars form and evolve using images from HTTP. The eBook utilizes emerging technology that works in conjunction with the built-in accessibility features in the Apple iPad to allow totally blind users to interactively explore complex astronomical images.

  4. Astronomical instruments.

    NASA Astrophysics Data System (ADS)

    Rai, R. N.

    Indian astronomers have devised a number of instruments and the most important of these is the armillary sphere. The earliest armillary spheres were very simple instruments. Ptolemy in his Almagest enumerates at least three. The simplest of all was the equinoctial armilla. They had also the solstitial armilla which was a double ring, erected in the plane of the meridian with a rotating inner circle. This was used to measure the solar altitude.

  5. Astronomical superhighways

    NASA Astrophysics Data System (ADS)

    Leach, D. C.

    1995-08-01

    The expansion of data supply has been prolific over the past decade. Publishers of text are only just beginning to consider what the aim of their publications should be in the light of competition from computer databases. Increasingly sources of data are becoming linked into a global network. The modem has revolutionised the way many astronomers interact with the outside world and each other. Access to data sources world wide can now be undertaken with a simple telephone call and a desktop computer.

  6. Hubble Space Telescope Image

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This photograph is a Hubble Space Telescope (HST) image of a sky full of glittering jewels. The HST peered into the Sagittarius star cloud, a narrow dust free region, providing this spectacular glimpse of a treasure chest full of stars.

  7. Hubble Discovers Bright New Spot on Io

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This NASA Hubble Space Telescope pair of images of Jupiter's volcanic moon Io shows the surprising emergence of a 200-mile diameter large yellowish-white feature near the center of the moon's disk (photo on the right). This is a more dramatic change in 16 months than any seen over the previous 15 years, say researchers. They suggest the spot may be a new class of transient feature on the moon. For comparison the photo on the left was taken in March 1994 -- before the spot emerged - - and shows that Io's surface had undergone only subtle changes since it was last seen close-up by the Voyager 2 probe in 1979. The new spot seen in the July 1995 Hubble image replaces a smaller whitish spot seen in about the same place in the March 1994 image. Note the much more subtle changes seen elsewhere on this face of Io over the 16 months between the images. Each image is a composite of frames taken at near-ultraviolet, violet, and yellow wavelengths, with Hubble's Wide Field and Planetary Camera 2. 'The new spot surrounds the volcano Ra Patera, which was photographed by Voyager, and is probably composed of material, probably frozen gas, ejected from Ra Patera by a large volcanic explosion or fresh lava flows...,' according to John Spencer of Lowell Observatory in Flagstaff, Arizona. The new bright spot is also unusual because it is much yellower than other bright regions of Io, which are whitish in color. The unusual color may result from the freshness of the deposit and will probably provide clues as to the composition of new volcanic materials on Io. The temperature on Io's surface is about -150 degrees Celsius (-238 degrees Fahrenheit); however, 'hot spots' associated with volcanic activity may be as warm as 1,000 degrees Celsius (1,800 degrees Fahrenheit). Follow-up observations by Hubble, in coordination with the Galileo spacecraft, scheduled to arrive at Jupiter and fly by Io in December 1995, will reveal the evolution and lifetime of the new feature. Galileo will be able to see much greater detail on Io in visible light, but will still rely on information gleaned from Hubble UV observations and Hubble observations taken at times when Galileo cannot observe Io. These further observations should also tell whether astronomers have witnessed, for the first time, one of the processes which creates the bright regions on Io.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  8. S PIKE : Intelligent Scheduling of Hubble Space Telescope Observations

    Microsoft Academic Search

    Mark D. Johnston; Glenn E. Miller

    1994-01-01

    This paper describes the S PIKE system, a general framework for scheduling which has been developed by the Space Telescope Science Institute for NASA's Hubble Space Tele-scope (HST). Efficient use of astronomical observatories is very important to the scientific community: the demand for research-grade telescopes far exceeds the supply. The need for efficient scheduling is especially keen for space-based facilities

  9. Hubble Space Telescope, High Speed Photometer

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This drawing illustrates the Hubble Space Telescope's (HST's) High Speed Photometer (HSP). The HSP measures the intensity of starlight (brightness), which will help determine astronomical distances. Its principal use will be to measure extremely-rapid variations or pulses in light from celestial objects, such as pulsating stars. The HSP produces brightness readings. Light passes into one of four special signal-multiplying tubes that record the data. The HSP can measure energy fluctuations from objects that pulsate as rapidly as once every 10 microseconds. From HSP data, astronomers expect to learn much about such mysterious objects as pulsars, black holes, and quasars. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors.

  10. Dark Matter: Astronomical Aspects

    NASA Astrophysics Data System (ADS)

    Trimble, Virginia

    2005-01-01

    Characteristic mass-to-light ratios rise as we look from short distance scales to long ones; hence the concept of dark matter. A reasonable graph of the correlation could have been drawn as early as 1939 using the Oort limit for the solar neighborhood Hubble's inner galaxies Babcock's extended rotation curve of M31 Holmberg's binary galaxies and Zwicky's and Smith's masses for the Coma and Virgo clusters. Holmberg actually noted the trend in 1937. Additional kinds of data including X-ray temperatures and gravitational lensing have tended to support the original trend as have modern applications of the older techniques (e.g. the velocity dispersions of satellite galaxies in the SDSS data base announced the day this abstract was written). The talk will attempt to probe whether there are any serious unsolved dark matter problems for which astronomical observations are likely to provide a solution for instance halo shapes cusps vs. cores and self-interacting DM whether the largest structures still have a slightly smaller M/L than the global value of 278 and limits on particular sorts of particle DM from upper limits to their decay and annihilation products.

  11. Dark Matter: Astronomical Aspects

    NASA Astrophysics Data System (ADS)

    Trimble, Virginia

    Characteristic mass-to-light ratios rise as we look from short distance scales to long ones; hence the concept of dark matter. A reasonable graph of the correlation could have been drawn as early as 1939 using the Oort limit for the solar neighborhood Hubble's inner galaxies Babcock's extended rotation curve of M31 Holmberg's binary galaxies and Zwicky's and Smith's masses for the Coma and Virgo clusters. Holmberg actually noted the trend in 1937. Additional kinds of data including X-ray temperatures and gravitational lensing have tended to support the original trend as have modern applications of the older techniques (e.g. the velocity dispersions of satellite galaxies in the SDSS data base announced the day this abstract was written). The talk will attempt to probe whether there are any serious unsolved dark matter problems for which astronomical observations are likely to provide a solution for instance halo shapes cusps vs. cores and self-interacting DM whether the largest structures still have a slightly smaller M/L than the global value of 278 and limits on particular sorts of particle DM from upper limits to their decay and annihilation products

  12. HUBBLE UNVEILS A GALAXY IN LIVING COLOR

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this view of the center of the magnificent barred spiral galaxy NGC 1512, NASA Hubble Space Telescope's broad spectral vision reveals the galaxy at all wavelengths from ultraviolet to infrared. The colors (which indicate differences in light intensity) map where newly born star clusters exist in both 'dusty' and 'clean' regions of the galaxy. This color-composite image was created from seven images taken with three different Hubble cameras: the Faint Object Camera (FOC), the Wide Field and Planetary Camera 2 (WFPC2), and the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). NGC 1512 is a barred spiral galaxy in the southern constellation of Horologium. Located 30 million light-years away, relatively 'nearby' as galaxies go, it is bright enough to be seen with amateur telescopes. The galaxy spans 70,000 light-years, nearly as much as our own Milky Way galaxy. The galaxy's core is unique for its stunning 2,400 light-year-wide circle of infant star clusters, called a 'circumnuclear' starburst ring. Starbursts are episodes of vigorous formation of new stars and are found in a variety of galaxy environments. Taking advantage of Hubble's sharp vision, as well as its unique wavelength coverage, a team of Israeli and American astronomers performed one of the broadest and most detailed studies ever of such star-forming regions. The results, which will be published in the June issue of the Astronomical Journal, show that in NGC 1512 newly born star clusters exist in both dusty and clean environments. The clean clusters are readily seen in ultraviolet and visible light, appearing as bright, blue clumps in the image. However, the dusty clusters are revealed only by the glow of the gas clouds in which they are hidden, as detected in red and infrared wavelengths by the Hubble cameras. This glow can be seen as red light permeating the dark, dusty lanes in the ring. 'The dust obscuration of clusters appears to be an on-off phenomenon,' says Dan Maoz, who headed the collaboration. 'The clusters are either completely hidden, enshrouded in their birth clouds, or almost completely exposed.' The scientists believe that stellar winds and powerful radiation from the bright, newly born stars have cleared away the original natal dust cloud in a fast and efficient 'cleansing' process. Aaron Barth, a co-investigator on the team, adds: 'It is remarkable how similar the properties of this starburst are to those of other nearby starbursts that have been studied in detail with Hubble.' This similarity gives the astronomers the hope that, by understanding the processes occurring in nearby galaxies, they can better interpret observations of very distant and faint starburst galaxies. Such distant galaxies formed the first generations of stars, when the universe was a fraction of its current age. Circumstellar star-forming rings are common in the universe. Such rings within barred spiral galaxies may in fact comprise the most numerous class of nearby starburst regions. Astronomers generally believe that the giant bar funnels the gas to the inner ring, where stars are formed within numerous star clusters. Studies like this one emphasize the need to observe at many different wavelengths to get the full picture of the processes taking place.

  13. HUBBLE AND KECK DISCOVER GALAXY BUILDING BLOCK

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This NASA Hubble Space Telescope image shows a very small, faint galaxy 'building block' newly discovered by a unique collaboration between ground- and space-based telescopes. Hubble and the 10-meter Keck Telescopes in Hawaii joined forces, using a galaxy cluster which acts as gravitational lens to detect what scientists believe is one of the smallest very distant objects ever found. The galaxy cluster Abell 2218 was used by a team of European and American astronomers led by Richard Ellis (Caltech) in their systematic search for intrinsically faint distant star-forming systems. Without help from Abell 2218's exceptional magnifying power to make objects appear about 30 times brighter, the galaxy building block would have been undetectable. In the image to the right, the object is seen distorted into two nearly identical, very red 'images' by the gravitational lens. The image pair represents the magnified result of a single background object gravitationally lensed by Abell 2218 and viewed at a distance of 13.4 billion light-years. The intriguing object contains only one million stars, far fewer than a mature galaxy, and scientists believe it is very young. Such young star-forming systems of low mass at early cosmic times are likely to be the objects from which present-day galaxies have formed. In the image to the left, the full overview of the galaxy cluster Abell 2218 is seen. This image was taken by Hubble in 1999 at the completion of Hubble Servicing Mission 3A. Credit: NASA, ESA, Richard Ellis (Caltech) and Jean-Paul Kneib (Observatoire Midi-Pyrenees, France) Acknowledgment: NASA, A. Fruchter and the ERO Team (STScI and ST-ECF)

  14. Climate instability on tidally locked exoplanets1 Edwin S. Kite2

    E-print Network

    Kite, Edwin

    Climate instability on tidally locked exoplanets1 Edwin S. Kite2 Department of Earth and Planetary planets, are expected to be in synchronous rotation (tidally locked). In this paper we investigate two

  15. HUBBLE SPIES A REALLY COOL STAR

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is a Hubble Space Telescope picture of one of the least massive and coolest stars even seen (upper right). It is a diminutive companion to the K dwarf star called GL 105A (also known as HD 16160) seen at lower left. The binary pair is located 27 light-years away in the constellation Cetus. Based on the Hubble observation, astronomers calculate that the companion, called GL 105C, is 25,000 times fainter than GL 105A in visible light. If the dim companion were at the distance of our Sun, it would be only four times brighter than the full moon. The Hubble observations confirm the detection of GL 105C last year by David Golimowski and his collaborators at Palomar Observatory in California. Although GL 105C was identified before, the Hubble view allows a more precise measurement of the separation between the binary components. Future Hubble observations of the binary orbit will allow the masses of both stars to be determined accurately. The Palomar group estimates that the companion's mass is 8-9 percent of the Sun's mass, which places it near the theoretical lower limit for stable hydrogen burning. Objects below this limit, called brown dwarfs, still 'shine' -- not by thermonuclear energy, but by the energy released through gravitational contraction. Two pictures, taken with Hubble's Wide Field Planetary Camera 2 (in PC mode) through different filters (in visible and near-infrared light) show that GL 105C is redder, hence cooler than GL 105A. The surface temperature of GL 105C is not precisely known, but may be as low as 2,600 degrees Kelvin (4,200 degrees Fahrenheit). This image was taken in near-infrared light, on January 5, 1995. GL 105C is located 3.4 arc seconds to the west-northwest of the larger GL 105A. (One arc second equals 1/3600 of a degree.) The bright spikes are caused by diffraction of light within the telescope's optical system, and the brighter white bar is an artifact of the CCD camera, which bleeds along a CCD column when a relatively bright object is in the field of view. These observations are part of a Guaranteed Time Observing Program for which William Fastie (the Johns Hopkins University, Baltimore, MD) and Dan Schroeder (Beloit College, Beloit, WI) were co-principal investigators. Credit: D. Golimowski (Johns Hopkins University), and NASA Image files in GIF and JPEG format may be accessed on Internet via anonymous ftp from oposite.stsci.edu in /pubinfo:

  16. From Galileo to Hubble

    NSDL National Science Digital Library

    This tutorial from the Space Telescope Science Institute covers the development of telescopes from Galileo to the Hubble Space Telescope, using images, animations, and text. Students must answer questions as they progress through the lesson. Telescopes covered include the Hooker, Hale, and Keck.

  17. HUBBLE SHOWS EXPANSION OF ETA CARINAE DEBRIS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The furious expansion of a huge, billowing pair of gas and dust clouds are captured in this NASA Hubble Space Telescope comparison image of the supermassive star Eta Carinae. To create the picture, astronomers aligned and subtracted two images of Eta Carinae taken 17 months apart (April 1994, September 1995). Black represents where the material was located in the older image, and white represents the more recent location. (The light and dark streaks that make an 'X' pattern are instrumental artifacts caused by the extreme brightness of the central star. The bright white region at the center of the image results from the star and its immediate surroundings being 'saturated' in one of the images.)Photo Credit: Jon Morse (University of Colorado), Kris Davidson (University of Minnesota), and NASA Image files in GIF and JPEG format and captions may be accessed on Internet via anonymous ftp from oposite.stsci.edu in /pubinfo.

  18. European astronaut selected for the third Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    1998-08-01

    The STS-104 crew will rendezvous with the orbiting Hubble Space Telescope, which is the size of a city bus, capture it using the Shuttle's Canadian robot arm and secure it in Columbia's payload bay. Then, working in teams of two, the four astronauts will leave the Shuttle's pressurised cabin and venture into the payload bay, performing a variety of tasks that will improve the productivity and reliability of the telescope. The four astronauts will perform a series of six "extravehicular" activities in the open space environment. Such activities are commonly called spacewalks, but this term does little justice to the considerable physical and mental efforts that astronauts need to make in doing the very demanding work involved. The Shuttle commander and pilot for this flight have not yet been appointed, but the four designated mission specialists begin training for the STS-104 mission immediately. "The ambitious nature of this mission, with its six spacewalks, made it important for the payload crew to begin training as early as possible," said David C. Leestma, NASA Director of Flight Crew Operations at the Johnson Space Center in Houston, to which Claude Nicollier is on resident assignment from ESA's European Astronaut Centre in Cologne, Germany, the home base of the European astronaut corps. The Hubble Space Telescope was launched into orbit in April 1990. It is one of the most capable optical telescopes available to astronomers today, producing images and spectral observations at the forefront of astronomy. The European Space Agency contributed a 15 share to the development of Hubble. One of the five scientific instruments on board, the Faint Object Camera, was built by a European industrial consortium made up of British Aerospace, Dornier and Matra under a contract with the European Space Agency. The solar arrays which provide Hubble with electrical power were manufactured by British Aerospace and Dornier. In its eight years of operation, the telescope has not only observed relatively near celestial objects, like the planets in our solar system, but also looked thousands of millions of light years into space, taking images of the most distant galaxies ever seen. "The observations and spectral measurements taken with Hubble have improved our understanding of the origin and age of the universe. In some cases, the Hubble Space Telescope has already changed our thinking about the evolution of planetary systems, stars and galaxies," points out Roger Bonnet, ESA's Director of Science. Astronomers throughout the world are using the telescope. European astronomers have a significant share in the scientific utilisation of Hubble. The Space Telescope Science Institute in Baltimore, USA, coordinates and schedules the various observations. Europe's centre for coordinating observations from Hubble, the Space Telescope European Coordination Facility, is located at the Headquarters of the European Southern Observatory (ESO) at Garching, near Munich, Germany. The Hubble Space Telescope is the first spacecraft ever built that has been designed for extensive in-orbit maintenance and refurbishment by astronauts. Unlike other satellites launched on unmanned rockets, Hubble is accessible by astronauts in orbit. It has numerous grapple fixtures and handholds for ease of access and the safety of astronauts. Hence the telescope's planned 15-year continuous operating time, despite the harsh environmental conditions, and the ability to upgrade it with more powerful instruments as technology progresses. At regular intervals of 3 to 4 years, the US Space Shuttle visits the telescope in orbit to replace components which have failed or reached the nominal end of their operational lifetime and to replace and upgrade instruments with newer, better ones. STS-104 will be the third Hubble servicing mission, after STS-61 in December 1993 and STS-82 in February 1997. To increase Hubble's scientific capability, Nicollier and his fellow crew members from NASA will remove the European-built Faint Object Camera, which has been wo

  19. 43Using a Gravity Lens to `Weigh' a Cluster of Galaxies The Hubble Space Telescope recently

    E-print Network

    Christian, Eric

    43Using a Gravity Lens to `Weigh' a Cluster of Galaxies The Hubble Space Telescope recently by this `gravity lens' astronomers can study the blue galaxy located 9.7 billion light years from Earth ­ details radius to determine the total mass of the cluster of galaxies, including any dark matter that it might

  20. HUBBLE PINPOINTS DISTANT SUPERNOVAE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These Hubble Space Telescope images pinpoint three distant supernovae, which exploded and died billions of years ago. Scientists are using these faraway light sources to estimate if the universe was expanding at a faster rate long ago and is now slowing down. Images of SN 1997cj are in the left hand column; SN 1997ce, in the middle; and SN 1997ck, on the right. All images were taken by the Hubble telescope's Wide Field and Planetary Camera 2. The top row of images are wider views of the supernovae. The supernovae were discovered in April 1997 in a ground-based survey at the Canada-France-Hawaii Telescope on Mauna Kea, Hawaii. Once the supernovae were discovered, the Hubble telescope was used to distinguish the supernovae from the light of their host galaxies. A series of Hubble telescope images were taken in May and June 1997 as the supernovae faded. Six Hubble telescope observations spanning five weeks were taken for each supernova. This time series enabled scientists to measure the brightness and create a light curve. Scientists then used the light curve to make an accurate estimate of the distances to the supernovae. Scientists combined the estimated distance with the measured velocity of the supernova's host galaxy to determine the expansion rate of the universe in the past (5 to 7 billion years ago) and compare it with the current rate. These supernovae belong to a class called Type Ia, which are considered reliable distance indicators. Looking at great distances also means looking back in time because of the finite velocity of light. SN 1997ck exploded when the universe was half its present age. It is the most distant supernova ever discovered (at a redshift of 0.97), erupting 7.7 billion years ago. The two other supernovae exploded about 5 billion years ago. SN 1997ce has a redshift of 0.44; SN 1997cj, 0.50. SN 1997ck is in the constellation Hercules, SN 1997ce is in Lynx, just north of Gemini; and SN 1997cj is in Ursa Major, near the Hubble Deep Field. Credits: Peter Garnavich, Harvard-Smithsonian Center for Astrophysics, the High-z Supernova Search Team, and NASA

  1. Hubble Space Telescope, Faint Object Camera

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This drawing illustrates Hubble Space Telescope's (HST's), Faint Object Camera (FOC). The FOC reflects light down one of two optical pathways. The light enters a detector after passing through filters or through devices that can block out light from bright objects. Light from bright objects is blocked out to enable the FOC to see background images. The detector intensifies the image, then records it much like a television camera. For faint objects, images can be built up over long exposure times. The total image is translated into digital data, transmitted to Earth, and then reconstructed. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors.

  2. Hubble Space Telescope Spies on 'Black Eye'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Residing roughly 17 million light years from Earth, in the northern constellation Coma Berenices, is a merged star system known as Messier 64 (M64). First cataloged in the 18th century by the French astronomer Messier, M64 is a result of two colliding galaxies and has an unusual appearance as well as bizarre internal motions. It has a spectacular dark band of absorbing dust in front of its bright nucleus, lending to it the nickname of the 'Black Eye' or 'Evil Eye' galaxy. Fine details of the dark band can be seen in this image of the central portion of M64 obtained by the Wide Field Planetary Camera (WFPC2) of NASA's Hubble Space Telescope (HST). Appearing to be a fairly normal pinwheel-shaped galaxy, the M64 stars are rotating in the same direction, clockwise, as in the majority of galaxies. However, detailed studies in the 1990's led to the remarkable discovery that the interstellar gas in the outer regions of M64 rotates in the opposite direction from the gas and stars in the irner region. Astronomers believe that the oppositely rotating gas arose when M64 absorbed a satellite galaxy that collided with it, perhaps more than one billion years ago. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST.

  3. HUBBLE PEEKS INTO A STELLAR NURSERY IN A NEARBY GALAXY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    HUBBLE PEEKS INTO A STELLAR NURSERY IN A NEARBY GALAXY NASA's Hubble Space Telescope has peered deep into a neighboring galaxy to reveal details of the formation of new stars. Hubble's target was a newborn star cluster within the Small Magellanic Cloud, a small galaxy that is a satellite of our own Milky Way. The new images show young, brilliant stars cradled within a nebula, or glowing cloud of gas, cataloged as N 81. These massive, recently formed stars inside N 81 are losing material at a high rate, sending out strong stellar winds and shock waves and hollowing out a cocoon within the surrounding nebula. The two most luminous stars, seen in the Hubble image as a very close pair near the center of N 81, emit copious ultraviolet radiation, causing the nebula to glow through fluorescence. Outside the hot, glowing gas is cooler material consisting of hydrogen molecules and dust. Normally this material is invisible, but some of it can be seen in silhouette against the nebular background, as long dust lanes and a small, dark, elliptical-shaped knot. It is believed that the young stars have formed from this cold matter through gravitational contraction. Few features can be seen in N 81 from ground-based telescopes, earning it the informal nick-name 'The Blob.' Astronomers were not sure if just one or a few hot stars were embedded in the cloud, or if it was a stellar nursery containing a large number of less massive stars. Hubble's high-resolution imaging shows the latter to be the case, revealing that numerous young, white-hot stars---easily visible in the color picture---are contained within N 81. This crucial information bears strongly on theories of star formation, and N 81 offers a singular opportunity for a close-up look at the turbulent conditions accompanying the birth of massive stars. The brightest stars in the cluster have a luminosity equal to 300,000 stars like our own Sun. Astronomers are especially keen to study star formation in the Small Magellanic Cloud, because its chemical composition is different from that of the Milky Way. All of the chemical elements, other than hydrogen and helium, have only about one-tenth the abundances seen in our own galaxy. The study of N81 thus provides an excellent template for studying the star formation that occurred long ago in very distant galaxies, before nuclear reactions inside stars had synthesized the elements heavier than helium. The Small Magellanic Cloud, named after the explorer Ferdinand Magellan, lies 200,000 light-years away, and is visible only from the Earth's southern hemisphere. N 81 is the 81st nebula cataloged in a survey of the SMC carried out in the 1950's by astronomer Karl Henize, who later became an astronomer-astronaut who flew into space aboard NASA's space shuttle. The Hubble Heritage image of N 81 is a color representation of data taken in September, 1997, with Hubble's Wide Field Planetary Camera 2. Color filters were used to sample light emitted by oxygen ([O III]) and hydrogen (H-alpha, H-beta). N 81 is the target of investigations by European astronomers Mohammad Heydari-Malayeri from the Paris Observatory in France; Michael Rosa from the Space Telescope-European Coordinating Facility in Munich, Germany; Hans Zinnecker of the Astrophysical Institute in Potsdam, Germany; Lise Deharveng of Marseille Observatory, France; and Vassilis Charmadaris of Cornell University, USA (formerly at Paris Observatory). Members of this team are interested in understanding the formation of hot, massive stars, especially under conditions different from those in the Milky Way. Image Credit: NASA and The Hubble Heritage Team (STScI/AURA) Acknowledgement: Mohammad Heydari-Malayeri (Paris Observatory, France) EDITOR'S

  4. Astronomers meet in phoenix, recount a stellar year.

    PubMed

    Flam, F

    1993-01-22

    Despite a tightening of the National Aeronautics and Space Administration's budget and the trouble with the Hubble Space Telescope, astronomers were starry-eyed over their latest findings, presented at the major annual meeting of the American Astronomical Society, (AAS) January 3 to 7. New images and measurements of stars, galaxies, cosmic microwaves, and mysterious gamma rays, along with an exciting nova explosion, made it a bright year for those working with existing orbiting satellites and ground-based telescopes, though uncertain funding clouds the future. PMID:17734156

  5. Edwin Grant Dexter: an early researcher in human behavioral biometeorology

    NASA Astrophysics Data System (ADS)

    Stewart, Alan E.

    2015-06-01

    Edwin Grant Dexter (1868-1938) was one of the first researchers to study empirically the effects of specific weather conditions on human behavior. Dexter (1904) published his findings in a book, Weather influences. The author's purposes in this article were to (1) describe briefly Dexter's professional life and examine the historical contexts and motivations that led Dexter to conduct some of the first empirical behavioral biometeorological studies of the time, (2) describe the methods Dexter used to examine weather-behavior relationships and briefly characterize the results that he reported in Weather influences, and (3) provide a historical analysis of Dexter's work and assess its significance for human behavioral biometeorology. Dexter's Weather influences, while demonstrating an exemplary approach to weather, health, and behavior relationships, came at the end of a long era of such studies, as health, social, and meteorological sciences were turning to different paradigms to advance their fields. For these reasons, Dexter's approach and contributions may not have been fully recognized at the time and are, consequently, worthy of consideration by contemporary biometeorologists.

  6. Edwin Grant Dexter: an early researcher in human behavioral biometeorology.

    PubMed

    Stewart, Alan E

    2015-06-01

    Edwin Grant Dexter (1868-1938) was one of the first researchers to study empirically the effects of specific weather conditions on human behavior. Dexter (1904) published his findings in a book, Weather influences. The author's purposes in this article were to (1) describe briefly Dexter's professional life and examine the historical contexts and motivations that led Dexter to conduct some of the first empirical behavioral biometeorological studies of the time, (2) describe the methods Dexter used to examine weather-behavior relationships and briefly characterize the results that he reported in Weather influences, and (3) provide a historical analysis of Dexter's work and assess its significance for human behavioral biometeorology. Dexter's Weather influences, while demonstrating an exemplary approach to weather, health, and behavior relationships, came at the end of a long era of such studies, as health, social, and meteorological sciences were turning to different paradigms to advance their fields. For these reasons, Dexter's approach and contributions may not have been fully recognized at the time and are, consequently, worthy of consideration by contemporary biometeorologists. PMID:25194751

  7. 75 FR 3761 - Southern Nuclear Operating Company, Inc., Edwin I. Hatch Nuclear Plant, Units 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-22

    ...NPF-5, issued to Southern Nuclear Operating Company, Inc...operation of the Edwin I. Hatch Nuclear Plant, Units 1 and 2 (HNP...No changes to the National Pollution Discharge Elimination System...Statement for License Renewal of Nuclear Plants: Edwin I. Hatch...

  8. HUBBLE SNAPSHOT CAPTURES LIFE CYCLE OF STARS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's Hubble Space Telescope has snapped a nearly face-on view of a swirling disk of dust and gas surrounding a developing star called AB Aurigae. The Hubble telescope image, taken in visible light by the Space Telescope Imaging Spectrograph, shows unprecedented detail in the disk, including clumps of dust and gas that may be the seeds of planet formation. Normally, a young star's bright light prevents astronomers from seeing material closer to it. That's why astronomers used a coronograph in these two images of AB Aurigae to block most of the light from the star. The rest of the disk material is illuminated by light reflected from the gas and dust surrounding the star. The image on the left represents the best ground-based coronographic observation of AB Aurigae. Paul Kalas of the Space Telescope Science Institute took the image with the University of Hawaii's 2.2-meter telescope. The telescope's coronograph eclipsed a 33.5-billion-mile (53.6-billion-kilometer) area centered on the star. This area is nine times larger than our solar system. The picture shows that the star resides in a region of dust clouds - the semicircular-shaped material to the left of the star. The Hubble telescope image on the right shows a windowpane-shaped occulting bar -- the dark bands running vertically through the middle of the image and horizontally across the upper part of it. The occulting bar covers the innermost part of the disk and star, about 7.1 billion miles (11.5 billion kilometers) or 1.4 times our solar system's diameter. The diagonal lines are the remnants of the diffraction spikes produced in Hubble telescope images of bright stars. The disk is extremely wide: its diameter is roughly 1,300 times Earth's distance from the Sun. The disk material seen in this image is at a distance equivalent to well beyond Pluto's orbit. One faint background star is visible at 5 o'clock. The star's disk shows a wealth of structure, with bright spiral-shaped bands from 9 o'clock to 6 o'clock and closer to the star from 12 o'clock to 3 o'clock. The outermost of these bands are seen in the ground-based image. The imaging spectrograph data show that these bands are themselves composed of numerous smaller bands. The smallest features include some bright knots of material to the left of the star. These knots are close in size to the resolution limit of the Hubble telescope and have diameters 1.3 to 3 billion miles (2 to 5 billion kilometers) wide or 14 to 32 times Earth's distance from the Sun. The brightest knot is at 9 o'clock. The image was taken Jan. 23 and 24, 1999. False colors were used to bring out details in AB Aurigae's disk. The wavelength range is 2,000 to 10,100 Angstroms. Credit: C.A. Grady (National Optical Astronomy Observatories, NASA Goddard Space Flight Center), B. Woodgate (NASA Goddard Space Flight Center), F. Bruhweiler and A. Boggess (Catholic University of America), P. Plait and D. Lindler (ACC, Inc., Goddard Space Flight Center), M. Clampin (Space Telescope Science Institute), and NASA.

  9. HUBBLE FINDS A BARE BLACK HOLE POURING OUT LIGHT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's Hubble Space Telescope has provided a never-before-seen view of a warped disk flooded with a torrent of ultraviolet light from hot gas trapped around a suspected massive black hole. [Right] This composite image of the core of the galaxy was constructed by combining a visible light image taken with Hubble's Wide Field Planetary Camera 2 (WFPC2), with a separate image taken in ultraviolet light with the Faint Object Camera (FOC). While the visible light image shows a dark dust disk, the ultraviolet image (color-coded blue) shows a bright feature along one side of the disk. Because Hubble sees ultraviolet light reflected from only one side of the disk, astronomers conclude the disk must be warped like the brim of a hat. The bright white spot at the image's center is light from the vicinity of the black hole which is illuminating the disk. [Left] A ground-based telescopic view of the core of the elliptical galaxy NGC 6251. The inset box shows Hubble Space Telescope's field of view. The galaxy is 300 million light-years away in the constellation Ursa Minor. Photo Credit: Philippe Crane (European Southern Observatory), and NASA

  10. Hubble's deepest view ever of the Universe unveils earliest galaxies

    NASA Astrophysics Data System (ADS)

    2004-03-01

    Hubble sees galaxies galore hi-res Size hi-res: 446 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble sees galaxies galore Galaxies, galaxies everywhere - as far as the NASA/ESA Hubble Space Telescope can see. This view of nearly 10,000 galaxies is the deepest visible-light image of the cosmos. Called the Hubble Ultra Deep Field, this galaxy-studded view represents a ‘deep’ core sample of the universe, cutting across billions of light-years. Hubble reveals galactic drama hi-res Size hi-res: 879 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble reveals galactic drama A galactic brawl. A close encounter with a spiral galaxy. Blue wisps of galaxies. These close-up snapshots of galaxies in the Hubble Ultra Deep Field reveal the drama of galactic life. Here three galaxies just below centre are enmeshed in battle, their shapes distorted by the brutal encounter. Hubble reveals galactic drama hi-res Size hi-res: 886 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble reveals galactic drama A galactic brawl. A close encounter with a spiral galaxy. Blue wisps of galaxies. These close-up snapshots of galaxies in the Hubble Ultra Deep Field reveal the drama of galactic life. Here three galaxies just below centre are enmeshed in battle, their shapes distorted by the brutal encounter. Hubble reveals galactic drama hi-res Size hi-res: 892 kb Credits: NASA, ESA, and S. Beckwith (STScI) and the HUDF Team Hubble reveals galactic drama A galactic brawl. A close encounter with a spiral galaxy. Blue wisps of galaxies. These close-up snapshots of galaxies in the Hubble Ultra Deep Field reveal the drama of galactic life. The galaxies in this panel were plucked from a harvest of nearly 10,000 galaxies in the Ultra Deep Field, the deepest visible-light image of the cosmos. This historic new view is actually made up by two separate images taken by Hubble's Advanced Camera for Surveys (ACS) and the Near Infrared Camera and Multi-object Spectrometer (NICMOS). Both images reveal some galaxies that are too faint to be seen by ground-based telescopes, or even in Hubble's previous faraway looks, called the Hubble Deep Fields (HDFs), taken in 1995 and 1998. The HUDF field contains an estimated 10,000 galaxies in a patch of sky just one-tenth the diameter of the full Moon. Besides the rich harvest of classic spiral and elliptical galaxies, there is a zoo of oddball galaxies littering the field. Some look like toothpicks; others like links on a bracelet. A few appear to be interacting. Their strange shapes are a far cry from the majestic spiral and elliptical galaxies we see today. These oddball galaxies chronicle a period when the Universe was more chaotic. Order and structure were just beginning to emerge. The combination of ACS and NICMOS images will be used to search for galaxies that existed between 400 and 800 million years after the Big Bang (in cosmological terms this corresponds to a 'redshift' range of 7 to 12). Astronomers around the world will use these data to understand whether in this very early stages the Universe appears to be the same as it did when the cosmos was between 1000 and 2000 million years old. Hubble's ACS allows astronomers to see galaxies two to four times fainter than Hubble could view previously, but the NICMOS sees even farther than the ACS. The NICMOS reveals the farthest galaxies ever seen because the expanding Universe has stretched their light into the near-infrared portion of the spectrum. The ACS uncovered galaxies that existed 800 million years after the Big Bang (at a redshift of 7). But the NICMOS might have spotted galaxies that lived just 400 million years after the birth of the cosmos (at a redshift of 12). Just like the previous HDFs, the new data are expected to galvanise the astronomical community and lead to dozens of research papers that will offer new insights into the birth and evolution of galaxies. This will hold the record as the deepest-ever view of the Universe until ESA together with NASA launches the James Webb Space Telescope in

  11. American Astronomical Society

    NSDL National Science Digital Library

    The major organization of professional astronomers in North America, the American Astronomical Society's (AAS) main goal "is to promote the advancement of astronomy and closely related branches of science." The website presents the Society's three scholarly journals and its numerous publications. The Education link offers an abundance of educational resources for users of all levels, answers to many astronomical questions, and fascinating news articles. Researchers can find out about grants, prizes, employment, and membership opportunities.

  12. The astronomical units

    E-print Network

    N. Capitaine; B. Guinot

    2008-12-16

    The IAU-1976 System of astronomical constants includes three astronomical units (i.e. for time, mass and length). This paper reports on the status of the astronomical unit of length (ua) and mass (MSun) within the context of the recent IAU Resolutions on reference systems and the use of modern observations in the solar system. We especially look at a possible re-definition of the ua as an astronomical unit of length defined trough a fixed relation to the SI metre by a defining number.

  13. The Hubble constant.

    PubMed Central

    Tully, R B

    1993-01-01

    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. PMID:11607391

  14. The Hubble constant.

    PubMed

    Tully, R B

    1993-06-01

    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. PMID:11607391

  15. Hubble Observes Surface of Titan

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Scientists for the first time have made images of the surface of Saturn's giant, haze-shrouded moon, Titan. They mapped light and dark features over the surface of the satellite during nearly a complete 16-day rotation. One prominent bright area they discovered is a surface feature 2,500 miles across, about the size of the continent of Australia.

    Titan, larger than Mercury and slightly smaller than Mars, is the only body in the solar system, other than Earth, that may have oceans and rainfall on its surface, albeit oceans and rain of ethane-methane rather than water. Scientists suspect that Titan's present environment -- although colder than minus 289 degrees Fahrenheit, so cold that water ice would be as hard as granite -- might be similar to that on Earth billions of years ago, before life began pumping oxygen into the atmosphere.

    Peter H. Smith of the University of Arizona Lunar and Planetary Laboratory and his team took the images with the Hubble Space Telescope during 14 observing runs between Oct. 4 - 18. Smith announced the team's first results last week at the 26th annual meeting of the American Astronomical Society Division for Planetary Sciences in Bethesda, Md. Co-investigators on the team are Mark Lemmon, a doctoral candidate with the UA Lunar and Planetary Laboratory; John Caldwell of York University, Canada; Larry Sromovsky of the University of Wisconsin; and Michael Allison of the Goddard Institute for Space Studies, New York City.

    Titan's atmosphere, about four times as dense as Earth's atmosphere, is primarily nitrogen laced with such poisonous substances as methane and ethane. This thick, orange, hydrocarbon haze was impenetrable to cameras aboard the Pioneer and Voyager spacecraft that flew by the Saturn system in the late 1970s and early 1980s. The haze is formed as methane in the atmosphere is destroyed by sunlight. The hydrocarbons produced by this methane destruction form a smog similar to that found over large cities, but is much thicker.

    Smith's group used the Hubble Space Telescope's WideField/Planetary Camera 2 at near-infrared wavelengths (between .85 and 1.05 microns). Titan's haze is transparent enough in this wavelength range to allow mapping of surface features according to their reflectivity. Only Titan's polar regions could not be mapped this way, due to the telescope's viewing angle of the poles and the thick haze near the edge of the disk. Their image-resolution (that is, the smallest distance seen in detail) with the WFPC2 at the near-infrared wavelength is 360 miles. The 14 images processed and compiled into the Titan surface map were as 'noise' free, or as free of signal interference, as the space telescope allows, Smith said.

    Titan makes one complete orbit around Saturn in 16 days, roughly the duration of the imaging project. Scientists have suspected that Titan's rotation also takes 16 days, so that the same hemisphere of Titan always faces Saturn, just as the same hemisphere of the Earth's moon always faces the Earth. Recent observations by Lemmon and colleagues at the University of Arizona confirm this true.

    It's too soon to conclude much about what the dark and bright areas in the Hubble Space Telescope images are -- continents, oceans, impact craters or other features, Smith said. Scientists have long suspected that Titan's surface was covered with a global ehtane-methane ocean. The new images show that there is at least some solid surface.

    Smith's team made a total 50 images of Titan last month in their program, a project to search for small scale features in Titan's lower atmosphere and surface. They have yet to analyze images for information about Titan's clouds and winds. That analysis could help explain if the bright areas are major impact craters in the frozen water ice-and-rock or higher-altitude features.

    The images are important information for the Cassini mission, which is to launch a robotic spacecraft on a 7-year journey to Saturn in October 1997. About three weeks before Cassini's first flyby

  16. HUBBLE SEES SUPERSONIC EXHAUST FROM NEBULA

    NASA Technical Reports Server (NTRS)

    2002-01-01

    2-9 is a striking example of a 'butterfly' or a bipolar planetary nebula. Another more revealing name might be the 'Twin Jet Nebula.' If the nebula is sliced across the star, each side of it appears much like a pair of exhausts from jet engines. Indeed, because of the nebula's shape and the measured velocity of the gas, in excess of 200 miles per second, astronomers believe that the description as a super-super-sonic jet exhaust is quite apt. Ground-based studies have shown that the nebula's size increases with time, suggesting that the stellar outburst that formed the lobes occurred just 1,200 years ago. The central star in M2-9 is known to be one of a very close pair which orbit one another at perilously close distances. It is even possible that one star is being engulfed by the other. Astronomers suspect the gravity of one star pulls weakly bound gas from the surface of the other and flings it into a thin, dense disk which surrounds both stars and extends well into space. The disk can actually be seen in shorter exposure images obtained with the Hubble telescope. It measures approximately 10 times the diameter of Pluto's orbit. Models of the type that are used to design jet engines ('hydrodynamics') show that such a disk can successfully account for the jet-exhaust-like appearance of M2-9. The high-speed wind from one of the stars rams into the surrounding disk, which serves as a nozzle. The wind is deflected in a perpendicular direction and forms the pair of jets that we see in the nebula's image. This is much the same process that takes place in a jet engine: The burning and expanding gases are deflected by the engine walls through a nozzle to form long, collimated jets of hot air at high speeds. M2-9 is 2,100 light-years away in the constellation Ophiucus. The observation was taken Aug. 2, 1997 by the Hubble telescope's Wide Field and Planetary Camera 2. In this image, neutral oxygen is shown in red, once-ionized nitrogen in green, and twice-ionized oxygen in blue. Credits: Bruce Balick (University of Washington), Vincent Icke (Leiden University, The Netherlands), Garrelt Mellema (Stockholm University), and NASA

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

    ERIC Educational Resources Information Center

    American Psychologist, 2012

    2012-01-01

    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…

  18. 79:2288-2302, 1998.J Neurophysiol Lance Zirpel, William R. Lippe and Edwin W Rubel

    E-print Network

    Rubel, Edwin

    . Oliver and Ian D. Forsythe Huaxia Tong, Joern R. Steinert, Susan W. Robinson, Tatyana Chernova, David J79:2288-2302, 1998.J Neurophysiol Lance Zirpel, William R. Lippe and Edwin W Rubel and C, Paul H. M. Kullmann, Deda C. Gillespie and Karl Kandler and Their Specific Activation by Synaptic

  19. Glucocorticoid receptor physiology Marjet D. Heitzer & Irene M. Wolf & Edwin R. Sanchez &

    E-print Network

    Toledo, University of

    Glucocorticoid receptor physiology Marjet D. Heitzer & Irene M. Wolf & Edwin R. Sanchez & Selma F, and repro- Rev Endocr Metab Disord (2007) 8:321­330 DOI 10.1007/s11154-007-9059-8 M. D. Heitzer :I. M. Wolf of Pediatrics, Children's Hospital of Pittsburgh, Pittsburgh, PA 15260, USA I. M. Wolf :E. R. Sanchez Department

  20. Logical Fallacies in Attacks Against the Bible: Eleven Edwin K. P. Chong

    E-print Network

    Chong, Edwin K. P.

    Logical Fallacies in Attacks Against the Bible: Eleven Examples Edwin K. P. Chong Version: August 26, 2003 In this essay, I describe, by way of examples, eleven fallacies of logic and their use are irrational. 2. You do not reject Biblical creation. 1 I assume a basic familiarity and understanding

  1. Reliable Reconfigurable Structures for Array Architectures y Edwin HsingMean Sha

    E-print Network

    Sha, Edwin

    Reliable Reconfigurable Structures for Array Architectures y Edwin Hsing­Mean Sha hms Grant DAAL03­89­K­0074. 1 #12; Running Head: Reliable Reconfigurable Structures for Array Architectures for reconfigurable array architectures. Given a working architecture (application graph), we add redundant hardware

  2. DSP Architectures: Past, Present and Future* Edwin J. Tan, Wendi B. Heinzelman

    E-print Network

    Heinzelman, Wendi

    DSP Architectures: Past, Present and Future* Edwin J. Tan, Wendi B. Heinzelman Department for audio and video data to complement text. Digital signal processing (DSP) is the sci- ence that enables and manipulation. In this paper, we will explain the various DSP architectures and its silicon implementation. We

  3. Ghrelin receptor gene polymorphisms and body size in children and adults Garcia Edwin A. 1 ,*

    E-print Network

    Paris-Sud XI, Université de

    Ghrelin receptor gene polymorphisms and body size in children and adults Garcia Edwin A. 1 the cognate receptor of ghrelin, a gut hormone that regulatesGHSR food intake and pituitary growth hormone adults or children.GHSR Author Keywords ghrelin ; ghrelin receptor ; body mass index ; gene ; growth

  4. A statistical perspective on data mining Jonathan Hosking, Edwin Pednault and Madhu Sudan

    E-print Network

    Sudan, Madhu

    A statistical perspective on data mining Jonathan Hosking, Edwin Pednault and Madhu Sudan IBM T. J, frequentist inference, PAC learning, statistical learning theory. 1 Introduction: a statistician looks at data for summarizing and identifying patterns in data. Many statistical models exist for explaining relationships

  5. Astronaut Edwin Aldrin in EMU verifies fit of Portable Life Support System

    NASA Technical Reports Server (NTRS)

    1969-01-01

    Astronaut Edwin E. Aldrin Jr., wearing an Extravehicular Mobility Unit (EMU), verifies fit of the Portable Life Support System (PLSS) strap length during lunar surface training at the Kennedy Space Center. Aldrin is the prime crew lunar module pilot of the Apollo 11 lunar landing mission. Aldrin's PLSS backpack is attached to a lunar weight simulator.

  6. Permission Regions for Race-Free Parallelism Edwin Westbrook Jisheng Zhao Zoran Budimlic Vivek Sarkar

    E-print Network

    Budimliæ, Zoran

    Permission Regions for Race-Free Parallelism Edwin Westbrook Jisheng Zhao Zoran Budimli´c Vivek parallel programs that are correct. This is because of the potential for data races, where parallel tasks is dynamic race detection, which has the benefits over other approaches that it works transparently

  7. Title: The Stratosphere and its Coupling to the Troposphere and Beyond Name: Edwin P. Gerber

    E-print Network

    Gerber, Edwin

    Title: The Stratosphere and its Coupling to the Troposphere and Beyond Name: Edwin P. Gerber Affil-1110 212-998-3268 (ph) 212-995-4121 (fax) gerber@cims.nyu.edu The Stratosphere and its Coupling the tropopause, marks the lower boundary of the stratosphere, which extends to approximately 50 km in height

  8. Hubble Space Telescope Optical Telescope Assembly

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This image illustrates the Hubble Space Telescope's (HST's) Optical Telescope Assembly (OTA). One of the three major elements of the HST, the OTA consists of two mirrors (a primary mirror and a secondary mirror), support trusses, and the focal plane structure. The mirrors collect and focus light from selected celestial objects and are housed near the center of the telescope. The primary mirror captures light from objects in space and focuses it toward the secondary mirror. The secondary mirror redirects the light to a focal plane where the Scientific Instruments are located. The primary mirror is 94.5 inches (2.4 meters) in diameter and the secondary mirror is 12.2 inches (0.3 meters) in diameter. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth Orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from the Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The spacecraft is 42.5 feet (13 meters) long and weighs 25,000 pounds (11,600 kilograms). The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  9. Hubble Space Telescope, Wide Field Planetary Camera

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This illustration is a diagram of the Hubble Space Telescope's (HST's), Wide Field Planetary Camera (WF/PC), one of the five Scientific Instruments. The WF/PC uses a four-sided pyramid mirror to split a light image into quarters. It then focuses each quadrant onto one of two sets of four sensors. The sensors are charge-coupled detectors and function as the electronic equivalent of extremely sensitive photographic plates. The WF/PC operates in two modes. The Wide-Field mode that will view 7.2-arcmin sections of the sky, and the Planetary mode that will look at narrower fields of view, such as planets or areas within other galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors.

  10. Astronomical Software Directory Service

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

    This is the final report on the development of the Astronomical Software Directory Service (ASDS), a distributable, 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 URL's indexed for full-text searching.

  11. Astronomical Time Series Analysis

    E-print Network

    Pelt, Jaan

    Astronomical Time Series Analysis Lecture Notes by Jaan Pelt Tartu Observatory Oulu University 23 October - 18 November, 2003 #12;ii #12;Introduction Astronomical time series are somewhat different if to compare with stan- dard time series often used in other branches of science and businesses. The random

  12. Nicolaus Copernicus Astronomical Center

    Microsoft Academic Search

    P. Murdin

    2000-01-01

    Nicolaus Copernicus Astronomical Center is the largest astronomical institution in Poland, located in Warsaw and founded in 1956. At present it is a government-funded research institute supervised by the Polish Academy of Sciences and licensed by the government of Poland to award PhD and doctor habilitatus degrees in astronomy and astrophysics. In September 1999 staff included 21 senior scientist...

  13. Nicolaus Copernicus Astronomical Center

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Nicolaus Copernicus Astronomical Center is the largest astronomical institution in Poland, located in Warsaw and founded in 1956. At present it is a government-funded research institute supervised by the Polish Academy of Sciences and licensed by the government of Poland to award PhD and doctor habilitatus degrees in astronomy and astrophysics. In September 1999 staff included 21 senior scientist...

  14. BISHOP'S UNIVERSITY ASTRONOMICAL OBSERVATORY

    E-print Network

    BISHOP'S UNIVERSITY ASTRONOMICAL OBSERVATORY PlaneWave CDK17 Equatorial Mount Telescope OPERATIONS that its new Astronomical Observatory has already welcomed its 4000th visitor. The Observatory of this observatory is that the telescope can be remotely controlled from anywhere in the world. People who have

  15. The SIMBAD astronomical database.

    NASA Astrophysics Data System (ADS)

    Egret, D.; Wenger, M.; Dubois, P.

    SIMBAD is the astronomical data base produced and maintained by the Centre de Données astronomiques de Strasbourg (CDS), at the Observatoire de Strasbourg, France. The acronym SIMBAD stands for Set of Identifications, Measurements, and Bibliography for Astronomical Data. The authors describe here the present status of the database, the features related to access, usage and updating, and finally describe the expected future developments.

  16. HUBBLE SNAPSHOT CAPTURES LIFE CYCLE OF STARS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In this stunning picture of the giant galactic nebula NGC 3603, the crisp resolution of NASA's Hubble Space Telescope captures various stages of the life cycle of stars in one single view. To the upper right of center is the evolved blue supergiant called Sher 25. The star has a unique circumstellar ring of glowing gas that is a galactic twin to the famous ring around the supernova 1987A. The grayish-bluish color of the ring and the bipolar outflows (blobs to the upper right and lower left of the star) indicates the presence of processed (chemically enriched) material. Near the center of the view is a so-called starburst cluster dominated by young, hot Wolf-Rayet stars and early O-type stars. A torrent of ionizing radiation and fast stellar winds from these massive stars has blown a large cavity around the cluster. The most spectacular evidence for the interaction of ionizing radiation with cold molecular-hydrogen cloud material are the giant gaseous pillars to the right and lower left of the cluster. These pillars are sculptured by the same physical processes as the famous pillars Hubble photographed in the M16 Eagle Nebula. Dark clouds at the upper right are so-called Bok globules, which are probably in an earlier stage of star formation. To the lower left of the cluster are two compact, tadpole-shaped emission nebulae. Similar structures were found by Hubble in Orion, and have been interpreted as gas and dust evaporation from possibly protoplanetary disks (proplyds). The 'proplyds' in NGC 3603 are 5 to 10 times larger in size and correspondingly also more massive. This single view nicely illustrates the entire stellar life cycle of stars, starting with the Bok globules and giant gaseous pillars, followed by circumstellar disks, and progressing to evolved massive stars in the young starburst cluster. The blue supergiant with its ring and bipolar outflow marks the end of the life cycle. The color difference between the supergiant's bipolar outflow and the diffuse interstellar medium in the giant nebula dramatically visualizes the enrichment in heavy elements due to synthesis of heavier elements within stars. This true-color picture was taken on March 5, 1999 with the Wide Field Planetary Camera 2. This picture is being presented at the 194th Meeting of the American Astronomical Society in Chicago. Credit: Wolfgang Brandner (JPL/IPAC), Eva K. Grebel (Univ. Washington), You-Hua Chu (Univ. Illinois Urbana-Champaign), and NASA

  17. Microlensing with Hubble

    NASA Astrophysics Data System (ADS)

    Ginsburg, Idan; Di Stefano, Rosanne; Lepine, Sebastien; Primini, Francis A.; Oprescu, Antonia; Tunbridge, Ben

    2014-06-01

    Microlensing can be used to study dark matter, galactic structure, and to search for extra-solar planets. However, a significant problem with microlensing is the mass determination of the lens. Typically, microlensing events provides only a single measured quantity that depends on the lens mass, the Einstein angle crossing time, ?, which also depends on the distances to the lens and source as well as the relative transverse velocity. Thus, it is difficult to derive unique mass estimates for the lens. Non-degenerate solutions are possible, as was shown by Alcock et al. for MACHO LMC-5, when the source and lens can be resolved. It may be possible to distinguish between the lens and source by re-observing a microlensing candidate years after the first observation. As it turns out, a substantial number of fields containing microlensing events have been observed by the Hubble Space Telescope (HST). We currently have identified over 180 possible matches to lensing events. In many of these cases, there was a time difference of years between the HST observation (or observations) and the ground-based detection. We present initial results from our archival program and discuss the implications for future studies.

  18. THE CARNEGIE HUBBLE PROGRAM

    SciTech Connect

    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

    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.

  19. The Astronomers' Data Manifesto

    NASA Astrophysics Data System (ADS)

    Norris, R. P.

    2006-08-01

    A draft manifesto is presented for discussion. The manifesto sets out guidelines to which the astronomical community should aspire to maximise the rate and cost-effectiveness of scientific discovery. The challenges are not underestimated, but can still be overcome if astronomers, observatories, journals, data centres, and the Virtual Observatory Alliance work together to overcome the hurdles. The key points of the manifesto are: 1. All major tables, images, and spectra published in journals should appear in the astronomical data centres. 2. All data obtained with publicly-funded observatories should, after appropriate proprietary periods, be placed in the public domain. 3. In any new major astronomical construction project, the data processing, storage, migration, and management requirements should be built in at an early stage of the project plan, and costed along with other parts of the project. 4. Astronomers in all countries should have the same access to astronomical data and information. 5. Legacy astronomical data can be valuable, and high-priority legacy data should be preserved and stored in digital form in the data centres. 6. The IAU should work with other international organisations to achieve our common goals and learn from our colleagues in other fields.

  20. HUBBLE SPACE TELESCOPE CAPTURES FIRST DIRECT IMAGE OF A STAR

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is the first direct image of a star other than the Sun, made with NASA's Hubble Space Telescope. Called Alpha Orionis, or Betelgeuse, it is a red supergiant star marking the shoulder of the winter constellation Orion the Hunter (diagram at right). The Hubble image reveals a huge ultraviolet atmosphere with a mysterious hot spot on the stellar behemoth's surface. The enormous bright spot, more than ten times the diameter of Earth, is at least 2,000 Kelvin degrees hotter than the surface of the star. The image suggests that a totally new physical phenomenon may be affecting the atmospheres of some stars. Follow-up observations will be needed to help astronomers understand whether the spot is linked to oscillations previously detected in the giant star, or whether it moves systematically across the star's surface under the grip of powerful magnetic fields. The observations were made by Andrea Dupree of the Harvard- Smithsonian Center for Astrophysics in Cambridge, MA, and Ronald Gilliland of the Space Telescope Science Institute in Baltimore, MD, who announced their discovery today at the 187th meeting of the American Astronomical Society in San Antonio, Texas. The image was taken in ultraviolet light with the Faint Object Camera on March 3, 1995. Hubble can resolve the star even though the apparent size is 20,000 times smaller than the width of the full Moon -- roughly equivalent to being able to resolve a car's headlights at a distance of 6,000 miles. Betelgeuse is so huge that, if it replaced the Sun at the center of our Solar System, its outer atmosphere would extend past the orbit of Jupiter (scale at lower left). Credit: Andrea Dupree (Harvard-Smithsonian CfA), Ronald Gilliland (STScI), NASA and ESA Image files in GIF and JPEG format and captions may be accessed on Internet via anonymous ftp from oposite.stsci.edu in /pubinfo.

  1. Astronomical Video Suites

    NASA Astrophysics Data System (ADS)

    Francisco Salgado, Jose

    2010-01-01

    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.

  2. Famous Astronomers and Astrophysicists

    NSDL National Science Digital Library

    Manley, D. Mark

    D. Mark Manley, a professor in the Physics Department at Kent State University, provides short introductions for almost one hundred famous astronomers and astrophysicists from the Classical Period to the present. By searching either chronologically or alphabetically, users can find out about a given astronomers major successes as well as birth years and places. A link is provided for each scientist listed, offering more in-depth information. Astronomers and historians can find inspiration by learning about the scientists' education and their important contribution to science. Most of the links also present a picture of the scientist and many interesting links.

  3. HUBBLE SNAPS 'FAMILY PORTRAIT'

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) has peered into the Cone Nebula, revealing a stunning image of six baby sun-like stars surrounding their mother, a bright, massive star. Known as NGC 2264 IRS, the massive star triggered the creation of these baby stars by releasing high-speed particles of dust and gas during its formative years. The image on the left, taken in visible light by a ground-based telescope, shows the Cone Nebula, located 2,500 light-years away in the constellation Monoceros. The white box pinpoints the location of the star nursery. The nursery cannot be seen in this image because dust and gas obscure it. The large cone of cold molecular hydrogen and dust rising from the lefthand edge of the image was created by the outflow from NGC 2264 IRS. The NICMOS image on the right shows this massive star - the brightest source in the region - and the stars formed by its outflow. The baby stars are only .04 to .08 light-years away from their brilliant mother. The rings surrounding the massive star and the spikes emanating from it are not part of the image. This pattern demonstrates the near-perfect optical performance of NICMOS. A near-perfect optical system should bend light from point-like sources, such as NGC 2264 IRS, forming these diffraction patterns of rings and spikes. This false color image was taken with 1.1-, 1.6-, and 2.2-micron filters. The image was taken on April 28, 1997. Credits: Rodger Thompson, Marcia Rieke and Glenn Schneider (University of Arizona), and NASA Image files in GIF and JPEG format and captions may be accessed on the Internet via anonymous ftp from ftp.stsci.edu in /pubinfo.

  4. HUBBLE'S ULTRAVIOLET VIEWS OF NEARBY GALAXIES YIELD CLUES TO EARLY UNIVERSE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Astronomers are using these three NASA Hubble Space Telescope images to help tackle the question of why distant galaxies have such odd shapes, appearing markedly different from the typical elliptical and spiral galaxies seen in the nearby universe. Do faraway galaxies look weird because they are truly weird? Or, are they actually normal galaxies that look like oddballs, because astronomers are getting an incomplete picture of them, seeing only the brightest pieces? Light from these galaxies travels great distances (billions of light-years) to reach Earth. During its journey, the light is 'stretched' due to the expansion of space. As a result, the light is no longer visible, but has been shifted to the infrared where present instruments are less sensitive. About the only light astronomers can see comes from regions where hot, young stars reside. These stars emit mostly ultraviolet light. But this light is stretched, appearing as visible light by the time it reaches Earth. Studying these distant galaxies is like trying to put together a puzzle with some of the pieces missing. What, then, do distant galaxies really look like? Astronomers studied 37 nearby galaxies to find out. By viewing these galaxies in ultraviolet light, astronomers can compare their shapes with those of their distant relatives. These three Hubble telescope pictures, taken with the Wide Field and Planetary Camera 2, represent a sampling from that survey. Astronomers observed the galaxies in ultraviolet and visible light to study all the stars that make up these 'cities of stars.' The results of their survey support the idea that astronomers are detecting the 'tip of the iceberg' of very distant galaxies. Based on these Hubble ultraviolet images, not all the faraway galaxies necessarily possess intrinsically odd shapes. The results are being presented today at the 197th meeting of the American Astronomical Society in San Diego, CA. The central region of the 'star-burst' spiral galaxy at far left, NGC 3310, shows young and old stars evenly distributed. If this were the case with most galaxies, astronomers would be able to recognize faraway galaxies fairly easily. In most galaxies, however, the stars are segregated by age, making classifying the distant ones more difficult. NGC 3310 is 46 million light-years from Earth in the constellation Ursa Major. The image was taken Sept. 12-13, 2000. The middle image is an example of a tiny, youthful spiral galaxy. ESO 418-008 is representative of the myriad of dwarf galaxies astronomers have seen in deep surveys. These galaxies are much smaller than typical ones like our Milky Way. In this galaxy, the population of stars is more strongly segregated by age. The older stars [red] reside in the center; the younger [blue], in the developing spiral arms. These small, young galaxies may be the building blocks of galaxy formation. ESO 418-008 is 56 million light-years from Earth in the southern constellation Fornax. The image was taken Oct. 10, 2000. The picture at right shows a cosmic collision between two galaxies, UGC 06471 and UGC 06472. These collisions occurred frequently in the early universe, producing galaxies of unusual shapes. The Hubble telescope has spied many such galaxies in the deep field surveys. The ultraviolet images of this galaxy merger suggest the presence of large amounts of dust, which were produced by massive stars that formed before or during this dramatic collision. This dust reddens the starlight in many places, just like a dusty atmosphere reddens the sunset. Studying the effects of this nearby collision could help astronomers explain the peculiar shapes seen in some of the distant galaxies. UGC 06471 and UGC 06472 are 145 million light-years from Earth in the constellation Ursa Major. The image was taken July 11, 2000. Photo credits: NASA, Rogier Windhorst (Arizona State University, Tempe, AZ), and the Hubble mid-UV team

  5. An astronomical murder?

    NASA Astrophysics Data System (ADS)

    Belenkiy, Ari

    2010-04-01

    Ari Belenkiy examines the murder of Hypatia of Alexandria, wondering whether problems with astronomical observations and the date of Easter led to her becoming a casualty of fifth-century political intrigue.

  6. Korean Astronomical Calendar, Chiljeongsan

    NASA Astrophysics Data System (ADS)

    Lee, Eun Hee

    In fifteenth century Korea, there was a grand project for the astronomical calendar and instrument making by the order of King Sejong ?? (1418-1450). During this period, many astronomical and calendrical books including Islamic sources in Chinese versions were imported from Ming ? China, and corrected and researched by the court astronomers of Joseon ?? (1392-1910). Moreover, the astronomers and technicians of Korea frequently visited China to study astronomy and instrument making, and they brought back useful information in the form of new published books or specifications of instruments. As a result, a royal observatory equipped with 15 types of instrument was completed in 1438. Two types of calendar, Chiljeongsan Naepyeon ????? and Chiljeongsan Oepyeon ?????, based on the Chinese and Islamic calendar systems, respectively, were published in 1444 with a number of calendrical editions such as corrections and example supplements (??) including calculation methods and results for solar and lunar eclipses.

  7. 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.

  8. HUBBLE CAPTURES BEST VIEW OF MARS EVER OBTAINED FROM EARTH

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Frosty white water ice clouds and swirling orange dust storms above a vivid rusty landscape reveal Mars as a dynamic planet in this sharpest view ever obtained by an Earth-based telescope. NASA's Earth-orbiting Hubble Space Telescope took the picture on June 26, when Mars was approximately 43 million miles (68 million km) from Earth -- the closest Mars has ever been to Earth since 1988. Hubble can see details as small as 10 miles (16 km) across. The colors have been carefully balanced to give a realistic view of Mars' hues as they might appear through a telescope. Especially striking is the large amount of seasonal dust storm activity seen in this image. One large storm system is churning high above the northern polar cap [top of image], and a smaller dust storm cloud can be seen nearby. Another large dust storm is spilling out of the giant Hellas impact basin in the Southern Hemisphere [lower right]. Hubble has observed Mars before, but never in such detail. The biennial close approaches of Mars and Earth are not all the same. Mars' orbit around the Sun is markedly elliptical; the close approaches to Earth can range from 35 million to 63 million miles. Astronomers are interested in studying the changeable surface and weather conditions on Mars, in part, to help plan for a pair of NASA missions to land rovers on the planet's surface in 2004. The Mars opposition of 2001 serves as a prelude for 2003 when Mars and Earth will come within 35 million miles of each other, the closest since 1924 and not to be matched until 2287. Image Credit: NASA and the Hubble Heritage Team (STScI/AURA) Acknowledgment: J. Bell (Cornell U.), P. James (U. Toledo), M. Wolff (Space Science Institute), A. Lubenow (STScI), J. Neubert (MIT/Cornell)

  9. HUBBLE DETECTION OF COMET NUCLEUS AT FRINGE OF SOLAR SYSTEM

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is sample data from NASA's Hubble Space Telescope that illustrates the detection of comets in the Kuiper Belt, a region of space beyond the orbit of the planet Neptune. This pair of images, taken with the Wide Field Planetary Camera 2 (WFPC2), shows one of the candidate Kuiper Belt objects found with Hubble. Believed to be an icy comet nucleus several miles across, the object is so distant and faint that Hubble's search is the equivalent of finding the proverbial needle-in-haystack. Each photo is a 5-hour exposure of a piece of sky carefully selected such that it is nearly devoid of background stars and galaxies that could mask the elusive comet. The left image, taken on August 22, 1994, shows the candidate comet object (inside circle) embedded in the background. The right picture, take of the same region one hour forty-five minutes later shows the object has apparently moved in the predicted direction and rate of motion for a kuiper belt member. The dotted line on the images is a possible orbit that this Kuiper belt comet is following. A star (lower right corner) and a galaxy (upper right corner) provide a static background reference. In addition, other objects in the picture have not moved during this time, indicating they are outside our solar system. Through this search technique astronomers have identified 29 candidate comet nuclei belonging to an estimated population of 200 million particles orbiting the edge of our solar system. The Kupier Belt was theorized 40 years ago, and its larger members detected several years ago. However, Hubble has found the underlying population of normal comet-sized bodies. Credit: A. Cochran (University of Texas) and NASA

  10. Hubble Extra Solar Planet Interferometer

    NASA Technical Reports Server (NTRS)

    Shao, M.

    1991-01-01

    This paper describes a proposed third-generation Hubble instrument for extra-solar planet detection, the Hubble Extra-Solar Planet Interferometer (HESPI). This instrument would be able to achieve starlight cancellation at the 10 exp 6 to 10 exp 8 level, given a stellar wavefront with phase errors comparable to the present Hubble telescope wavefront. At 10 exp 6 starlight cancellation, HESPI would be able to detect a Jupiter-like planet next to a star at a distance of about 10 parsec, for which there are about 400 candidate stars. This paper describes a novel approach for starlight suppression, using a combination of active control and single-mode spatial filters, to achieve starlight suppression far below the classical limit set by scattering due to microsurface imperfections. In preliminary lab experiments, suppression by a factor of 40 below the classical scatter limit due to optical wavefront errors has been demonstrated.

  11. HUBBLE REVEALS THE HEART OF THE WHIRLPOOL GALAXY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    New images from NASA's Hubble Space Telescope are helping researchers view in unprecedented detail the spiral arms and dust clouds of a nearby galaxy, which are the birth sites of massive and luminous stars. The Whirlpool galaxy, M51, has been one of the most photogenic galaxies in amateur and professional astronomy. Easily photographed and viewed by smaller telescopes, this celestial beauty is studied extensively in a range of wavelengths by large ground- and space-based observatories. This Hubble composite image shows visible starlight as well as light from the emission of glowing hydrogen, which is associated with the most luminous young stars in the spiral arms. M51, also known as NGC 5194, is having a close encounter with a nearby companion galaxy, NGC 5195, just off the upper edge of this image. The companion's gravitational pull is triggering star formation in the main galaxy, as seen in brilliant detail by numerous, luminous clusters of young and energetic stars. The bright clusters are highlighted in red by their associated emission from glowing hydrogen gas. This Wide Field Planetary Camera 2 image enables a research group, led by Nick Scoville (Caltech), to clearly define the structure of both the cold dust clouds and the hot hydrogen and link individual clusters to their parent dust clouds. Team members include M. Polletta (U. Geneva); S. Ewald and S. Stolovy (Caltech); R. Thompson and M. Rieke (U. of Arizona). Intricate structure is also seen for the first time in the dust clouds. Along the spiral arms, dust 'spurs' are seen branching out almost perpendicular to the main spiral arms. The regularity and large number of these features suggests to astronomers that previous models of 'two-arm' spiral galaxies may need to be revisited. The new images also reveal a dust disk in the nucleus, which may provide fuel for a nuclear black hole. The team is also studying this galaxy at near-infrared wavelengths with the NICMOS instrument onboard Hubble. At these wavelengths, the dusty clouds are more transparent and the true distribution of stars is more easily seen. In addition, regions of star formation that are obscured in the optical images are newly revealed in the near-infrared images. This image was composed by the Hubble Heritage Team from Hubble archival data of M51 and is superimposed onto ground-based data taken by Travis Rector (NOAO) at the 0.9-meter telescope at the National Science Foundation's Kitt Peak National Observatory (NOAO/AURA) in Tucson, AZ. Image Credit: NASA and The Hubble Heritage Team (STScI/AURA) Acknowledgment: N. Scoville (Caltech) and T. Rector (NOAO)

  12. He2-90'S APPEARANCE DECEIVES ASTRONOMERS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Astronomers using NASA's Hubble Space Telescope have stumbled upon a mysterious object that is grudgingly yielding clues to its identity. A quick glance at the Hubble picture at top shows that this celestial body, called He2-90, looks like a young, dust-enshrouded star with narrow jets of material streaming from each side. But it's not. The object is classified as a planetary nebula, the glowing remains of a dying, lightweight star. But the Hubble observations suggest that it may not fit that classification, either. The Hubble astronomers now suspect that this enigmatic object may actually be a pair of aging stars masquerading as a single youngster. One member of the duo is a bloated red giant star shedding matter from its outer layers. This matter is then gravitationally captured in a rotating, pancake-shaped accretion disk around a compact partner, which is most likely a young white dwarf (the collapsed remnant of a sun-like star). The stars cannot be seen in the Hubble images because a lane of dust obscures them. The Hubble picture at top shows a centrally bright object with jets, appearing like strings of beads, emanating from both sides of center. (The other streaks of light running diagonally from He2-90 are artificial effects of the telescope's optical system.) Each jet possesses at least six bright clumps of gas, which are speeding along at rates estimated to be at least 375,000 miles an hour (600,000 kilometers an hour). These gaseous salvos are being ejected into space about every 100 years, and may be caused by periodic instabilities in He2-90's accretion disk. The jets from very young stars behave in a similar way. Deep images taken from terrestrial observatories show each jet extending at least 100,000 astronomical units (one astronomical unit equals the Earth-Sun distance, 93 million miles). The jets' relatively modest speed implies that one member of the duo is a white dwarf. Observations by the Compton Gamma-Ray Observatory, however, discovered a gamma-ray source in the vicinity of He2-90, suggesting that the companion may be a neutron star or a black hole (the compact corpses of dying, massive stars). But the jets from accretion disks around neutron stars or black holes travel at a few tenths the speed of light, much faster than the plodding pace of He2-90's jets. The Hubble astronomers are planning more observations to pinpoint the gamma-ray source to determine whether it is associated with He2-90. An accretion disk needs gravity to form. For gravity to create He2-90's disk, the pair of stars must reside at a cozy distance from each other: within about 10 astronomical units. Although the astronomers are uncertain about the details, they believe that magnetic fields associated with the accretion disk produce and constrict the pencil-thin jets seen in the Hubble image. The close-up Hubble photo at bottom shows a dark, flaring, disk-like structure [off-center] bisecting the bright light from the object. The disk is seen edge-on. Although too large to be an accretion disk, this dark, flaring disk may provide indirect proof of the other's existence. Most theories for producing jets require the presence of an accretion disk. The jets are seen streaming from both sides of the central object. The round, white objects at the lower left and upper right corners are two bright clumps of gas in the jets. The astronomers traced the jets to within 1,000 astronomical units of the central obscured star. The star ejected this jet material about 30 years ago. Scientists discovered this puzzling object while taking a census of planetary nebulae. They knew it had been classified as a dying, sun-like star. He2-90 is enshrouded in very hot (17,500 degrees Fahrenheit or 10,000 degrees Kelvin), glowing gas, a typical feature of planetary nebulae. And yet the disk and jets indicated the presence of an embryonic star. The mystified astronomers needed more information. Since embryonic stars are usually associated with cool, dense clouds of gas and dust, they used a ground-based radio telescope in Chile to look for evidence of such

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

    PubMed

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

    2006-02-01

    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

  14. High School Teachers as Astronomers

    ERIC Educational Resources Information Center

    Sather, Robert

    1977-01-01

    Discusses a joint research program between several high school teachers and solar system astronomers in which data were collected on photoelectric observations of asteroids and minor planets via astronomical telescopes. (MLH)

  15. Comparison of astronomical journals.

    NASA Astrophysics Data System (ADS)

    Pottasch, S. R.; Praderie, F.

    1988-09-01

    At the request of the Board of Oirectors of Astronomy and Astrophysics (AA), we have undertaken a comparison of the more important astronomical journals. The original reports covered the amount of material published, financial aspects, time delays in publication, aspects of refereeing and rejection of articles and the very difficult question of the overall scientific quality. Because of the general interest among astronomers in publishing and publications we have prepared this summary of the reports. Some of the information used has been supplied by Or. H. Abt, editor of the Astrophysical Journal (ApJ) and Prof. R.J. Tayler, editor of the Monthly Notices of the Royal Astron. Soc. (MNRAS). We have limited our comparison mainly to the three journals mentioned, plus the Astronomical Journal (AJ).

  16. The Astronomical Journal

    NSDL National Science Digital Library

    2013-01-01

    Based at the University of Wisconsin-Madison, the Astronomical Journal (AJ) publishes original astronomical research, with "an emphasis on significant scientific results derived from observations, including descriptions of data capture, surveys, analysis techniques, and astronomical interpretation." The publication was founded in 1849 in Cambridge, Massachusetts and since that time it has become highly regarded. Visitors to the site can read past issues for free and they can use the Most Read, Most Cited, and Latest Articles tabs to dive right in. Recent pieces in the AJ have addressed supernovae, infrared scientific measurement devices, and the numerical integration of rotational motion. On the site, visitors can contact the editorial board, learn about submission guidelines, and peruse the AJ's ethics policy. It is a rather wonderful way to learn about the latest research in this field and is a resource that users will want to bookmark for future consideration. [KMG

  17. Space Telescope Programs Hubble Observatory

    E-print Network

    Colorado at Boulder, University of

    other STS safety issues) input to BATC for Safety Presentation at Instrument Level to JSC ­ UCB (UCB-COS-RPT-1134) in-work · Input to COS Instrument Safety Reviews A/R #12;Space Telescope Programs Hubble Observatory HST-COS FUV PER 11/8/00 FUV Detector System Materials

  18. VENUS CLOUD TOPS VIEWED BY HUBBLE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is a NASA Hubble Space Telescope ultraviolet-light image of the planet Venus, taken on January 24 1995, when Venus was at a distance of 70.6 million miles (113.6 million kilometers) from Earth. Venus is covered with clouds made of sulfuric acid, rather than the water-vapor clouds found on Earth. These clouds permanently shroud Venus' volcanic surface, which has been radar mapped by spacecraft and from Earth-based telescope. At ultraviolet wavelengths cloud patterns become distinctive. In particular, a horizontal 'Y'-shaped cloud feature is visible near the equator. Similar features were seen from Mariner 10, Pioneer Venus, and Galileo spacecrafts. This global feature might indicate atmospheric waves, analogous to high and low pressure cells on Earth. Bright clouds toward Venus' poles appear to follow latitude lines. The polar regions are bright, possibly showing a haze of small particles overlying the main clouds. The dark regions show the location of enhanced sulfur dioxide near the cloud tops. From previous missions, astronomers know that such features travel east to west along with the Venus' prevailing winds, to make a complete circuit around the planet in four days. Because Venus is closer to the Sun than Earth, the planet appears to go through phases, like the Moon. When Venus swings close to Earth the planet's disk appears to grow in size, but changes from a full disk to a crescent. The image was taken with the Wide Field Planetary Camera-2, in PC mode. False color has been used enhance cloud features. Credit: L. Esposito (University of Colorado, Boulder), and NASA

  19. Hubble Space Telescope, Faint Object Spectrograph

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This drawing illustrates the Hubble Space Telescope's (HST's), Faint Object Spectrograph (FOS). The HST's two spectrographs, the Goddard High-Resolution Spectrograph and the FOS, can detect a broader range of wavelengths than is possible from the Earth because there is no atmosphere to absorb certain wavelengths. Scientists can determine the chemical composition, temperature, pressure, and turbulence of the stellar atmosphere producing the light, all from spectral data. The FOC can detect detail in very faint objects, such as those at great distances, and light ranging from ultraviolet to red spectral bands. Both spectrographs operate in essentially the same way. The incoming light passes through a small entrance aperture, then passes through filters and diffraction gratings, that work like prisms. The filter or grating used determines what range of wavelength will be examined and in what detail. Then the spectrograph detectors record the strength of each wavelength band and sends it back to Earth. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors.

  20. Star Witness News: Birthday Wishes for Hubble

    NSDL National Science Digital Library

    This story celebrates the 17th anniversary of the launch of the Hubble Space Telescope. The anniversary image of the Carina Nebula is described and Hubble’s most significant scientific discoveries are identified. The article is from the Amazing Space science newspaper, The Star Witness, which can be used as a science content reading.

  1. The Planetarium and the Astronomer (An Overview)

    NASA Astrophysics Data System (ADS)

    Petersen, Carolyn Collins

    1995-05-01

    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.

  2. HUBBLE CAPTURES THE HEART OF STAR BIRTH

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA Hubble Space Telescope's Wide Field and Planetary Camera 2 (WFPC2) has captured a flurry of star birth near the heart of the barred spiral galaxy NGC 1808. On the left are two images, one superimposed over the other. The black-and-white picture is a ground-based view of the entire galaxy. The color inset image, taken with the Hubble telescope's Wide Field and Planetary Camera 2 (WFPC2), provides a close-up view of the galaxy's center, the hotbed of vigorous star formation. The ground-based image shows that the galaxy has an unusual, warped shape. Most spiral galaxies are flat disks, but this one has curls of dust and gas at its outer spiral arms (upper right-hand corner and lower left-hand corner). This peculiar shape is evidence that NGC 1808 may have had a close interaction with another nearby galaxy, NGC 1792, which is not in the picture Such an interaction could have hurled gas towards the nucleus of NGC 1808, triggering the exceptionally high rate of star birth seen in the WFPC2 inset image. The WFPC2 inset picture is a composite of images using colored filters that isolate red and infrared light as well as light from glowing hydrogen. The red and infrared light (seen as yellow) highlight older stars, while hydrogen (seen as blue) reveals areas of star birth. Colors were assigned to this false-color image to emphasize the vigorous star formation taking place around the galaxy's center. NGC 1808 is called a barred spiral galaxy because of the straight lines of star formation on both sides of the bright nucleus. This star formation may have been triggered by the rotation of the bar, or by matter which is streaming along the bar towards the central region (and feeding the star burst). Filaments of dust are being ejected from the core into a faint halo of stars surrounding the galaxy's disk (towards the upper left corner) by massive stars that have exploded as supernovae in the star burst region. The portion of the galaxy seen in this 'wide-field' image is about 35,000 light-years across. The right-hand image, taken by WFPC2, provides a closer look at the flurry of star birth at the galaxy's core. The star clusters (blue) can be seen (and many more are likely obscured) amid thick lanes of gas and dust. This image shows that stars are often born in compact clusters within star bursts, and that dense gas and dust heavily obscures the star burst region. The brightest knot of star birth seen here is probably a giant cluster of stars, about 100 light-years in diameter, at the very center of the galaxy. The other star clusters are about 10 to 50 light-years in diameter. The entire star burst region shown here is about 3,000 light-years across. This galaxy is about 40 million light-years away in the southern constellation Columba. The observation was taken Aug. 14, 1997, and was the last of 13 Hubble Space Telescope amateur programs. Credits: Jim Flood, an amateur astronomer affiliated with Sperry Observatory at Union College in New Jersey, and Max Mutchler, a member of the Space Telescope Science Institute staff who volunteered to work with Jim.

  3. The Knorre astronomers' dynasty

    NASA Astrophysics Data System (ADS)

    Pinigin, G.

    2009-06-01

    We attempt to throw light upon the poorly known astronomical dynasty of Knorre and describe its contribution to astronomy. The founder of the dynasty, Ernst Christoph Friedrich Knorre (1759-1810), was born in Germany in 1759, and since 1802 he was a Professor of Mathematics at the Tartu University, and observer at its temporary observatory. He determined the first coordinates of Tartu by stellar observations. Karl Friedrich Knorre (1801-1883) was the first director of the Naval Observatory in Nikolaev since the age of 20, provided the Black Sea navy with accurate time and charts, trained mariners in astronomical navigation, and certified navigation equipment. He compiled star maps and catalogues, and determined positions of comets and planets. He also participated in Bessel's project of the Academic Star Charts, and was responsible for Hora 4, published by the Berlin Academy of Sciences. This sheet permitted to discover two minor planets, Astraea and Flora. Viktor Knorre (1840-1919) was born in Nikolaev. In 1862 he left for Berlin to study astronomy. After defending his thesis for a doctor's degree, he went to Pulkovo as an astronomical calculator in 1867. Since 1873 Viktor worked as an observer of the Berlin Observatory Fraunhofer refractor. His main research focussed on minor planets, comets and binary stars. He discovered the minor planets Koronis, Oenone, Hypatia and Penthesilea. Viktor Knorre also worked on improving astronomical instrumentation, e.g. the Knorre / Heele equatorial telescope mounting.

  4. Astronomical education in Mongolia

    NASA Astrophysics Data System (ADS)

    Dulmaa, A.; Tsolmon, R.; Lkhagvajav, Ch.; Jargalsuren, Sh.; Bayartungalag, B.; Zaya, M.

    2011-06-01

    The history, current situation, education and future directions of modern Mongolian space science and astronomy is reviewed. This paper discusses recent efforts to develop astronomy education and research capacity in Mongolia with cooperation of the International Astronomical Union. Various capacity-building initiatives in space science including remote sensing in Mongolia are discussed.

  5. Johannes Kepler's astronomical instruments

    Microsoft Academic Search

    V. L. Chenakal

    1975-01-01

    The life and activity of Kepler coincided with an important period in the history of astronomy, when every decade new instruments were being invented, bringing about many great discoveries. At this time many scientists and artisans participated in the construction of astronomical instruments. The contribution made by them is fairly well known, but Kepler's work in this field has been

  6. Ancient Chinese Astronomical Technologies

    NASA Astrophysics Data System (ADS)

    Walsh, Jennifer Robin

    2004-05-01

    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

  7. Svetloe Radio Astronomical Observatory

    NASA Technical Reports Server (NTRS)

    Smolentsev, Sergey; Rahimov, Ismail

    2013-01-01

    This report summarizes information about the Svetloe Radio Astronomical Observatory activities in 2012. Last year, a number of changes took place in the observatory to improve some technical characteristics and to upgrade some units to their required status. The report provides an overview of current geodetic VLBI activities and gives an outlook for the future.

  8. Zelenchukskaya Radio Astronomical Observatory

    NASA Technical Reports Server (NTRS)

    Smolentsev, Sergey; Dyakov, Andrei

    2013-01-01

    This report summarizes information about Zelenchukskaya Radio Astronomical Observatory activities in 2012. Last year a number of changes took place in the observatory to improve some technical characteristics and to upgrade some units to the required status. The report provides an overview of current geodetic VLBI activities and gives an outlook for the future.

  9. Chandra and Hubble Composite Image of Spiral Galaxy NGC 4631

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This image shows the central region of the spiral galaxy NGC 4631 as seen edge-on from the Chandra X-Ray Observatory (CXO) and the Hubble Space Telescope (HST). The Chandra data, shown in blue and purple, provide the first unambiguous evidence for a halo of hot gas surrounding a galaxy that is very similar to our Milky Way. The structure across the middle of the image and the extended faint filaments, shown in orange, represent the observation from the HST that reveals giant bursting bubbles created by clusters of massive stars. Scientists have debated for more than 40 years whether the Milky Way has an extended corona, or halo, of hot gas. Observations of NGC 4631 and similar galaxies provide astronomers with an important tool in the understanding our own galactic environment. A team of astronomers, led by Daniel Wang of the University of Massachusetts at Amherst, observed NGC 4631 with CXO's Advanced Charge-Coupled Device (CCD) Imaging Spectrometer (ACIS). The observation took place on April 15, 2000, and its duration was approximately 60,000 seconds.

  10. HUBBLE SERVES UP A GALAXY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    What may first appear as a sunny side up egg is actually NASA Hubble Space Telescope's face-on snapshot of the small spiral galaxy NGC 7742. But NGC 7742 is not a run-of-the-mill spiral galaxy. In fact, this spiral is known to be a Seyfert 2 active galaxy, a type of galaxy that is probably powered by a black hole residing in its core. The core of NGC 7742 is the large yellow 'yolk' in the center of the image. The lumpy, thick ring around this core is an area of active starbirth. The ring is about 3,000 light-years from the core. Tightly wound spiral arms also are faintly visible. Surrounding the inner ring is a wispy band of material, which is probably the remains of a once very active stellar breeding ground. Credit: Hubble Heritage Team (AURA/STScI/NASA)

  11. COSMOS: Hubble Space Telescope Observations

    Microsoft Academic Search

    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

    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

  12. Hubble Captures Best View of Mars Ever Obtained from Earth

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Frosty white water ice clouds and swirling orange dust storms above a vivid rusty landscape reveal Mars as a dynamic planet in this sharpest view ever obtained by an Earth-based telescope.

    NASA's Earth-orbiting Hubble Space Telescope took the picture on June 26, when Mars was approximately 43 million miles (68 million km) from Earth -- the closest Mars has ever been to Earth since 1988. Hubble can see details as small as 10 miles (16 km) across. The colors have been carefully balanced to give a realistic view of Mars' hues as they might appear through a telescope.

    Especially striking is the large amount of seasonal dust storm activity seen in this image. One large storm system is churning high above the northern polar cap [top of image], and a smaller dust storm cloud can be seen nearby. Another large dust storm is spilling out of the giant Hellas impact basin in the Southern Hemisphere [lower right].

    Hubble has observed Mars before, but never in such detail. The biennial close approaches of Mars and Earth are not all the same. Mars' orbit around the Sun is markedly elliptical; the close approaches to Earth can range from 35 million to 63 million miles.

    Astronomers are interested in studying the changeable surface and weather conditions on Mars, in part, to help plan for a pair of NASA missions to land rovers on the planet's surface in 2004.

    The Mars opposition of 2001 serves as a prelude for 2003 when Mars and Earth will come within 35 million miles of each other, the closest since 1924 and not to be matched until 2287.

  13. Algorithm for astronomical, extended source, signal-to-noise radio calculations

    NASA Technical Reports Server (NTRS)

    Jayroe, R. R.

    1984-01-01

    An algorithm was developed to simulate the expected signal-to-noise ratio as a function of observation time in the charge coupled device detector plane of an optical telescope located outside the Earth's atmosphere for an extended, uniform astronomical source embedded in a uniform cosmic background. By choosing the appropriate input values, the expected extended source signal-to-noise ratios can be computed for the Hubble Space Telescope using the Wide Field/Planetary Camera science instrument.

  14. Nanoengineered Astronomical Optics

    E-print Network

    E. F. Borra; A. M. Ritcey; R. Bergamasco; P. Laird; J. Gingras; M. Dallaire; L. Da Silva; H. Yockell-Lelievre

    2003-04-05

    We describe a technology for the fabrication of inexpensive and versatile mirrors through the use of a new type of nanoengineered optical material composed by the spreading of a self-assembling reflective colloidal film spread at the surface of a liquid. These new reflecting liquids offer interesting possibilities for astronomical instrumentation. For example, they can replace mercury in conventional rotating liquid mirrors. The main advantages offered include extremely low cost and, by coating a viscous liquid, the possibility of tilting the mirror by a few tens of degrees. We also have coated ferromagnetic liquids with these reflecting films. The resulting surfaces can be shaped by the application of a magnetic field, yielding reflecting surfaces that can have complicated shapes that can rapidly shift with time. These inexpensive and versatile optical elements could have numerous scientific and technological applications. Among possible astronomical applications, they could be used to make large inexpensive adaptive mirrors exhibiting strokes ranging from nanometers to several millimeters.

  15. Ancient Egyptian Astronomical Calander

    NASA Astrophysics Data System (ADS)

    Marshall, Patrice; Lodhi, M. A. K.

    2001-03-01

    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 by events, as determined in the heavens, in developing their calendar system. Along with astronomical observations by the ancient people of Egypt, there were several outside cultures that helped develop their calendar system and Egyptian idea of how life was created on this planet, most notably the inclusion of the star Sirius in the constellation of Canis Major. We give a brief discussion of these influences. For the ancient Egyptians, the cycle of life and death is a concept that ties in with a calendar system used to determine daily events.

  16. Commission 6: Astronomical Telegrams

    NASA Astrophysics Data System (ADS)

    Gilmore, Alan C.; Samus, Nicolay N.; Aksnes, Kaare; Green, Daniel W. E.; Marsden, Brian G.; Nakano, Syuichi; Roemer, Elizabeth; Tichá, Jana; Yamaoka, Hitoshi

    From Director Dan Green's report, following this report, it is obvious that the Central Bureau for Astronomical Telegrams (CBAT) continues its excellent work. The Electronic Telegrams (CBETs), established in the previous triennium, have become the regular means for fast communication, with the Circulars providing the official and archival record of discoveries and designations. It is regretted that subscriptions to the printed Circulars continue to decline, but inevitable in this age of electronic communication.

  17. 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.

  18. Modeling and Optimization of Polymer based Bulk Heterojunction (BH) Solar cell * Biswajit Ray, Pradeep R. Nair, R. Edwin Garca1

    E-print Network

    Alam, Muhammad A.

    , Pradeep R. Nair, R. Edwin García1 and Muhammad A. Alam *Email: ray0@purdue.edu , alam@purdue.edu Phone.5 1 -0.1 -0.05 0 0.05 freeenergy(J/m3 ) ø0øA øB f0 fsep 0 0.5 1 300 400 500 600 Volume fraction

  19. Detecting multiple texture planes using local spectral distortion Eraldo Ribeiro, Antonio Robles-Kelly, Edwin R. Hancock*

    E-print Network

    Martin, Ralph R.

    Science B.V. All rights reserved. Keywords: Shape-from-texture; Spectral Analysis; Surface normal-Kelly, Edwin R. Hancock* Department of Computer Science, University of York, York Y01 5DD, UK Received 10 June clustering; Texture analysis; Planar surface recovery 1. Introduction The identification of perspective

  20. Why Reason? A Conversation About Logic With Edwin J. Delattre Conducted by Thomas J. Donovan. National Humanities Faculty Why Series.

    ERIC Educational Resources Information Center

    Delattre, Edwin J.; Donovan, Thomas J.

    This booklet is one of the National Humanities Faculty publications designed to examine the question of what is taught, and why. This dialogue between Edwin Delattre and Thomas Donovan explores how humans go about reasoning and solving problems according to their collective, reflective intelligence. (Author/MJ)

  1. Edwin Zaccai (d.), Sustainable consumption, ecology and fair trade, Londres, Routledge, 2007 Is large-scale fair trade possible?

    E-print Network

    Paris-Sud XI, Université de

    Edwin Zaccai (éd.), Sustainable consumption, ecology and fair trade, Londres, Routledge, 2007 1 Is large-scale fair trade possible? Ronan Le Velly Abstract The article presents the changes in the nature of the market relationship that are induced by the expansion of fair trade. It shows that the increase

  2. Hubble Systems Optimize Hospital Schedules

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Don Rosenthal, a former Ames Research Center computer scientist who helped design the Hubble Space Telescope's scheduling software, co-founded Allocade Inc. of Menlo Park, California, in 2004. Allocade's OnCue software helps hospitals reclaim unused capacity and optimize constantly changing schedules for imaging procedures. After starting to use the software, one medical center soon reported noticeable improvements in efficiency, including a 12 percent increase in procedure volume, 35 percent reduction in staff overtime, and significant reductions in backlog and technician phone time. Allocade now offers versions for outpatient and inpatient magnetic resonance imaging (MRI), ultrasound, interventional radiology, nuclear medicine, Positron Emission Tomography (PET), radiography, radiography-fluoroscopy, and mammography.

  3. Star Witness News: Hubble’s Picture Book of the Universe

    NSDL National Science Digital Library

    This news story celebrates the 15th anniversary of the launch of the Hubble Space Telescope. Information about the top ten discoveries made by Hubble is included. This selection was written in conjunction with the HubbleSite press release: Hubble Celebrates 15th Anniversary with Spectacular New Images. The article is from the Amazing Space science newspaper, The Star Witness, which can be used as a science content reading.

  4. Planning and scheduling the Hubble Space Telescope: Practical application of advanced techniques

    NASA Technical Reports Server (NTRS)

    Miller, Glenn E.

    1994-01-01

    NASA's Hubble Space Telescope (HST) is a major astronomical facility that was launched in April, 1990. In late 1993, the first of several planned servicing missions refurbished the telescope, including corrections for a manufacturing flaw in the primary mirror. Orbiting above the distorting effects of the Earth's atmosphere, the HST provides an unrivaled combination of sensitivity, spectral coverage and angular resolution. The HST is arguably the most complex scientific observatory ever constructed and effective use of this valuable resource required novel approaches to astronomical observation and the development of advanced software systems including techniques to represent scheduling preferences and constraints, a constraint satisfaction problem (CSP) based scheduler and a rule based planning system. This paper presents a discussion of these systems and the lessons learned from operational experience.

  5. ASTRONOMICAL DATA ANALYSIS 1 Astronomical Data Analysis and Sparsity: from

    E-print Network

    Starck, Jean-Luc

    ten years. A quick search with ADS (NASA Astrophysics Data System, adswww.harvard.edu) showsASTRONOMICAL DATA ANALYSIS 1 Astronomical Data Analysis and Sparsity: from Wavelets to Compressed now in astronomy for many purposes, ranging from data filtering and deconvolution, to star and galaxy

  6. Hubble Witnesses The Final Blaze Of Glory Of Sun-Like Stars

    NSDL National Science Digital Library

    1997-01-01

    The Space Telescope Science Institute has released this stunning photograph from the Hubble Space Telescope, the "supersonic exhaust from [planetary] nebula M2-9." This is an example of a "bipolar planetary nebula" and is estimated to be ten times the diameter of Pluto's orbit. This picture, along with others, contributes to astronomers' understanding of the complex processes that can result from the death throes of Sun-like stars. The site contains the M2-9 photo in several resolutions and formats, an explanatory caption, a photo gallery of other planetary nebulas, a QuickTime movie illustrating the process, and other explanatory material.

  7. An expert system for ground support of the Hubble space telescope

    NASA Technical Reports Server (NTRS)

    Rosenthal, Don; Monger, Patricia; Miller, Glenn; Johnston, Mark

    1986-01-01

    The Hubble Space Telescope is an orbiting optical observatory due to be launched by the Space Shuttle in late 1987. It is a complex, multi-instrument observatory whose resources will be available to the world-wide astronomical community. The 'Transformation' system is a hybrid system which utilizes a rule-based expert system to convert scientific proposals into pre-optimized linked hierarchies of spacecraft activities. These activities are generated in a format that can be directly scheduled by the planning and scheduling component of the Space Telescope ground support system. The Transformation system will be described in detail in this paper, with particular attention given to the rule base.

  8. Hubble Space Telescope: High speed photometer instrument handbook. Version 2.0

    NASA Technical Reports Server (NTRS)

    White, Richard L. (editor)

    1990-01-01

    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 overview of the instrument; (2) a detailed description of some details of the HSP-ST system that may be important for some observations; (3) tables and figures describing the sensitivity and limitations of the HSP; (4) how to go about planning an observation with the HSP; and (5) a description of the standard calibration to be applied to HSP data and the resulting data products.

  9. Hubble's View of Transiting Planets

    E-print Network

    David Charbonneau

    2004-10-27

    The Hubble Space Telescope is uniquely able to study planets that are observed to transit their parent stars. The extremely stable platform afforded by an orbiting spacecraft, free from the contaminating effects of the Earth's atmosphere, enables HST to conduct ultra-high precision photometry and spectroscopy of known transiting extrasolar planet systems. Among HST's list of successful observations of the first such system, HD 209458, are (1) the first detection of the atmosphere of an extrasolar planet, (2) the determination that gas is escaping from the planet, and (3) a search for Earth-sized satellites and circumplanetary rings. Numerous wide-field, ground-based transit surveys are poised to uncover a gaggle of new worlds for which HST may undertake similar studies, such as the newly-discovered planet TrES-1. With regard to the future of Hubble, it must be noted that it is the only observatory in existence capable of confirming transits of Earth-like planets that may be detected by NASA's Kepler mission. Kepler could reveal Earth-like transits by the year 2010, but without a servicing mission it is very unlikely that HST would still be in operation.

  10. Jeremiah Horrocks, astronomer and poet

    Microsoft Academic Search

    R Horrocks

    2012-01-01

    This paper will consider the work of Jeremiah Horrocks, the first astronomer to observe the transit of Venus, with reference to his book on the subject (Venus in sole visa). It also explores a New Zealand connection. The paper focuses on Horrocks's interest in writing poetry, the relationship between his poetry and his astronomical work, and what this can tell

  11. Astronomical Instruments in India

    NASA Astrophysics Data System (ADS)

    Sarma, Sreeramula Rajeswara

    The earliest astronomical instruments used in India were the gnomon and the water clock. In the early seventh century, Brahmagupta described ten types of instruments, which were adopted by all subsequent writers with minor modifications. Contact with Islamic astronomy in the second millennium AD led to a radical change. Sanskrit texts began to lay emphasis on the importance of observational instruments. Exclusive texts on instruments were composed. Islamic instruments like the astrolabe were adopted and some new types of instruments were developed. Production and use of these traditional instruments continued, along with the cultivation of traditional astronomy, up to the end of the nineteenth century.

  12. Milestones of general relativity: Hubble’s law (1929) and the expansion of the universe

    NASA Astrophysics Data System (ADS)

    MacCallum, Malcolm A. H.

    2015-06-01

    Hubble’s announcement of the magnitude–redshift relation (Hubble 1929 Proc. Natl. Acad. Sci. USA 15 168–73) brought about a major change in our understanding of the Universe. After tracing the pre-history of Hubble’s work, and the hiatus in our understanding which his underestimate of distances led to, this review focuses on the development and success of our understanding of the expanding Universe up to the present day, and the part that general relativity plays in that success.

  13. Visualizing Astronomical Data with Blender

    NASA Astrophysics Data System (ADS)

    Kent, Brian R.

    2013-06-01

    Astronomical data take on a multitude of forms - catalogs, data cubes, images, and simulations. The availability of software for rendering high-quality three-dimensional graphics lends itself to the paradigm of exploring the incredible parameter space afforded by the astronomical sciences. The software program Blender gives astronomers a useful tool for displaying data in a manner used by three-dimensional (3D) graphics specialists and animators. The interface to this popular software package is introduced with attention to features of interest in astronomy. An overview of the steps for generating models, textures, animations, camera work, and renders is outlined. An introduction is presented on the methodology for producing animations and graphics with a variety of astronomical data. Examples from subfields of astronomy with different kinds of data are shown with resources provided to members of the astronomical community. An example video showcasing the outlined principles and features is provided along with scripts and files for sample visualizations.

  14. The Hubble Ultra Deep Field

    NASA Astrophysics Data System (ADS)

    Beckwith, Steven V. W.; Stiavelli, Massimo; Koekemoer, Anton M.; Caldwell, John A. R.; Ferguson, Henry C.; Hook, Richard; Lucas, Ray A.; Bergeron, Louis E.; Corbin, Michael; Jogee, Shardha; Panagia, Nino; Robberto, Massimo; Royle, Patricia; Somerville, Rachel S.; Sosey, Megan

    2006-11-01

    This paper presents the Hubble Ultra Deep Field (HUDF), a 1 million s exposure of an 11 arcmin2 region in the southern sky with the Advanced Camera for Surveys on the Hubble Space Telescope using Director's Discretionary Time. The exposure time was divided among four filters, F435W (B435), F606W (V606), F775W (i 775), and F850LP (z850), to give approximately uniform limiting magnitudes mAB~29 for point sources. The image contains at least 10,000 objects, presented here as a catalog, the vast majority of which are galaxies. Visual inspection of the images shows few if any galaxies at redshifts greater than ~4 that resemble present-day spiral or elliptical galaxies. The image reinforces the conclusion from the original Hubble Deep Field that galaxies evolved strongly during the first few billion years in the infancy of the universe. Using the Lyman break dropout method to derive samples of galaxies at redshifts between 4 and 7, it is possible to study the apparent evolution of the galaxy luminosity function and number density. Examination of the catalog for dropout sources yields 504 B435 dropouts, 204 V 606 dropouts, and 54 i775 dropouts. The i775 dropouts are most likely galaxies at redshifts between 6 and 7. Using these samples, which are at different redshifts but derived from the same data, we find no evidence for a change in the characteristic luminosity of galaxies but some evidence for a decrease in their number densities between redshifts of 4 and 7. Assessing the factors needed to derive the luminosity function from the data suggests that there is considerable uncertainty in parameters from samples discovered with different instruments and derived using independent assumptions about the source populations. This assessment calls into question some of the strong conclusions of recently published work on distant galaxies. The ultraviolet luminosity density of these samples is dominated by galaxies fainter than the characteristic luminosity, and the HUDF reveals considerably more luminosity than shallower surveys. The apparent ultraviolet luminosity density of galaxies appears to decrease from redshifts of a few to redshifts greater than 6, although this decrease may be the result of faint-end incompleteness in the most distant samples. The highest redshift samples show that star formation was already vigorous at the earliest epochs at which galaxies have been observed, less than 1 billion years after the big bang.

  15. Strasbourg's "First" astronomical observatory

    NASA Astrophysics Data System (ADS)

    Heck, André

    2011-08-01

    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.

  16. Hubble Space Telescope Berthed in Columbia's Cargo Bay

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is a photo of the Hubble Space Telescope (HST),in its origianl configuration, berthed in the cargo bay of the Space Shuttle Columbia during the STS-109 mission silhouetted against the airglow of the Earth's horizon. The telescope was captured and secured on a work stand in Columbia's payload bay using Columbia's robotic arm, where 4 of the 7-member crew performed 5 spacewalks completing system upgrades to the HST. Included in those upgrades were: replacement of the solar array panels; replacement of the power control unit (PCU); replacement of the Faint Object Camera (FOC) with a new advanced camera for Surveys (ACS); and installation of the experimental cooling system for the Hubble's Near-Infrared Camera and Multi-object Spectrometer (NICMOS), which had been dormant since January 1999 when its original coolant ran out. The Marshall Space Flight Center had the responsibility for the design, development, and construction of the the HST, which is the most complex and sensitive optical telescope ever made, to study the cosmos from a low-Earth orbit. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than is visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. Launched March 1, 2002 the STS-109 HST servicing mission lasted 10 days, 22 hours, and 11 minutes. It was the 108th flight overall in NASA's Space Shuttle Program.

  17. Hubble Discovery Image of New Moon Orbiting Saturn

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This four-picture sequence (spanning 30 minutes) shows one of four new moons discovered by the Hubble Space Telescope, in images taken of Saturn on May 22, 1995, when Saturn's rings were tilted edge-on to Earth.

    Identified as S/1995 S3, the moon appears as an elongated white spot near the center of each image. The new moon lies just outside Saturn's outermost 'F' ring and is no bigger than about 15 miles across. The brighter object to the left is the moon Epimetheus, which was discovered during the ring-plane crossing of 1966. Both moons change position from frame to frame because they are orbiting the planet.

    Saturn appears as a bright white disk at far right, and the edge-on rings extend diagonally to the upper left. To the left of the vertical line, each image has been processed to remove residual light from the rings and accentuate any faint satellites orbiting near the rings. The long observing times necessary to detect the faint satellites have resulted in Saturn's bright, overexposed appearance.

    Saturn ring plane crossings happen only once every 15 years, and historically have given astronomers an opportunity to discover new satellites that are normally lost in the glare of the planet's bright ring system.

    The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  18. Life as an Astronomer: 1. What do Astronomers Study?

    E-print Network

    Groppi, Christopher

    years to B.S. High School course work: college prep physic, chemistry, math (pre-calc) Advanced or Astrophysics degree B average or better and decent GRE scores #12;14 Life as an Astronomer: 5. Job Timeline

  19. Hubble Space Telescope Servicing begins.

    NASA Astrophysics Data System (ADS)

    1993-12-01

    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.

  20. HUBBLE PROBES THE COMPLEX HISTORY OF A DYING STAR

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This NASA Hubble Space Telescope image shows one of the most complex planetary nebulae ever seen, NGC 6543, nicknamed the 'Cat's Eye Nebula.' Hubble reveals surprisingly intricate structures including concentric gas shells, jets of high-speed gas and unusual shock-induced knots of gas. Estimated to be 1,000 years old, the nebula is a visual 'fossil record' of the dynamics and late evolution of a dying star. A preliminary interpretation suggests that the star might be a double-star system. The dynamical effects of two stars orbiting one another most easily explains the intricate structures, which are much more complicated than features seen in most planetary nebulae. (The two stars are too close together to be individually resolved by Hubble, and instead, appear as a single point of light at the center of the nebula.) According to this model, a fast 'stellar wind' of gas blown off the central star created the elongated shell of dense, glowing gas. This structure is embedded inside two larger lobes of gas blown off the star at an earlier phase. These lobes are 'pinched' by a ring of denser gas, presumably ejected along the orbital plane of the binary companion. The suspected companion star also might be responsible for a pair of high-speed jets of gas that lie at right angles to this equatorial ring. If the companion were pulling in material from a neighboring star, jets escaping along the companion's rotation axis could be produced. These jets would explain several puzzling features along the periphery of the gas lobes. Like a stream of water hitting a sand pile, the jets compress gas ahead of them, creating the 'curlicue' features and bright arcs near the outer edge of the lobes. The twin jets are now pointing in different directions than these features. This suggests the jets are wobbling, or precessing, and turning on and off episodically. The image was taken with the Wide Field Planetary Camera-2 on September 18, 1994. NGC 6543 is 3,000 light-years away in the northern constellation Draco. The term planetary nebula is a misnomer; dying stars create these cocoons when they lose outer layers of gas. The process has nothing to do with planet formation, which is predicted to happen early in a star's life. This material was presented at the 185th meeting of the American Astronomical Society in Tucson, AZ on January 11, 1995. Credit: J.P. Harrington and K.J. Borkowski (University of Maryland), and NASA

  1. The Panchromatic Hubble Andromeda Treasury

    NASA Astrophysics Data System (ADS)

    Dalcanton, Julianne J.; Williams, Benjamin F.; Lang, Dustin; Lauer, Tod R.; Kalirai, Jason S.; Seth, Anil C.; Dolphin, Andrew; Rosenfield, Philip; Weisz, Daniel R.; Bell, Eric F.; Bianchi, Luciana C.; Boyer, Martha L.; Caldwell, Nelson; Dong, Hui; Dorman, Claire E.; Gilbert, Karoline M.; Girardi, Léo; Gogarten, Stephanie M.; Gordon, Karl D.; Guhathakurta, Puragra; Hodge, Paul W.; Holtzman, Jon A.; Johnson, L. Clifton; Larsen, Søren S.; Lewis, Alexia; Melbourne, Jason L.; Olsen, Knut A. G.; Rix, Hans-Walter; Rosema, Keith; Saha, Abhijit; Sarajedini, Ata; Skillman, Evan D.; Stanek, Krzysztof Z.

    2012-06-01

    The Panchromatic Hubble Andromeda Treasury is an ongoing Hubble Space Telescope Multi-Cycle Treasury program to image ~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 deg2area 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 F275W = 25.1, m F336W = 24.9, m F475W = 27.9, m F814W = 27.1, m F110W = 25.5, and m 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.

  2. Annotations of a Public Astronomer

    NASA Astrophysics Data System (ADS)

    Adamo, A.

    2011-06-01

    Angelo Adamo is an Italian astronomer and artist interested in inspiring people with scientifically-based tales. He has recently published two illustrated books exploring the relationships between mankind and cosmos through physics, art, literature, music, cartoons, and movies.

  3. Astronomical databases of Nikolaev Observatory

    NASA Astrophysics Data System (ADS)

    Protsyuk, Y.; Mazhaev, A.

    2008-07-01

    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.

  4. Islamic Astronomical Instruments and Observatories

    NASA Astrophysics Data System (ADS)

    Heidarzadeh, Tofigh

    This chapter is a brief survey of astronomical instruments being used and developed in Islamic territories from the eighth to the fifteenth centuries as well as a concise account of major observatories and observational programs in this period.

  5. COSMOS : Hubble Space Telescope Observations

    E-print Network

    N. Scoville; A. Benson; A. W. Blain; D. Calzetti; A. Comastri; P. Capak; C. Carilli; J. E. Carlstrom; C. M. Carollo; J. Colbert; E. Daddi; R. S. Ellis; M. Elvis; S. P. Ewald; M. Fall; A. Franceschini; M. Giavalisco; W. Green; 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. Tyson; C. M. Urry; L. Van Waerbeke; P. Vettolani; S. D. M. White; L. Yan; G Zamorani

    2007-02-19

    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$\\sq$\\deg) has been imaged with single-orbit ACS I-F814W exposures with 50% completeness for sources 0.5\\arcsec in diameter at I$_{AB} $ = 26.0 mag. The ACS imaging is a key part of the COSMOS survey, providing very high sensitivity and high resolution (0.09\\arcsec FWHM, 0.05\\arcsec pixels) imaging and detecting 1.2 million objects to a limiting magnitude of 26.5 (AB). These images yield resolved morphologies for several hundred thousand galaxies. The small HST PSF also provides greatly enhanced sensitivity for weak lensing investigations of the dark matter distribution.

  6. A Hubble Diagram for Quasars

    E-print Network

    Risaliti, Guido

    2015-01-01

    We present a new method to test the cosmological model, and to estimate the cosmological parameters, based on the non-linear relation between ultraviolet and X-ray luminosity of quasars. We built a data set of ~1,250 quasars by merging several literature samples with X-ray measurements at 2 keV and SDSS photometry, which was used to estimate the extinction-corrected 2500~\\AA\\ flux. We obtained three main results: (1) we checked the non-linear relation between X-ray and UV luminosities in small redshift bins up to z~6, confirming that it holds at all redshifts with the same slope; (2) we built a Hubble diagram for quasars up to z~6, which is well matched to that of supernovae in the common z=0-1.4 redshift interval, and extends the test of the cosmological model up to z~6; (3) we showed that this non-linear relation is a powerful tool to estimate cosmological parameters. With present data, assuming a $\\Lambda$CDM model, we obtain $\\Omega_M$=0.21$^{+0.08}_{-0.10}$ and $\\Omega_\\Lambda$=0.95$^{+0.30}_{-0.20}$ ($\\...

  7. The Hubble Space Telescope (HST) Transportation Operation

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Ready for transportation to the Kennedy Space Center, the Hubble Space Telescope (HST) is pictured onboard the strongback dolly at the Vertical Processing Facility (VPF) at the Lockheed assembly plant upon completion of final testing and verification.

  8. Testing astronomically tuned age models

    NASA Astrophysics Data System (ADS)

    Zeeden, Christian; Meyers, Stephen R.; Lourens, Lucas J.; Hilgen, Frederik J.

    2015-04-01

    Astrochronology is fundamental to many paleoclimate studies, but a standard statistical test has yet to be established for validating stand-alone astronomically tuned time scales (those lacking detailed independent time control) against their astronomical insolation tuning curves. Shackleton et al. (1995) proposed that the modulation of precession's amplitude by eccentricity can be used as an independent test for the successful tuning of paleoclimate data. Subsequent studies have demonstrated that eccentricity-like amplitude modulation can be artificially generated in random data, following astronomical tuning. Here we introduce a new statistical approach that circumvents the problem of introducing amplitude modulations during tuning and data processing, thereby allowing the use of amplitude modulations for astronomical time scale evaluation. The method is based upon the use of the Hilbert transform to calculate instantaneous amplitude following application of a wide band precession filter and subsequent low-pass filtering of the instantaneous amplitude to extract potential eccentricity modulations. Statistical significance of the results is evaluated using phase-randomized surrogates that preserve the power spectrum structure of the data but have randomized amplitude modulations. Application of the new testing algorithm to two astronomically tuned data sets demonstrates the efficacy of the technique and confirms the presence of astronomical signals. Additionally, it is demonstrated that a minimal tuning approach using (at maximum) one precession cycle per ~100 kyr eccentricity cycle does not introduce systematic frequency modulations, even when a narrow band-pass filter is applied, allowing direct comparison of data amplitudes and orbital eccentricity.

  9. Hubble’s 25th Anniversary: A Quarter-Century of Discovery and Inspiration

    NASA Astrophysics Data System (ADS)

    Straughn, Amber; Jirdeh, Hussein

    2015-01-01

    April 24, 2015 marks the 25th anniversary of the launch of the Hubble Space Telescope. In its quarter-century in orbit, the Hubble Space Telescope has transformed the way we understand the Universe, helped us find our place among the stars, and paved the way to incredible advancements in science and technology. NASA and ESA, including STScI and partners, will use the 25th anniversary of Hubble's launch as a unique opportunity to communicate to the widest possible audience the significance of the past quarter-century of discovery with the Hubble Space Telescope and to highlight that Hubble will continue to produce groundbreaking science results. We will enhance public understanding of Hubble's many contributions to the scientific world, and will capitalize on Hubble's cultural popularity by emphasizing its' successor, the James Webb Space Telescope. This poster highlights many of the upcoming opportunities to join in the anniversary activities, both in-person and online. Find out more at hubble25th.org and follow #Hubble25 on social media.

  10. The Hubble Tuning Fork Strikes A New Note

    NASA Astrophysics Data System (ADS)

    Block, D. L.; Freeman, K. C.; Puerari, I.; Combes, F.; Buta, R.; Jarrett, T.; Worthey, G.

    2004-01-01

    Astronomer have for decades referred to the Hubble tuning fork. We show that the actual originator of the Tuning Fork is that of Sir James Jeans. We next focus our attention on the duality of spiral structure and the temporal evolution of bars in our local Universe. Next, we present deep-IR observations of M33, which show gargantuan arcs of thermally pulsing asymptotic giant branch carbon stars; we attribute this intermediate age stellar population in the outer disk, to accretion of gas in the disk building process. We then consider power spectra of galaxies and Kolmogorov turbulence in gaseous population I disks and the fractal nature of Population II disks. In particular, power spectra may serve as excellent diagnostics of the regime wherein vertical and horizontal gravitational instabilities in stellar disks are coupled. Finally, we argue that quantitative dust-penetrated templates for galaxies in our local Universe may also serve as excellent templates for galaxies at higher-z, because of the duality of spiral structure expected from gaseous to stellar disks.

  11. High-Redshift Supernovae in the Hubble Deep Field

    SciTech Connect

    Gilliland, R.L. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)] [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Nugent, P.E. [E.O. Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 50-232, Berkeley, CA 94720 (United States)] [E.O. Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 50-232, Berkeley, CA 94720 (United States); Phillips, M.M. [Carnegie Institution of Washington, Las Campanas Observatory, Casilla 601, La Serena (Chile)] [Carnegie Institution of Washington, Las Campanas Observatory, Casilla 601, La Serena (Chile)

    1999-08-01

    Two supernovae detected in the Hubble Deep Field (HDF) using the original 1995 December epoch and data from a shorter (63,000 s in F814W) 1997 December visit with {ital HST} are discussed. The supernovae (SNe) are both associated with distinct galaxies at redshifts of 0.95 (spectroscopic) from Cohen et al. and 1.32 (photometric) from the work of Fern{acute a}ndez-Soto, Lanzetta, & Yahil. These redshifts are near, in the case of 0.95, and well beyond, for 1.32, the greatest distance reported previously for SNe. We show that our observations are sensitive to supernovae to z{approx_lt}1.8 in either epoch for an event near peak brightness. Detailed simulations are discussed that quantify the level at which false events from our search phase would start to arise and the completeness of our search as a function of both SN brightness and host galaxy redshift. The number of Type Ia and Type II SNe expected as a function of redshift in the two HDF epochs are discussed in relation to several published predictions and our own detailed calculations. A mean detection frequency of one SN per epoch for the small HDF area is consistent with expectations from current theory. {copyright} {ital {copyright} 1999.} {ital The American Astronomical Society}

  12. Stereo 3-D Presentation of Hubble Space Telescope Imagery

    NASA Astrophysics Data System (ADS)

    Levay, Zoltan G.; Bacon, G.; Bond, H. E.; Borders, T. M.; Christian, C. A.; Frattare, L. M.; Hamilton, F.; Januszewski, W.; Livio, M.; Mutchler, M.; Noll, K. S.; Summers, F.

    2011-01-01

    3-dimensional (3-D) visualizations are a means of adding depth to otherwise 2-dimensional images. For astronomical images, depth is frequently not measured, but relative depth relationships can be inferred. We present a 3-D visualization of a portion of the Carina Nebula imaged with the Hubble Space Telescope. The source image is a color composite of two datasets obtained with the Advanced Camera for Surveys. Images in the H?+[N II] filter (F658N) were taken from a 2005 Carina Nebula survey mosaic by Smith et al. (2010, MNRAS, 405, 1153). Images in the [O III] filter (F502N) were obtained by our team in 2010 in parallel to WFC3 observations of the nearby HH 901 region (HST proposal 12050). A 3-D model was constructed from the color composite image by separating it into several planes. Stars and nebular structures were extracted from the image and placed on different planes in 3-D digital modeling software using morphology of nebular features to infer relative depth. Relief texture was added to some of the nebular structures in the model to further enhance the perception of depth. For a static image, frames rendered from the 3-D model at two different viewpoints are composited into a single image in anaglyph (red-blue) stereo that will be shown.

  13. HUBBLE UNCOVERS MYSTERY OBJECTS IN THE DENSE CORE OF A NEARBY STAR CLUSTER

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Piercing the heart of a glittering swarm of stars, NASA's sharp-eyed Hubble Space Telescope unveils the central region of the globular cluster M22, a 12- to 14-billion-year-old grouping of stars in the constellation Sagittarius. The telescope's view of the cluster's core measures 3.3 light-years across. The stars near the cluster's core are 100,000 times more numerous than those in the Sun's neighborhood. Buried in the glow of starlight are about six 'mystery objects,' which astronomers estimate are no larger than one quarter the mass of the giant planet Jupiter, the solar system's heftiest planet. The mystery objects are too far and dim for Hubble to see directly. Instead, the orbiting observatory detected these unseen celestial bodies by looking for their gravitational effects on the light from far distant stars. In this case, the stars are far beyond the cluster in the galactic bulge, about 30,000 light-years from Earth at the center of the Milky Way Galaxy. M22 is 8,500 light-years away. The invisible objects betrayed their presence by bending the starlight gravitationally and amplifying it, a phenomenon known as microlensing. From February 22 to June 15, 1999, Hubble's Wide Field and Planetary Camera 2 looked through this central region and monitored 83,000 stars. During that time the orbiting observatory recorded six unexpectedly brief microlensing events. In each case a background star jumped in brightness for less than 20 hours before dropping back to normal. These transitory spikes in brightness mean that the object passing in front of the star must have been much smaller than a normal star. Hubble also detected one clear microlensing event. In that observation a star appeared about 10 times brighter over an 18-day span before returning to normal. Astronomers traced the leap in brightness to a dwarf star in the cluster floating in front of the background star. The inset photo shows the entire globular cluster of about 10 million stars. M22 is about 60 light-years wide. The image was taken in June 1995 by the Burrell Schmidt telescope at the Case Western Reserve University's Warner and Swasey Observatory on Kitt Peak in Arizona. This release is issued jointly by NASA and ESA. Credits for Hubble image: NASA, Kailash Sahu, Stefano Casertano, Mario Livio, Ron Gilliland (Space Telescope Science Institute), Nino Panagia (European Space Agency/Space Telescope Science Institute), Michael Albrow and Mike Potter (Space Telescope Science Institute) Credits for ground-based image: Nigel A.Sharp, REU program/AURA/NOAO/NSF

  14. Student Projects for the Introductory Astronomy Course Using the Hubble Data Archive and Related Resources.

    NASA Astrophysics Data System (ADS)

    English, T.

    1999-12-01

    Many students in the introductory course lack understanding about how astronomy is done at big observatories and about how scientific investigations are carried out in general. This presentation outlines the latest steps in an ongoing effort at Gardner-Webb University to build research projects into the course that develop an appreciation and understanding of the latest astronomical research and the methods of doing science. A significant percentage of students come into the course with the misconception that the Hubble Space Telescope somehow travels to remote destinations around the universe taking snapshots. To address this problem, they are asked to develop proposals to use Hubble to observe objects of their choice. Students make use of HST proposal abstracts, images, and other information available through the online data archive, along with press releases, tutorials, and other resources at the STScI web site to develop their proposals. Despite some initial reluctance from the students to wade into the technical information in the Data Archive, the assignment has been generally successful thus far. Students leave the course with a good working knowledge of the operation of Hubble, and a few ideas developed by the students are now being implemented by real observers using HST.

  15. ISO Results Presented at International Astronomical Union

    NASA Astrophysics Data System (ADS)

    1997-08-01

    Some of the work being presented is collected in the attached ESA Information Note N 25-97, ISO illuminates our cosmic ancestry. A set of six colour images illustrating various aspects have also been released and are available at http://www.estec.esa.nl/spdwww/iso1808.htm or in hard copy from ESA Public Relations Paris (fax:+33.1.5369.7690). These pictures cover: 1. Distant but powerful infrared galaxies 2. A scan across the milky way 3. Helix nebula: the shroud of a dead star 4. Supernova remnant Cassiopeia A 5. Trifid nebula: a dusty birthplace of stars 6. Precursors of stars and planets The International Astronomical Union provides a forum where astronomers from all over the world can develop astronomy in all its aspects through international co-operation. General Assemblies are held every three years. It is expected that over 1600 astronomers will attend this year's meeting, which is being held in Kyoto, Japan from 18-30 August. Further information on the meeting can be found at: www.tenmon.or.jp/iau97/ . ISO illuminates our cosmic ancestry The European Space Agency's Infrared Space Observatory, ISO, is unmatched in its ability to explore and analyse many of the universal processes that made our existence possible. We are children of the stars. Every atom in our bodies was created in cosmic space and delivered to the Sun's vicinity in time for the Earth's formation, during a ceaseless cycle of birth, death and rebirth among the stars. The most creative places in the sky are cool and dusty, and opaque even to the Hubble Space Telescope. Infrared rays penetrating the dust reveal to ISO hidden objects, and the atoms and molecules of cosmic chemistry. "ISO is reading Nature's recipe book," says Roger Bonnet, ESA's director of science. "As the world's only telescope capable of observing the Universe over a wide range of infrared wavelengths, ISO plays an indispensable part in astronomical discoveries that help to explain how we came to exist." This Information Note describes several stages in our cosmic ancestry, revealed when ISO examines their counterparts still observable today. The evolving galaxies In the beginning was hydrogen, mixed with helium and minute traces of other light atoms. These were the atomic products of the Big Bang, the hypothetical cataclysm that created the Universe more than 10 billion years ago. The primeval gas was very dull. Nature could not make dust from it, never mind a living creature. But gravity gathered the hydrogen and helium into stars, and by nuclear reactions the stars glowed. As the first stars aged, the reactions made novel chemical elements like carbon, oxygen and silicon. Expelled into the stars' surroundings, these materials reacted with one another and with hydrogen to make the icy, tarry and stony grains of cosmic dust. The vast assemblies of stars called galaxies became crucibles where Nature could use physics and chemistry to make new materials and new stars. Rays from the most distant galaxies have taken so many billions of years to reach us that we see them as they were when they were young. The farthest galaxy observed so far by ISO is a quasar called BR 1202-0225, dating from a time when the Universe was less than one-tenth of its present age. Already it is dusty. ISO has also observed many galaxies at about half the age of the Universe, by staring long and hard through a window in the dust of our own Milky Way Galaxy, called the Lockman Hole. In those that glow most brightly in the infrared, astronomers suspect that frantic star-making is in progress, in episodes called starbursts. In nearer galaxies, ISO's astronomers can relate strong infrared emissions to collisions and to violent eruptions in the galactic cores, which have punctuated the evolution of the galaxies. "Having ISO in space brings special opportunities for the study of the history of the galaxies," says the Japanese astronomer Yoshiaki Taniguchi of Tohoku University. "By detecting infrared wavelengths that are hard to observe from the Earth, ISO picks out very clearly th

  16. XEphem: Interactive Astronomical Ephemeris

    NASA Astrophysics Data System (ADS)

    Downey, Elwood Charles

    2011-12-01

    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.

  17. Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant

    Microsoft Academic Search

    Wendy L. Freedman; Barry F. Madore; Brad K. Gibson; Laura Ferrarese; Daniel D. Kelson; Shoko Sakai; Jeremy R. Mould; Robert C. Kennicutt Jr.; Holland C. Ford; John A. Graham; John P. Huchra; Shaun M. G. Hughes; Garth D. Illingworth; Lucas M. Macri; Peter B. Stetson; P. B. Stetson

    2001-01-01

    We present here the final results of the Hubble Space Telescope (HST) Key Project to measure the Hubble constant. We summarize our method, the results, and the uncertainties, tabulate our revised distances, and give the implications of these results for cosmology. Our results are based on a Cepheid calibration of several secondary distance methods applied over the range of about

  18. Interactive Visualization and Simulation of Astronomical Nebulae

    E-print Network

    Wenger, Stephan; Steffen, Wolfgang; Koning, Nico; Weiskopf, Daniel; Magnor, Marcus

    2012-01-01

    Interactive visualization and simulation of astrophysical phenomena help astronomers and enable digital planetariums and television documentaries to take their spectators on a journey into deep space to explore the astronomical wonders of our universe in 3D.

  19. 114The Hubble Search for the Farthest Galaxy in the Universe Astronomers have recently discovered

    E-print Network

    Christian, Eric

    = (1029-121)/121 = 7.5 Problem 2 ­ According to the Big Bang theory, the redshift of a galaxy is related was the redshift of the new galaxy based on the lyman-alpha spectral line? Problem 2 ­ According to the Big Bang_GND_5296? Problem 3 ­ The Big Bang occurred 13.8 billion years ago. How soon after the Big Bang

  20. HUBBLE'S NEW IMPROVED OPTICS PROBE THE CORE OF A DISTANT GALAXY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This comparison image of the core of the galaxy M100 shows the dramatic improvement in Hubble Space Telescope's view of the universe. The new image was taken with the second generation Wide Field and Planetary Camera (WFPC-2) which was installed during the STS-61 Hubble Servicing Mission. The picture beautifully demonstrates that the corrective optics incorporated within the WFPC-2 compensate fully for optical aberration in Hubble's primary mirror. The new camera will allow Hubble to probe the universe with unprecedented clarity and sensitivity, and to fulfill many of the most important scientific objectives for which the telescope was originally built. [ Right ] The core of the grand design spiral galaxy M100, as imaged by Hubble Space Telescope's Wide Field Planetary Camera 2 in its high resolution channel. The WFPC-2 contains modified optics that correct for Hubble's previously blurry vision, allowing the telescope for the first time to cleanly resolve faint structure as small as 30 light-years across in a galaxy which is tens of millions of light years away. The image was taken on December 31, 1993. [Left ] For comparison, a picture taken with the WFPC-1 camera in wide field mode, on November 27, 1993, just a few days prior to the STS-61 servicing mission. The effects of optical aberration in HST's 2.4-meter primary mirror blur starlight, smear out fine detail, and limit the telescope's ability to see faint structure. Both Hubble images are 'raw;' they have not been subject to computer image reconstruction techniques commonly used in aberrated images made before the servicing mission. TARGET INFORMATION: M100 The galaxy M100 (100th object in the Messier Catalog of non-stellar objects) is one of the brightest members of the Virgo Cluster of galaxies. The galaxy is in the spring constellation Coma Berenices and can be seen through a moderate-sized amateur telescope. M100 is spiral shaped, like our Milky Way, and tilted nearly face-on as seen from earth. The galaxy has two prominent arms of bright stars and several fainter arms. Though the galaxy is estimated to be tens of millions of light-years away, Hubble reveals the sort of detail only seen previously (with ground based telescopes) in neighboring galaxies that are ten times closer. Before HST, astronomers could only see such a level of detail in roughly a dozen galaxies in our Local Group. Now, with Hubble's improved vision, the portion of the universe which can be studied with such clarity has grown a thousand fold. Only the future will tell what revelations await as Hubble's spectacular vision is applied to a host of fascinating and important questions about the universe and our place in it. PHOTO RELEASE NO.: STScI-PR94-01

  1. Photonic lattices for astronomical interferometry

    NASA Astrophysics Data System (ADS)

    Minardi, S.

    2012-05-01

    Regular 2D lattices of evanescently coupled waveguides may provide in the near future photonic components capable of combining interferometrically and simultaneously a large number of telescopes, thus easing the imaging capabilities of optical interferometers. In this paper, the theoretical modelling of the so-called discrete beam combiners (DBCs) is described and compared to the conventional model used for photonic beam combiners for astronomical interferometry. The performance of DBCs as compared to an ideal ABCD beam combiner is discussed and applications to astronomical instrumentation are analysed.

  2. Astronomical Archive at Tartu Observatory

    NASA Astrophysics Data System (ADS)

    Annuk, K.

    2007-10-01

    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.

  3. Astronomers Discover Six-Image Gravitational Lens

    NASA Astrophysics Data System (ADS)

    2001-08-01

    An international team of astronomers has used the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope and NASA's Hubble Space Telescope (HST) to discover the first gravitational lens in which the single image of a very distant galaxy has been split into six different images. The unique configuration is produced by the gravitational effect of three galaxies along the line of sight between the more-distant galaxy and Earth. Optical and Radio Images of Gravitational Lens "This is the first gravitational lens with more than four images of the background object that is produced by a small group of galaxies rather than a large cluster of galaxies," said David Rusin, who just received his Ph.D. from the University of Pennsylvania. "Such systems are expected to be extremely rare, so this discovery is an important stepping stone. Because this is an intermediate case between gravitational lenses produced by single galaxies and lenses produced by large clusters of galaxies, it will give us insights we can't get from other types of lenses," Rusin added. The gravitational lens, called CLASS B1359+154, consists of a galaxy more than 11 billion light-years away in the constellation Bootes, with a trio of galaxies more than 7 billion light-years away along the same line of sight. The more-distant galaxy shows signs that it contains a massive black hole at its core and also has regions in which new stars are forming. The gravitational effect of the intervening galaxies has caused the light and radio waves from the single, more-distant galaxy to be "bent" to form six images as seen from Earth. Four of these images appear outside the triangle formed by the three intermediate galaxies and two appear inside that triangle. "This lens system is a very interesting case to study because it is more complicated than lenses produced by single galaxies, and yet simpler than lenses produced by clusters of numerous galaxies," said Chris Kochanek of the Harvard-Smithsonian Center for Astrophysics (CfA). "When we understand this system, we will have a much clearer picture of how galaxies are changed by being part of a bigger cluster of galaxies," he added. B1359+154 was discovered in 1999 by the Cosmic Lens All-Sky Survey, an international collaboration of astronomers who use radio telescopes to search the sky for gravitational lenses. Images made by the NSF's Very Large Array in New Mexico and by Britain's MERLIN radio telescope showed six objects suspected of being gravitational-lens images, but the results were inconclusive. Rusin and his team used the VLBA and HST in 1999 and 2000 to make more-detailed studies of B1359+154. The combination of data from the VLBA and HST convinced the astronomers that B1359+154 actually consists of six lensed images of a single background galaxy. The VLBA images were made from data collected during observations at a radio frequency of 1.7 GHz. "This is a great example of modern, multi-wavelength astronomy," said Rusin. "We need the radio telescopes to detect the gravitational lenses in the first place, then we need the visible-light information from Hubble to show us additional detail about the structure of the system." Armed with the combined VLBA and HST data about the positions and brightnesses of the six images of the background galaxy as well as the positions of the three intermediate galaxies, the astronomers did computer simulations to show how the gravitation of the three galaxies could produce the lens effect. They were able to design a computer model of the system that, in fact, produces the six images seen in B1359+154. "Our computer model certainly is not perfect, and we need to do more observations of this system to refine it, but we have clearly demonstrated that the three galaxies we see can produce a six-image lens system," said Martin Norbury, a graduate student at Jodrell Bank Observatory in Britain. "We think this work will give us an excellent tool for studying much-denser clusters of gala

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

    NASA Astrophysics Data System (ADS)

    Struck, James

    2011-09-01

    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.

  5. Hubble Heritage Observations of LBN 67

    NASA Astrophysics Data System (ADS)

    Levay, Zolt

    2014-10-01

    We are proposing new observations for the Hubble Heritage project in cycle 22. We have identified a new target that will be used to produce high-quality, high-impact images that ensure continued public support for the Hubble mission. This proposal is submitted to the cycle 22 DD program to provide new images that will be obtained and released over the coming year. Our continuing ability to do science with HST and our hopes for JWST depend crucially on public support generated by our continuing commitment to sharing new images with the public.

  6. Decelerating universes older than their Hubble times

    E-print Network

    J. C. Jackson; Marina Dodgson

    2001-09-21

    Recent observations suggest that Hubble's constant is large, and hence that the Universe appears to be younger than some of its constituents. The traditional escape route, which assumes that the expansion is accelerating, appears to be blocked by observations of Type 1a supernovae, which suggest(ed) that the Universe is decelerating. These observations are reconciled in a model in which the Universe has experienced an inflationary phase in the recent past, driven by an ultra-light inflaton whose Compton wavelength is of the same order as the Hubble radius.

  7. Decelerating universes older than their Hubble times

    E-print Network

    Jackson, J C; Dodgson, Marina

    1998-01-01

    Recent observations suggest that Hubble's constant is large, and hence that the Universe appears to be younger than some of its constituents. The traditional escape route, which assumes that the expansion is accelerating, appears to be blocked by observations of Type 1a supernovae, which suggest(ed) that the Universe is decelerating. These observations are reconciled in a model in which the Universe has experienced an inflationary phase in the recent past, driven by an ultra-light inflaton whose Compton wavelength is of the same order as the Hubble radius.

  8. HUBBLE SPACE TELESCOPE ON TRACK FOR MEASURING THE EXPANSION RATE OF THE UNIVERSE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Two international teams of astronomers, using NASA's Hubble Space Telescope, are reporting major progress in converging on an accurate measurement of the Universe's rate of expansion -- a value which has been debated for over half a century. These new results yield ranges for the age of the Universe from 9-12 billion years, and 11-14 billion years, respectively. The goal of the project is to measure the Hubble Constant to ten percent accuracy. The Hubble Space Telescope Key Project team, an international group of over 20 astronomers, is led by Wendy Freedman of Carnegie Observatories, Pasadena, CA, Robert Kennicutt, University of Arizona, Tucson, AZ, and Jeremy Mould, Mount Stromlo and Siding Springs Observatory, Australia. The group's interim results, announced at a meeting held at the Space Telescope Science Institute (STScI) in Baltimore, Maryland, are consistent with their preliminary result, announced in 1994, of 80 kilometers per second per megaparsec (km/sec/Mpc), based on observations of a galaxy in the Virgo cluster. 'We have five different ways of measuring the Hubble Constant with HST,' said Dr. Freedman. 'The results are coming in between 68 and 78 km/sec/Mpc.' (For example, at an expansion rate of 75 km/sec/Mpc, galaxies appear to be receding from us at a rate of 162,000 miles per hour for every 3.26 million light-years farther out we look). Two months ago, a second team, led by Allan Sandage, also of the Carnegie Observatories, Abhijit Saha, STScI, Gustav Tammann and Lukas Labhardt, Astronomical Institute, University of Basel, Duccio Macchetto and Nino Panagia, STScI/European Space Agency, reported a slower expansion rate of 57 km/sec/Mpc. The value of the Hubble Constant allows astronomers to calculate the expansion age of the Universe, the time elapsed since the Big Bang. Astronomers have been arguing recently whether the time since the Big Bang is consistent with the ages of the oldest stars. The ages are calculated from combining the expansion rate with an estimate of how much matter is in space. The younger age values from each team assume the Universe is at a critical density where it contains just enough matter to expand indefinitely. The higher age estimates are calculated based on a low density of matter in space. (See 'Science Background' for more information on the expanding Universe.) 'A point of great interest is whether the age of the Universe arrived at this way is really older than the independently derived ages of the oldest stars,' said Saha, an investigator on both Hubble teams. 'The numbers lean on the side that the stellar ages are a little lower, or that the hypothesis that we live in a critical density universe needs to be questioned,' said Saha. 'As further results accumulate over the next few years, we hope to tighten the constraints on these issues.' THE OBSERVATIONS The Key Project team is midway along in their three-year program to derive the expansion rate of the Universe based on precise distance measurements to galaxies. They have now measured Cepheid distances to a dozen galaxies, and are about halfway through their overall program. The Key Project team also presented a preliminary estimate of the distance to the Fornax cluster of galaxies. The estimate was obtained through the detection and measurement with the Hubble Space Telescope of pulsating stars known as Cepheid variables found in the Fornax cluster. The Fornax cluster is measured to be approximately as far away as the Virgo cluster of galaxies -- about 60 million light-years. The Key Project team member who led this effort, Caltech astronomer Barry Madore said, 'This cluster allows us to make independent estimates of the expansion rate of the Universe using a number of different techniques. All of these methods are now in excellent agreement. With Fornax we are now at turning point in this field.' The team is measuring Cepheid distances to the Virgo and Fornax clusters of galaxies as a complementary test. Their strategy is to compare and contrast expansion numbers from a variety of distance indicators. The Key Projec

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

    NASA Astrophysics Data System (ADS)

    2009-03-01

    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

  10. Real Explorations in Astronomical Learning

    Microsoft Academic Search

    Jennifer Wilhelm; R. Wilhelm

    2007-01-01

    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

  11. NASA Conference Publication 2489 Astronomical

    E-print Network

    Rathbun, Julie A.

    NASA Conference Publication 2489 Future Astronomical 0bservatories on the Moon Edited by Jack 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 PART I - REASONS FOR PERFORMING ASTRONOMY ON THE MOON . . . . . . . . . . 9 SCIENCE OBJECTIVES IN THE LUNAR BASE ADVOCACY ...................... 11 Wendell W. Mendell, NASA Lyndon B. Johnson Space Center

  12. The Hubble Space Telescope: Problems and Solutions.

    ERIC Educational Resources Information Center

    Villard, Ray

    1990-01-01

    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)

  13. Hubble Space Telescope solar array damper

    Microsoft Academic Search

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

    1999-01-01

    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

  14. The Meaning of Color in Hubble Images

    NSDL National Science Digital Library

    This web site contains information on the use of different wavelength filters to determine astronomical information by the Hubbble Space Telescope. The use of color to enhance black and white images is included. The site also contains several series of images at different wavelengths to illustrate the presentation.

  15. HUBBLE OBSERVES SPIRAL GAS DISK IN ACTIVE GALAXY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA Hubble Space Telescope image of a spiral-shaped disk of hot gas in the core of active galaxy M87. HST measurements show the disk is rotating so rapidly it contains a massive black hole at its hub. A black hole is an object that is so massive yet compact nothing can escape its gravitational pull, not even light. The object at the center of M87 fits that description. It weights as much as three billion suns, but is concentrated into a space no larger than our solar system. Now that astronomers have seen the signature of the tremendous gravitational field at the center of M87, it is clear that the region contains only a fraction of the number of stars that would be necessary to create such a powerful attraction. The giant elliptical galaxy M87 is located 50 million light-years away in the constellation Virgo. Earlier observations suggested the black hole was present, but were not decisive. A brilliant jet of high- speed electrons that emits from the nucleus (diagonal line across image) is believed to be produced by the black hole 'engine.' The image was taken with HST's Wide Field Planetary Camera 2 Credit: Holland Ford, Space Telescope Science Institute/Johns Hopkins University; Richard Harms, Applied Research Corp.; Zlatan Tsvetanov, Arthur Davidsen, and Gerard Kriss at Johns Hopkins; Ralph Bohlin and George Hartig at Space Telescope Science Institute; Linda Dressel and Ajay K. Kochhar at Applied Research Corp. in Landover, Md.; and Bruce Margon from the University of Washington in Seattle. NASA PHOTO CAPTION STScI-PR94-23a

  16. Hubble Space Telescope, Goddard High-Resolution Spectrograph

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This drawing illustrates the Hubble Space Telescope's (HST's), Goddard High-Resolution Spectrograph (GHRS). The HST's two spectrographs, the GHRS and the Faint Object Spectrograph (FOS), can detect a broader range of wavelengths than is possible from Earth because there is no atmosphere to absorb certain wavelengths. Scientists can determine the chemical composition, temperature, pressure, and turbulence of the stellar atmosphere producing the light, all from spectral data. The GHRS can detect fine details in the light from somewhat brighter objects but only ultraviolet light. Both spectrographs operate in essentially the same way. The incoming light passes through a small entrance aperture, then passes through filters and diffraction gratings, that work like prisms. The filter or grating used determines what range of wavelength will be examined and in what detail. Then the spectrograph detectors record the strength of each wavelength band and sends it back to Earth. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors.

  17. PBS Online NewsHour: Hubble and Webb Telescopes

    NSDL National Science Digital Library

    In-depth coverage of the Hubble Space Telescope and the next generation of orbiting observatories. Includes interactive on orbiting telescopes, slide show of Hubble images, and reports on the debate over keeping Hubble operating and over coloring its images. The main story and some of the archived stories are available as streaming video and RealAudio as well as text.

  18. HUBBLE FINDS THOUSANDS OF GASEOUS FRAGMENTS SURROUNDING DYING STAR

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Resembling a bizarre setting from a science fiction movie, dramatic images sent back by NASA's Hubble Space Telescope have surprised astronomers by uncovering thousands of gigantic tadpole-shaped objects surrounding a dying star. Dubbed 'cometary knots' because their glowing heads and gossamer tails superficially resemble comets, they are probably the result of a dying star's final outbursts. Though ground-based telescopic observations have hinted at such objects, they have not previously been seen in such abundance, say researchers. The knots were detected by Hubble astronomer C. Robert O'Dell and graduate student Kerry P. Handron of Rice University in Houston, Texas, while exploring the Helix nebula, a ring of glowing gases blown off the surface of a sunlike star late in its life. O'Dell expects the gaseous knots, which are each several billion miles across, will eventually dissipate and vanish into the cold emptiness of interstellar space. However, he speculates that if the objects contract to form permanent solid bodies, they may contribute to a fraction (less than ten percent) of the missing mass of our galaxy, simply because of their sheer abundance around a typical dying star. (This so-called dark matter is a known source of gravity that affects the motions of stars in the galaxy). The mysterious 'space pods' came into view as O'Dell used Hubble's Wide Field Planetary Camera 2 to survey the Helix nebula, located 450 light-years away in the constellation Aquarius and the closest planetary nebula to Earth -- so close that its angular size is almost half that of the full Moon. The most visible cometary knots all lie along the inner edge of the ring, at a distance of trillions of miles from the central star. Their comet-like tails, each stretching a hundred billion miles, form a radial pattern around the star like the spokes on a wagon wheel. Though previous ground-based observations show a spoke pattern in the Helix, and some structure, O'Dell emphasizes that the Hubble images reveal an underlying population of many more smaller objects. O'Dell made the observation because he was curious if these objects were the result of the star's final outburst which would bring comets out of 'cold storage' by boiling off the icy, solid comet nuclei. This is how comets behave as they swing near our Sun. The knots have just the right appearance and are at just the right distance from the dying star to be a long-sought comet cloud -- much like the hypothesized Oort cloud encircling our solar system. However, each gaseous cometary 'head' is at least twice the diameter of our solar system -- far too large for the gaseous shell, called a coma, that surrounds an active comet as we know it. The most likely explanation is the objects have been formed during the final years of a star's life when it ejects shells of gas into space. This 'planetary nebula' formation happens in stages where, toward the end of the process, a faster moving shell of gas ejected off the doomed star collides with slower moving gas released ten thousand years before. This collision of hot, lower density gas with cooler, higher density gas forms an unstable condition where the two gases intermix and fragment the previously smooth cloud. This process, called a Rayleigh-Taylor instability, breaks the cloud into smaller and denser finger-like droplets, like dripping paint. Standard models predict that the knots should expand and dissipate within a few hundred thousand years. However, dust particles inside each gas ball might collide and stick together, snowballing to planet- sized bodies over time. The resulting objects would be like Earth- sized copies of the frigid, icy planet Pluto. These icy worlds would escape the dead star and presumably roam interstellar space forever. If this phenomena is common among stars, then our galaxy could be littered with trillions of these objects, O'Dell concludes. 'Planetary nebulae have been formed in our galaxy for billions of years and about one new one is created every year since this is the usual ending for the billions of sunl

  19. THE LONGEST MEANDERING FLOODPLAIN ON MARS: THE AEOLIS MEANDERS Edwin S. Kite (UC Berkeley), Rebecca M.E. Williams (Planetary Science Institute), Noah J. Finnegan (UC Santa

    E-print Network

    Kite, Edwin

    THE LONGEST MEANDERING FLOODPLAIN ON MARS: THE AEOLIS MEANDERS Edwin S. Kite (UC Berkeley), Rebecca Berkeley), and Michael Manga (UC Berkeley). email: kite@berkeley.edu Introduction: We propose a landing of floodplain deposits within the landing ellipse, which could trap fine-grained ma- terials washed down from

  20. HUBBLE SPIES HUGE CLUSTERS OF STARS FORMED

    NASA Technical Reports Server (NTRS)

    2002-01-01

    BY ANCIENT ENCOUNTER This stunningly beautiful image [right] taken with the NASA Hubble Space Telescope shows the heart of the prototypical starburst galaxy M82. The ongoing violent star formation due to an ancient encounter with its large galactic neighbor, M81, gives this galaxy its disturbed appearance. The smaller picture at upper left shows the entire galaxy. The image was taken in December 1994 by the Kitt Peak National Observatory's 0.9-meter telescope. Hubble's view is represented by the white outline in the center. In the Hubble image, taken by the Wide Field and Planetary Camera 2, the huge lanes of dust that crisscross M82's disk are another telltale sign of the flurry of star formation. Below the center and to the right, a strong galactic wind is spewing knotty filaments of hydrogen and nitrogen gas. More than 100 super star clusters -- very bright, compact groupings of about 100,000 stars -- are seen in this detailed Hubble picture as white dots sprinkled throughout M82's central region. The dark region just above the center of the picture is a huge dust cloud. A collaboration of European and American scientists used these clusters to date the ancient interaction between M82 and M81. About 600 million years ago, a region called 'M82 B' (the bright area just below and to the left of the central dust cloud) exploded with new stars. Scientists have discovered that this ancient starburst was triggered by the violent encounter with M81. M82 is a bright (eighth magnitude), nearby (12 million light-years from Earth) galaxy in the constellation Ursa Major (the Great Bear). The Hubble picture was taken Sept. 15, 1997. The natural-color composite was constructed from three Wide Field and Planetary Camera 2 exposures, which were combined in chromatic order: 4,250 seconds through a blue filter (428 nm); 2,800 seconds through a green filter (520 nm); and 2,200 seconds through a red (820 nm) filter. Credits for Hubble image: NASA, ESA, R. de Grijs (Institute of Astronomy, Cambridge, UK) Credits for ground-based picture: N.A. Sharp (Association of Universities for Research in Astronomy, National Optical Astronomy Observatories, National Science Foundation)

  1. Hubble Camera Resumes Science Operation With Picture Of 'Butterfly' In Space.

    NASA Technical Reports Server (NTRS)

    2002-01-01

    he Hubble Space Telescope's Wide Field and Planetary Camera 2 (WFPC2) is back at work, capturing this black-and-white image of the 'butterfly wing'-shaped nebula, NGC 2346. The nebula is about 2,000 light-years away from Earth in the direction of the constellation Monoceros. It represents the spectacular 'last gasp' of a binary star system at the nebula's center. The image was taken on March 6, as part of the recommissioning of the Hubble Space Telescope's previously installed scientific instruments following the successful servicing of the HST by NASA astronauts in February. WFPC2 was installed in HST during the servicing mission in 1993. At the center of the nebula lies a pair of stars that are so close together that they orbit around each other every 16 days. This is so close that, even with Hubble, the pair of stars cannot be resolved into its two components. One component of this binary is the hot core of a star that has ejected most of its outer layers, producing the surrounding nebula. Astronomers believe that this star, when it evolved and expanded to become a red giant, actually swallowed its companion star in an act of stellar cannibalism. The resulting interaction led to a spiraling together of the two stars, culminating in ejection of the outer layers of the red giant. Most of the outer layers were ejected into a dense disk, which can still be seen in the Hubble image, surrounding the central star. Later the hot star developed a fast stellar wind. This wind, blowing out into the surrounding disk, has inflated the large, wispy hourglass-shaped wings perpendicular to the disk. These wings produce the butterfly appearance when seen in projection. The total diameter of the nebula is about one-third of a light-year, or 2 trillion miles. Our own Sun will eject a nebula about 5 billion years from now. However, the Sun is not a double star, so its nebula may well be more spherical in shape. The image was taken through a filter that shows the light of glowing nitrogen atoms. Scientists are still testing and calibrating the newly installed instruments on Hubble , the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) and the Space Telescope Imaging Spectrograph (STIS). These instruments will be ready to make observations in a few weeks. Credit: Massimo Stiavelli (STScI), and NASA other team member: Inge Heyer (STScI) Image files in GIF and JPEG format and captions may be accessed on the Internet via anonymous ftp from oposite.stsci.edu in /pubinfo.

  2. Atmospheric Scintillation in Astronomical Photometry

    E-print Network

    Osborn, J; Dhillon, V S; Wilson, R W

    2015-01-01

    Scintillation noise due to the Earth's turbulent atmosphere can be a dominant noise source in high-precision astronomical photometry when observing bright targets from the ground. Here we describe the phenomenon of scintillation from its physical origins to its effect on photometry. We show that Young's (1967) scintillation-noise approximation used by many astronomers tends to underestimate the median scintillation noise at several major observatories around the world. We show that using median atmospheric optical turbulence profiles, which are now available for most sites, provides a better estimate of the expected scintillation noise and that real-time turbulence profiles can be used to precisely characterise the scintillation noise component of contemporaneous photometric measurements. This will enable a better understanding and calibration of photometric noise sources and the effectiveness of scintillation correction techniques. We also provide new equations for calculating scintillation noise, including ...

  3. Astronomy Teaching with Astronomical Catalogues

    NASA Astrophysics Data System (ADS)

    Oostra, Benjamin

    2006-03-01

    For quite a few years I have been teaching introductory astronomy at the Universidad de Los Andes, Bogotá to undergraduate students of all majors. One of my goals has always been: Try to have the students learn from their own experience. I built some apparatus and wrote many guidelines to help them do real observations, but many discoveries are beyond our experimental possibilities. A helpful remedy is the use of online astronomical catalogues.

  4. Random Numbers from Astronomical Imaging

    E-print Network

    Kevin A. Pimbblet; Michael Bulmer

    2004-08-16

    This article describes a method to turn astronomical imaging into a random number generator by using the positions of incident cosmic rays and hot pixels to generate bit streams. We subject the resultant bit streams to a battery of standard benchmark statistical tests for randomness and show that these bit streams are statistically the same as a perfect random bit stream. Strategies for improving and building upon this method are outlined.

  5. Astronomical Research Institute Photometric Results

    NASA Astrophysics Data System (ADS)

    Linder, Tyler R.; Sampson, Ryan; Holmes, Robert

    2013-01-01

    The Astronomical Research Institute (ARI) conducts astrometric and photometric studies of asteroids with a concentration on near-Earth objects (NEOs). A 0.76-m autoscope was used for photometric studies of seven asteroids of which two were main-belt targets and five were NEOs, including one potentially hazardous asteroid (PHA). These objects are: 3122 Florence, 3960 Chaliubieju, 5143 Heracles, (6455) 1992 HE, (36284) 2000 DM8, (62128) 2000 SO1, and 2010 LF86.

  6. New Horizons: Long-Range Kuiper Belt Targets Observed by the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Benecchi, Susan D.; Noll, Keith; Weaver, Harold; Spencer, John; Stern, S. A.; Buie, Marc; Parker, Alex

    2014-11-01

    We will report on Hubble Space Telescope (HST) observations of three Kuiper Belt Objects (KBOs), discovered in our dedicated ground-based search campaign, that are candidates for long-range observations from the New Horizons spacecraft: 2011 JY31, 2011 HZ102, and 2013 LU35. Astrometry with HST enables both current and future critical accuracy improvements for orbit precision, required for possible New Horizons observations, beyond what can be obtained from the ground. Photometric colors of all three objects are red, typical of the Cold Classical dynamical population within which they reside; they are also the faintest KBOs to have had their colors measured. None are observed to be binary with HST above separations of ~0.02 arcsec 700 km at 44 AU) and ?m ? 0.5. This research is based in part on ground-based data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan, and on data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile. Space-based observations were made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  7. Artist's Concept of Hubble-Discovered Ancient Gas-Giant Planet

    NASA Technical Reports Server (NTRS)

    2003-01-01

    NASA's Hubble Space Telescope (HST) precisely measured the mass of the oldest known planet in our Milky Way Galaxy bringing closure to a decade of speculation. Scientists weren't sure if the object was a planet or a brown dwarf. Hubble's analysis shows that the object is 2.5 times the mass of Jupiter, confirming that it is indeed a planet. At an estimated age of 13 billion years, the planet is more than twice the age of Earth's 4.5 billion years. It formed around a young, sun-like star barely 1 million years after our universe's birth in the Big Bang. The ancient planet resides in an unlikely, rough neighborhood. It orbits a peculiar pair of burned-out stars in the crowded core cluster of more than 100,000 stars. Its very existence provides evidence that the first planets formed rapidly, within a billion years of the Big Bang, and leads astronomers to conclude that planets may be very abundant in our galaxy. This artist's concept depicts the planet with a view of a rich star filled sky.

  8. Hubble Tarantula Treasury Project: Unraveling Tarantula's Web

    NASA Astrophysics Data System (ADS)

    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

    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.

  9. Hubble Space Telescope: Battery Capacity Trend Studies

    NASA Technical Reports Server (NTRS)

    Rao, M. Gopalakrishna; Hollandsworth, Roger; Armantrout, Jon

    2004-01-01

    Battery cell wear out mechanisms and signatures are examined and compared to orbital data from the six on-orbit Hubble Space Telescope (HST) batteries, and the Flight Spare Battery (FSB) Test Bed at Marshall Space Flight Center (MSFC), which is instrumented with individual cell voltage monitoring. Capacity trend data is presented which suggests HST battery replacement is required in 2005-2007 or sooner.

  10. Hubble space telescope onboard battery performance

    NASA Technical Reports Server (NTRS)

    Rao, Gopalakrishna M.; Wajsgras, Harry; Vaidyanathan, Hari; Armontrout, Jon D.

    1996-01-01

    The performance of six 88 Ah Nickel-Hydrogen (Ni-H2) batteries that are used onboard in the Hubble Space Telescope (Flight Spare Module (FSM) and Flight Module 2 (FM2)) is discussed. These batteries have 22 series cells per battery and a common bus that would enable them to operate at a common voltage. It is launched on April 24, 1990. This paper reviews: the cell design, battery specification, system constraints, operating parameters, onboard battery management, and battery performance.

  11. The Hubble Space Telescope and other initiatives

    SciTech Connect

    Norman, C.A. (Texas Univ., Richardson (USA))

    1989-01-01

    The scientific investigations which are planned for the Hubble Space Telescope (HST) are discussed. The possibility of detecting planetary systems around stars other than the sun using the HST is addressed, and investigations of exotic systems, the interstellar medium, and other galaxies using the HST are summarized. The use of AXAF to study distant quasars, the inner regions of Seyfert nuclei, and other phenomena is briefly discussed. 7 refs.

  12. Rare Hubble Portrait of Io and Jupiter

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This image, shows Jupiter's volcanic moon Io passing above the turbulent clouds of the giant planet, on July 24, 1996. The conspicuous black spot on Jupiter is Io's shadow. The shadow is about the size of Io (3,640 kilometers or 2,262 miles across) and sweeps across the face of Jupiter at 17 kilometers per second (38,000 miles per hour).

    The smallest details visible on Io and Jupiter are about 100 miles across. Bright patches visible on Io are regions of sulfur dioxide frost. Io is roughly the size of Earth's moon, but 2,000 times farther away.

    This one of a series of images of Io taken by Hubble to complement the close-up images currently being taken by the Galileo spacecraft now orbiting Jupiter. Though the Galileo images show much finer detail, Hubble provides complementary information because it can observe Io at ultraviolet wavelengths not seen by Galileo, can observe Io at different times than Galileo, and can view Io under more consistent viewing conditions.

    The image was taken at violet wavelengths, with the Wide Field Planetary Camera 2, in PC mode.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http:// oposite.stsci.edu/pubinfo/

  13. Upgrading a CCD camera for astronomical use 

    E-print Network

    Lamecker, James Frank

    1993-01-01

    Existing charge-coupled device (CCD) video cameras have been modified to be used for astronomical imaging on telescopes in order to improve imaging times over those of photography. An astronomical CCD camera at the Texas A&M Observatory would...

  14. Amateur Astronomers: Secret Agents of EPO

    Microsoft Academic Search

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

    2008-01-01

    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

  15. 42Planetary Conjunctions Since 1995, astronomers have

    E-print Network

    42Planetary Conjunctions Since 1995, astronomers have detected over 350 planets orbiting distant stars. Our solar system has 8 planets, and for thousands of years astronomers have studied their motions. The most interesting events happen when planets are seen close together in the sky. These are called

  16. Conceptual Astronomy Knowledge among Amateur Astronomers

    Microsoft Academic Search

    Margaret L. Berendsen

    2005-01-01

    Amateur astronomers regularly serve as informal astronomy educators for their communities. This research inquires into the level of knowledge of basic astronomy concepts among amateur astronomers and examines factors related to amateur astronomy that affect that knowledge. Using the concept questions from the Astronomy Diagnostic Test Version 2, an online survey was developed as an assessment. In particular, astronomy club

  17. Astronomical photometry from the Moon

    NASA Astrophysics Data System (ADS)

    Hudson, Hugh S.

    1994-06-01

    The Moon would be an excellent platform for photometric astronomical observations. This paper discusses such observations, emphasizing time-series photometry of oscillating stars (asteroseismology), of faint gravitating bodies (microlensing), and of the interplanetary medium. To prepare for the deployment of major new telescopes and instrumentation on the surface of the Moon, I suggest that smaller 'site survey' instruments be put in place as soon as possible. Each application suggested can derive great benefits from small site-survey instruments established relatively soon, and each would ultimately need extensive arrays of large instruments.

  18. Visualizing Astronomical Data with Blender

    NASA Astrophysics Data System (ADS)

    Kent, Brian R.

    2014-01-01

    We present methods for using the 3D graphics program Blender in the visualization of astronomical data. The software's forte for animating 3D data lends itself well to use in astronomy. The Blender graphical user interface and Python scripting capabilities can be utilized in the generation of models for data cubes, catalogs, simulations, and surface maps. We review methods for data import, 2D and 3D voxel texture applications, animations, camera movement, and composite renders. Rendering times can be improved by using graphic processing units (GPUs). A number of examples are shown using the software features most applicable to various kinds of data paradigms in astronomy.

  19. Senenmut: An Ancient Egyptian Astronomer

    NASA Astrophysics Data System (ADS)

    Novakovic, B.

    2008-10-01

    The celestial phenomena have always been a source of wonder and interest to people, even as long ago as the ancient Egyptians. While the ancient Egyptians did not know all the things about astronomy that we do now, they had a good understanding of some celestial phenomena. The achievements in astronomy of ancient Egyptians are relatively well known, but we know very little about the people who made these achievements. The goal of this paper is to bring some light on the life of Senenmut, the chief architect and astronomer during the reign of Queen Hatshepsut.

  20. Glacial cycles and astronomical forcing

    SciTech Connect

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

    1997-07-11

    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.

  1. Star Witness News: Hubble--A Lunar Prospecting Machine

    NSDL National Science Digital Library

    This story explains how the Hubble Space Telescope was used to assist scientists in finding natural resources on the Moon. This information can be used to introduce the idea of using reflected light to identify different materials on the Moon's surface. This selection is an adaptation of the HubbleSite press release: NASA's Hubble Looks for Possible Moon Resources. The article is from the Amazing Space science newspaper, The Star Witness, which can be used as a science content reading.

  2. ViewSpace: A model for advancing public understanding of astronomical research through museum-based multimedia

    NASA Astrophysics Data System (ADS)

    Stoke, J. M.

    2002-05-01

    The Office of Public Outreach (OPO) of the Space Telescope Science Institute (STScI) has developed a unique multimedia presentation product that orchestrates images, digital video animations, music and interpretive text to provide a frequently-updated astronomy display suitable for mini-theater environments in museum-based exhibit galleries and planetarium lobbies (that may be, otherwise, seldom updated). "ViewSpace" utilizes the scientific expertise of STScI astronomers and puts Hubble discoveries into publically-accessible contexts. The program, which is offered at no charge to the museum and planetarium community in the United States, has been received with strong enthusiasm by the informal science education community. Future aspirations include higher-definition and immersive presentation formats, multi-lingual text display, an audible description track for the visually impaired, an associated interactive kiosk, and correlated education guides. Astronomers with interesting science stories to tell are invited to participate in the development of a ViewSpace segment.

  3. Hubble Deep Fever: A faint galaxy diagnosis

    E-print Network

    S. P. Driver

    1998-02-26

    The longstanding faint blue galaxy problem is gradually subsiding as a result of technological advancement, most notably from high-resolution Hubble Space Telescope imaging. In particular two categorical facts have recently been established, these are: 1) The excess faint blue galaxies are of irregular morphologies, and, 2) the majority of these irregulars occur at redshifts 1 2. Taking these facts together we favour a scenario where the faint blue excess is primarily due to the formation epoch of spiral systems via merging at redshifts 1 < z < 2. The final interpretation now awaits refinements in our understanding of the local galaxy population !

  4. Hubble Deep Fever A faint galaxy diagnosis

    E-print Network

    Driver, S P

    1998-01-01

    The longstanding faint blue galaxy problem is gradually subsiding as a result of technological advancement, most notably from high-resolution Hubble Space Telescope imaging. In particular two categorical facts have recently been established, these are: 1) The excess faint blue galaxies are of irregular morphologies, and, 2) the majority of these irregulars occur at redshifts 1 2. Taking these facts together we favour a scenario where the faint blue excess is primarily due to the formation epoch of spiral systems via merging at redshifts 1 < z < 2. The final interpretation now awaits refinements in our understanding of the local galaxy population !

  5. HUBBLE SEES AURORAL EMISSION ARCS FOLLOWING THE K IMPACT

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This far-ultraviolet image of Jupiter taken with NASA's Hubble Space Telescope (HST) shows narrow auroral 'arcs' that appeared at northern mid-latitudes following the impact of the K nucleus fragment of comet P/Shoemaker-Levy 9. (The dark K impact region is on the left limb, followed, from left to right, by the C, A, and E comet impact regions.) The image was taken on 19 July 1994, 45 minutes after the K nucleus slammed into the gas giant planet. The image shows arc-like auroral emissions near the western (left) limb at mid-latitudes in the north, and fainter but remarkably similar emissions near the K impact site in the south. The 'arcs' are being produced by energetic charged particles, like the other auroral emissions, except that they appear to last less than one hour and they are at a location where Jupiter normally does not have aurora. They were apparently produced by the K impact, even though they appear bright in the northern hemisphere nearly 70,000 miles away from the impact site. The overlay of magnetic field lines shows the path of the charged particles near Jupiter (from a model based on Pioneer and Voyager spacecraft data), starting at the northern 'arcs' and tracing the magnetic field back to the impact site in the southern atmosphere. (There is an overlay of a longitude/latitude grid to indicate locations on Jupiter). Aurorae, also known as the northern and southern lights, are produced by high energy charged particles, trapped in Jupiter's magnetic field, that cause atmosphereic gasses to glow. Based on comparison with ROSAT satellite X-ray images of Jupiter also taken at time of the K impact, astronomers know that the northern disturbance was brightest near the time of the K impact, and then faded. If HST images had been taken during the K impact, they would likely have shown far brighter arcs than those observed 45 min. later. The image was taken with the Wide Field Planetary Camera-2 at UV wavelengths (1300-2100 Angstroms), where the polar regions normally appear dark and the northern and southern lights are clearly visible. Credit: John T. Clarke (U. of Michigan), and NASA

  6. Astronomical Methods in Aerial Navigation

    NASA Technical Reports Server (NTRS)

    Beij, K Hilding

    1925-01-01

    The astronomical method of determining position is universally used in marine navigation and may also be of service in aerial navigation. The practical application of the method, however, must be modified and adapted to conform to the requirements of aviation. Much of this work of adaptation has already been accomplished, but being scattered through various technical journals in a number of languages, is not readily available. This report is for the purpose of collecting under one cover such previous work as appears to be of value to the aerial navigator, comparing instruments and methods, indicating the best practice, and suggesting future developments. The various methods of determining position and their application and value are outlined, and a brief resume of the theory of the astronomical method is given. Observation instruments are described in detail. A complete discussion of the reduction of observations follows, including a rapid method of finding position from the altitudes of two stars. Maps and map cases are briefly considered. A bibliography of the subject is appended.

  7. Astronomical Data Center Bulletin, volume 1, no. 1

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    Information about work in progress on astronomical catalogs is presented. In addition to progress reports, an upadated status list for astronomical catalogs available at the Astronomical Data Center is included. Papers from observatories and individuals involved with astronomical data are also presented.

  8. Hubble Reopens Eye on the Universe

    NSDL National Science Digital Library

    2000-01-01

    The Hubble Telescope has reopened for business following the successful December 1999 servicing mission, and the first images to come back are magnificent. The first of these sites offers images and explanatory text related to the "Eskimo" Nebula, "the glowing remains of a dying, Sun-like star." The nebula is called the "Eskimo" because, when viewed from a ground-based telescope, it resembles a face surrounded by a fur parka. This parka is actually "a disk of material embellished with a ring of comet-shaped objects, with their tails streaming away from the central, dying star." Users can read about the nebula and view some beautiful images at the above URL. The second significant new view from the Hubble is of a huge cluster of galaxies called Abell 2218. This cluster is so massive that it actually deflects light passing through it, magnifying and distorting images from distant objects. Thus, "the cluster's magnifying powers provides a powerful 'zoom lens' for viewing distant galaxies that could not normally be observed with the largest telescopes." Text and photos in several formats can be accessed from the introductory page.

  9. 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.

  10. 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)

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

    2011-01-01

    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.

  11. America's foremost early astronomer. [David Rittenhouse

    NASA Technical Reports Server (NTRS)

    Rubincam, David Parry; Rubincam, Milton, II

    1995-01-01

    The life of 18th century astronomer, craftsman, and partriot David Rittenhouse is detailed. As a craftsman, he distinguished himself as one of the foremost builders of clocks. He also built magnetic compasses and surveying instruments. The finest examples of his craftsmanship are considered two orreries, mechanical solar systems. In terms of astronomical observations, his best-known contribution was his observation of the transit of Venus in 1769. Rittenhouse constructed the first diffraction grating. Working as Treasurer of Pennsylvania throughout the Revolution, he became the first director of the Mint in 1792. Astronomical observations in later life included charting the position of Uranus after its discovery.

  12. Hubble Space Telescope characterized by using phase-retrieval algorithms

    E-print Network

    Fienup, James R.

    Hubble Space Telescope characterized by using phase-retrieval algorithms J. R. Fienup, J. C. Marron, T. J. Schulz, and J. H. Seldin We describe several results characterizing the Hubble Space Telescope of the optical axis of a camera relay telescope relative to the main telescope. After we accounted for measured

  13. Hubble Provides A Moving Look At Neptune's Stormy Disposition

    NSDL National Science Digital Library

    1998-01-01

    NASA offers these images from the Hubble Space Telescope and the Galileo Project. Simultaneous observations at Hubble and NASA's Infrared Telescope Facility on Mauna Kea, Hawaii have also provided glimpses into Neptune's huge storms and equatorial winds of 900 mph. The site provides a press release, images, and a Quicktime animation.

  14. William Doberck - double star astronomer

    NASA Astrophysics Data System (ADS)

    MacKeown, P. Kevin

    2007-03-01

    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.

  15. Sparse Representation of Astronomical Images

    E-print Network

    Laura Rebollo-Neira; James Bowley

    2012-09-12

    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.

  16. An astronomical observatory for Peru

    NASA Astrophysics Data System (ADS)

    del Mar, Juan Quintanilla; Sicardy, Bruno; Giraldo, Víctor Ayma; Callo, Víctor Raúl Aguilar

    2011-06-01

    Peru and France are to conclude an agreement to provide Peru with an astronomical observatory equipped with a 60-cm diameter telescope. The principal aims of this project are to establish and develop research and teaching in astronomy. Since 2004, a team of researchers from Paris Observatory has been working with the University of Cusco (UNSAAC) on the educational, technical and financial aspects of implementing this venture. During an international astronomy conference in Cusco in July 2009, the foundation stone of the future Peruvian Observatory was laid at the top of Pachatusan Mountain. UNSAAC, represented by its Rector, together with the town of Oropesa and the Cusco regional authority, undertook to make the sum of 300,000€ available to the project. An agreement between Paris Observatory and UNSAAC now enables Peruvian students to study astronomy through online teaching.

  17. Goddard Geophysical and Astronomical Observatory

    NASA Technical Reports Server (NTRS)

    Figueroa, Ricardo

    2013-01-01

    This report summarizes the technical parameters and the technical staff of the VLBI system at the fundamental station GGAO. It also gives an overview about the VLBI activities during the report year. The Goddard Geophysical and Astronomical Observatory (GGAO) consists of a 5-meter radio telescope for VLBI, a new 12-meter radio telescope for VLBI2010 development, a 1-meter reference antenna for microwave holography development, an SLR site that includes MOBLAS-7, the NGSLR development system, and a 48" telescope for developmental two-color Satellite Laser Ranging, a GPS timing and development lab, a DORIS system, meteorological sensors, and a hydrogen maser. In addition, we are a fiducial IGS site with several IGS/IGSX receivers. GGAO is located on the east coast of the United States in Maryland. It is approximately 15 miles NNE of Washington, D.C. in Greenbelt, Maryland.

  18. HUBBLE'S DEEPEST VIEW OF THE UNIVERSE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [Left] A NASA Hubble Space Telescope view of the faintest galaxies ever seen in the universe, taken in infrared light with the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). The picture contains over 300 galaxies having spiral, elliptical and irregular shapes. Though most of these galaxies were first seen in 1995 when Hubble was used to take a visible-light deep exposure of the same field, NICMOS uncovers many new objects. Most of these objects are too small and faint to be apparent in the full field NICMOS view. Some of the reddest and faintest of the newly detected objects may be over 12 billion light-years away, as derived from a standard model of the universe. However, a powerful new generation of telescopes will be needed to confirm the suspected distances of these objects. The field of view is 2 million light-years across, at its maximum. Yet, on a cosmic scale, it represents only a thin pencil beam look across the universe. The area of sky is merely 1/100th the apparent diameter on the full moon. [Right] Two close-up NICMOS views of candidate objects which may be over 12 billion light-years away. Each candidate is centered in the frame. The reddish color may mean all of the starlight has been stretched to infrared wavelengths by the universe's expansion. Alternative explanations are that the objects are closer to us, but the light has been reddened by dust scattering. A new generation of telescopes will be needed to make follow-up observations capable of establishing true distance. The image was taken in January 1998 and required an exposure time of 36 hours to detect objects down to 30th magnitude. Hubble was aimed in the direction of the constellation Ursa Major, in a region just above the handle of the Big Dipper. The color corresponds to blue (0.45 microns), green (1.1 microns) and red (1.6 microns). Credit: Rodger I. Thompson (University of Arizona), and NASA

  19. Astronomical Image Processing with Hadoop

    NASA Astrophysics Data System (ADS)

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

    2011-07-01

    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 commercial world, new techniques that utilize cloud computing have been developed to handle massive data streams. In this paper we describe how cloud computing, and in particular the map-reduce paradigm, can be used in astronomical data processing. We will focus on our experience implementing a scalable image-processing pipeline for the SDSS database using Hadoop (http://hadoop.apache.org). This multi-terabyte imaging dataset approximates future surveys such as those which will be conducted with the LSST. Our pipeline performs image coaddition in which multiple partially overlapping images are registered, integrated and stitched into a single overarching image. We will first present our initial implementation, then describe several critical optimizations that have enabled us to achieve high performance, and finally describe how we are incorporating a large in-house existing image processing library into our Hadoop system. The optimizations involve prefiltering of the input to remove irrelevant images from consideration, grouping individual FITS files into larger, more efficient indexed files, and a hybrid system in which a relational database is used to determine the input images relevant to the task. The incorporation of an existing image processing library, written in C++, presented difficult challenges since Hadoop is programmed primarily in Java. We will describe how we achieved this integration and the sophisticated image processing routines that were made feasible as a result. We will end by briefly describing the longer term goals of our work, namely detection and classification of transient objects and automated object classification.

  20. Hubble Space Telescope Battery Capacity Update

    NASA Technical Reports Server (NTRS)

    Hollandsworth, Roger; Armantrout, Jon; Rao, Gopalakrishna M.

    2007-01-01

    Orbital battery performance for the Hubble Space Telescope is discussed and battery life is predicted which supports decision to replace orbital batteries by 2009-2010 timeframe. Ground characterization testing of cells from the replacement battery build is discussed, with comparison of data from battery capacity characterization with cell studies of Cycle Life and 60% Stress Test at the Naval Weapons Surface Center (NWSC)-Crane, and cell Cycle Life testing at the Marshal Space Flight Center (MSFC). The contents of this presentation includes an update to the performance of the on-orbit batteries, as well as a discussion of the HST Service Mission 4 (SM4) batteries manufactured in 1996 and activated in 2000, and a second set of SM4 backup replacement batteries which began manufacture Jan 11, 2007, with delivery scheduled for July 2008.

  1. Hubble Space Telescope Image of Omega Nebula

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In this sturning image provided by the Hubble Space Telescope (HST), the Omega Nebula (M17) resembles the fury of a raging sea, showing a bubbly ocean of glowing hydrogen gas and small amounts of other elements such as oxygen and sulfur. The nebula, also known as the Swan Nebula, is a hotbed of newly born stars residing 5,500 light-years away in the constellation Sagittarius. The wavelike patterns of gas have been sculpted and illuminated by a torrent of ultraviolet radiation from the young massive stars, which lie outside the picture to the upper left. The ultraviolet radiation is carving and heating the surfaces of cold hydrogen gas clouds. The warmed surfaces glow orange and red in this photograph. The green represents an even hotter gas that masks background structures. Various gases represented with color are: sulfur, represented in red; hydrogen, green; and oxygen blue.

  2. Hubble Space Telescope particulate optical test

    NASA Astrophysics Data System (ADS)

    Metheny, Wayne; Pope, Tom; Rosenberg, William; Sharbaugh, Ron

    1987-01-01

    The Particulate Optical Test was designed to record and measure particulate contaminants on the Hubble Space Telescope primary mirror. The objective of the test was to quantify the primary mirror particulate contamination prior to launch. The test consists of taking dark-field photographs of the primary mirror from in front of the telescope's aperture door. These photographs are subsequently digitized and analyzed to produce the areal coverage estimates. The estimated particulate areal obscuration is approximately 1.0 percent of the primary mirror surface in the usable region. This level of contamination is within the budget value of 2.5 percent and indicates that there was little increase in particulate contamination during the HST assembly process or the acoustic test period.

  3. Dark Matter in the Hubble Frontier Fields

    NASA Astrophysics Data System (ADS)

    Diego, J. M.

    2015-05-01

    We present results on the dark matter distribution of the Hubble Frontier Fields (HFF). The HFF represents the best collection of strong lensing data in merging clusters. We study the first two clusters from the HFF program using a free-form method that makes no assumptions about the mass distribution to reconstruct the dark matter that best fits the strong lensing data. Our reconstructed dark matter distributions exhibit some interesting features including very shallow profiles and possible offsets between the baryonic and dark matter distribution. For the first time, we find evidence that suggests that the strong lensing data seems to be sensitive to the mass of the X-ray plasma. Also, by analyzing the strong lensing in one individual galaxy we are able to constrain the shape of the dark matter halo around that galaxy. Our results support the standard models of dark matter and disfavours alternative models like MOND.

  4. Bianchi I meets the Hubble diagram

    NASA Astrophysics Data System (ADS)

    Schücker, Thomas; Tilquin, André; Valent, Galliano

    2014-11-01

    We improve existing fits of the Bianchi I metric to the Hubble diagram of supernovae and find an intriguing yet non-significant signal for anisotropy that should be verified or falsified in the near future by the Large Synoptic Survey Telescope. Since the literature contains two different formulas for the apparent luminosity as a function of time of flight in Bianchi I metrics, we present an independent derivation confirming the result by Saunders. The present fit differs from earlier ones by Koivisto & Mota and by Campanelli et al. in that we use Saunders' formula, a larger sample of supernovae, Union 2 and Joint Light curve Analysis, and we use the general Bianchi I metric with three distinct eigenvalues.

  5. Cosmographic Hubble fits to the supernova data

    SciTech Connect

    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

    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.

  6. Comparing Stellar Populations Across the Hubble Sequence

    NASA Astrophysics Data System (ADS)

    Loeffler, Shane; Kaleida, Catherine C.; Parkash, Vaishali

    2015-01-01

    Previous work (Jansen et al., 2000, Taylor et al., 2005) has revealed trends in the optical wavelength radial profiles of galaxies across the Hubble Sequence. Radial profiles offer insight into stellar populations, metallicity, and dust concentrations, aspects which are deeply tied to the individual evolution of a galaxy. The Nearby Field Galaxy Survey (NFGS) provides a sampling of nearby galaxies that spans the range of morphological types, luminosities, and masses. Currently available NFGS data includes optical radial surface profiles and spectra of 196 nearby galaxies. We aim to look for trends in the infrared portion of the spectrum for these galaxies, but find that existing 2MASS data is not sufficiently deep. Herein, we expand the available data for the NGFS galaxy IC1639 deeper into the infrared using new data taken with the Infrared Sideport Imager (ISPI) on the 4-m Blanco Telescope at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. Images taken in J, H, and Ks were reduced using standard IRAF and IDL procedures. Photometric calibrations were completed by using the highest quality (AAA) 2MASS stars in the field. Aperture photometry was then performed on the galaxy and radial profiles of surface brightness, J-H color, and H-Ks color were produced. For IC1639, the new ISPI data reveals flat color gradients and surface brightness gradients that decrease with radius. These trends reveal an archetypal elliptical galaxy, with a relatively homogeneous stellar population, stellar density decreasing with radius, and little-to-no obscuration by dust. We have obtained ISPI images for an additional 8 galaxies, and further reduction and analysis of these data will allow for investigation of radial trends in the infrared for galaxies across the Hubble Sequence.

  7. Explanatory Supplement to the Astronomical Almanac

    Microsoft Academic Search

    P. Kenneth Seidelmann

    1992-01-01

    The Explanatory Supplement provides a detailed description of how to perform practical astronomy or spherical astronomy. This completely revised and rewritten edition is an authoritative source on astronomical phenomena and calendars.

  8. Support of cooled components in astronomical instruments

    NASA Astrophysics Data System (ADS)

    Hastings, P. R.; Montgomery, D. M.

    The methods used at the Royal Observatory Edinburgh (ROE) for supporting cooled components in astronomical instruments are described. Support methods and materials are detailed and compared. Thermal compensation of truss structures is described. Specimen design calculations are appended.

  9. An astronomical database on earth environmental science

    Microsoft Academic Search

    Hongfeng Guo

    1997-01-01

    An astronomical database on earth environmental science has been established in the Beijing astronomical Data Center\\/World Data Center-D for Astronomy (BDC\\/WDC-D-A). The contents and structure, the environment and functions, as well as the application system of the database and one of its sub-databases, the Chinese Solar-Geophysical Data sub-database, are introduced in this paper.

  10. Astronomical researches in Poincaré's and Romanian works

    NASA Astrophysics Data System (ADS)

    Stavinschi, M.; Mioc, V.

    2005-09-01

    Henri Poincaré was not only a honorary member of the Romanian Academy, but also an important collaborator of many Romanian mathematicians and astronomers. It is sufficient to mention Spiru Haret, the first doctor in mathematics at Sorbonne, or Nicolae Coculescu, the first director of the Astronomical Observatory of Bucharest. The 150th anniversary of the birth of the illustrious French personality offered us a good opportunity to study the relations he and two other Poincaré, Raymond and Lucien, had with Romania.

  11. Publication and citation statistics for UK astronomers

    E-print Network

    A. J. Blustin

    2007-12-28

    This article presents a survey of publication and citation statistics for 835 UK professional astronomers: the majority of academics and contract researchers within the UK astronomical community. I provide histograms of these bibliometrics for the whole sample as well as of the median values for the individual departments. I discuss the distribution of top bibliometric performers in the sample, and make some remarks on the usage of bibliometrics in a real-world assessment exercise.

  12. ASDS: The Astronomical Software and Documentation Service

    NASA Astrophysics Data System (ADS)

    Payne, H. E.; Hanisch, R. J.; Bryson, Liz

    1998-12-01

    The Astronomical Software and Documentation Service (ASDS) is a network service that allows you to find existing astronomical resources for solving your problem. ASDS started as as site devoted entirely to astronomical software packages and their associated on-line documentation. But in 1998 its scope was expanded to include astronomical observing sites and their associated telescope and instrument manuals, taken from a listing maintained by Liz Bryson. The primary objective of the telescope manuals side of ASDS is to allow astronomers to easily locate the information required when preparing an observing proposal or planning an observing session. The telescope manual service consists of two complementary collections: (1) a page of information for each site, including a short description, a link to the home page, and a list of manuals, each with its own short description, and (2) a distributed set of telescope manuals, observer guides, instrument and calibration handbooks, proposal preparation guides, etc. Both collections are indexed for full-text searching and logically grouped both for browsing and for more highly targeted searching. We are happy to add pointers to more software packages and telescope manuals. We are especially interested in items that would otherwise be hard to find. Please stop by our poster for a chat if you have items in either category of interest to the astronomical community. Submission forms are also available on our web site, and we have a mailing list. Please note that ASDS is not an archive or distribution service.

  13. HUBBLE'S 100,000TH EXPOSURE CAPTURES IMAGE OF DISTANT QUASAR

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Hubble Space Telescope achieved its 100,000th exposure June 22 with a snapshot of a quasar that is about 9 billion light-years from Earth. The Wide Field and Planetary Camera 2 clicked this image of the quasar, the bright object in the center of the photo. The fainter object just above it is an elliptical galaxy. Although the two objects appear to be close to each other, they are actually separated by about 2 billion light-years. Located about 7 billion light-years away, the galaxy is almost directly in front of the quasar. Astronomer Charles Steidel of the California Institute of Technology in Pasadena, Calif., indirectly discovered the galaxy when he examined the quasar's light, which contained information about the galaxy's chemical composition. The reason, Steidel found, was that the galaxy was absorbing the light at certain frequencies. The astronomer is examining other background quasars to determine which kinds of galaxies absorb light at the same frequencies. Steidel also was somewhat surprised to discover that the galaxy is an elliptical, rather than a spiral. Elliptical galaxies are generally believed to contain very little gas. However, this elliptical has a gaseous 'halo' and contains no visible stars. Part of the halo is directly in front of the quasar. The bright object to the right of the quasar is a foreground star. The quasar and star are separated by billions of light-years. The quasar looks as bright as the star because it produces a tremendous amount of light from a compact source. The 'disturbed-looking' double spiral galaxy above the quasar also is in the foreground. Credit: Charles Steidel (California Institute of Technology, Pasadena, CA) and NASA. Image files in GIF and JPEG format and captions may be accessed on Internet via anonymous ftp from ftp.stsci.edu in /pubinfo.

  14. A SURVEY OF ASTRONOMICAL RESEARCH: A BASELINE FOR ASTRONOMICAL DEVELOPMENT

    SciTech Connect

    Ribeiro, V. A. R. M. [Astrophysics, Cosmology and Gravity Centre, Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Russo, P. [EU Universe Awareness, Leiden Observatory, Leiden University, PO 9513 Leiden, 2300 RA (Netherlands); Cárdenas-Avendaño, A., E-mail: vribeiro@ast.uct.ac.za, E-mail: russo@strw.leidenuniv.nl [Departamento de Física, Universidad Nacional de Colombia, Carrera 45 No 26-85, Edificio Gutierréz, Bogotá, DC (Colombia)

    2013-12-01

    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.

  15. Images From Hubbles's ACS Tell A Tale Of Two Record-Breaking Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    2004-01-01

    Looking back in time nearly 9 billion years, an international team of astronomers found mature galaxies in a young universe. The galaxies are members of a cluster of galaxies that existed when the universe was only 5 billion years old, or about 35 percent of its present age. This compelling evidence that galaxies must have started forming just after the big bang was bolstered by observations made by the same team of astronomers when they peered even farther back in time. The team found embryonic galaxies a mere 1.5 billion years after the birth of the cosmos, or 10 percent of the universe's present age. The "baby galaxies" reside in a still-developing cluster, the most distant proto-cluster ever found. The Advanced Camera for Surveys (ACS) aboard NASA's Hubble Space Telescope was used to make observations of the massive cluster, RDCS 1252.9-2927, and the proto-cluster, TN J1338-1942. Observations by NASA's Chandra X-ray Observatory yielded the mass and heavy element content of RDCS 1252, the most massive known cluster for that epoch. These observations are part of a coordinated effort by the ACS science team to track the formation and evolution of clusters of galaxies over a broad range of cosmic time. The ACS was built especially for studies of such distant objects. These findings further support observations and theories that galaxies formed relatively early in the history of the cosmos. The existence of such massive clusters in the early universe agrees with a cosmological model wherein clusters form from the merger of many sub-clusters in a universe dominated by cold dark matter. The precise nature of cold dark matter, however, is still not known. The first Hubble study estimated that galaxies in RDCS 1252 formed the bulk of their stars more than 11 billion years ago (at redshifts greater than 3). The results were published in the Oct. 20, 2003 issue of the Astrophysical Journal. The paper's lead author is John Blakeslee of the Johns Hopkins University in Baltimore, Md. Optical Image of RDCS 1252.9-2927 HST Optical Image of RDCS 1252.9-2927 The second Hubble study uncovered, for the first time, a proto-cluster of "infant galaxies" that existed more than 12 billion years ago (at redshift 4.1). These galaxies are so young that astronomers can still see a flurry of stars forming within them. The galaxies are grouped around one large galaxy. These results will be published in the Jan. 1, 2004 issue of Nature. The paper's lead author is George Miley of Leiden Observatory in the Netherlands. "Until recently people didn't think that clusters existed when the universe was only about 5 billion years old," Blakeslee explained. "Even if there were such clusters," Miley added, "until recently astronomers thought it was almost impossible to find clusters that existed 8 billion years ago. In fact, no one really knew when clustering began. Now we can witness it." Both studies led the astronomers to conclude that these systems are the progenitors of the galaxy clusters seen today. "The cluster RDCS 1252 looks like a present-day cluster," said Marc Postman of the Space Telescope Science Institute in Baltimore, Md., and co-author of both research papers. "In fact, if you were to put it next to a present-day cluster, you wouldn't know which is which." A Tale of Two Clusters How can galaxies grow so fast after the big bang? "It is a case of the rich getting richer," Blakeslee said. "These clusters grew quickly because they are located in very dense regions, so there is enough material to build up the member galaxies very fast." This idea is strengthened by X-ray observations of the massive cluster RDCS 1252. Chandra and the European Space Agency's XMM-Newton provided astronomers with the most accurate measurements to date of the properties of an enormous cloud of hot gas that pervades the massive cluster. This 160-million-degree Fahrenheit (70-million-degree Celsius) gas is a reservoir of most of the heavy elements in the cluster and an accurate tr

  16. HUBBLE PROVIDES COMPLETE VIEW OF JUPITER'S AURORAS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's Hubble Space Telescope has captured a complete view of Jupiter's northern and southern auroras. Images taken in ultraviolet light by the Space Telescope Imaging Spectrograph (STIS) show both auroras, the oval- shaped objects in the inset photos. While the Hubble telescope has obtained images of Jupiter's northern and southern lights since 1990, the new STIS instrument is 10 times more sensitive than earlier cameras. This allows for short exposures, reducing the blurring of the image caused by Jupiter's rotation and providing two to five times higher resolution than earlier cameras. The resolution in these images is sufficient to show the 'curtain' of auroral light extending several hundred miles above Jupiter's limb (edge). Images of Earth's auroral curtains, taken from the space shuttle, have a similar appearance. Jupiter's auroral images are superimposed on a Wide Field and Planetary Camera 2 image of the entire planet. The auroras are brilliant curtains of light in Jupiter's upper atmosphere. Jovian auroral storms, like Earth's, develop when electrically charged particles trapped in the magnetic field surrounding the planet spiral inward at high energies toward the north and south magnetic poles. When these particles hit the upper atmosphere, they excite atoms and molecules there, causing them to glow (the same process acting in street lights). The electrons that strike Earth's atmosphere come from the sun, and the auroral lights remain concentrated above the night sky in response to the 'solar wind,' as Earth rotates underneath. Earth's auroras exhibit storms that extend to lower latitudes in response to solar activity, which can be easily seen from the northern U. S. But Jupiter's auroras are caused by particles spewed out by volcanoes on Io, one of Jupiter's moons. These charged particles are then magnetically trapped and begin to rotate with Jupiter, producing ovals of auroral light centered on Jupiter's magnetic poles in both the day and night skies. Scientists are comparing the Hubble telescope images with measurements taken by NASA's Galileo spacecraft of Jupiter's magnetic field and co-rotating charged particles. They believe the data will help them understand the production of Jupiter's auroras. Both auroras clearly show vapor trails of light left by Io. These vapor trails are the white, comet-shaped streaks just outside both auroral ovals. These streaks are not part of the auroral ovals. They are caused when an invisible electrical current of charged particles (equal to about 1 million amperes), ejected from Io, flow along Jupiter's magnetic field lines to the planets north and south magnetic poles. This enormous current produces a bright but localized aurora where it enters Jupiter's atmosphere at both magnetic poles. The brightest part of both emissions (on the left in both images) pinpoints where Io's magnetic field lines leave its footprint on the planet. The trail of light following both emissions extends to the right all the way to Jupiter's edge and represents the most sensitive detection of ultraviolet emissions from Jupiter to date. These emissions are related to magnetically trapped ions and electrons that are carried by Jupiter's magnetic field along Io's orbital path, and some of these charged particles continue to be driven down into Jupiter's atmosphere for several hours after Io has passed by. The images were taken Sept. 20, 1997. The artificial colors used here have been constructed by combining images taken in two different ultraviolet band passes, with one ultraviolet color presented as blue and the other as red. In this color representation, the planet's reflected sunlight appears brown, while the auroral emissions appear white or shades of blue or red. Credits: John Clarke (University of Michigan), and NASA Co-investigators: Joe Ajello, Kent Tobiska, and John Trauger (NASA's Jet Propulsion Laboratory) Gilda Ballester (University of Michigan) Lotfi Ben jaffel (IAP Paris) Jack Connerney (NASA's Goddard Space Flight Center) Jean-Claude Gerard (University of Liege, Belgium) Randy Glads

  17. Measuring the Hubble Constant with the HST

    NASA Astrophysics Data System (ADS)

    Kennicutt, R. C.

    1994-12-01

    The spectacular success of the Hubble Space Telescope repair mission now makes it possible to realize one of the astrophysical goals for which HST was designed. Recent progress in groundbased observations of galaxy distances has reduced the longstanding factor-of-two uncertainty in the Hubble constant, but lingering inconsistencies between different methods and concerns over the accuracy of the distance scale remain. The incompatibility of high values of H_0 with the stellar age scale in an Omega =1, Lambda =0 universe underscores the need for a definitive calibration of the distance scale. The objective of the HST Extragalactic Distance Scale Key Project is to calibrate H_0 to an accuracy of +/-10%. This will be accomplished by measuring Cepheid distances to ~ 20 galaxies with redshift velocities of <=2000 km/s. These galaxies will serve as local benchmarks which can be used to calibrate a wide range of secondary distance indicators in the future. Within the Key Project the data will be used to recalibrate 5 secondary distance indicators, and these will be applied in turn to extend the local distance scale into the region of Hubble flow, and provide a global measurement of H_0. Cepheid distances to galaxies in the cores of the Virgo and Fornax clusters will provide another, direct estimate of H_0, independent of the secondary indicators. Intercomparison of these 6 distance scales will provide a robust measurement of H_0 and a direct determination of its uncertainty. The sample selection, observing and data analysis procedures, and error budget are conservatively designed to minimize susceptibility to the kinds of systematic errors which have frequently plagued distance scale measurements. The recent identification of 20 Cepheids in the Virgo cluster spiral M100 confirms the feasibility of the project, and offers a spectacular demonstration of HST's unprecedented capabilities for this application. This talk will briefly review the current status of the distance scale problem and describe the ongoing HST programs, with emphasis on the Key Project. Examples of recently obtained data will be shown, and distances determined the first galaxies in the program, including M81, M101, and M100 will be discussed. The ultimate goal of measuring H_0 to +/-10% awaits successful completion of the program over the next 2 years, but our M100 distance (17.1+/-1.8 Mpc) already constrains its value to the range H_0 = 80 +/- 17\\ km/s/Mpc. The implications of this result will be discussed. This work was carried out in collaboration with the other members of the HST Key Project team, W. Freedman, J. Mould, F. Bresolin, S. Faber, L. Ferrarese, H. Ford, J. Graham, J. Gunn, M. Han, P. Harding, R. Hill, J. Hoessel, J. Huchra, S. Hughes, G. Illingworth, D. Kelson, B. Madore, R. Phelps, A. Saha, N. Silbermann, P. Stetson, and A. Turner.

  18. HUBBLE VIEWS OF THREE STELLAR JETS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These NASA Hubble Space Telescope views of gaseous jets from three newly forming stars show a new level of detail in the star formation process, and are helping to solve decade-old questions about the secrets of star birth. Jets are a common 'exhaust product' of the dynamics of star formation. They are blasted away from a disk of gas and dust falling onto an embryonic star. [upper left] - This view of a protostellar object called HH-30 reveals an edge-on disk of dust encircling a newly forming star. Light from the forming star illuminates the top and bottom surfaces of the disk, making them visible, while the star itself is hidden behind the densest parts of the disk. The reddish jet emanates from the inner region of the disk, and possibly directly from the star itself. Hubble's detailed view shows, for the first time, that the jet expands for several billion miles from the star, but then stays confined to a narrow beam. The protostar is 450 light-years away in the constellation Taurus. Credit: C. Burrows (STScI and ESA), the WFPC 2 Investigation Definition Team, and NASA [upper right] - This view of a different and more distant jet in object HH-34 shows a remarkable beaded structure. Once thought to be a hydrodynamic effect (similar to shock diamonds in a jet aircraft exhaust), this structure is actually produced by a machine-gun-like blast of 'bullets' of dense gas ejected from the star at speeds of one-half million miles per hour. This structure suggests the star goes through episodic 'fits' of construction where chunks of material fall onto the star from a surrounding disk. The protostar is 1,500 light- years away and in the vicinity of the Orion Nebula, a nearby star birth region. Credit: J. Hester (Arizona State University), the WFPC 2 Investigation Definition Team, and NASA [bottom] - This view of a three trillion mile-long jet called HH-47 reveals a very complicated jet pattern that indicates the star (hidden inside a dust cloud near the left edge of the image) might be wobbling, possibly caused by the gravitational pull of a companion star. Hubble's detailed view shows that the jet has burrowed a cavity through the dense gas cloud and now travels at high speed into interstellar space. Shock waves form when the jet collides with interstellar gas, causing the jet to glow. The white filaments on the left reflect light from the obscured newborn star. The HH-47 system is 1,500 light-years away, and lies at the edge of the Gum Nebula, possibly an ancient supernova remnant which can be seen from Earth's southern hemisphere. Credit: J. Morse/STScI, and NASA The scale in the bottom left corner of each picture represents 93 billion miles, or 1,000 times the distance between Earth and the Sun. All images were taken with the Wide Field Planetary Camera 2 in visible light. The HH designation stands for 'Herbig-Haro' object -- the name for bright patches of nebulosity which appear to be moving away from associated protostars.

  19. Astronomical observatories on the Moon

    NASA Astrophysics Data System (ADS)

    Swanson, Paul N.; Cutts, James A.

    1994-06-01

    The Space Exploration Initiative presents an opportunity to construct astronomical telescopes on the Moon using the infrastructure provided by the lunar outpost. Small automatically deployed telescopes can be carried on the survey missions, be deployed on the lunar surface and be operated remotely from the Earth. Possibilities for early, small optical telescopes are a zenith pointed transit telescope, a student telescope, and a 0.5 to 1 meter automatic, fully steerable telescope. After the lunar outpost is established the lunar interferometers will be constructed in an evolutionary fashion. There are three lunar interferometers which have been studied. The most ambitious is the optical interferometer with a 1 to 2 -km baseline and seven 1.5 aperture elements arranged in a 'Y' configuration with a central beam combiner. The Submillimeter interferometer would use seven, 5-m reflectors in a 'Y' or circular configuration with a 1-km baseline. The Very Low Frequency (VLF) array would operate below 30 mHz with as many as 100 elements and a 200-km baseline.

  20. A Future Astronomical Software Environment

    NASA Astrophysics Data System (ADS)

    Grosböl, P.; Tody, D.; Paioro, L.; Granet, Y.; Garilli, B.; Surace, C.; Opticon Fase Network

    2012-09-01

    Analyzing data sets in astronomy has become more and more complex and has driven the development of specific tools, functions and tasks. In order to integrate these tools in a global environment and thereby preserving them, the OPTICON Network 9.2 in coordination with US-VAO has outlined requirements, defined an architectural concept and developed a prototype of a Future Astronomical Software Environment (FASE). Important features are support for user scripting (e.g. Python), access to legacy applications (e.g. IRAF, MIDAS), integration with the Virtual Observatory (VO) for access to remote data and computation, and scalability supporting desktops to distributed cluster systems. A first prototype has been implemented and demonstrates the feasibility by offering access to numerous applications (e.g. ds9, ESO CPL pipelines, MIDAS, topcat) from a Python or Unix shell using VO-SAMP as a software bus. A simple packaging system is also provided to allow easy definition and sharing of applications at a Web portal.

  1. Lunar astronomical observatories - Design studies

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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.

  2. Generating Mosaics of Astronomical Images

    NASA Technical Reports Server (NTRS)

    Bergou, Attila; Berriman, Bruce; Good, John; Jacob, Joseph; Katz, Daniel; Laity, Anastasia; Prince, Thomas; Williams, Roy

    2005-01-01

    "Montage" is the name of a service of the National Virtual Observatory (NVO), and of software being developed to implement the service via the World Wide Web. Montage generates science-grade custom mosaics of astronomical images on demand from input files that comply with the Flexible Image Transport System (FITS) standard and contain image data registered on projections that comply with the World Coordinate System (WCS) standards. "Science-grade" in this context signifies that terrestrial and instrumental features are removed from images in a way that can be described quantitatively. "Custom" refers to user-specified parameters of projection, coordinates, size, rotation, and spatial sampling. The greatest value of Montage is expected to lie in its ability to analyze images at multiple wavelengths, delivering them on a common projection, coordinate system, and spatial sampling, and thereby enabling further analysis as though they were part of a single, multi-wavelength image. Montage will be deployed as a computation-intensive service through existing astronomy portals and other Web sites. It will be integrated into the emerging NVO architecture and will be executed on the TeraGrid. The Montage software will also be portable and publicly available.

  3. Chrysanthos Notaras as an Astronomer

    NASA Astrophysics Data System (ADS)

    Rovithis, P.

    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.

  4. Scalable Machine Learning for Massive Astronomical Datasets

    NASA Astrophysics Data System (ADS)

    Ball, Nicholas M.; Gray, A.

    2014-04-01

    We present the ability to perform data mining and machine learning operations on a catalog of half a billion astronomical objects. This is the result of the combination of robust, highly accurate machine learning algorithms with linear scalability that renders the applications of these algorithms to massive astronomical data tractable. We demonstrate the core algorithms kernel density estimation, K-means clustering, linear regression, nearest neighbors, random forest and gradient-boosted decision tree, singular value decomposition, support vector machine, and two-point correlation function. Each of these is relevant for astronomical applications such as finding novel astrophysical objects, characterizing artifacts in data, object classification (including for rare objects), object distances, finding the important features describing objects, density estimation of distributions, probabilistic quantities, and exploring the unknown structure of new data. The software, Skytree Server, runs on any UNIX-based machine, a virtual machine, or cloud-based and distributed systems including Hadoop. We have integrated it on the cloud computing system of the Canadian Astronomical Data Centre, the Canadian Advanced Network for Astronomical Research (CANFAR), creating the world's first cloud computing data mining system for astronomy. We demonstrate results showing the scaling of each of our major algorithms on large astronomical datasets, including the full 470,992,970 objects of the 2 Micron All-Sky Survey (2MASS) Point Source Catalog. We demonstrate the ability to find outliers in the full 2MASS dataset utilizing multiple methods, e.g., nearest neighbors. This is likely of particular interest to the radio astronomy community given, for example, that survey projects contain groups dedicated to this topic. 2MASS is used as a proof-of-concept dataset due to its convenience and availability. These results are of interest to any astronomical project with large and/or complex datasets that wishes to extract the full scientific value from its data.

  5. Scalable Machine Learning for Massive Astronomical Datasets

    NASA Astrophysics Data System (ADS)

    Ball, Nicholas M.; Astronomy Data Centre, Canadian

    2014-01-01

    We present the ability to perform data mining and machine learning operations on a catalog of half a billion astronomical objects. This is the result of the combination of robust, highly accurate machine learning algorithms with linear scalability that renders the applications of these algorithms to massive astronomical data tractable. We demonstrate the core algorithms kernel density estimation, K-means clustering, linear regression, nearest neighbors, random forest and gradient-boosted decision tree, singular value decomposition, support vector machine, and two-point correlation function. Each of these is relevant for astronomical applications such as finding novel astrophysical objects, characterizing artifacts in data, object classification (including for rare objects), object distances, finding the important features describing objects, density estimation of distributions, probabilistic quantities, and exploring the unknown structure of new data. The software, Skytree Server, runs on any UNIX-based machine, a virtual machine, or cloud-based and distributed systems including Hadoop. We have integrated it on the cloud computing system of the Canadian Astronomical Data Centre, the Canadian Advanced Network for Astronomical Research (CANFAR), creating the world's first cloud computing data mining system for astronomy. We demonstrate results showing the scaling of each of our major algorithms on large astronomical datasets, including the full 470,992,970 objects of the 2 Micron All-Sky Survey (2MASS) Point Source Catalog. We demonstrate the ability to find outliers in the full 2MASS dataset utilizing multiple methods, e.g., nearest neighbors, and the local outlier factor. 2MASS is used as a proof-of-concept dataset due to its convenience and availability. These results are of interest to any astronomical project with large and/or complex datasets that wishes to extract the full scientific value from its data.

  6. HUBBLE OPENS ITS EYE ON THE UNIVERSE AND CAPTURES A COSMIC MAGNIFYING GLASS

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Scanning the heavens for the first time since the successful December 1999 servicing mission, NASA's Hubble Space Telescope has imaged a giant, cosmic magnifying glass, a massive cluster of galaxies called Abell 2218. This 'hefty' cluster resides in the constellation Draco, some 2 billion light-years from Earth. The cluster is so massive that its enormous gravitational field deflects light rays passing through it, much as an optical lens bends light to form an image. This phenomenon, called gravitational lensing, magnifies, brightens, and distorts images from faraway objects. The cluster's magnifying powers provides a powerful 'zoom lens' for viewing distant galaxies that could not normally be observed with the largest telescopes. This useful phenomenon has produced the arc-shaped patterns found throughout the Hubble picture. These 'arcs' are the distorted images of very distant galaxies, which lie 5 to 10 times farther than the lensing cluster. This distant population existed when the universe was just a quarter of its present age. Through gravitational lensing these remote objects are magnified, enabling scientists to study them in more detail. This analysis provides a direct glimpse of how star-forming regions are distributed in remote galaxies and yields other clues to the early evolution of galaxies. The picture is dominated by spiral and elliptical galaxies. Resembling a string of tree lights, the biggest and brightest galaxies are members of the foreground cluster. Researchers are intrigued by a tiny red dot just left of top center. This dot may be an extremely remote object made visible by the cluster's magnifying powers. Further investigation is needed to confirm the object's identity. The Hubble telescope first viewed this cluster in 1994, producing one of the most spectacular demonstrations of gravitational lensing up to that time. Scientists who analyzed that black-and-white picture discovered more than 50 remote, young galaxies. Hubble's latest multicolor image of the cluster will allow astronomers to probe in greater detail the internal structure of these early galaxies. The color picture already reveals several arc-shaped features that are embedded in the cluster and cannot be easily seen in the black-and-white image. The colors in this picture yield clues to the ages, distances, and temperatures of stars, the stuff of galaxies. Blue pinpoints hot young stars. The yellow-white color of several of the galaxies represents the combined light of many stars. Red identifies cool stars, old stars, and the glow of stars in distant galaxies. This view is only possible by combining Hubble's unique image quality with the rare lensing effect provided by the magnifying cluster. The picture was taken Jan. 11 to 13, 2000, with the Wide Field and Planetary Camera 2. Credits: NASA, Andrew Fruchter (STScI), and the ERO team (STScI, ST-ECF)

  7. The Hubble Space Telescope attitude observer anomaly

    NASA Astrophysics Data System (ADS)

    Van Arsdall, Morgan M.; Ramsey, Patrick R.; Swain, Scott R.

    2006-06-01

    In mid-2004, the Hubble Space Telescope (HST) began experiencing occasional losses of lock during Fine Guidance Sensor (FGS) guide star acquisitions, threatening a potential loss of science. These failures were associated with an increasing disparity between the FGS-derived estimates of gyro bias calculated in orbit day and those calculated in orbit night. Early efforts to mitigate the operational effects of this Attitude Observer Anomaly (AOA) succeeded; however, the magnitude of the anomaly continued to increase at a linear rate and operational problems resumed in mid-2005. Continued analysis led to an additional on-orbit mitigation strategy that succeeded in reducing the AOA signature. Before the investigation could be completed, HST began operations under the life-extending Two Gyro Science mode. This eliminated both the operational effects of and the visibility into the AOA phenomenon. Possible causes of the anomaly at the vehicle system level included component hardware failures, flight software errors in control law processing, distortion of the telescope optical path, and deformation of vehicle structure. Although the mechanism of the AOA was not definitively identified, the Anomaly Review Board (ARB) chartered to investigate the anomaly concluded that the most likely root cause lies within one of HST's 6 rate-integrating gyroscopes. This paper provides a summary of the initial paths of investigation, the analysis and testing performed to attempt to isolate the source, and a review of the findings of the ARB. The possibility of future operational impacts and available methods of on-orbit mitigation are also addressed.

  8. Deuterium, Lithium, and the Hubble Deep Field

    NASA Astrophysics Data System (ADS)

    Casuso, E.; Beckman, J. E.

    1999-11-01

    This article presents a theoretical framework for the evolution of the light-element nuclides in the Galactic disk. By understanding this evolution correctly, we can reliably obtain the primordial abundances of the nuclides D, 4He, and 7Li. We use two key assumptions, those of (1) infall of metal-poor gas to the disk at an increasing rate and (2) destruction, as well as production (except for D), of fragile nuclides in hot, relatively dense supergiant envelopes. Light nuclides are accelerated by supernova shocks, and many are confined to hot interstellar zones by magnetic fields. Their repeated passage through the hot envelopes causes depletion, which peaked during the main star-forming phase of Galaxy evolution around z~1, as measured from the Hubble Deep Field. This mechanism has dominated stellar depletion in reducing the D/H abundance from its primordial value of ~=2x10-4 to its solar system value of ~=2.5x10-5 and subsequently to the current interstellar medium value of 1.5x10-5. The model accounts well for the solar system and the current ratios of 7Li/6Li and 11B/10B. It fits extremely well a standard big bang nucleosynthesis model with baryon density ~=0.05.

  9. Hubble Space Telescope Briefing: HST Science Overview

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This NASA Kennedy Space Center video release presents a broad overview of the science that is now possible as a result of the servicing of the Hubble Space Telescope (HST). Dr. Ed Weiler (HST Program Scientist, NASA Headquarters), Dr. Dave Leckrone (HST, Senior Project Scientist, Goddard Space Flight Center (GSFC)), Dr. John Trauger (Wide Field Planetary Camera 2 (WFPC2) Principal Investigator, Jet Propulsion Lab. (JPL)), Dr. Chris Burrows (WFPC2 Co-Investigator, Space Telescope Science Inst.(STSci)-European Space Agency (ESA), Jim Crocker ((Corrective Optics Space Telescope Axial Replacement) COSTAR Team Leader, STSci), Dr. Holland Ford (COSTAR Project Scientist, Johns Hopkins Univ., STSci), and Dr. Duccio Machetto (European Space Agency (ESA)) give brief presentations, which feature images of stars and galaxies taken from the ground, from WFPC1 (prior to the servicing mission), and from WFPC2 (after the servicing mission). The main theme of the discussions center around the spherical aberration that was found in the images prior to servicing and the corrected images seen without the aberration following servicing. A question and answer period rounds out the press conference, with questions posed from scientific journalists at GSFC and other NASA centers.

  10. The Hubble flow around the Local Group

    E-print Network

    I. D. Karachentsev; O. G. Kashibadze; D. I. Makarov; R. B. Tully

    2008-11-27

    We use updated data on distances and velocities of galaxies in the proximity of the Local Group (LG) in order to establish properties of the local Hubble flow. For 30 neighbouring galaxies with distances 0.7 velocity sigma_v = 25 km/s, corrected for errors of radial velocity measurements (~4 km/s) and distance measurements (~10 km/s), as well as the radius of the zero-velocity surface R_0 = (0.96+/-0.03) Mpc. The minimum value for sigma_v is achieved when the barycenter of the LG is located at the distance D_c = (0.55+/-0.05) D_M31 towards M31 corresponding to the Milky Way-to-M31 mass ratio M_MW / M_M31 ~ 4/5. In the reference frame of the 30 galaxies at 0.7 - 3.0 Mpc, the LG barycenter has a small peculiar velocity ~(24+/-4) km/s towards the Sculptor constellation. The derived value of R_0 corresponds to the total mass M_T(LG) = (1.9+/-0.2) 10^12 M_sun with Omega_m = 0.24 and a topologically flat universe, a value in good agreement with the sum of virial mass estimates for the Milky Way and M31.

  11. UV/Visible Telescope with Hubble Disposal

    NASA Technical Reports Server (NTRS)

    Benford, Dominic J.

    2013-01-01

    Submission Overview: Our primary objective is to convey a sense of the significant advances possible in astrophysics investigations for major Cosmic Origins COR program goals with a 2.4m telescope asset outfitted with one or more advanced UV visible instruments. Several compelling science objectives were identified based on community meetings these science objectives drove the conceptual design of instruments studied by the COR Program Office during July September 2012. This RFI submission encapsulates the results of that study, and suggests that a more detailed look into the instrument suite should be conducted to prove viability and affordability to support the demonstrated scientific value. This study was conducted in the context of a larger effort to consider the options available for a mission to dispose safely of Hubble hence, the overall architecture considered for the mission we studied for the 2.4m telescope asset included resource sharing. This mitigates combined cost and risk and provides naturally for a continued US leadership role in astrophysics with an advanced, general-purpose UV visible space telescope.

  12. Cepheid Parallaxes and the Hubble Constant

    E-print Network

    van Leeuwen, Floor; Whitelock, Patricia A; Laney, Clifton D

    2007-01-01

    Revised Hipparcos parallaxes for classical Cepheids are analysed together with 10 HST-based parallaxes (Benedict et al.). In a reddening-free V,I relation we find that the coefficient of logP is the same within the uncertainties in our Galaxy as in the LMC, contrary to some previous suggestions. Cepheids in the inner region of NGC4258 with near solar metallicities (Macri et al.) confirm this result. We obtain a zero-point for the reddening-free relation and apply it to Cepheids in galaxies used by Sandage et al. to calibrate the absolute magnitudes of SNIa and to derive the Hubble constant. We revise their result from 62 to 70+/-5 km/s/Mpc. The Freedman et al. 2001 value is revised from 72 to 76+/-8 km/s/Mpc. These results are insensitive to Cepheid metallicity corrections. The Cepheids in the inner region of NGC4258 yield a modulus of 29.22+/-0.03(int) compared with a maser-based modulus of 29.29+/-0.15. Distance moduli for the LMC, uncorrected for any metallicity effects, are; 18.52+/-0.03 from a reddening-...

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

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    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.

  14. How Long Can the Hubble Space Telescope Operate Reliably?

    NASA Technical Reports Server (NTRS)

    Xapsos, M. A.; Stauffer, C.; Jordan, T.; Poivey, C.; Lum, G.; Haskins, D. N.; Pergosky, A. M.; Smith, D. C.; LaBel, K. A.

    2014-01-01

    Total ionizing dose exposure of electronic parts in the Hubble Space Telescope is analyzed using 3-D ray trace and Monte Carlo simulations. Results are discussed along with other potential failure mechanisms for science operations.

  15. Hubble Spies Huge Cluster of Stars Formed by Ancient Encounter

    NASA Astrophysics Data System (ADS)

    2001-03-01

    This release marks the beginning of a new outlet for the Space Telescope Science Institute, the 'Hubble Minute'. Hubble Minute is an edited vignette suitable for use in newscasts, magazine shows, and as an interstitial program. The Minute explains how scientists are determining when M82 and M81 collided, and how dating the crash may result in a better understanding of how our own galaxy formed.

  16. Hubble Space Telescope: Goddard high resolution spectrograph instrument handbook. Version 2.1

    NASA Technical Reports Server (NTRS)

    Duncan, Douglas K.; Ebbets, Dennis

    1990-01-01

    The Goddard High Resolution Spectrograph (GHRS) is an ultraviolet spectrometer which has been designed to exploit the imaging and pointing capabilities of the Hubble Space Telescope. It will obtain observations of astronomical sources with greater spectral, spatial and temporal resolution than has been possible with previous space-based instruments. Data from the GHRS will be applicable to many types of scientific investigations, including studies of the interstellar medium, stellar winds, chromospheres and coronae, the byproducts and endproducts of stellar evolution, planetary atmospheres, comets, and many kinds of extragalactic sources. This handbook is intended to introduce the GHRS to potential users. The main purpose is to provide enough information to explore the feasibility of possible research projects and to plan, propose and execute a set of observations. An overview of the instrument performance, which should allow one to evaluate the suitability of the GHRS to specific projects, and a somewhat more detailed description of the GHRS hardware are given. How observing programs will be carried out, the various operating modes of the instrument, and the specific information about the performance of the instrument needed to plan an observation are discussed.

  17. Real-time, On-line Astronomical Observing Andrew Norton

    E-print Network

    Norton, Andrew J.

    Astronomic de Mallorca, attended by over 200 students each year, split between six residential weeks. As part at the Observatori Astronomic de Mallorca (OAM). At the OU campus in Milton Keynes we have the George Abell

  18. Astronomical Data Center Bulletin, volume 1, number 2

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

  19. Curva de luz en el óptico de la supernova tipo Ia 1998bu en M96 y calibración de la constante de Hubble

    NASA Astrophysics Data System (ADS)

    Suntzeff, N. B.; Phillips, M. M.; Covarrubias, R.; Navarrete, M.; Pérez, J. J.; Guerra, A.; Acevedo, M. T.; Doyle, L. R.; Harrison, T.; Kane, S.; Long, K. S.; Maza, J.; Miller, S.; Piatti, A. E.; Clariá, J. J.; Ahumada, A. V.; Pritzl, B.; Winkler, P. F.

    We present the UBV(RI)KC light curves of the Type Ia supernova SN 1998bu, which appeared in the nearby galaxy M96 (NGC 3368). M96 is a spiral galaxy in the Leo I group that has a Cepheid-based distance. Our photometry allows us to calculate the absolute magnitude and reddening of this supernova. These data, when combined with measurements of the four other well-observed supernovae with Cepheid-based distances, allow us to calculate the Hubble constant with respect to the Hubble flow defined by the distant Calán/Tololo Type Ia sample. We find a Hubble constant of 63.9 ± 2.2 (internal) ± 3.5 (external) km s-1 Mpc-1, consistent with most previous estimates based on Type Ia supernovae. We note that the two well-observed Type Ia supernovae in Fornax, if placed at the Cepheid distance to the possible Fornax spiral NGC 1365, are apparently too faint with respect to the Calán/Tololo sample calibrated with the five Type Ia supernovae with Cepheid distance to the host galaxies. The results obtained in this study appeared in The Astronomical Journal 117, 1175 (1999).

  20. Aligning Astronomical Telescopes via Identification of Stars

    NASA Technical Reports Server (NTRS)

    Whorton, Mark

    2010-01-01

    A proposed method of automated, precise alignment of a ground-based astronomical telescope would eliminate the need for initial manual alignment. The method, based on automated identification of known stars and other celestial objects in the telescope field of view, would also eliminate the need for an initial estimate of the aiming direction. The method does not require any equipment other than a digital imaging device such as a charge-coupled-device digital imaging camera and control computers of the telescope and camera, all of which are standard components in professional astronomical telescope systems and in high-end amateur astronomical telescope systems. The method could be implemented in software running in the telescope or camera control computer or in an external computer communicating with the telescope pointing mount and camera control computers.

  1. The Utrecht Astronomical Institute, 1632 to 2012

    NASA Astrophysics Data System (ADS)

    de Jager, C.

    2013-01-01

    Utrecht University was founded in 1636. In 1642 the university's astronomical observatory was founded. It was, after that of Leyden, the second university observatory in the world. The observatory was initially located at the Smeetoren, a fortification dating from 1145. In 1854 it moved to Sonnenborgh, a stronghold dating from 1554. In 1987 the personnel moved again, this time to the university campus, the Uithof. We describe the development of research and education in Utrecht over the centuries, with emphasis on the period after 1920. In 2009 the faculty formulated a very favorable advice to the university, viz. that in view of its good potentials astronomical research and education should be strengthened in Utrecht. This decision was accentuated by a likely positive advice of an international visitation committee. But briefly after that the university decided to terminate astronomical education and research in Utrecht, an incomprehensible decision.

  2. Ancient Maya Astronomical Tables from Xultun, Guatemala

    NASA Astrophysics Data System (ADS)

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

    2012-05-01

    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.

  3. Public perception of astronomers Revered, reviled and ridiculed

    NASA Astrophysics Data System (ADS)

    West, Michael J.

    2011-06-01

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

  4. Biographies and Portraits of British and Other Astronomers

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

    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).

  5. Hubble Space Telescope Image of Omega Nebula

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This sturning image, taken by the newly installed Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST), is an image of the center of the Omega Nebula. It is a hotbed of newly born stars wrapped in colorful blankets of glowing gas and cradled in an enormous cold, dark hydrogen cloud. The region of nebula shown in this photograph is about 3,500 times wider than our solar system. The nebula, also called M17 and the Swan Nebula, resides 5,500 light-years away in the constellation Sagittarius. The Swan Nebula is illuminated by ultraviolet radiation from young, massive stars, located just beyond the upper-right corner of the image. The powerful radiation from these stars evaporates and erodes the dense cloud of cold gas within which the stars formed. The blistered walls of the hollow cloud shine primarily in the blue, green, and red light emitted by excited atoms of hydrogen, nitrogen, oxygen, and sulfur. Particularly striking is the rose-like feature, seen to the right of center, which glows in the red light emitted by hydrogen and sulfur. As the infant stars evaporate the surrounding cloud, they expose dense pockets of gas that may contain developing stars. One isolated pocket is seen at the center of the brightest region of the nebula. Other dense pockets of gas have formed the remarkable feature jutting inward from the left edge of the image. The color image is constructed from four separate images taken in these filters: blue, near infrared, hydrogen alpha, and doubly ionized oxygen. Credit: NASA, H. Ford (JHU), G. Illingworth (USCS/LO), M. Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA.

  6. Book Review: Scientific Writing for Young Astronomers

    NASA Astrophysics Data System (ADS)

    Broens, E.

    2013-06-01

    Part 1, 165 pp., hardcover, EAS Publication Series Volume 49, ISBN 978-2-7598-0506-8. Price 36 Euro, including VAT (http://www.edition-sciences.com/scientific-writing-for-young-astronomers-part-1.htm). Part 2, 298 pp., hardcover, EAS Publication Series Volume 50, ISBN 987-2-7598-0639-3. Price 61 Euro, including VAT (http://www.edition-sciences.com/scientific-writing-for-young-astronomers-part-2.htm). Both parts include subject and name index and list of acronyms. Published by EAS, EDP Sciences, Les Ulis, France.

  7. Network-access interface to astronomical image data in CD-ROMs developed at the Astronomical Data Analysis Center

    Microsoft Academic Search

    M. Watanabe; K. Aoki

    1999-01-01

    A network access interface has been developed to astronomical CD-ROMs image data at Astronomical Data Analysis Center of the National Astronomical Observatory of Japan. The interface offers a couple of unique functions such as to identify galaxies listed in the \\

  8. Carnegie Hubble Program: A Mid-Infrared Calibration of the Hubble Constant

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    Using a mid-infrared calibration of the Cepheid distance scale based on recent observations at 3.6 micrometers 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 micrometers data for 10 high-metallicity, MilkyWay Cepheids having independently measured trigonometric parallaxes. We have adopted the slope of the PL relation using time-averaged 3.6micrometers 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) kilometers per second Mpc(sup -1), corresponding to a 2.8% systematic uncertainty in the Hubble constant. This result, in combination with WMAP7measurements 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.

  9. Astronomers debate diamonds in space

    NASA Astrophysics Data System (ADS)

    1999-04-01

    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

  10. Improved Astronomical Inferences via Nonparametric Density Estimation

    E-print Network

    Wolfe, Patrick J.

    Improved Astronomical Inferences via Nonparametric Density Estimation Chad M. Schafer, InCA Group. Richards 2 #12;Motivation Theory predicts the distribution of observables as a function of cosmological difficult to justify. Nonparametric density estimation drops these restrictions 8 #12;Nonparametric Density

  11. Combined ultraviolet studies of astronomical sources

    NASA Technical Reports Server (NTRS)

    Dupree, A. K.; Giampapa, M. S.; Huchra, J. P.; Noyes, R. W.; Hartmann, L. W.; Raymond, J. C.

    1982-01-01

    Ultraviolet studies of astronomical sources are discussed. Some studies utilized IVE data. Non-radiative shock at the edge of the Cygnses Loop, stellar flares, local interestellar medium, hot galaxies, stellar mass ejection, contact binaries, double quasars, and stellar chromosphere and coronae are discussed.

  12. An Astronomer's View of Optical Turbulence

    NASA Astrophysics Data System (ADS)

    Racine, René

    2009-09-01

    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.

  13. How do Astronomers Get Their Information?

    Microsoft Academic Search

    P. B. Boyce

    2002-01-01

    A sample of the AAS membership was surveyed in late 2001 as to their usage and opinions regarding the electronic information services available to the astronomical community. The major conclusions are: * Everyone knows about and uses the ADS service. * 85 services, e.g. astro-ph. * 75 service in the last year. * only 55 the last two years. *

  14. Prospective Science Teachers' Conceptions about Astronomical Subjects

    ERIC Educational Resources Information Center

    Küçüközer, Hüseyin

    2007-01-01

    The main objective of this study was to identify prospective science teachers' conceptions on basic astronomical phenomena. A questionnaire consisting of nine open-ended questions was administered to 327 prospective science teachers. The questionnaire was constructed after extensive review of the literature and took into consideration the reported…

  15. Space Place: How Astronomers "Detwinkle" the Stars

    NSDL National Science Digital Library

    This article contains a series of kinesthetic activities, explaining and demonstrating why stars twinkle and what astronomers can do to minimize it. The activities can be used to demonstrate how Earth's atmosphere distorts starlight and how advanced telescope technology (adaptive optics) is used to compensate for this distortion.

  16. Algorithms for Large-Scale Astronomical Problems

    E-print Network

    ;Keywords: big data, eScience, astronomy applications, distributed computing, data mining #12;For people to the following astronomical problems: We developed algorithms to better work with big data. We found out techniques to the quasar detection problem. Additionally, in the context of big data, we also evaluated

  17. Public software for the astronomer - An overview

    NASA Technical Reports Server (NTRS)

    Feigelson, Eric D.; Murtagh, Fionn

    1992-01-01

    Sources of public software are described that are available over wide-area research networks in journals and from government sources which may be valuable to the astronomer and astrophysicist. A very large amount of high-quality public software is accessible at all times. Locations with material useful for research are emphasized with practical suggestions regarding access.

  18. The Virtual Astronomical Observatory Users Forum

    NASA Astrophysics Data System (ADS)

    Muench, August A.; Emery Bunn, S.; Astronomical Observatory, Virtual

    2013-01-01

    We present the online forum astrobabel.com, which has the goal of being a gathering place for the collective community intelligence about astronomical computing. The audience for this forum is anyone engaged in the analysis of astronomical or planetary data, whether that data be observational or theoretical. It is a free, community driven site where discussions are formulated primarily around the "question and answer" format. Current topics on the forum range from “Is there a photometry package in Python?” to “Where are the support forums for astronomy software packages?” and “Why is my SDSS SkyQuery query missing galaxies?” The poster will detail the full scope of discussions in the forum, and provide some basic guidelines for ensuring high quality forum posts. We will highlight the ways astronomers can discover and participate in discussions. Further, we view this as an excellent opportunity to gather feedback and feature requests from AAS221 attendees. Acknowledgement: The Virtual Astronomical Observatory (VAO) is managed by the VAO, LLC, a non-profit company established as a partnership of the Associated Universities, Inc. and the Association of Universities for Research in Astronomy, Inc. The VAO is sponsored by the National Science Foundation and the National Aeronautics and Space Administration.

  19. Laser Frequency Combs for Astronomical Observations

    Microsoft Academic Search

    Tilo Steinmetz; Tobias Wilken; Constanza Araujo-Hauck; Ronald Holzwarth; Theodor W. Hänsch; Luca Pasquini; Antonio Manescau; Sandro D'Odorico; Michael T. Murphy; Thomas Kentischer; Wolfgang Schmidt; Thomas Udem

    2008-01-01

    A direct measurement of the universe's expansion history could be made by observing in real time the evolution of the cosmological redshift of distant objects. However, this would require measurements of Doppler velocity drifts of ~1 centimeter per second per year, and astronomical spectrographs have not yet been calibrated to this tolerance. We demonstrated the first use of a laser

  20. IYL Blog: Astronomers travel in time and space with light

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    2015-01-01

    As an astronomer, I use light to travel through the universe, and to look back in time to when the universe was young. So do you! All of us see things as they were when the light was emitted, not as they are now. The farthest thing you can easily see without a telescope is the Andromeda Nebula, which is a galaxy like the Milky Way, about 2.5 million light years away. You see it as it was 2.5 million years ago, and we really don't know what it looks like today; the disk will have rotated a bit, new stars will have been born, there could have been all kinds of exploding stars, and the black hole in the middle could be lighting up. People may be skeptical of the Big Bang theory, even though we have a TV show named for it, but we (I should say Penzias and Wilson) measured its heat radiation 51 years ago at Bell Telephone Labs in New Jersey. Their discovery marks the beginning of the era of cosmology as a measurement science rather than speculation. Penzias and Wilson received the Nobel Prize in 1978 for their finding, which had been predicted in 1948 by Alpher and Herman. By the way, heat radiation is just another form of light - we call it radiation because we can't see it, but it's exactly the same phenomenon of electromagnetic waves, and the only difference is the wavelength. In the old days of analog television, if you tuned your TV in between channels, about 1% of the snow that you could see came from the Big Bang. So when we look at the heat radiation of the early universe, we really are gazing right at what seems to us a cosmic fireball, which surrounds us completely. It's a bit of an illusion; if you can imagine what astronomers in other galaxies would see, they would also feel surrounded by the fireball, and they would also think they were in the middle. So from a mathematical version of imagination, we conclude that there is no observable center and no edge of our universe, and that the heat of the fireball fills the entire universe uniformly. Astronomers are also using light to find out whether we are alone in the universe. The Kepler observatory showed that thousands of stars blink a little when their orbiting planets pass between us and them, and other observatories use light to measure the wobble of stars as their planets pull on them. Eventually, we will find out whether planets like Earth have atmospheres like Earth's too - with water, carbon dioxide, oxygen, methane, and other gases that would be evidence of photosynthetic life. I think in a few decades we will have evidence that some planets do have life, and it will be done using light for remote chemical analysis. Also, astronomers at the SETI project are using light (long wavelength light we can pick up with radio telescopes) to look for signals from intelligent civilizations. That's a harder project because we don't know what to look for. But if we wanted to send signals all the way across the Milky Way, we could do it with laser beams, and if somebody over there knew what to look for, he or she could decode the message. On with the search! Dr. John C. Mather is a Senior Astrophysicist and is the Senior Project Scientist for the James Webb Space Telescope at NASA's Goddard Space Flight Center in Greenbelt, MD. His research centers on infrared astronomy and cosmology. With the Cosmic Background Explorer (COBE) team, he showed that the cosmic microwave background radiation has a blackbody spectrum within 50 parts per million, confirming the expanding universe model (aka the Big Bang Theory) to extraordinary accuracy, and initiating the study of cosmology as a precision science. The COBE team also made the first map of the hot and cold spots in the background radiation. The COBE maps have been confirmed and improved by two succeeding space missions, the Wilkinson Microwave Anisotropy Probe (WMAP, built by GSFC with Princeton University), and the Planck mission built by ESA. Based on these maps, astronomers have now developed a "standard model" of cosmology and have built detailed numerical simulations that begin to match Hubble observations, and

  1. Radio Astronomers Reveal "Bizarre" Behavior of Gamma-Ray Burster

    NASA Astrophysics Data System (ADS)

    1997-06-01

    Radio astronomers today revealed that the first gamma-ray burster ever detected at radio wavelengths has surprised them by its erratic behavior. "We expected the burster to act at radio wavelengths much as it does at X-ray and visible wavelengths -- that is, rise in brightness, then slowly become weaker," said Dr. Dale Frail of the National Radio Astronomy Observatory (NRAO). "Instead, it has completely surprised us." The announcement was made at the American Astronomical Society meeting in Winston-Salem, NC. Frail and Dr. Greg Taylor, also of NRAO, used the National Science Foundation's Very Large Array (VLA) and Very Long Baseline Array (VLBA) radio telescopes to study the gamma ray burst which exploded on May 8. The VLA was turned on the region of the burst within four hours of its discovery by the new orbiting Italian-Dutch observatory, Beppo-SAX. The radio astronomers have observed the object on a near-daily basis since then, and that monitoring has revealed the burster's unexpected behavior. "It is remaining at a roughly steady level of brightness, but has occasional flares in which it brightens by factors of two to three," Frail said. These variations are seen not only by the VLA, but also by the VLBA, a continent-wide radio telescope system that shows the object to be less than a few light years in size. The VLBA observations show a level of detail more than 50 times greater than that of the Hubble Space Telescope at optical wavelengths. For years, positions of gamma-ray bursts were known only to within several degrees in the sky, because of the limitations of earlier gamma-ray telescopes. Using the VLBA, the astronomers now have pinpointed a position for the May 8 burst to within a thousandth of a second of arc. "In only a year, this field of research has progressed to the point that we have a position more than a million times more accurate than before," Taylor said. This has allowed the researchers to show that the burster has not moved in the month since its discovery. What causes the unexpected flares in the radio output of this object? "One idea is that we are seeing the radio analogy of stars twinkling in the night sky," Frail said. This would require the object to be very small. Another idea is that the variations in the radio emission are not connected to the burst itself, but are arising within an active galaxy in which the burst occurred. "In order to solve the 30-year mystery of what causes gamma-ray bursts, we need to know what kind of galaxies give rise to them," Frail said. Both the VLA and VLBA will continue to observe this burster to gain additional information about its behavior in the coming months. "Theorists have made detailed predictions about how the radio intensity of such objects should behave over time. The ongoing VLA monitoring will test those predictions. Similarly, the great resolving power of the VLBA may allow us to track changes in the structure of the object over time." Gamma ray bursts were first discovered in the 1960s, and have mystefied scientists since then. Because the positions of these bursts could not be well determined before the launch of BeppoSAX, it was difficult for optical and radio astronomers to follow up on the gamma-ray detections. A longstanding controversy arose over whether the explosions creating these powerful bursts of radiation are occuring within our own Milky Way Galaxy or in other galaxies perhaps billions of light-years distant. Optical studies of the May 8 burst indicate that it is at least 7 billion light-years away, thus apparently resolving the distance question. The exact nature ot the explosions is still a question for further study. The VLA and VLBA are instruments of the National Radio Astronomy Observatory, a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

  2. 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)

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

    2011-03-01

    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.

  3. Interpretation of the Hubble diagram in a nonhomogeneous universe

    E-print Network

    Pierre Fleury; Hélène Dupuy; Jean-Philippe Uzan

    2013-07-01

    In the standard cosmological framework, the Hubble diagram is interpreted by assuming that the light emitted by standard candles propagates in a spatially homogeneous and isotropic spacetime. However, the light from "point sources"--such as supernovae--probes the Universe on scales where the homogeneity principle is no longer valid. Inhomogeneities are expected to induce a bias and a dispersion of the Hubble diagram. This is investigated by considering a Swiss-cheese cosmological model, which (1) is an exact solution of the Einstein field equations, (2) is strongly inhomogeneous on small scales, but (3) has the same expansion history as a strictly homogeneous and isotropic universe. By simulating Hubble diagrams in such models, we quantify the influence of inhomogeneities on the measurement of the cosmological parameters. Though significant in general, the effects reduce drastically for a universe dominated by the cosmological constant.

  4. Interpretation of the Hubble diagram in a nonhomogeneous universe

    NASA Astrophysics Data System (ADS)

    Fleury, Pierre; Dupuy, Hélène; Uzan, Jean-Philippe

    2013-06-01

    In the standard cosmological framework, the Hubble diagram is interpreted by assuming that the light emitted by standard candles propagates in a spatially homogeneous and isotropic spacetime. However, the light from “point sources”—such as supernovae—probes the Universe on scales where the homogeneity principle is no longer valid. Inhomogeneities are expected to induce a bias and a dispersion of the Hubble diagram. This is investigated by considering a Swiss-cheese cosmological model, which (1) is an exact solution of the Einstein field equations, (2) is strongly inhomogeneous on small scales, but (3) has the same expansion history as a strictly homogeneous and isotropic universe. By simulating Hubble diagrams in such models, we quantify the influence of inhomogeneities on the measurement of the cosmological parameters. Though significant in general, the effects reduce drastically for a universe dominated by the cosmological constant.

  5. Hubble's Universe and the WorldWide Telescope

    NASA Astrophysics Data System (ADS)

    Summers, Frank; Kakadelis, S.; Godfrey, C.

    2008-05-01

    Hubble's Universe is an astronomy podcast that not only explains the science behind the magnificent Hubble images, but also places the specific and cutting-edge results within the larger context of understanding the broad themes of the universe. Going further, we have partnered with Microsoft's soon to be released WorldWide Telescope (WWT) software to enable browsing, exploring, and experiencing the cosmos in a way never before seen. We can now zoom from the backyard wide-angle view down to see every last pixel in the highest resolution images, while at the same time presenting the breakthrough science and amazing visuals of Hubble within the intuitive interface of viewing the sky. We will discuss the research and production aspects, as well as the oppotunities and limitations, of both the podcast and the WWT avenues for astronomy outreach.

  6. Statistical Analysis of Quasar Data and Hubble Law

    E-print Network

    Sisir Roy; Dhrubajit Datta; Malabika Roy; Menas Kafatos

    2006-05-15

    The linearity of the Hubble relationship (i.e. between m and z) has been tested for galaxies and supernovea for low redshifts. We have studied this relationship for quasars for data taken from Veron Cetti Catalogue(2003).The data from Veron Cetti Catalogue for quasars appear to be truncated. The data have been analyzed using various statistical methods which are suitable for analysing the truncated data. This analysis shows lineraity (in log z) of Hubble law for very small z but non-linearity for high redshift.This will shed new light not only on the quasar astronomy but also in the cosmological debate.

  7. Artificial intelligence approaches to astronomical observation scheduling

    NASA Technical Reports Server (NTRS)

    Johnston, Mark D.; Miller, Glenn

    1988-01-01

    Automated scheduling will play an increasing role in future ground- and space-based observatory operations. Due to the complexity of the problem, artificial intelligence technology currently offers the greatest potential for the development of scheduling tools with sufficient power and flexibility to handle realistic scheduling situations. Summarized here are the main features of the observatory scheduling problem, how artificial intelligence (AI) techniques can be applied, and recent progress in AI scheduling for Hubble Space Telescope.

  8. Relativistic effects in astronomical timing measurements

    NASA Technical Reports Server (NTRS)

    Hellings, R. W.

    1986-01-01

    In this paper the relativistic transformations that are necessary to transform the results of earth-based astronomical timing observations from the terrestrial frame in which the observations are made to the proper frame of the astronomical object being observed are derived. Two coordinate systems are considered, the first being the parametrized post-Newtonian coordinate system and the second being a coordinate system based on the use of temps dynamique barycentrique as a time coordinate. Effects due to propagation of signals through curved spacetime and due to the relativistic gravitational time dilation for the earth are derived in each system. The results are then applied to three modern accurate data types spacecraft ranging, pulsar timing, and VLBI. A new effect is found in the analysis of VLBI data, amounting to a rescaling of VLBI-determined baselines produced by the curvature of space in the neighborhood of the sun.

  9. Astronomical context coder for image compression

    NASA Astrophysics Data System (ADS)

    Pata, Petr; Schindler, Jaromir

    2015-05-01

    Recent lossless still image compression formats are powerful tools for compression of all kind of common images (pictures, text, schemes, etc.). Generally, the performance of a compression algorithm depends on its ability to anticipate the image function of the processed image. In other words, a compression algorithm to be successful, it has to take perfectly the advantage of coded image properties. Astronomical data form a special class of images and they have, among general image properties, also some specific characteristics which are unique. If a new coder is able to correctly use the knowledge of these special properties it should lead to its superior performance on this specific class of images at least in terms of the compression ratio. In this work, the novel lossless astronomical image data compression method will be presented. The achievable compression ratio of this new coder will be compared to theoretical lossless compression limit and also to the recent compression standards of the astronomy and general multimedia.

  10. Identifying seasonal stars in Kaurna astronomical traditions

    E-print Network

    Hamacher, Duane W

    2015-01-01

    Early ethnographers and missionaries recorded Aboriginal languages and oral traditions across Australia. Their general lack of astronomical training resulted in misidentifications, transcription errors, and omissions in these records. Additionally, many of these early records are fragmented. In western Victoria and southeast South Australia, many astronomical traditions were recorded, but curiously, some of the brightest stars in the sky were omitted. Scholars claimed these stars did not feature in Aboriginal traditions. This under-representation continues to be repeated in the literature, but current research shows that some of these stars may in fact feature in Aboriginal traditions and could be seasonal calendar markers. This paper uses established techniques in cultural astronomy to identify seasonal stars in the traditions of the Kaurna Aboriginal people of the Adelaide Plains, South Australia.

  11. Advances in detectors for astronomical spectroscopy

    NASA Astrophysics Data System (ADS)

    Boksenberg, A.

    1982-11-01

    It is pointed out that spectroscopy is the most important investigative technique applied in astronomy. In many respects it is far more challenging to find appropriate image-reproducing detectors for astronomical spectroscopy than for direct-imaging applications. A functional tree is presented to show the operation of various practical imaging detectors in current or planned use. A clear trend in the use of detectors in astronomy in recent years has been the increased application of electronic data processing and computer techniques. An account is given of some of the techniques implied in the functional tree, taking into account detectors suitable for astronomical applications in the ultraviolet, optical, and near infrared (to about 1 micrometer) spectral ranges. Attention is given to photographic emulsions, electronography, image intensifiers, integrating television camera tubes, image photon-counting systems, and solid-state detectors.

  12. Astronomical Research with liquid mirror telescopes

    E-print Network

    E. F. Borra

    1997-06-11

    I discuss the modalities of zenith observing with LMTs, their limitations and advantages. The main limitation comes from the relatively small regions of the sky that LMTs can access. The main advantage comes from low cost, for inexpensive large LMTs can be dedicated to very specialized goals. Large surveys, cosmological studies, variability studies are prime examples of astronomical research where LMTs can have a major impact. I examine the performance of a 4-m telescope equipped with wide band filters and its use for astronomical research. The data could be used to select targets for the VLT. I examine the usage of the data for variability studies and, in particular, for a supernova search.

  13. Physicists, Mathematicians and Astronomers- communists (Part 2)

    NASA Astrophysics Data System (ADS)

    Gaina, Alex

    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.

  14. Identifying seasonal stars in Kaurna astronomical traditions

    NASA Astrophysics Data System (ADS)

    Hamacher, Duane W.

    2015-03-01

    Early ethnographers and missionaries recorded Aboriginal languages and oral traditions across Australia. Their general lack of astronomical training resulted in misidentifications, transcription errors and omissions in these records. In western Victoria and southeast South Australia many astronomical traditions were recorded but, cur- iously, some of the brightest stars in the sky were omitted. Scholars claimed these stars did not feature in Aboriginal traditions. This continues to be repeated in the literature, but current research shows that these stars may in fact feature in Aboriginal traditions and could be seasonal calendar markers. This paper uses established techniques to identify seasonal stars in the traditions of the Kaurna Aboriginal people of the Adelaide Plains, South Australia.

  15. Laser frequency combs for astronomical observations

    E-print Network

    Tilo Steinmetz; Tobias Wilken; Constanza Araujo-Hauck; Ronald Holzwarth; Theodor W. Hänsch; Luca Pasquini; Antonio Manescau; Sandro D'Odorico; Michael T. Murphy; Thomas Kentischer; Wolfgang Schmidt; Thomas Udem

    2008-09-09

    A direct measurement of the universe's expansion history could be made by observing in real time the evolution of the cosmological redshift of distant objects. However, this would require measurements of Doppler velocity drifts of about 1 centimeter per second per year, and astronomical spectrographs have not yet been calibrated to this tolerance. We demonstrate the first use of a laser frequency comb for wavelength calibration of an astronomical telescope. Even with a simple analysis, absolute calibration is achieved with an equivalent Doppler precision of approximately 9 meters per second at about 1.5 micrometers - beyond state-of-the-art accuracy. We show that tracking complex, time-varying systematic effects in the spectrograph and detector system is a particular advantage of laser frequency comb calibration. This technique promises an effective means for modeling and removal of such systematic effects to the accuracy required by future experiments to see direct evidence of the universe's putative acceleration.

  16. Laser frequency combs for astronomical observations

    E-print Network

    Steinmetz, Tilo; Araujo-Hauck, Constanza; Holzwarth, Ronald; Hänsch, Theodor W; Pasquini, Luca; Manescau, Antonio; D'Odorico, Sandro; Murphy, Michael T; Kentischer, Thomas; Schmidt, Wolfgang; Udem, Thomas

    2008-01-01

    A direct measurement of the universe's expansion history could be made by observing in real time the evolution of the cosmological redshift of distant objects. However, this would require measurements of Doppler velocity drifts of about 1 centimeter per second per year, and astronomical spectrographs have not yet been calibrated to this tolerance. We demonstrate the first use of a laser frequency comb for wavelength calibration of an astronomical telescope. Even with a simple analysis, absolute calibration is achieved with an equivalent Doppler precision of approximately 9 meters per second at about 1.5 micrometers - beyond state-of-the-art accuracy. We show that tracking complex, time-varying systematic effects in the spectrograph and detector system is a particular advantage of laser frequency comb calibration. This technique promises an effective means for modeling and removal of such systematic effects to the accuracy required by future experiments to see direct evidence of the universe's putative acceler...

  17. A website for astronomical news in Spanish

    NASA Astrophysics Data System (ADS)

    Ortiz-Gil, A.

    2008-06-01

    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.

  18. Research of Computer Assisted Astronomical Positioning Algorithm

    Microsoft Academic Search

    Zhao Xin; Jia Haihong; Wu Jianhua; Ma Zhuang

    2009-01-01

    The key of astronomical navigation positioning algorithm is the artificial look-up table and calculation, but also ship's position can be obtained through mapping, it is not only time-consuming but also laborious. Positioning measurement is usually required a few dozen minutes once a time, seriously affected the positioning accuracy and speed, but there are still calculating the look-up table interpolation error,

  19. 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.

  20. Astronomical image denoising using dictionary learning

    NASA Astrophysics Data System (ADS)

    Beckouche, S.; Starck, J. L.; Fadili, J.

    2013-08-01

    Astronomical images suffer a constant presence of multiple defects that are consequences of the atmospheric conditions and of the intrinsic properties of the acquisition equipment. One of the most frequent defects in astronomical imaging is the presence of additive noise which makes a denoising step mandatory before processing data. During the last decade, a particular modeling scheme, based on sparse representations, has drawn the attention of an ever growing community of researchers. Sparse representations offer a promising framework to many image and signal processing tasks, especially denoising and restoration applications. At first, the harmonics, wavelets and similar bases, and overcomplete representations have been considered as candidate domains to seek the sparsest representation. A new generation of algorithms, based on data-driven dictionaries, evolved rapidly and compete now with the off-the-shelf fixed dictionaries. Although designing a dictionary relies on guessing the representative elementary forms and functions, the framework of dictionary learning offers the possibility of constructing the dictionary using the data themselves, which provides us with a more flexible setup to sparse modeling and allows us to build more sophisticated dictionaries. In this paper, we introduce the centered dictionary learning (CDL) method and we study its performance for astronomical image denoising. We show how CDL outperforms wavelet or classic dictionary learning denoising techniques on astronomical images, and we give a comparison of the effects of these different algorithms on the photometry of the denoised images. The current version of the code is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/556/A132

  1. Laser frequency combs for astronomical observations

    Microsoft Academic Search

    Tilo Steinmetz; Tobias Wilken; Constanza Araujo-Hauck; Ronald Holzwarth; Theodor W. Hänsch; Luca Pasquini; Antonio Manescau; Sandro D'Odorico; Michael T. Murphy; Thomas Kentischer; Wolfgang Schmidt; Thomas Udem

    2008-01-01

    A direct measurement of the universe's expansion history could be made by\\u000aobserving in real time the evolution of the cosmological redshift of distant\\u000aobjects. However, this would require measurements of Doppler velocity drifts of\\u000aabout 1 centimeter per second per year, and astronomical spectrographs have not\\u000ayet been calibrated to this tolerance. We demonstrate the first use of a

  2. A Guided Inquiry on Hubble Plots and the Big Bang

    ERIC Educational Resources Information Center

    Forringer, Ted

    2014-01-01

    In our science for non-science majors course "21st Century Physics," we investigate modern "Hubble plots" (plots of velocity versus distance for deep space objects) in order to discuss the Big Bang, dark matter, and dark energy. There are two potential challenges that our students face when encountering these topics for the…

  3. Multicolor Observations of the Hubble Deep Field South

    Microsoft Academic Search

    Eros Vanzella; Stefano Cristiani; Paolo Saracco; Stephane Arnouts; Simone Bianchi; Sandro D'Odorico; Adriano Fontana; Emanuele Giallongo; Andrea Grazian

    2001-01-01

    We present a deep multicolor (U, B, V, I, Js, H, Ks) catalog of galaxies in the Hubble Deep Field South, based on observations obtained with the HST WFPC2 in 1998 and VLT-ISAAC in 1999. The photometric procedures were tuned to derive a catalog optimized for the estimation of photometric redshifts. In particular we adopted a ``conservative'' detection threshold, which

  4. Geologic Mapping of Vesta from 1994 Hubble Space Telescope Images

    Microsoft Academic Search

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

    1997-01-01

    We utilize the 56 images of Asteroid 4 Vesta obtained through four mineralogically diagnostic filters by the Hubble Space Telescope (Zellneret 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 Thomaset al.1997,Icarus) is dominated by units interpreted to be impact excavated

  5. Hubble Space Telescope characterized by using phase-retrieval algorithms

    Microsoft Academic Search

    J. R. Fienup; J. C. Marron; T. J. Schulz; J. H. Seldin

    1993-01-01

    We describe several results characterizing the Hubble Space Telescope from measured point spread functions by using phase-retrieval algorithms. The Cramer-Rao lower bounds show that point spread functions taken well out of focus result in smaller errors when aberrations are estimated and that, for those images, photon noise is not a limiting factor. Reconstruction experiments with both simulated and real data

  6. 150th Anniversary of the Astronomical Observatory Library of Sciences

    NASA Astrophysics Data System (ADS)

    Solntseva, T.

    The scientific library of the Astronomical observatory of Kyiv Taras Shevchenko University is one of the oldest ones of such a type in Ukraine. Our Astronomical Observatory and its scientific library will celebrate 150th anniversary of their foundation. 900 volumes of duplicates of Olbers' private library underlay our library. These ones were acquired by Russian Academy of Sciences for Poulkovo observatory in 1841 but according to Struve's order were transmitted to Kyiv Saint Volodymyr University. These books are of great value. There are works edited during Copernicus', Kepler's, Galilei's, Newton's, Descartes' lifetime. Our library contains more than 100000 units of storage - monographs, periodical astronomical editions from the first (Astronomische Nachrichten, Astronomical journal, Monthly Notices etc.), editions of the majority of the astronomical observatories and institutions of the world, unique astronomical atlases and maps

  7. GalileoMobile: Astronomical activities in schools

    NASA Astrophysics Data System (ADS)

    Dasi Espuig, Maria; Vasquez, Mayte; Kobel, Philippe

    GalileoMobile is an itinerant science education initiative run on a voluntary basis by an international team of astronomers, educators, and science communicators. Our team's main goal is to make astronomy accessible to schools and communities around the globe that have little or no access to outreach actions. We do this by performing teacher workshops, activities with students, and donating educational material. Since the creation of GalileoMobile in 2008, we have travelled to Chile, Bolivia, Peru, India, and Uganda, and worked with 56 schools in total. Our activities are centred on the GalileoMobile Handbook of Activities that comprises around 20 astronomical activities which we adapted from many different sources, and translated into 4 languages. The experience we gained in Chile, Bolivia, Peru, India, and Uganda taught us that (1) bringing experts from other countries was very stimulating for children as they are naturally curious about other cultures and encourages a collaboration beyond borders; (2) high-school students who were already interested in science were always very eager to interact with real astronomers doing research to ask for career advice; (3) inquiry-based methods are important to make the learning process more effective and we have therefore, re-adapted the activities in our Handbook according to these; (4) local teachers and university students involved in our activities have the potential to carry out follow-up activities, and examples are those from Uganda and India.

  8. Hydroxide catalysis bonding for astronomical instruments

    NASA Astrophysics Data System (ADS)

    van Veggel, Anna-Maria A.; Killow, Christian J.

    2014-06-01

    Hydroxide catalysis bonding (HCB) as a jointing technique has been under development for astronomical applications since ˜1998 (patented by D.-H. Gwo). It uses an aqueous hydroxide solution to form a chemical bond between oxide or oxidisable materials (e.g., SiO2, sapphire, silicon and SiC). It forms strong, extremely thin bonds, and is suitable for room temperature bonding, precision alignment, operation in ultra-low vacuum and down to temperatures of 2.5 K. It has been applied in the NASA satellite mission Gravity Probe B and in the ground-based gravitational wave (GW) detector GEO600. It will soon fly again on the ESA LISA Pathfinder mission and is currently being implemented in the Advanced LIGO and Virgo ground-based GW detectors. This technique is also of considerable interest for use in other astronomical fields and indeed more broadly, due to its desirable, and adjustable, combination of properties. This paper gives an overview of how HCB has been and can be applied in astronomical instruments, including an overview of the current literature on the properties of hydroxide catalysis bonds.

  9. The preparation and archiving of machine-readable astronomical data

    NASA Technical Reports Server (NTRS)

    Warren, W. H., Jr.

    1985-01-01

    The preparation of machine-readable astronomical catalogs for archiving and distribution from the ADC is described. Examples of specific format and data structure changes to improve compatibility with other computers, to homogenize the presentation of astronomical data among catalogs, and to increase storage efficiency are given. Various checks which are often made to insure internal consistency and for comparison with published versions are identified and the importance of permanently archiving astronomical data in the best possible condition is emphasized.

  10. Bucharest-Nikolaev Astronomical Observatories' Collaboration in Astronomy

    NASA Astrophysics Data System (ADS)

    Pinigin, Gennadiy; Stavinschi, Magda

    2008-09-01

    Scientific collaboration between Bucharest Observatory of the Astronomical Institute (Romania) and Nikolaev Astronomical Observatory (Ukraine), based on the similar research directions and scientific traditions from the beginning of 1990s. The main research field was positional astronomy with compilation of catalogues of star positions in the fields around selected ERS from the CCD observations in Nikolaev and photographical observations in the Bucharest Observatory. Many conferences and workshops, mutual visits of astronomers from both observatories were organized and held in Nikolaev and Bucharest.

  11. Relativistic description of astronomical objects in multiple reference systems

    Microsoft Academic Search

    Chongming Xu; Zhenghong Tang

    2010-01-01

    Many astronomical systems require for their description in the frame of Einstein's theory of gravity not just one but several reference systems. In the first post-Newtonian approximation the Damour-Soffel-Xu (DSX) formalism presents a new and improved treatment of celestial mechanics and astronomical reference systems for the gravitational N-body problem. In the DSX-formalism the astronomical bodies are characterized by their Blanchet-Damour

  12. New Eyes for Space Exploration: Upgrading the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Grunsfeld, John

    2002-09-01

    In March 2002, a team of seven astronauts launched from the KennedyCenter aboard Space Shuttle Columbia in route to the Hubble SpaceTelescope. The Hubble Space Telescope was designed to be servicedperiodically to upgrade its instruments and fix broken equipment. TheSTS-109 mission, the fourth Hubble servicing mission, was the mostambitious repair mission to date. Over a series of five space walks,astronauts in space suits replaced the solar arrays and power system,installed a new sensitive camera, and brought an infra-red cameraback to life. Details of the mission will be presented, as well assome of the first exciting pictures from the new camera.John Mace Grunsfeld received a B.S. degree in physics fromM.I.T. ; an M.S. degree and Ph.D. in physics from the University ofChicago. Dr. Grunsfeld studies binary pulsars and energetic x-ray andgamma ray sources using the NASA Compton Gamma Ray Observatory, x-rayastronomy satellites, radio telescopes, and optical telescopesincluding the NASA Hubble Space Telescope. He became an astronaut in1992 and led a team of scientists tasked with defining and producingthe crew displays for command and control of the International SpaceCenter (ISS). He has logged over 45 days in space, including 5 spacewalks. He participated in the second flight of the astro observatoryin 1995. He served as flight engineer of a 10 day mission to dockwith Russia's Space Station Mir in 1997. He has participated in twoservicing missions of the Hubble Telescope in 1999 and 2002.

  13. New Eyes for Space Exploration: Upgrading the Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Grunsfeld, John

    2002-10-01

    In March 2002, a team of seven astronauts launched from the KennedyCenter aboard Space Shuttle Columbia in route to the Hubble SpaceTelescope. The Hubble Space Telescope was designed to be servicedperiodically to upgrade its instruments and fix broken equipment. TheSTS-109 mission, the fourth Hubble servicing mission, was the mostambitious repair mission to date. Over a series of five space walks,astronauts in space suits replaced the solar arrays and power system,installed a new sensitive camera, and brought an infra-red cameraback to life. Details of the mission will be presented, as well assome of the first exciting pictures from the new camera.John Mace Grunsfeld received a B.S. degree in physics fromM.I.T. ; an M.S. degree and Ph.D. in physics from the University ofChicago. Dr. Grunsfeld studies binary pulsars and energetic x-ray andgamma ray sources using the NASA Compton Gamma Ray Observatory, x-rayastronomy satellites, radio telescopes, and optical telescopesincluding the NASA Hubble Space Telescope. He became an astronaut in1992 and led a team of scientists tasked with defining and producingthe crew displays for command and control of the International SpaceCenter (ISS). He has logged over 45 days in space, including 5 spacewalks. He participated in the second flight of the astro observatoryin 1995. He served as flight engineer of a 10 day mission to dockwith Russia's Space Station Mir in 1997. He has participated in twoservicing missions of the Hubble Telescope in 1999 and 2002.

  14. The future of space imaging. Report of a community-based study of an advanced camera for the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Brown, Robert A. (editor)

    1993-01-01

    The scientific and technical basis for an Advanced Camera (AC) for the Hubble Space Telescope (HST) is discussed. In March 1992, the NASA Program Scientist for HST invited the Space Telescope Science Institute to conduct a community-based study of an AC, which would be installed on a scheduled HST servicing mission in 1999. The study had three phases: a broad community survey of views on candidate science program and required performance of the AC, an analysis of technical issues relating to its implementation, and a panel of experts to formulate conclusions and prioritize recommendations. From the assessment of the imaging tasks astronomers have proposed for or desired from HST, we believe the most valuable 1999 instrument would be a camera with both near ultraviolet/optical (NUVO) and far ultraviolet (FUV) sensitivity, and with both wide field and high resolution options.

  15. Amateur astronomers in support of observing campaigns

    NASA Astrophysics Data System (ADS)

    Yanamandra-Fisher, P.

    2014-07-01

    The Pro-Am Collaborative Astronomy (PACA) project evolved from the observational campaign of C/2012 S1 or C/ISON. The success of the paradigm shift in scientific research is now implemented in other comet observing campaigns. While PACA identifies a consistent collaborative approach to pro-am collaborations, given the volume of data generated for each campaign, new ways of rapid data analysis, mining access, and storage are needed. Several interesting results emerged from the synergistic inclusion of both social media and amateur astronomers: - the establishment of a network of astronomers and related professionals that can be galvanized into action on short notice to support observing campaigns; - assist in various science investigations pertinent to the campaign; - provide an alert-sounding mechanism should the need arise; - immediate outreach and dissemination of results via our media/blogger members; - provide a forum for discussions between the imagers and modelers to help strategize the observing campaign for maximum benefit. In 2014, two new comet observing campaigns involving pro-am collaborations have been identified: (1) C/2013 A1 (C/Siding Spring) and (2) 67P/Churyumov-Gerasimenko (CG). The evolving need for individual customized observing campaigns has been incorporated into the evolution of PACA (Pro-Am Collaborative Astronomy) portal that currently is focused on comets: from supporting observing campaigns for current comets, legacy data, historical comets; interconnected with social media and a set of shareable documents addressing observational strategies; consistent standards for data; data access, use, and storage, to align with the needs of professional observers. The integration of science, observations by professional and amateur astronomers, and various social media provides a dynamic and evolving collaborative partnership between professional and amateur astronomers. The recent observation of comet 67P, at a magnitude of 21.2, from Siding Spring, Australia, via robotic telescope network, also detected several asteroids in a crowded star field (SSI, Press Release, May 2014). These may be useful in support of the ESA/Gaia mission, which will characterize asteroids and comets to a magnitude of 20. While its network of amateur astronomers has already been established (Thuillot, 2005, ESASP, 576), such observations by robotic telescope networks can provide both astrometry and subsequent science analysis of the data acquired. An additional benefit of amateur network will be to unequivocally recognize asteroids and comets via complementary imaging that is not possible for the mission itself.

  16. Infrared upconversion for astronomical applications. [laser applications to astronomical spectroscopy of infrared spectra

    NASA Technical Reports Server (NTRS)

    Abbas, M. M.; Kostiuk, T.; Ogilvie, K. W.

    1975-01-01

    The performance of an upconversion system is examined for observation of astronomical sources in the low to middle infrared spectral range. Theoretical values for the performance parameters of an upconversion system for astronomical observations are evaluated in view of the conversion efficiencies, spectral resolution, field of view, minimum detectable source brightness and source flux. Experimental results of blackbody measurements and molecular absorption spectrum measurements using a lithium niobate upconverter with an argon-ion laser as the pump are presented. Estimates of the expected optimum sensitivity of an upconversion device which may be built with the presently available components are given.

  17. Scholastic intercourse between Shogunal Astronomer Shibukawa Kagesuke and Nagasaki-based astronomer Mine Gensuke

    NASA Astrophysics Data System (ADS)

    Ito, Setsuko

    2004-04-01

    It is important to know how scholastic tradition of Tenmon-kata (Shogunal Astronomical Office) was transferred to local astronomers over the 19th century, since it is likely that modernization of Japan in science and technology after the Meiji-restoration (1868) has its root in the pre-Meiji period. In this report, as a case-study of such line-of-thoughts, I took up a local astronomer Mine Gensuke, from Omura-han (clan) of Nagasaki. Mine, at his age of 25 (1850), came to Edo and learned astronomy for six years under the supervision of Shibukawa Kagesuke, the top-ranking Shogunal astronomer at that time. After returning to Nagasaki, Mine was assigned to be the land-surveyer of Omura-han. In Mine's book-collection preserved at the Nagasaki Municipal Museum, I found several books and notebooks copied and annotated by Mine, whose original author was Shibukawa. Through a research to those materials, I discuss what and how Mine learned from Shibukawa.

  18. US Gateway to SIMBAD Astronomical Database

    NASA Technical Reports Server (NTRS)

    Eichhorn, G.

    1998-01-01

    During the last year the US SIMBAD Gateway Project continued to provide services like user registration to the US users of the SIMBAD database in France. User registration is required by the SIMBAD project in France. Currently, there are almost 3000 US users registered. We also provide user support by answering questions from users and handling requests for lost passwords. We have worked with the CDS SIMBAD project to provide access to the SIMBAD database to US users on an Internet address basis. This will allow most US users to access SIMBAD without having to enter passwords. This new system was installed in August, 1998. The SIMBAD mirror database at SAO is fully operational. We worked with the CDS to adapt it to our computer system. We implemented automatic updating procedures that update the database and password files daily. This mirror database provides much better access to the US astronomical community. We also supported a demonstration of the SIMBAD database at the meeting of the American Astronomical Society in January. We shipped computer equipment to the meeting and provided support for the demonstration activities at the SIMBAD booth. We continued to improve the cross-linking between the SIMBAD project and the Astro- physics Data System. This cross-linking between these systems is very much appreciated by the users of both the SIMBAD database and the ADS Abstract Service. The mirror of the SIMBAD database at SAO makes this connection faster for the US astronomers. The close cooperation between the CDS in Strasbourg and SAO, facilitated by this project, is an important part of the astronomy-wide digital library initiative called Urania. It has proven to be a model in how different data centers can collaborate and enhance the value of their products by linking with other data centers.

  19. Expansion of The Astronomical Almanac Online Website

    NASA Astrophysics Data System (ADS)

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

    2010-01-01

    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.

  20. Large-scale bulk motions complicate the Hubble diagram

    NASA Astrophysics Data System (ADS)

    Cooray, Asantha; Caldwell, Robert R.

    2006-05-01

    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.

  1. A Nuclear Data Approach for the Hubble Constant Measurements

    E-print Network

    Pritychenko, B

    2015-01-01

    An extraordinary number of Hubble constant measurements challenges physicists with selection of the best numerical value. The standard U.S. Nuclear Data Program (USNDP) codes and procedures have been applied to resolve this issue. The nuclear data approach has produced the most probable or recommended Hubble constant value of 67.00(770) (km/sec)/Mpc. This recommended value is based on the last 25 years of experimental research and includes contributions from different types of measurements. The present result implies (14.6$\\pm$1.7)$\\times$10$^{9}$ years as a rough estimate for the age of the Universe. The complete list of recommended results is given and possible implications are discussed.

  2. Large-Scale Bulk Motions Complicate the Hubble Diagram

    E-print Network

    Cooray, A R; Cooray, Asantha; Caldwell, Robert R.

    2006-01-01

    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 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.

  3. Large-Scale Bulk Motions Complicate the Hubble Diagram

    E-print Network

    Asantha Cooray; Robert R. Caldwell

    2006-01-17

    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 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.

  4. CORRELATION BETWEEN TOMS AEROSOL INDEX AND THE ASTRONOMICAL EXTINCTION

    E-print Network

    Liske, Jochen

    CORRELATION BETWEEN TOMS AEROSOL INDEX AND THE ASTRONOMICAL EXTINCTION El Arbi Siher a,d , Sergio and Earth Probe observations with CAMC visual extinction over La Palma from 1984 to 1997, to investigate the possibility to calibrate TOMS data in terms of astronomical extinction. The results show that the correlation

  5. Use of Astronomical Literature - A Report on Usage Patterns

    Microsoft Academic Search

    Edwin A. Henneken; Michael J. Kurtz; Alberto Accomazzi; Carolyn Stern-grant; Donna M. Thompson; Elizabeth Bohlen; Stephen S. Murray

    2008-01-01

    In this paper we present a number of metrics for usage of the SAO\\/NASA Astrophysics Data System (ADS). Since the ADS is used by the entire astronomical community, these are indica- tive of how the astronomical literature is used. We will show how the use of the ADS has changed both quantitatively and qualitatively. We will also show that different

  6. The Sociology of Astronomical Publication Using ADS and ADAMS

    Microsoft Academic Search

    Eric Schulman; James C. French; Allison L. Powell; Stephen S. Murray; Guenther Eichhorn; Michael J. Kurtz

    1997-01-01

    We use the NASA Astrophysics Data System database of astronomical abstracts in seven major astronomy journals to study trends in astronomical publication over the last twenty years. Two of the most interesting trends are the decreasing fractions of papers with one author and the increasing number of authors per paper.

  7. Astronomical Dating of Edvard Munch's Summer Sky Paintings

    Microsoft Academic Search

    Ava Pope; Donald Olson

    2009-01-01

    Norwegian painter Edvard Munch, most famous for The Scream, created many spectacular works depicting the skies of Norway. Our Texas State group used astronomical methods to analyze three of these paintings: Starry Night, The Storm, and Sunrise in Asgardstrand. Astronomical dating of these paintings has some importance because the precise days when Munch visited Asgardstrand are unknown. Our research group

  8. Astronomical Dating of Edvard Munch's Summer Sky Paintings

    Microsoft Academic Search

    Ava Pope; Donald Olson

    2010-01-01

    Norwegian painter Edvard Munch, most famous for The Scream, created many spectacular works depicting the skies of Norway. Our Texas State group used astronomical methods to analyze three of these paintings: Starry Night, The Storm, and Sunrise in Asgardstrand. Astronomical dating of these paintings has some importance because the precise days when Munch visited Asgardstrand are unknown. Our research group

  9. National and international astronomical activities in Chile 1849--2002

    Microsoft Academic Search

    H. W. Duerbeck

    2003-01-01

    At all times and in many ways, Chilean astronomy has been influenced externally, either by astronomical expeditions from other parts of the world, or by astronomers that immigrated from other countries. We outline the history of the Chilean National Observatory, beginning with its origins out of Gilliss' US Naval Expedition to the Southern Hemisphere, over its directors Moesta, Vergara, Obrecht,

  10. An Augmented Reality System for Astronomical Observations Andrei Lintu

    E-print Network

    Magnor, Marcus

    of an astronomical telescope knows that, with the exception of the Moon and the plan- ets, extra-solar astronomical. This surely happens when "easy to observe", bright objects such as the Moon or the planets are the targets camera to display the live image formed at the telescope focus on e-mail:lintu@mpii.de e

  11. Software design for panoramic astronomical pipeline processing

    E-print Network

    Lior Shamir; Robert J. Nemiroff; David O. Torrey; Wellesley E. Pereira

    2005-11-23

    We describe the software requirement and design specifications for all-sky panoramic astronomical pipelines. The described software aims to meet the specific needs of super-wide angle optics, and includes cosmic-ray hit rejection, image compression, star recognition, sky opacity analysis, transient detection and a web server allowing access to real-time and archived data. The presented software is being regularly used for the pipeline processing of 11 all-sky cameras located in some of the world's premier observatories. We encourage all-sky camera operators to use our software and/or our hosting services and become part of the global Night Sky Live network.

  12. Illinois­—Where Astronomical Photometry Grew Up

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

    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.

  13. Anglo-Australian Observatory Astronomical Images

    NSDL National Science Digital Library

    Malin, David.

    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).

  14. Astronomical Beliefs in Medieval Georgia: Innovative Approaches

    NASA Astrophysics Data System (ADS)

    Sauter, Jefferson; Orchiston, W.; Stephenson, F.

    2014-01-01

    Written sources from medieval Georgia show, among other things, how astronomical ideas were adapted on the periphery of the Byzantine and Islamic worlds. In this paper, we investigate a number of Georgian beliefs about the heavens from a calendrical work and a celestial prognostication text, but also from less expected sources including the medieval life of a saint and an epic poem. For the most part, these sources were derived from Byzantine or Persian models. We show the extent to which the sources nevertheless conform to a specifically Georgian view of the cosmos. We argue that, in so doing, medieval Georgian authors employed several innovative approaches hitherto unnoticed by modern scholars.

  15. Distant Red Galaxies in the Hubble Ultra Deep Field

    Microsoft Academic Search

    S. Toft; P. van Dokkum; M. Franx; R. I. Thompson; G. D. Illingworth; R. J. Bouwens; M. Kriek

    2005-01-01

    We take advantage of the Hubble Ultra Deep Field data to study the rest-frame optical and UV morphologies of the novel population of distant red galaxies (DRGs). Six galaxies with J-Ks>2.3 are found to Ks=21.5, five of which have photometric redshifts zphot>~2, corresponding to a surface density of 0.9 arcmin-2. The surface brightness distributions of the zphot>~2 galaxies are better

  16. WFPC2 Observations of the Hubble Deep Field South

    Microsoft Academic Search

    Stefano Casertano; Duília de Mello; Mark Dickinson; Henry C. Ferguson; Andrew S. Fruchter; Rosa A. Gonzalez-Lopezlira; Inge Heyer; Richard N. Hook; Zolt Levay; Ray A. Lucas; Jennifer Mack; Russell B. Makidon; Max Mutchler; T. Ed Smith; Massimo Stiavelli; Michael S. Wiggs; Robert E. Williams

    2000-01-01

    The Hubble Deep Field South (HDF-S) observations targeted a high Galactic latitude field near QSO J2233-606. We present Wide Field Planetary Camera 2 observations of the field in four wide bandpasses centered at roughly 300, 450, 606, and 814 nm. Observations, data reduction procedures, and noise properties of the final images are discussed in detail. A catalog of sources is

  17. Analysis of Retrieved Hubble Space Telescope Thermal Control Materials

    Microsoft Academic Search

    Jacqueline A. Townsend; Patricia A. Hansen; Joyce A. Dever; Jack J. Triolo

    1998-01-01

    The mechanical and optical properties of the thermal control materials on the Hubble Space Telescope (HST) have degraded over the nearly seven years the telescope has been in orbit. Astronaut observations and photographs from the Second Servicing Mission (SM2) revealed large cracks in the metallized Teflon FEP, the outer-layer of the multi-layer insulation (MLI), in many locations around the telescope.

  18. The Hubble Slow Roll Expansion for Multi Field Inflation

    Microsoft Academic Search

    Richard Easther; John T Giblin Jr

    2005-01-01

    We examine the dynamics of inflation driven by multiple, interacting scalar\\u000afields and derive a multi field version of the Hubble slow roll expansion. We\\u000ashow that the properties of this expansion naturally generalize those of the\\u000asingle field case. We present an analogous hierarchy of slow roll parameters,\\u000aand derive the system of ``flow'' equations that describes their evolution,

  19. The Hubble time inferred from 10 time-delay lenses

    E-print Network

    P. Saha; J. Coles; A. V. Maccio'; L. L. R. Williams

    2006-07-12

    We present a simultaneous analysis of 10 galaxy lenses having time-delay measurements. For each lens we derive a detailed free-form mass map, with uncertainties, and with the additional requirement of a shared value of the Hubble parameter across all the lenses. We test the prior involved in the lens reconstruction against a galaxy-formation simulation. Assuming a concordance cosmology, we obtain 1/H_0 = 13.5 (+2.5/-1.3) Gyr

  20. Hubble Space Telescope EVA Power Ratchet Tool redesign

    Microsoft Academic Search

    Paul W. Richards; Chan Park; Lee Brown

    1993-01-01

    The Power Ratchet Tool (PRT) is a self contained, power-driven, 3\\/8 inch drive ratchet wrench which will be used by astronauts during Extravehicular Activities (EVA). This battery-powered tool is controlled by a dedicated electonic controller. The PRT was flown during the Hubble Space Telescope (HST) Deployment Mission STS-31 to deploy the solar arrays if the automatic mechanisms failed. The PRT

  1. Understanding the Optimal Redshift Range for the Supernovae Hubble Diagram

    E-print Network

    Eric V. Linder

    2001-08-16

    The supernovae Hubble diagram traces the expansion history of the universe, including the influence of dark energy. Its use to probe the cosmological model can fruitfully be guided by heuristic study of the features of the model curves. By relating these directly to the physics of the expansion we can understand simply the optimal redshift range for supernovae observations, requiring a survey depth of z=1.5-2 to distinguish evolution in dark energy properties.

  2. The Hubble Space Telescope nickel-hydrogen battery design

    NASA Technical Reports Server (NTRS)

    Nawrocki, D. E.; Armantrout, J. D.; Standlee, D. J.; Baker, R. C.; Lanier, J. R.

    1990-01-01

    Details are presented of the HST (Hubble Space Telescope) battery cell, battery package, and module mechanical and electrical designs. Also included are a summary of acceptance, qualification, and vibration tests and thermal vacuum testing. Unique details of battery cell charge retention performance characteristics associated with prelaunch hold conditions are discussed. Special charge control methods to minimize thermal dissipation during pad charging operations are summarized. This module design meets all NASA fracture control requirements for manned missions.

  3. Nickel-hydrogen battery testing for Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Baggett, Randy M.; Whitt, Thomas H.

    1989-01-01

    The authors identify objectives and provide data from several nickel-hydrogen battery tests designed to evaluate the possibility of launching Ni-H2 batteries on the Hubble Space Telescope (HST). Test results from a 14-cell battery, a 12-cell battery, and a 4-cell pack are presented. Results of a thermal vacuum test to verify the battery-module/bay heat rejection capacity are reported. A 6-battery system simulation breadboard is described, and test results are presented.

  4. Large-scale bulk motions complicate the Hubble diagram

    Microsoft Academic Search

    Asantha Cooray; Robert R. Caldwell

    2006-01-01

    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

  5. A Hubble Space Telescope Study of Extragalactic OB Associations

    NASA Astrophysics Data System (ADS)

    Bresolin, Fabio; Kennicutt, Robert C., Jr.; Ferrarese, Laura; Gibson, Brad K.; Graham, John A.; Macri, Lucas M.; Phelps, Randy L.; Rawson, Daya M.; Sakai, Shoko; Silbermann, N. A.; Stetson, Peter B.; Turner, Anne M.

    1998-07-01

    We present a study of OB associations, identified by objective means, in seven spiral galaxies observed with the Hubble Space Telescope as part of the Key Project on the distance scale. The properties of the associations, including their size distribution and average diameter, and the luminosity function of their brightest stars, do not vary significantly among galaxies, even for changes in Hubble type. These findings support previous suggestions about the existence of similarly sized elementary cells of star formation in galaxies, and the conclusion, obtained by others with more extensive data, that the upper stellar mass function does not vary significantly. The data suggest that the average number of stars in associations changes with morphological type, confirming previous studies of the integrated magnitudes of OB associations in H ii regions. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.

  6. Testing the Copernican principle with the Hubble parameter

    NASA Astrophysics Data System (ADS)

    Zhang, Zhi-Song; Zhang, Tong-Jie; Wang, Hao; Ma, Cong

    2015-03-01

    Using the longitudinal expression of Hubble expansion rate for the general Lemaître-Tolman-Bondi (LTB) metric as a function of cosmic time, we examine the scale on which the Copernican principle holds in the context of a void model. By way of performing parameter estimation on the constrained Garcia-Bellido-Haugbolle void model, we show that the Hubble parameter data favors a void with a characteristic radius of 2-3 Gpc. This brings the void model closer, but not yet enough, to harmony with observational indications given by the background kinetic Sunyaev-Zel'dovich effect and the normalization of near-infrared galaxy luminosity function. However, the test of such void models may ultimately lie in the future detection of the discrepancy between longitudinal and transverse expansion rates, a touchstone of inhomogeneous models. With the proliferation of observational Hubble parameter data and future large-scale structure observation, a definitive test could be performed on the question of cosmic homogeneity. Particularly, the spherical LTB void models have been ruled out, but more general nonspherical inhomogeneities still need to be tested by observation. In this paper, we utilize a spherical void model to provide guidelines into how observational tests may be done with more general models in the future.

  7. Optical System of Chinese First Antarctic Astronomical Telescope-CSTAR

    NASA Astrophysics Data System (ADS)

    Liu, G. R.; Yuan, X. Y.

    2009-04-01

    Chinese Small Telescope Array (CSTAR) , used for astronomical observation in Antarctic, was successfully mounted in the inland highest plateau- Dome A in Jan. 2008 by Chinese 24th research expedition team, which is the first Chinese Antarctic astronomical telescope. Just like what the astronomers predicted, Dome A is an excellent astronomical site. The clear images sent back by the CSTAR have further proved the possibility and advantages for doing astronomical research in Antarctic. This paper emphasizes on the part of the optical system of CSTAR, and the methods adopted to guarantee a high quality images under the ultra-low temperature in Dome A. The real observation results from Dome A are also given at the end of the paper.

  8. Relativistic description of astronomical objects in multiple reference systems

    NASA Astrophysics Data System (ADS)

    Xu, Chongming; Tang, Zhenghong

    2010-01-01

    Many astronomical systems require for their description in the frame of Einstein's theory of gravity not just one but several reference systems. In the first post-Newtonian approximation the Damour-Soffel-Xu (DSX) formalism presents a new and improved treatment of celestial mechanics and astronomical reference systems for the gravitational N-body problem. In the DSX-formalism the astronomical bodies are characterized by their Blanchet-Damour (BD) mass- and spin-multipole moments. However, the time dependence of these moments requires additional dynamical equations, usually local flow equations describing the internal motions inside the bodies or additional assumptions about them. In this article the internal motion of astronomical bodies will be adressed within the 1st post-Newtonian approximation to Einstein's theory of gravity. A concept of quasi-rigid bodies will be introduced; after that, astronomical fluid and elastic bodies will be discussed.

  9. Optical Metrology for the Filter Set for the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS)

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.; Boucarut, Rene A.; Content, David A.; Keski-Kuha, Ritva A.; Krebs, Carolyn A.; Miner, Linda A.; Norton, Todd A.; Mehalick, Kimberly; Petrone, Peter; Bush, Frank D.; Puc, Bernard; Standley, Clive; Tsvetanov, Zlatan; Kral, Catherine

    1998-01-01

    The Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) will employ a wide variety of spectral filtration components including narrow band, medium band, wide band, and far ultraviolet (FUV) long pass filters, spatially- variable filters (ramp filters), VIS/IR polarizers, NUV polarizers, FUV prisms, and a grism. These components are spread across ACS's Wide Field, High Resolution, and Solar Blind channels which provide diffraction-limited imaging of astronomical targets using aberration-correcting optics which remove most aberrations from HST's Optical Telescope Assembly (OTA). In order for ACS to be truly advanced, these filters must push the state-of-the-art in performance in a number of key areas at the same time. Important requirements which these filters must meet include outstanding transmitted wavefront, high transmittance, uniform transmittance across each filter, spectrally structure-free bandpasses, exceptionally high out of band rejection, and a high degree of parfocality. These constitute a very stringent set of requirements indeed, especially for filters which are up to 90 mm in diameter. The development of optical metrology stations used to demonstrate that each ACS filter will meet its design specifications is discussed. Of particular note are specially-designed spectral transmissometers and interferometers.

  10. Reprinted from the Astronomical Journal, vol 107, pages 10221040, 1994; copyrighted by the American Astronomical Society and used by permission.

    E-print Network

    Richmond, Michael W.

    to The Astronomical Journal 1 Presidential Young Investigator. 1 #12; ABSTRACT We present photometry of SN 1993J in MReprinted from the Astronomical Journal, vol 107, pages 1022­1040, 1994; copyrighted Electronic mail: richmond@astro.princeton.edu Richard R. Treffers, Alexei V. Filippenko 1 , and Young Paik

  11. Multicolor Observations of the Hubble Deep Field South

    NASA Astrophysics Data System (ADS)

    Vanzella, Eros; Cristiani, Stefano; Saracco, Paolo; Arnouts, Stephane; Bianchi, Simone; D'Odorico, Sandro; Fontana, Adriano; Giallongo, Emanuele; Grazian, Andrea

    2001-11-01

    We present a deep multicolor (U, B, V, I, Js, H, Ks) catalog of galaxies in the Hubble Deep Field South, based on observations obtained with the HST WFPC2 in 1998 and VLT-ISAAC in 1999. The photometric procedures were tuned to derive a catalog optimized for the estimation of photometric redshifts. In particular we adopted a ``conservative'' detection threshold, which resulted in a list of 1611 objects. The behavior of the observed source counts is in general agreement with the previous results of Casertano et al. in the Hubble Deep Field South and Williams et al. in the Hubble Deep Field North, while the corresponding counts in the Hubble Deep Field North provided by Fernández-Soto, Lanzetta, & Yahil are systematically lower by a factor 1.5 beyond IAB=26. After correcting for the incompleteness of the source counts, the object surface density at IAB<=27.5 is estimated to be 220 arcmin-2, in agreement with the corresponding measure of Volonteri et al. and providing an estimate of the extragalactic background light in the I band consistent with the work of Madau & Pozzetti. The comparison between the median V-I color in the Hubble Deep Field North and South shows a significant difference around IAB~26, possibly due to the presence of large-scale structure at z~1 in the HDF-N. High-redshift galaxy candidates (90 U dropouts and 17 B dropouts) were selected by means of color diagrams, down to a magnitude IAB=27, with a surface density of (21+/-1) and (3.9+/-0.9) arcmin-2, respectively. Eleven extremely red objects [with (I-K)AB>2.7] were selected down to KAB=24, plus three objects whose upper limit to the Ks flux is still compatible with the selection criterion. The corresponding surface density of EROs is (2.5+/-0.8) arcmin-2 [(3.2+/-0.9) arcmin-2 if we include the three Ks upper limits]. They show a remarkably nonuniform spatial distribution and are classified with roughly equal fractions in the categories of elliptical and starburst galaxies.

  12. Harvey Butcher: a passion for astronomical instrumentation

    NASA Astrophysics Data System (ADS)

    Bhathal, Ragbir

    2014-11-01

    This paper covers some aspects of the scientific life of Harvey Butcher who was the Director of the Research School for Astronomy and Astrophysics at the Australian National University in Canberra from September 2007 to January 2013. He has made significant contributions to research on the evolution of galaxies, nucleosynthesis, and on the design and implementation of advanced astronomical instrumentation including LOFAR (Low Frequency Array Radio telescope). He is well known for his discovery of the Butcher-Oemler effect. Before coming to Australia he was the Director of the Netherlands Foundation for Research in Astronomy from September 1991 to January 2007. In 2005 he was awarded a Knighthood in the Order of the Netherlands Lion for contributions to interdisciplinary science, innovation and public outreach.This paper is based on an interview conducted by the author with Harvey Butcher for the National Project on Significant Australian Astronomers sponsored by the National Library of Australia. Except otherwise stated, all quotations used in this paper are from the Butcher interview which has been deposited in the Oral History Archives of the National Library.

  13. Powerful Radio Burst Indicates New Astronomical Phenomenon

    NASA Astrophysics Data System (ADS)

    2007-09-01

    Astronomers studying archival data from an Australian radio telescope have discovered a powerful, short-lived burst of radio waves that they say indicates an entirely new type of astronomical phenomenon. Region of Strong Radio Burst Visible-light (negative greyscale) and radio (contours) image of Small Magellanic Cloud and area where burst originated. CREDIT: Lorimer et al., NRAO/AUI/NSF Click on image for high-resolution file ( 114 KB) "This burst appears to have originated from the distant Universe and may have been produced by an exotic event such as the collision of two neutron stars or the death throes of an evaporating black hole," said Duncan Lorimer, Assistant Professor of Physics at West Virginia University (WVU) and the National Radio Astronomy Observatory (NRAO). The research team led by Lorimer consists of Matthew Bailes of Swinburne University in Australia, Maura McLaughlin of WVU and NRAO, David Narkevic of WVU, and Fronefield Crawford of Franklin and Marshall College in Lancaster, Pennsylvania. The astronomers announced their findings in the September 27 issue of the online journal Science Express. The startling discovery came as WVU undergraduate student David Narkevic re-analyzed data from observations of the Small Magellanic Cloud made by the 210-foot Parkes radio telescope in Australia. The data came from a survey of the Magellanic Clouds that included 480 hours of observations. "This survey had sought to discover new pulsars, and the data already had been searched for the type of pulsating signals they produce," Lorimer said. "We re-examined the data, looking for bursts that, unlike the usual ones from pulsars, are not periodic," he added. The survey had covered the Magellanic Clouds, a pair of small galaxies in orbit around our own Milky Way Galaxy. Some 200,000 light-years from Earth, the Magellanic Clouds are prominent features in the Southern sky. Ironically, the new discovery is not part of these galaxies, but rather is much more distant. "It was a bit of luck that the survey included some observations of the sky surrounding the clouds," Narkevic said. It was from those "flanking" observations that the mysterious radio burst appeared in the data. The burst of radio waves was strong by astronomical standards, but lasted less than five milliseconds. The signal was spread out, with higher frequencies arriving at the telescope before the lower frequencies. This effect, called dispersion, is caused by the signal passing through ionized gas in interstellar and intergalactic space. The amount of this dispersion, the astronomers said, indicates that the signal likely originated about three billion light-years from Earth. No previously-detected cosmic radio burst has the same set of characteristics. "This burst represents an entirely new astronomical phenomenon," Bailes said. The astronomers estimate on the basis of their results that hundreds of similar events should occur over the sky each day. "Few radio surveys have the necessary sensitivity to such short-duration bursts, which makes them notoriously difficult to detect with current instruments," added Crawford. The next generation of radio telescopes currently under development should be able to detect many of these bursts across the sky. Although the nature of the mysterious new object is unclear, the astronomers have some ideas of what may cause such a burst. One idea is that it may be part of the energy released when a pair of superdense neutron stars collide and merge. Such an event is thought by some scientists to be the cause of one type of gamma-ray burst, but the only radio emission seen so far from these has been from the long-lived "afterglow" that follows the original burst. Another, more exotic, candidate is a burst of energy from an evaporating black hole. Black holes, concentrations of mass so dense that not even light can escape their powerful gravity, can lose mass and energy through a process proposed by famed British physicist Stephen Hawking. The newly-

  14. Database-Driven Analyses of Astronomical Spectra

    NASA Astrophysics Data System (ADS)

    Cami, Jan

    2012-03-01

    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

  15. The run & administration of the astronomical literature & information resources network of the Chinese Academy of Sciences.

    NASA Astrophysics Data System (ADS)

    Wang, Yanping

    1999-06-01

    The astronomical literature & information resources network fills in the gap in the astronomical database and resource sharing in Chinese astronomical circle. It is very important to excahnge astronomical information between China and other countries.. The designing idea, the secure administration, the resource constructing and access, the information exchange methods, etc. are described.

  16. Hubble studies generations of star formation in neighbouring galaxy

    NASA Astrophysics Data System (ADS)

    2004-07-01

    N11B Credits: NASA/ESA and the Hubble Heritage Team (AURA/STScI)/HEIC The iridescent tapestry of star birth The NASA/ESA Hubble Space Telescope captures the iridescent tapestry of star birth in a neighbouring galaxy in this panoramic view of glowing gas, dark dust clouds, and young, hot stars. The star-forming region, catalogued as N11B lies in the Large Magellanic Cloud (LMC), located only 160 000 light-years from Earth. With its high resolution, the Hubble Space Telescope is able to view details of star formation in the LMC as easily as ground-based telescopes are able to observe stellar formation within our own Milky Way galaxy. One neighbouring galaxy, the Large Magellanic Cloud (LMC), lies in the constellation of Dorado and contains a number of regions harbouring recent and ongoing star formation. One of these star-forming region, N11B, is shown in this Hubble image. It is a subregion within a larger area of star formation called N11. N11 is the second largest star-forming region in LMC. It is only surpassed in the size and activity by ‘the king of stellar nurseries’, 30 Doradus, located at the opposite side of LMC. N11B Credits: NASA/ESA and the Hubble Heritage Team (AURA/STScI)/HEIC A view of star formation The NASA/ESA Hubble Space Telescope captures the iridescent tapestry of star birth in a neighbouring galaxy in this panoramic view of glowing gas, dark dust clouds, and young, hot stars. The star-forming region, catalogued as N11B lies in the Large Magellanic Cloud (LMC), located only 160 000 light-years from Earth. With its high resolution, the Hubble Space Telescope is able to view details of star formation in the LMC as easily as ground-based telescopes are able to observe stellar formation within our own Milky Way galaxy. One neighbouring galaxy, the Large Magellanic Cloud (LMC), lies in the constellation of Dorado and contains a number of regions harbouring recent and ongoing star formation. One of these star-forming regions, N11B, is shown in this Hubble image. It is a subregion within a larger area of star formation called N11. N11 is the second largest star-forming region in LMC. It is only surpassed in the size and activity by ‘the king of stellar nurseries’, 30 Doradus, located at the opposite side of LMC. This image shows the full Wide Field Planetary Camera 2 frame. N11B Credits: NASA/ESA and Digitized Sky Survey 2 Ground-based view of N11B This is a ground-based view of the N11B in the Large Magellanic Cloud. The image spans a square of one degree and was constructed from two images from the Digitized Sky Survey 2 taken through infrared and red filters (shown as blue and red respectively). LMC Credits: Eckhard Slawik Ground-based view of the Large Magellanic Cloud This ground-based image of the Large Magellanic Cloud was taken by the German astrophotographer Eckhard Slawik. It spans 10 x 10 degrees. Just to the left of the middle of this image the largest star-forming region in the Local Group of galaxies, 30 Doradus, is seen as a red patch. N11B itself is seen in the upper right part of the LMC. The star-forming region, catalogued as N11B lies in the Large Magellanic Cloud (LMC), located only 160 000 light-years from Earth. With its high resolution, the Hubble Space Telescope is able to view details of star formation in the LMC as easily as ground-based telescopes are able to observe stellar formation within our own Milky Way galaxy. One neighbouring galaxy, the Large Magellanic Cloud (LMC), lies in the constellation of Dorado and contains a number of regions harbouring recent and ongoing star formation. One of these star-forming regions, N11B, is shown in this Hubble image. It is a subregion within a larger area of star formation called N11. N11 is the second largest star-forming region in LMC. It is only surpassed in the size and activity by ‘the king of stellar nurseries’, the Tarantula nebula (or 30 Doradus), located at the opposite side of LMC. The image illustrates a perfect example of so-called sequential star formation in a nearby galaxy - new starbirth triggered by old massive

  17. The Virtual Astronomical Observatory: Re-engineering Access to Astronomical Data

    E-print Network

    Hanisch, R J; Lazio, T J W; Bunn, S Emery; Evans, J; McGlynn, T A; Plante, R

    2015-01-01

    The U.S. Virtual Astronomical Observatory was a software infrastructure and development project designed both to begin the establishment of an operational Virtual Observatory (VO) and to provide the U.S. coordination with the international VO effort. The concept of the VO is to provide the means by which an astronomer is able to discover, access, and process data seamlessly, regardless of its physical location. This paper describes the origins of the VAO, including the predecessor efforts within the U.S. National Virtual Observatory, and summarizes its main accomplishments. These accomplishments include the development of both scripting toolkits that allow scientists to incorporate VO data directly into their reduction and analysis environments and high-level science applications for data discovery, integration, analysis, and catalog cross-comparison. Working with the international community, and based on the experience from the software development, the VAO was a major contributor to international standards ...

  18. The Case for a Hubble Constant of 30 km s-1 Mpc-1.

    PubMed

    Bartlett, J G; Blanchard, A; Silk, J; Turner, M S

    1995-02-17

    Although recent determinations of the distance to the Virgo cluster based on Cepheid variable stars represent an important step in pinning down the Hubble constant, after 65 years a definitive determination of the Hubble constant still eludes cosmologists. At present, most of the observational determinations place the Hubble constant between 40 and 90 kilometers per second per megaparsec (km s(-1) Mpc(-1)). The case is made here for a Hubble constant that is even smaller than the lower bound of the accepted range on the basis of the great advantages, all theoretical in nature, of a Hubble constant of around 30 kilometers per second per megaparsec. Such a value for the Hubble cures all of the ills of the current theoretical orthodoxy, that is, a spatially flat universe composed predominantly of cold dark matter. PMID:17811436

  19. Astronomical Dating of Edvard Munch's Summer Sky Paintings

    NASA Astrophysics Data System (ADS)

    Pope, Ava; Olson, Donald

    2010-02-01

    Norwegian painter Edvard Munch, most famous for The Scream, created many spectacular works depicting the skies of Norway. Our Texas State group used astronomical methods to analyze three of these paintings: Starry Night, The Storm, and Sunrise in Asgardstrand. Astronomical dating of these paintings has some importance because the precise days when Munch visited Asgardstrand are unknown. Our research group traveled to Norway in August 2008 to find the locations from which Munch painted these three works. We then used astronomical calculations, topographical analysis, historical photographs, and weather records to determine the precise dates and times for the scenes depicted in these paintings. )

  20. Astronomical Dating of Edvard Munch's Summer Sky Paintings

    NASA Astrophysics Data System (ADS)

    Pope, Ava; Olson, Donald

    2009-10-01

    Norwegian painter Edvard Munch, most famous for The Scream, created many spectacular works depicting the skies of Norway. Our Texas State group used astronomical methods to analyze three of these paintings: Starry Night, The Storm, and Sunrise in Asgardstrand. Astronomical dating of these paintings has some importance because the precise days when Munch visited Asgardstrand are unknown. Our research group traveled to Norway in August 2008 to find the locations from which Munch painted these three works. We then used astronomical calculations, topographical analysis, historical photographs, and weather records to determine the precise dates and times for the scenes depicted in these paintings.

  1. IYA2009 Asks a Better Astronomical Education in Europe

    NASA Astrophysics Data System (ADS)

    Stavinschi, Magda

    2007-08-01

    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.

  2. HUBBLE SPIES BROWN DWARFS IN NEARBY STELLAR NURSERY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Probing deep within a neighborhood stellar nursery, NASA's Hubble Space Telescope uncovered a swarm of newborn brown dwarfs. The orbiting observatory's near-infrared camera revealed about 50 of these objects throughout the Orion Nebula's Trapezium cluster [image at right], about 1,500 light-years from Earth. Appearing like glistening precious stones surrounding a setting of sparkling diamonds, more than 300 fledgling stars and brown dwarfs surround the brightest, most massive stars [center of picture] in Hubble's view of the Trapezium cluster's central region. All of the celestial objects in the Trapezium were born together in this hotbed of star formation. The cluster is named for the trapezoidal alignment of those central massive stars. Brown dwarfs are gaseous objects with masses so low that their cores never become hot enough to fuse hydrogen, the thermonuclear fuel stars like the Sun need to shine steadily. Instead, these gaseous objects fade and cool as they grow older. Brown dwarfs around the age of the Sun (5 billion years old) are very cool and dim, and therefore are difficult for telescopes to find. The brown dwarfs discovered in the Trapezium, however, are youngsters (1 million years old). So they're still hot and bright, and easier to see. This finding, along with observations from ground-based telescopes, is further evidence that brown dwarfs, once considered exotic objects, are nearly as abundant as stars. The image and results appear in the Sept. 20 issue of the Astrophysical Journal. The brown dwarfs are too dim to be seen in a visible-light image taken by the Hubble telescope's Wide Field and Planetary Camera 2 [picture at left]. This view also doesn't show the assemblage of infant stars seen in the near-infrared image. That's because the young stars are embedded in dense clouds of dust and gas. The Hubble telescope's near-infrared camera, the Near Infrared Camera and Multi-Object Spectrometer, penetrated those clouds to capture a view of those objects. The brown dwarfs are the faintest objects in the image. Surveying the cluster's central region, the Hubble telescope spied brown dwarfs with masses equaling 10 to 80 Jupiters. Researchers think there may be less massive brown dwarfs that are beyond the limits of Hubble's vision. The near-infrared image was taken Jan. 17, 1998. Two near-infrared filters were used to obtain information on the colors of the stars at two wavelengths (1.1 and 1.6 microns). The Trapezium picture is 1 light-year across. This composite image was made from a 'mosaic' of nine separate, but adjoining images. In this false-color image, blue corresponds to warmer, more massive stars, and red to cooler, less massive stars and brown dwarfs, and stars that are heavily obscured by dust. The visible-light data were taken in 1994 and 1995. Credits for near-infrared image: NASA; K.L. Luhman (Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.); and G. Schneider, E. Young, G. Rieke, A. Cotera, H. Chen, M. Rieke, R. Thompson (Steward Observatory, University of Arizona, Tucson, Ariz.) Credits for visible-light picture: NASA, C.R. O'Dell and S.K. Wong (Rice University)

  3. Die Gerling Sternwarte (Gerling Astronomical Observatory)

    E-print Network

    Schrimpf, Andreas

    2015-01-01

    Christian Ludwig Gerling's 1817 appointment as Professor for Mathematics, Physics and Astronomy resulted in the foundation of the Mathematical and Physical Institute of the Philipps University. In 1838, Gerling moved onto new premises in the main building of the former D\\"ornberger Hof in Renthof Street where the Philipps University's astronomical observatory was installed in the upper part of the old tower in 1841. The most important device at that time was a transit instrument which served to measure the transit times of stars in the meridian. Precise alignment required the use of a meridian stone, an artificial point of reference exactly north of and at about four kilometers' distance from the observatory. The scientists observed planets and their moons, the asteroids that were only discovered at the beginning of the 19th century, and some fainter stars in order to improve stellar charts. The Gerling Observatory is the first place in Hesse, where positions of asteroids were read.

  4. Data Mining and Discovery of Astronomical Knowledge

    NASA Astrophysics Data System (ADS)

    Al-Naymat, Ghazi

    Spatial data is essentially different from transactional data in its nature. The objects in a spatial database are distinguished by a spatial (location) and several non-spatial (aspatial) attributes. For example, an astronomy database that contains galaxy data may contain the x, y and z coordinates (spatial features) of each galaxy, their types and other attributes. Spatial datasets often describe geo-spatial or astro-spatial (astronomy related) data. In this work, we use a large astronomical dataset containing the location of different types of galaxies. Datasets of this nature provide opportunities and challenges for the use of data mining techniques to generate interesting patterns. One such pattern is the co-location pattern. A co-location pattern is a group of objects (such as galaxies) each of which is located in the neighborhood (within a given distance) of another object in the group.

  5. Applications of transputers to astronomical instruments

    NASA Astrophysics Data System (ADS)

    Stewart, J. M.; Beard, S. M.; Kelly, B. D.; Paterson, M. J.

    1990-04-01

    The application of parallel processing techniques based on transputers to astronomical instruments under development at the Royal Observatory Edinburgh is discussed. On the Cosmos plate-measuring machine, a data farm of transputers allows backgrounds to be determined in real time instead of requiring 1.5 h of offline VAX processing per plate. Transputers have been adopted as the embedded processors in a submm bolometer array instrument, and their use is planned in future applications such as thermal-IR array instruments and data compression applied to remote observing. The techniques of interfacing transputers to external hardware and to VAX/VMS computers are discussed. It is concluded that the use of transputers makes it possible to reconcile the requirements of performance, flexibility, and ease of use. The frequent existence of geometric parallelism allows easy exploitation of the power of parallel processing.

  6. The Astronomical Inscription from Keskintos, Rhodes

    NASA Astrophysics Data System (ADS)

    Jones, A.

    A Greek astronomical inscription from about 100 B.C. found near Lardos, Rhodes in the late 19th century contains a table of numbers associated with various kinds of periodic behaviour of the planets. The inscription might have accompanied a votive object, perhaps representing the heavenly bodies in some manner. The underlying conception of celestial phenomena is significantly different from the tradition propagated by Ptolemy's Almagest. A long common period is assumed in which all periodicities of all planets are supposed to repeat exactly. This period was constructed as a product of the smallest whole factors, 2, 3, and 5. The relationships subsisting among many of the numbers in the inscription also reflect an assumption that small whole numbers underly the apparent complexity of planetary motion.

  7. Intensity Scintillation and Astronomical Quantum Observation

    E-print Network

    Jiang Dong

    2009-11-02

    Holography is 3D imaging which can record intensity and phase at the same time. The importance of construct hologram is holographic recording and wavefront reconstruction. It is surprised that holography be discovered in study interstellar scintillation for pulsar provide a coherent light source recently. I think that is speckle hologram and speckle interference(i.e. intensity interference), and use modern technique which include phased array,CCD, digital signal processing and supercomputer can achieve that digital and computer holography from radio to X-ray astronomy. This means we can use it to image the universe and beyond the limited of telescope for cosmos provide much coherent light from pulsar,maser, black hole to 21cm recombination line. It gives a probe to the medium of near the black hole et al. From those coherent light sources in the sky, we can uncover one different universe that through astronomical quantum observation which use intensity interference.

  8. Astronomical and space-based systems engineering

    NASA Astrophysics Data System (ADS)

    Mosser, Benoît; Abergel, Alain

    2011-06-01

    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 in subsystems, equipment and engineering systems, and also for future project managers, working in the aerospace industry or similar technological industries or in national and European agencies. The 1-year course is given in collaboration with national and international institutions, laboratories and industries. It includes an extended training period (5 to 6 months) and a theoretical and practical specialization given by university and industrial teachers. It benefits from the network of laboratories associated with the Astronomy and Astrophysics doctorate school of the Île-de-France.

  9. IAU Commission 50 on Astronomical Site Protection

    NASA Astrophysics Data System (ADS)

    Walker, Constance E.; Green, R. F.

    2014-01-01

    Increasing world population and activity in remote areas are leading to encroachment of artificial noise background into the sky in both optical and radio wavelengths. IAU Commission 50 is working to engage astronomers in countries that host, support, or use ground-based observing facilities on the urgency of this issue through informational meetings, outreach, and provision of content for presentations. We encourage and endorse local initiatives and represent the IAU on site protection issues to agencies like URSI and UNESCO. IAU C50 also engages with the lighting industry through their professional societies, CIE and IESNA. The presentation gives examples of recent activity and links to material valuable for protection of US sites.

  10. Astronomical Observations of Volatiles on Asteroids

    E-print Network

    Rivkin, Andrew S; Emery, Joshua P; Howell, Ellen S; Licandro, Javier; Takir, Driss; Vilas, Faith

    2015-01-01

    We have long known that water and hydroxyl are important components in meteorites and asteroids. However, in the time since the publication of Asteroids III, evolution of astronomical instrumentation, laboratory capabilities, and theoretical models have led to great advances in our understanding of H2O/OH on small bodies, and spacecraft observations of the Moon and Vesta have important implications for our interpretations of the asteroidal population. We begin this chapter with the importance of water/OH in asteroids, after which we will discuss their spectral features throughout the visible and near-infrared. We continue with an overview of the findings in meteorites and asteroids, closing with a discussion of future opportunities, the results from which we can anticipate finding in Asteroids V. Because this topic is of broad importance to asteroids, we also point to relevant in-depth discussions elsewhere in this volume.

  11. Leslie Peltier, Amateur Astronomer and Observer Extraordinaire

    NASA Astrophysics Data System (ADS)

    Corbin, B. G.

    2003-12-01

    Leslie Copus Peltier, (Jan. 2, 1900-May 10, 1980) was called "the world's greatest non-professional astronomer" by none other than Harlow Shapley, and also referred to as the "the world's greatest living amateur astronomer". He began observing variable stars on March 1, 1918 with an observation of R. Leonis and at the time of his death had made a total of 132,123 observations of variable stars. These were reported to the AAVSO on a consecutive monthly basis stretching from 1918 to his death in 1980. As of October 2003, he was still on AAVSO's list of the top 25 observers in its history. Born on a farm near Delphos, Ohio, his parents were well read and their home was filled with books on different subjects, including nature guides. As a young man he studied the flora and fauna of the area and in 1915 began his study of the heavens with Vega being the first star he identified. After the purchase of a 2-inch spyglass, his observations of variable stars began to be noticed by professional astronomers and the AAVSO loaned him a 4-inch Mogey refractor; shortly thereafter Henry Norris Russell of Princeton loaned him via the AAVSO a 6-inch refractor, a comet seeker of short focus. He discovered 12 comets, 10 of which carry his name, and 6 novae or recurring novae. His design of the "Merry-Go-Round Observatory" was a novel approach with the whole observatory revolving around the observer while seated in his observing chair. Miami University (Ohio) later donated to him their 12-inch Clark refractor with its dome. His first book, Starlight Nights: The Adventures of a Star-Gazer, appeared in 1965. This autobiography, an ode to the joys of observing both the night sky and nature, was written in beautifully descriptive language that helped lead countless readers into astronomy. Departing from astronomy, in 1977 he published The Place on Jennings Creek. Written in the style of the 19th century naturalist, the book was devoted to his family's home, Brookhaven, and its natural surroundings. Peltier was a shy person who rarely left Delphos, and worked as a designer of children's furniture and toys until his death. However, he was widely recognized during his lifetime with articles about him appearing in popular magazines such as Reader's Digest and Newsweek. Many famous astronomers visited him at Delphos including W.W. Morgan, W.A. Hiltner, Donald Menzel, the Boks, and others. He received many honors including an honorary Doctor of Science degree from Bowling Green State University (Ohio) and the AAVSO's first Merit Award in 1934. Starlight Nights returned to print in 1999 with a foreword by David Levy, and is now introducing a new generation to the beauty and thrill of observing.

  12. The astronomical revolution. Copernicus - Kepler - Borelli.

    NASA Astrophysics Data System (ADS)

    Koyré, A.

    The work was originally published in 1961 under the title "La révolution astronomique" as part of the series, Histoire de la pensée. This book is an unabridged and unaltered republication of the English translation, by R. E. W. Maddison, originally published in 1973 (see 10.003.074). The author elucidates, precisely and in stages, the revolutionary ideas of Nicolaus Copernicus as well as the work of two other thinkers who made major contributions to the astronomical revolution: Johannes Kepler and Giovanni Borelli. He illuminates the exact contribution of each man, placing his work in its historical context and dispelling a host of misconceptions about it. In order to effectively recapture the ferment and flavor of the times, the author, whenever possible, has allowed Copernicus, Kepler and Borelli to speak for themselves by quoting key passages from their writings. Many of these passages were here translated for the first time.

  13. The Hubble Slow Roll Expansion for Multi Field Inflation

    E-print Network

    Richard Easther; John T Giblin Jr

    2005-08-05

    We examine the dynamics of inflation driven by multiple, interacting scalar fields and derive a multi field version of the Hubble slow roll expansion. We show that the properties of this expansion naturally generalize those of the single field case. We present an analogous hierarchy of slow roll parameters, and derive the system of ``flow'' equations that describes their evolution, and show that when this system is truncated at finite order, it can always be solved exactly. Lastly, we express the scalar and tensor perturbation spectra in terms of the slow roll parameters.

  14. Star Formation in Tadpole Galaxies in the Hubble UDF

    NASA Astrophysics Data System (ADS)

    Elmegreen, Debra M.; Elmegreen, B. G.

    2010-01-01

    Tadpoles are starbursting galaxies that each have a massive star-forming clump near an end, and a long tail that sometimes contains smaller clumps. We identify over 100 tadpoles in the Hubble Ultra Deep Field out to redshift z=4. Photometric measurements of the clumps and tails in ACS BVIz filters are fit to Bruzual-Charlot evolutionary models including extinction, intergalactic absorption, and exponential decay times in order to derive ages, masses, and surface densities. These are compared to clump and interclump regions in clump cluster and chain galaxies in order to understand whether they are all part of the same evolutionary sequence toward modern spirals.

  15. HST battery test expert systems. [Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Johnson, Yvette B.; Baggett, Randy M.

    1989-01-01

    During the testing of nickel-cadmium and nickel-hydrogen batteries for the Hubble Space Telescope, an urgent need for data management was recognized. Testing of these batteries generates much needed data that is used for vital decision making, such as when to recondition, change the charging scheme, or adjust the workload of the batteries. To solve this problem, an expert system called NICBES was developed. NICBES can recognize a testbed anomaly, identify the malfunctioning component, recommend a course of action, evaluate battery status, and provide decision support. A description of NICBES and some of its enhancements are given.

  16. Hubble Space Telescope NiH2 six battery test

    NASA Technical Reports Server (NTRS)

    Whitt, Thomas H.; Lanier, J. Roy

    1991-01-01

    The primary objectives of the test are: (1) to get a better understanding of the operating characteristics of the NiH2 batteries in the Hubble Space Telescope (HST) Electric Power Subsystem (EPS) by simulating every aspect of the expected operating environment; (2) to determine the optimum charge level and charge scheme for the NiH2 batteries in the HST EPS; (3) to predict the performance of the actual HST EPS; (4) to observe the aging characteristics of the batteries; and (5) to test different EPS anomalies before experiencing the anomalies on the actual HST.

  17. Hubble space telescope six-battery test bed

    NASA Technical Reports Server (NTRS)

    Pajak, J. A.; Bush, J. R., Jr.; Lanier, J. R., Jr.

    1990-01-01

    A test bed for a large space power system breadboard for the Hubble Space Telescope (HST) was designed and built to test the system under simulated orbital conditions. A discussion of the data acquisition and control subsystems designed to provide for continuous 24 hr per day operation and a general overview of the test bed is presented. The data acquisition and control subsystems provided the necessary monitoring and protection to assure safe shutdown with protection of test articles in case of loss of power or equipment failure over the life of the test (up to 5 years).

  18. HUBBLE SPIES HUGE CLUSTERS OF STARS FORMED BY ANCIENT ENCOUNTER

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's Hubble Space Telescope snapped these two views of the heart of the galaxy M82. The image at left was taken in visible light; the picture at right, in infrared light. In the infrared view, the telescope's Near Infrared Camera and Multi-Object Spectrometer peered through thick dust lanes to find some of the galaxy's more than 100 super star clusters. The clusters are the larger pink and yellow dots scattered throughout the picture. They were formed during a violent collision with the galaxy M81 about 600 million years ago. The galaxy is 12 million light-years from Earth in the constellation Ursa Major. The pictures were taken Sept. 15, 1997. Credits: NASA, ESA, R. de Grijs (Institute of Astronomy, Cambridge, UK) NOTE TO EDITORS: For additional information, please contact Richard de Grijs, Institute of Astronomy, Cambridge University, Madingley Road, Cambridge CB3 0HA, UK, +44(0)1223-337528 (phone), +44(0)1223-337523 (fax), grijs@ast.cam.ac.uk (e-mail). The Space Telescope Science Institute (STScI) is operated by the Association of Universities for Research in Astronomy, Inc. (AURA), for NASA, under contract with the Goddard Space Flight Center, Greenbelt, MD. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency (ESA). This image is issued jointly by NASA and ESA. Electronic images, animation and additional information are available at: http://oposite.stsci.edu/pubinfo/pr/2001/08 and via links in http://oposite.stsci.edu/pubinfo/latest.html http://oposite.stsci.edu/pubinfo/pictures.html http://hubble.stsci.edu/go/news http://hubble.esa.int To receive STScI press releases electronically, send an Internet electronic mail message to public-request@stsci.edu. Leave the subject line blank, and type the word subscribe in the body of the message. The system will respond with a confirmation of the subscription, and you will receive new press releases as they are issued. Please subscribe using the email account with which you would like to receive list messages. To unsubscribe, send mail to public-request@stsci.edu. Leave the subject line blank, and type the word unsubscribe in the body of the message. Please unsubscribe using the email account that you used to subscribe to the list.

  19. Felinic principle and measurement of the Hubble parameter

    E-print Network

    Piškur, Yodovina

    2013-01-01

    Intelligent life can only appear in Universes, whose physical laws support sufficient complexity to make evolution of intelligent beings possible. Even inside those Universes, intelligent life does not appear randomly, but in parts with realized complexity, e.g. around stars in our Universe. As a consequence, the observational point of an intelligent observer cannot be assumed to be random and one must correct for this selection effect. In this paper we calculate how direct measurements of the Hubble parameter are affected when subject to the condition that they are observed from a Milky Way-like galaxy.

  20. HUBBLE PROVIDES THE FIRST IMAGES OF SATURN'S AURORA (Top)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This is the first image ever taken of bright aurorae at Saturn's northern and southern poles, as seen in far ultraviolet light by the Wide Field and Planetary Camera 2 aboard NASA's Hubble Space Telescope. Hubble resolves a luminous, circular band centered on the north pole, where an enormous auroral curtain rises as far as 1,200 miles (2,000 kilometers) above the cloudtops. This curtain changed rapidly in brightness and extent over the two hour period of our HST observations, though the brightest emissions remained at a position fixed in sun angle, near 'dawn' in the north auroral band. The image was taken on October 9, 1994, when Saturn was at a distance of 831 million miles (1.3 billion kilometers) from Earth. The aurora is produced as trapped charged particles precipitating from the magnetosphere collide with atmospheric gases -- molecular and atomic hydrogen in Saturn's case. As a result of the bombardment, Saturn's gases glow at far-ultraviolet wavelengths (110-160 nanometers) which are absorbed by the Earth's atmosphere, and so can only be observed from space-based telescopes. Saturn's magnetic field is nearly perfectly aligned with the planet's rotation, giving the auroral 'ring' its symmetry centered on the pole. (The southern aurora is faintly visible in this view despite the fact that Saturn's northern pole is now tilted slightly toward Earth.) The Hubble images demonstrate our capability to record from the Earth the auroral brightness and distribution about Saturn's poles, which will ultimately complement the in situ measurements of Saturn's magnetic field and charged particles to be made by the NASA/ESA Cassini spacecraft near the turn of the century. Study of the aurora on Saturn had its beginnings a few decades ago. The Pioneer 11 probe observed a far-ultraviolet brightening on Saturn's poles in 1979. Beginning in 1980, a series of spectroscopic observations by the International Ultraviolet Explorer (IUE) have sporadically detected emissions from Saturn's auroral zones. The Saturn flybys of the Voyager 1 and 2 spacecraft, in the early 1980s, found auroral emissions confined to a circumpolar ring. (Bottom) - For comparison, this is a visible-light color composite image of Saturn as seen by Hubble on December 1, 1994. Unlike the ultraviolet image, Saturn's familiar atmospheric belts and zones are clearly seen. The lower cloud deck is not visible at UV wavelengths because sunlight is reflected from higher in the atmosphere. Credits: J.T. Trauger (JPL), J.T. Clarke (Univ. of Michigan), the WFPC2 science team, and NASA Image files in GIF and JPEG format may be accessed on Internet via anonymous ftp from oposite.stsci.edu in /pubinfo.

  1. US Gateway to SIMBAD Astronomical Database

    NASA Technical Reports Server (NTRS)

    Eichhorn, G.; Oliversen, R. (Technical Monitor)

    1999-01-01

    During the last year the US SIMBAD Gateway Project continued to provide services like user registration to the US users of the SIMBAD database in France. Currently there are over 3400 US users registered. We also provide user support by answering questions from users and handling requests for lost passwords when still necessary. We have implemented in cooperation with the CDS SIMBAD project access to the SIMBAD database for US users on an Internet address basis. This allows most US users to access SIMBAD without having to enter passwords. We have maintained the mirror copy of the SIMBAD database on a server at SAO. This has allowed much faster access for the US users. We also supported a demonstration of the SIMBAD database at the meeting of the American Astronomical Society in January. We shipped computer equipment to the meeting and provided support for the demonstration activities at the SIMBAD booth. We continued to improve the cross-linking between the SIMBAD project and the Astrophysics Data System. This cross-linking between these systems is very much appreciated by the users of both the SIMBAD database and the ADS Abstract Service. The mirror of the SIMBAD database at SAO makes this connection faster for the US astronomers. We exchange information between the ADS and SIMBAD on a daily basis. The close cooperation between the CDS in Strasbourg and SAO, facilitated by this project, is an important part of the astronomy-wide digital library initiative called Urania. It has proven to be a model in how different data centers can collaborate and enhance the value of their products by linking with other data centers.

  2. Hubble Space Telescope observations of Orion Nebula, Helix Nebula, and NGC 6822

    NASA Technical Reports Server (NTRS)

    Spitzer, Lyman; Fitzpatrick, Ed

    1999-01-01

    This grant covered the major part of the work of the Principal Investigator and his collaborators as a Guaranteed Time Observer on the Hubble Space Telescope. The work done naturally divided itself into two portions the first being study of nebular objects and the second investigation of the interstellar medium between stars. The latter investigation was pursued through a contract with Princeton University, with Professor Lyman Spitzer as the supervising astronomer, assisted by Dr. Ed Fitzpatrick. Following the abrupt death of Professor Spitzer, his responsibilities were shifted to Dr. Fitzpatrick. When Dr. Fitzpatrick relocated to Villanova University the concluding work on that portion of this grant was concluded under a direct service arrangement. This program has been highly successful and the resulting publications in scientific journals are listed below. To the scientist, this is the bottom line, so that I shall simply try to describe the general nature of what was accomplished. There were three nebular programs conducted, one on the Orion Nebula, the second on the Helix Nebula, and the third on NGC 6822. The largest program was that on the Orion Nebula. This involved both HST observations and supporting groundbased observations obtained with a variety of instruments, including the Coude Feed Telescope at the Kitt Peak National observatory in Arizona, the Cerro Tololo observatory in Chile, and the Keck Observatory on Mauna Kea, Hawaii. Moreover, considerable theoretical modeling was done and all of the data analysis was performed at the Rice University in Houston, except for the PI's period of sabbatical leave (6-96 through 7-97) when he was based at the Max Planck Institute for Astronomy in Heidelberg, Germany. The Orion Nebula program was the most productive part, resulting in numerous papers, but more important in the discovery of a new class of objects, for which we coined the name "proplyds". The proplyds are protoplanetary disks surrounding very young stars still in the process of creation. The Orion Nebula is the residual material from a burst of star formation that occurred about 300,000 years ago. Each of these new stars has a surrounding disk of protoplanetary material. The same physics that renders the Nebula so highly visible means that the proto-planetary disks are also quite visible. With the wisdom of hindsight, we now see that this was to be expected and that we should have been searching specifically for this type of object. The discovery of these objects and their subsequent detailed investigation has lead to an accurate assessment of the frequency of protoplanetary disks in young stars and determination of the likelihood of survival of these disks into an era where planets actually form.

  3. Architecture and performance of astronomical adaptive optics systems

    NASA Technical Reports Server (NTRS)

    Bloemhof, E.

    2002-01-01

    In recent years the technological advances of adaptive optics have enabled a great deal of innovative science. In this lecture I review the system-level design of modern astronomical AO instruments, and discuss their current capabilities.

  4. Book Review: Astronomical Society of the Pacific, Leaflets, Vol. III

    Microsoft Academic Search

    W. A. Calder

    1943-01-01

    General notes on the following topics: Dr. E. C. Slipher; Dr. Frederick C. Leonard; Texas Observers' Bulletin; An Unprofitable Visit; Copernican Quadricentennial Observed by The Joliet Astronomical Society; Third Nation-wide Science Talent Search

  5. I. INTRODUCTION This report covers astronomical activities primarily

    E-print Network

    Gruner, Daniel S.

    . G. Wentzel, and A. S. Wilson; Emeritus Professors W. C. Erickson and F. J. Kerr; Adjunct Professors Society. D. Wentzel organized the IAU International Schools for Young Astronomers meetings in India (Jan

  6. The Persian-Toledan Astronomical Connection and the European Renaissance

    E-print Network

    Heydari-Malayeri, M

    2007-01-01

    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 that period. After a brief introduction dealing mainly with a couple of terminological remarks, I will present a glimpse of the historical context in which Muslim science developed. In Section 3, the origins of Muslim astronomy will be briefly examined. Section 4 will be concerned with Khwarizmi, the Persian astronomer/mathematician who wrote the first major astronomical work in the Muslim world. His influence on later Andalusian astronomy will be looked into in Section 5. Andalusian astronomy flourished in the 11th century, as will be studied in Section 6. Among its major achievements were the Toledan Tab...

  7. Hosting an `Ask the Astronomer' Site on the Internet

    NASA Astrophysics Data System (ADS)

    Odenwald, S. F.

    1996-12-01

    Since 1995, the World Wide Web has explosively evolved into a significant medium for dispensing astronomical information to the general public. In addition to the numerous image archives that have proliferated, an increasing number of sites invite visitors to pose questions about astronomy and receive answers provided by professional astronomers. In this paper, I describe the operation of an Ask the Astronomer site that was opened on the WWW during August, 1995 as part of an astronomy education resource area called the "Astronomy Cafe" (URL=http://www2.ari.net/home/odenwald/cafe.html). The Astronomy Cafe includes a number of documents describing: a career in astronomy; how research papers are written; essays about cosmology, hyperspace and infrared astronomy; and the results from a 100-question, just for fun, personality test which distinguishes astronomers from non-astronomers. The Ask the Astronomer site is operated by a single astronomer through private donations and is now approaching its 500th day of operation. It contains over 2000+ questions and answers with a growth rate of 5 - 10 questions per day. It has attracted 70,000 visitors who are responsible for nearly 1 million 'hits' during the site's lifetime. The monthly statistics provide a unique survey of the kinds of individuals and organizations who visit Ask the Astronomer-type web sites, moreover, the accumulated questions provide a diagnostic X-ray into the public mind in the area of astronomy. I will present an analysis of the user demographics, and the types of questions that appear to be the most frequently asked. A paper copy of the complete index of these questions will be available for inspection.

  8. Astronomical guidance for directed searches for continuous gravitational waves

    NASA Astrophysics Data System (ADS)

    Owen, Benjamin

    2014-01-01

    The LIGO Scientic Collaboration and Virgo Collaboration have published a search for continuous gravitational-waves from the non-pulsing neutron star in supernova remnant Cas A and, more recently, from the galactic center. More such searches, where the direction is known but no pulsar timing is available, are under way. I describe the astronomical criteria for good targets for such gravitational-wave searches, list classes of astronomical objects, and give examples of each class.

  9. Real-time earthquake warning for astronomical observatories

    NASA Astrophysics Data System (ADS)

    Coughlin, Michael; Stubbs, Christopher; Barrientos, Sergio; Claver, Chuck; Harms, Jan; Chris Smith, R.; Warner, Michael

    2015-06-01

    Early earthquake warning is a rapidly developing capability that has significant ramifications for many fields, including astronomical observatories. In this work, we describe the susceptibility of astronomical facilities to seismic events, including large telescopes as well as second-generation ground-based gravitational-wave interferometers. We describe the potential warning times for observatories from current seismic networks and propose locations for future seismometers to maximize warning times.

  10. ARNICA, the Arcetri near-infrared camera: Astronomical performance assessment.

    NASA Astrophysics Data System (ADS)

    Hunt, L. K.; Lisi, F.; Testi, L.; Baffa, C.; Borelli, S.; Maiolino, R.; Moriondo, G.; Stanga, R. M.

    1996-01-01

    The Arcetri near-infrared camera ARNICA was built as a users' instrument for the Infrared Telescope at Gornergrat (TIRGO), and is based on a 256x256 NICMOS 3 detector. In this paper, we discuss ARNICA's optical and astronomical performance at the TIRGO and at the William Herschel Telescope on La Palma. Optical performance is evaluated in terms of plate scale, distortion, point spread function, and ghosting. Astronomical performance is characterized by camera efficiency, sensitivity, and spatial uniformity of the photometry.

  11. Panchromatic Hubble Andromeda Treasury Survey: Resolved Stellar Photometry

    NASA Astrophysics Data System (ADS)

    Williams, Benjamin F.; Dalcanton, J. J.; Dolphin, A. E.; Lang, D.; Weisz, D.; Seth, A. C.; Kalirai, J.; Lauer, T.; Rosema, K.

    2012-01-01

    The PHAT survey is collecting photometric data with 3 cameras aboard the Hubble Space Telescope covering about one quarter of the M31 inner disk and bulge. The observing strategy allows coverage of the full survey area in 6 broad bands from the Near-UV to the Near-IR. Initial survey photometry has been performed on the data from each camera separately, then the resulting catalogs have been matched to improve astrometry and provide our first 6-band catalogs. We provide a summary of our crowding-optimized point spread function measuring technique. We present color-magnitude diagrams showing our data quality in each camera for areas of varying surface brightness in M31, and we present color-color diagrams to show the quality of our current ability to match stars across all 6 bands. These data are samples of the survey's first public data release to the Hubble data archive. Finally we present preliminary results from simultaneous photometry across all 6 bands where matching is done at the pixel level, eliminating the need for catalog matching. This new ability provides optimal depth in overlapping fields and more reliable matching of all 6 bands. Future survey data releases will include such optimized 6-band photometry. PHAT is supported by HST GO-12055 administered by NASA.

  12. UV Clumpy Galaxies in the Hubble Ultra Deep Field

    NASA Astrophysics Data System (ADS)

    Soto, Emmaris; De Mello, D. F.; Bond, N. A.; Straughn, A.; Gardner, J. P.; Teplitz, H. I.

    2013-01-01

    We present an investigation of the ultraviolet morphologies of galaxies in the Hubble Ultra Deep Field in the rest-frame UV. We performed an analysis of individual star-forming clumps in 18 galaxies at 0.62Hubble Space Telescope WFC3 UVIS camera. A gallery of images in the optical and near infrared wavelengths was compiled using the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) data. We measured sizes of the clumps using the angular diameters of contour levels which were between 5 to 12 sigma above the background in the F275W band. The contours reveal a larger number of detected clumps in comparison to previous results from WFPC2 F300W using similar method (Voyer et al. 2012). We find that clumps are two times smaller than the previous results ranging from 0.8 to 1.2 kpc. Our results show that the increased spatial resolution of WFC3/UVIS images is well suited for the analysis of clumps that are indicative of star forming regions.

  13. The Hubble Space Telescope Education and Public Outreach Program

    NASA Astrophysics Data System (ADS)

    Teays, T. J.; Eisenhamer, B.; Eisenhamer, J.; Amazing Space Team

    2001-05-01

    The Hubble Space Telescope has conducted a long-standing and vigorous program in education and public outreach. This program uses a variety of methods to reach a broad spectrum of audiences. Education products are developed in a team environment that partners educators, curriculum experts, scientists, and production experts, such as graphic artists, Web designers, programmers, and education evaluators. A popular Web site is maintained, and has been substantially augmented in the past year. The Amazing Space program consists of a suite of online, interactive modules for use in the kindergarten through 12th grade classroom. The program is rooted in the national education standards and benefits from a robust evaluation process. The HST images and data are used to engage students in learning basic science and mathematics concepts. The activity/lessons include extensive, online assistance for educators, so that they can be readily used in the classroom. Hardcopy products such as posters, lithographs, teacher guides, and trading cards are generally tied to online products, to provide multiple entries to the material. We also provide training for teachers in the use of our products, as appropriate. Informal science education is supported by providing services to museums, planetariums, libraries and related institutions. The very popular ViewSpace, a computer-based video service is being used by many informal science facilities. In addition, HST has supported the creation of both permanent and traveling exhibits about HST. The Space Telescope Science Institute operates the Hubble Space Telescope for NASA.

  14. Star formation rates, galaxy morphology, and the Hubble sequence

    NASA Astrophysics Data System (ADS)

    Sandage, A.

    1986-06-01

    The fraction of the mass ever made into stars that is forever locked-up in those stars is calculated. The shape of the integrated birth rate (IBR) and the integrated lock-up rate (ILUR) functions as the termination mass at the faint end of the initial mass function (IMF) is varied is discussed. The observed IBR and the derived ILUR for the LMC, SMC, and Sextans A galaxies are listed. The time to consume the remaining gas in LMC, SMC, and Sextans A, and the factor by which this time can be increased if bimodal star formation exists for various faint termination masses, MT, of the IMF is given. An empirical calibration of the Scoville and Young (1983) method of obtaining the IBR (and from it, the ILUR) using the total luminosity of the young stars is given. Application of these calculations to the Virgo cluster Sm/Im dwarfs is presented. The gas consumption times for bimodal star formation with Mi(limit) = 2 M_sun; are set out. Finally, the evolution of the Hubble sequence with time for various Hubble types is discussed in terms of the time variation of the star formation rate.

  15. More evidence for an oscillation superimposed on the Hubble flow

    NASA Astrophysics Data System (ADS)

    Bell, M. B.; Comeau, S. P.

    2014-01-01

    In a recent investigation evidence was presented for a low-level sinusoidal oscillation superimposed on top of the Hubble flow. This oscillation was in V CMB , in a sample of type Ia Supernovae sources with accurate distances, and it was found to have a wavelength close to 40 Mpc. It became easily visible after the removal of several previously identified discrete velocity components. Its amplitude like that of the Hubble velocity showed an increase with distance, as would be expected for a constant-amplitude space oscillation. Here we report that this oscillation is also present in distance clumping in these sources, with the same wavelength, but in phase quadrature. The discrete velocity components do not play a role in detecting the distance clumping wavelength. Assuming that time proceeds from high cosmological redshift to low, the blue-shifted velocity peaks, which represent the contraction stage of the velocity oscillation, then lead the density peaks. With the discrete velocity components removed we also find evidence for at least one other, weaker velocity oscillation. It is found to have a wavelength similar to one reported in density clumping by previous investigators. In those cases the source samples were much larger.

  16. Cosmic Variance and the Measurement of the Local Hubble Parameter

    NASA Astrophysics Data System (ADS)

    Marra, Valerio; Amendola, Luca; Sawicki, Ignacy; Valkenburg, Wessel

    2013-06-01

    There is an approximately 9% discrepancy, corresponding to 2.4?, between two independent constraints on the expansion rate of the Universe: one indirectly arising from the cosmic microwave background and baryon acoustic oscillations and one more directly obtained from local measurements of the relation between redshifts and distances to sources. We argue that by taking into account the local gravitational potential at the position of the observer this tension—strengthened by the recent Planck results—is partially relieved and the concordance of the Standard Model of cosmology increased. We estimate that measurements of the local Hubble constant are subject to a cosmic variance of about 2.4% (limiting the local sample to redshifts z>0.010) or 1.3% (limiting it to z>0.023), a more significant correction than that taken into account already. Nonetheless, we show that one would need a very rare fluctuation to fully explain the offset in the Hubble rates. If this tension is further strengthened, a cosmology beyond the Standard Model may prove necessary.

  17. HUBBLE HERITAGE PROJECT'S FIRST ANNIVERSARY(NGC 2261)

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NGC 2346, in contrast to the first two young objects, is a so-called 'planetary nebula,' which is ejected from Sun-like stars which are near the ends of their lives. NGC 2346 is remarkable because its central star is known to be actually a very close pair of stars, orbiting each other every 16 days. It is believed that the binary star was originally more widely separated. However, when one component of the binary evolved, expanded in size, and became a red-giant star, it literally swallowed its companion star. The companion star then spiralled downwards inside the red giant, and in the process spewed out gas into a ring around the binary system. Later on, when the hot core of the red giant was exposed, it developed a faster stellar wind, which emerged perpendicularly to the ring and inflated two huge 'bubbles.' This two-stage process is believed to have resulted in the butterfly-like shape of the nebula. NGC 2346 lies about 2,000 light-years away from us, and is about one-third of a light-year in size. The Hubble Heritage team made this image from observations of NGC 2346 acquired by Massimo Stiavelli (STScI), Inge Heyer (STScI), and collaborators. Image Credit: NASA/The Hubble Heritage Team (AURA/STScI).

  18. The Persian-Toledan Astronomical Connection and the European Renaissance

    E-print Network

    M. Heydari-Malayeri

    2007-09-08

    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 that period. After a brief introduction dealing mainly with a couple of terminological remarks, I will present a glimpse of the historical context in which Muslim science developed. In Section 3, the origins of Muslim astronomy will be briefly examined. Section 4 will be concerned with Khwarizmi, the Persian astronomer/mathematician who wrote the first major astronomical work in the Muslim world. His influence on later Andalusian astronomy will be looked into in Section 5. Andalusian astronomy flourished in the 11th century, as will be studied in Section 6. Among its major achievements were the Toledan Tables and the Alfonsine Tables, which will be presented in Section 7. The Tables had a major position in European astronomy until the advent of Copernicus in the 16th century. Since Ptolemy's models were not satisfactory, Muslim astronomers tried to improve them, as we will see in Section 8. This Section also shows how Andalusian astronomers took part in this effort, which was necessary in the path to the Scientific Revolution. Finally, Section 9 presents the Spanish influence on the eve of the Renaissance.

  19. "Movie Star" Acting Strangely, Radio Astronomers Find

    NASA Astrophysics Data System (ADS)

    1999-01-01

    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

  20. The Virtual Astronomical Observatory: Re-engineering access to astronomical data

    NASA Astrophysics Data System (ADS)

    Hanisch, R. J.; Berriman, G. B.; Lazio, T. J. W.; Emery Bunn, S.; Evans, J.; McGlynn, T. A.; Plante, R.

    2015-06-01

    The US Virtual Astronomical Observatory was a software infrastructure and development project designed both to begin the establishment of an operational Virtual Observatory (VO) and to provide the US coordination with the international VO effort. The concept of the VO is to provide the means by which an astronomer is able to discover, access, and process data seamlessly, regardless of its physical location. This paper describes the origins of the VAO, including the predecessor efforts within the US National Virtual Observatory, and summarizes its main accomplishments. These accomplishments include the development of both scripting toolkits that allow scientists to incorporate VO data directly into their reduction and analysis environments and high-level science applications for data discovery, integration, analysis, and catalog cross-comparison. Working with the international community, and based on the experience from the software development, the VAO was a major contributor to international standards within the International Virtual Observatory Alliance. The VAO also demonstrated how an operational virtual observatory could be deployed, providing a robust operational environment in which VO services worldwide were routinely checked for aliveness and compliance with international standards. Finally, the VAO engaged in community outreach, developing a comprehensive web site with on-line tutorials, announcements, links to both US and internationally developed tools and services, and exhibits and hands-on training at annual meetings of the American Astronomical Society and through summer schools and community days. All digital products of the VAO Project, including software, documentation, and tutorials, are stored in a repository for community access. The enduring legacy of the VAO is an increasing expectation that new telescopes and facilities incorporate VO capabilities during the design of their data management systems.

  1. 141Hubble Spies Colliding Asteroids! It doesn't look like much, but this

    E-print Network

    141Hubble Spies Colliding Asteroids! It doesn't look like much, but this picture taken by the Hubble Space Telescope on January 25, 2010 shows all that remains of two asteroids that collided! The object, called P/2010 A2, was discovered in the asteroid belt 290 million kilometers from the sun

  2. IMAGE OF A DISTANT GALAXY CANDIDATE IN THE HUBBLE DEEP FIELD

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Small portion of the Hubble Deep Field image -- the deepest view of the universe taken with NASA's Hubble Space Telescope. Arrow points to a very faint galaxy that appears to be more distant than any known previously. Other galaxies in the image are at smaller distances. Credit: Ken Lanzetta and Amos Yahil (State University of New York at Stony Brook), and NASA

  3. NRAO Astronomer Wins Prestigious Guggenheim Fellowship

    NASA Astrophysics Data System (ADS)

    2010-04-01

    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.

  4. The New North Georgia Astronomical Observatory.

    NASA Astrophysics Data System (ADS)

    Jones, J. H.; Chapman, E. K.

    1999-12-01

    The mission of NGCSU's observatory over the last 30 years has been to provide a quality environment for student and public viewing and a professional platform for student/faculty research. During the fall of 1997 a large illuminated parking lot was constructed less than 100 feet from the old observatory site. Fortunately, the administration at that time recognized the impact that the lot would have on the observatory's mission and was able to find funds to relocate the Boller & Chivens 16 inch telescope to a new observatory built on school property four miles west of the campus. The new observatory became operational at the beginning of the fall semester 1999. We report here on the outcome of the many unique design features which we tried to incorporate into the building. Features for optimizing student and public viewing such as a "downslope" roll away enclosure and a wide "no steps" observing deck entrance. An ongoing student project to measure and compare photometric calibration coefficients as well as zenith sky brightness and "seeing" parameters with previously determined parameters will evaluate the building features which were designed to enhance the performance of the telescope and its instrumentation. We would especially like to thank university president (retired) Dr. Sherman R. Day for supporting this project, not only financially, but also for supporting the legacy of astronomical education and student research at NGCSU. We also would like to thank the current president, Dr. Nathaniel Hansford, and his administration for continuing that support.

  5. The Blue Comet: A Railroad's Astronomical Heritage

    NASA Astrophysics Data System (ADS)

    Rumstay, Kenneth S.

    2009-01-01

    Between 1929 February 21 and 1941 September 27, the Central New Jersey Railroad operated a luxury passenger train between Jersey City and Atlantic City. Named The Blue Comet, the locomotive, tender, and coaches sported a unique royal blue paint scheme designed to evoke images of celestial bodies speeding through space. Inside each car were etched window panes and lampshades featuring stars and comets. And each coach sported the name of a famous comet on its side; these comets were of course named for their discoverers. Some of the astronomers honored in this unique fashion remain famous to this day, or at least their comets do. The names D'Arrest, Barnard, Encke, Faye, Giacobini, Halley, Olbers, Temple, Tuttle, and Westphal are familiar ones. But Biela, Brorsen, deVico, Spitaler, and Winnecke have now largely faded into obscurity; their stories are recounted here. Although more than sixty years have elapsed since its last run, The Blue Comet, perhaps the most famous passenger train in American history, lives on in the memories of millions of passengers and railfans. This famous train returned to the attention of millions of television viewers on the evening of 2007 June 3, in an episode of the HBO series The Sopranos. This work was supported by a faculty development grant from Valdosta State University.

  6. Is astronomical research appropriate for developing countries?

    NASA Astrophysics Data System (ADS)

    Snowden, Michael S.

    An unproductive 45-cm astronomical telescope, given by JICA (Japan) to Sri Lanka, raises general questions as to the reasons for unproductive pure science in developing countries. Before installation, site, maintenance, and scientific objectives were discussed. The facility was launched with a conference organised by the UN Office for Outer Space Affairs. Unfortunately, no research or significant education has resulted after four years. The annual operating cost is U.S. $5000 per year, including salary for a trainee, maintenance, and a modest promotional programme. Comparison with a similar installation in Auckland suggests lack of funding or technical competence do not explain the failure in Sri Lanka. The facility in New Zealand, on the roof of Auckland University's Physics Department, has a slightly smaller budget but has led to modest but useful research and teaching. Lack of financial backing and expertise are often blamed for weak science in developing countries, but examination shows most of these countries have adequately skilled people, and plenty of resources for religion and military. General lack of motivation for science appears to be the principal reason. This lack of interest and highly inefficient bureaucracies are common to scientifically unproductive countries. They mostly lack the cultural and philosophical base of the European Renaissance that motivate the pursuit of modern science, an activity that violates human preferences. There are excellent facilities (ESO, SAAO, Cerro Tololo, and GONG) in some of these same countries, when administered from the West.

  7. Radiation events in astronomical CCD images

    SciTech Connect

    Smith, A.R.; McDonald, R.J.; Hurley, D.L.; Holland, S.E.; Groom, D.E.; Brown, W.E.; Gilmore, D.K.; Stover, R.J.; Wei, M.

    2001-12-18

    The remarkable sensitivity of depleted silicon to ionizing radiation is a nuisance to astronomers. ''Cosmic rays'' degrade images because of struck pixels, leading to modified observing strategies and the development of algorithms to remove the unwanted artifacts. In the new-generation CCD's with thick sensitive regions, cosmic-ray muons make recognizable straight tracks and there is enhanced sensitivity to ambient gamma radiation via Compton-scattered electrons (''worms''). Beta emitters inside the dewar, for example high-potassium glasses such as BK7, also produce worm-like tracks. The cosmic-ray muon rate is irreducible and increases with altitude. The gamma rays are mostly by-products of the U and Th decay chains; these elements always appear as traces in concrete and other materials. The Compton recoil event rate can be reduced significantly by the choice of materials in the environment and dewar and by careful shielding. Telescope domes appear to be significantly cleaner than basement laboratories and Coude spectrograph rooms. Radiation sources inside the dewar can be eliminated by judicious choice of materials. Cosmogenic activation during high-altitude flights does not appear to be a problem. Our conclusions are supported by tests at the Lawrence Berkeley National Laboratory low-level counting facilities in Berkeley and at Oroville, California (180 m underground).

  8. Astronomical Approach to Physical Science Curriculum

    NASA Astrophysics Data System (ADS)

    Manning, H. L. K.; Churukian, A. D.

    2004-11-01

    The Astronomical Approach to Physical Science Curriculum (AAPS Curriculum) is an innovative curriculum that incorporates an astronomy theme into an inquiry-based physical science curriculum for pre-service, elementary school teachers. Many physical science courses are a non-cohesive collection of topics required for the state teaching license. Through the use of astronomy and space science examples, the AAPS Curriculum will have a coherent theme that ties the wide variety of physical science topics together and provides many real world applications for the topics covered in the course. This new curriculum will incorporate the applications of knowledge to complete the learning cycle-exploration, concept introduction, application. Astronomy and space science applications will be emphasized throughout the curriculum. The theme of astronomy was chosen to prepare elementary school teachers for teaching astronomy and space science in their classroom, as this is a topic in which many school children are consistently interested. Since astronomy is a topic that can be used as a springboard to teach many other areas of study, we want teachers who are knowledgeable in topics of astronomy so they are capable of preparing creative lessons throughout their entire curriculum that are exciting to their students. The AAPS Curriculum will train college students to become teachers who are comfortable with physical science and astronomy topics and who are excited to teach these topics in their classroom. Funding for this work is provided by the IDEAS grant program of the Space Telescope Science Institute.

  9. User Support in the Virtual Astronomical Observatory

    NASA Astrophysics Data System (ADS)

    Stobie, E.; Seaman, R.; Mighell, K.; Bunn, S. E.; Williams, R.

    2010-12-01

    As we anticipate the U.S. Virtual Astronomical Observatory (VAO) entering its operational phase, support for a growing number of users will become ever more important. The role of VAO User Support will be considered as having responsibility in three key areas: (1) for maintaining and expanding the VAO Help Desk and Web Site, which will give access to any catalogs, services, and tools that the VAO may provide; (2) for conducting aggressive Testing and Readiness Reviews, so that those tools and services will work reliably and will be well documented; and (3) for pursuing deverse opportunities for Training and Advocacy, including tutorials, seminars, and support for advanced use of the VAO. The authors present our view of how such pieces should work together with the hope of receiving feedback from the community to inform the development of program plans for VAO User Support. Funding for the VAO is pending and specific program activities and services are subject to the review and approval of the NSF and NASA.

  10. Hydrated Minerals on Asteroids: The Astronomical Record

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    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-micron 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 steroids, 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 Hydroxl-bearing minerals on asteroids.

  11. Initial Hubble Diagram Results from the Nearby Supernova Factory

    E-print Network

    S. Bailey; G. Aldering; P. Antilogus; C. Aragon; C. Baltay; S. Bongard; C. Buton; M. Childress; Y. Copin; E. Gangler; S. Loken; P. Nugent; R. Pain; E. Pecontal; R. Pereira; S. Perlmutter; D. Rabinowitz; G. Rigaudier; P. Ripoche; K. Runge; R. Scalzo; G. Smadja; C. Tao; R. C. Thomas; C. Wu

    2008-10-21

    The use of Type Ia supernovae as distance indicators led to the discovery of the accelerating expansion of the universe a decade ago. Now that large second generation surveys have significantly increased the size and quality of the high-redshift sample, the cosmological constraints are limited by the currently available sample of ~50 cosmologically useful nearby supernovae. The Nearby Supernova Factory addresses this problem by discovering nearby supernovae and observing their spectrophotometric time development. Our data sample includes over 2400 spectra from spectral timeseries of 185 supernovae. This talk presents results from a portion of this sample including a Hubble diagram (relative distance vs. redshift) and a description of some analyses using this rich dataset.

  12. Teaching physics with Hubble's law and dark matter

    NASA Astrophysics Data System (ADS)

    Wallace, Colin S.; Prather, Edward E.

    2012-05-01

    Physics instructors can enrich, enliven, and enhance their courses with conceptually rich cosmology content. In this paper, we specifically discuss how instructors can integrate lessons on Hubble's law (as it relates to the expansion of the universe and dark energy) and spiral galaxies' rotation curves (as they relate to the presence of dark matter) into an introductory, college-level course on mechanics. These cosmology topics intersect with the content of introductory physics in a number of areas, such as students' abilities to read and interpret graphs and their conceptual understandings of both kinematics and dynamics. Throughout this paper, we draw upon the results from, and research-validated curricula informed by, physics and astronomy education research. In particular, we feature the results from a national study we recently completed with introductory college-level general education astronomy students on the teaching and learning of cosmology.

  13. HUBBLE'S PANORAMIC PICTURE OF COMET SHOEMAKER-LEVY 9

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA Hubble Space Telescope (HST) image of comet P/Shoemaker-Levy 9, taken on May 17, 1994, with the Wide Field Planetary Camera-2 (WFPC-2) in wide field mode. When the comet was observed, its train of 21 icy fragments stretched across 710 thousand miles (1.1 million km) of space, or 3 times the distance between Earth and the Moon. This required 6 WFPC exposures spaced along the comet train to include all the nuclei. The image was taken in red light. The comet was approximately 410 million miles (660 million km) from Earth when the picture was taken, on a mid-July collision course with the gas giant planet Jupiter. Credit: H.A. Weaver, T.E. Smith (Space Telescope Science Institute), and NASA

  14. Second generation spectrograph for the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Woodgate, B. E.; Boggess, A.; Gull, T. R.; Heap, S. R.; Krueger, V. L.; Maran, S. P.; Melcher, R. W.; Rebar, F. J.; Vitagliano, H. D.

    1986-01-01

    The preliminary design for the Space Telescope Imaging Spectrograph (STIS), which has been selected by NASA for definition study for future flight as a second-generation instrument on the Hubble Space Telescope (HST), is presented. STIS is a two-dimensional spectrograph that will operate from 1050 A to 11,000 A at the limiting HST resolution of 0.05 arcsec FWHM, with spectral resolutions of 100, 1200, 20,000, and 100,000 and a maximum field-of-view of 50 x 50 arcsec. Its basic operating modes include echelle model, long slit mode, slitless spectrograph mode, coronographic spectroscopy, photon time-tagging, and direct imaging. Research objectives are active galactic nuclei, the intergalactic medium, global properties of galaxies, the origin of stellar systems, stelalr spectral variability, and spectrographic mapping of solar system processes.

  15. Determining the Hubble Constant from Ryle Telescope observations

    E-print Network

    Keith Grainge; Michael E. Jones; Guy Pooley; Richard Saunders; Alastair Edge; Rudiger Kneissl

    2001-03-09

    We describe our algorithm for measuring the Hubble constant from Ryle Telescope (RT) interferometric observations of the Sunyaev-Zel'dovich (SZ) effect from a galaxy cluster and observation of the cluster X-ray emission. We analyse the error budget in this method: as well as radio and X-ray random errors, we consider the effects of clumping and temperature differences in the cluster gas, of the kinetic SZ effect, of bremsstrahlung emission at radio wavelengths, of the gravitational lensing of background radio sources and of primary calibration error. Using RT, ASCA and ROSAT observations of the cluster Abell 1413, we find that random errors dominate over systematic ones, and estimate H_0 = 57^{+23}_{-16} km/s/Mpc (1-sigma errors).

  16. Hubble Space Telescope: the new telemetry archiving system

    NASA Astrophysics Data System (ADS)

    Miebach, Manfred P.

    2000-07-01

    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 of the ground system re- engineering effort, a project called 'Vision 2000 Control Center System (CCS),' are to reduce both development and operating costs significantly for the remaining years of HST's lifetime. Development costs are reduced by providing a more modern hardware and software architecture and utilizing commercial off the shelf (COTS) products wherever possible. Part of CCS is a Space Telescope Engineering Data Store, the design of which is based on current Data Warehouse technology. The Data Warehouse (Red Brick), as implemented in the CCS Ground System that operates and monitors the Hubble Space Telescope, represents the first use of a commercial Data Warehouse to manage engineering data. The purpose of this data store is to provide a common data source of telemetry data for all HST subsystems. This data store will become the engineering data archive and will provide a queryable database for the user to analyze HST telemetry. The access to the engineering data in the Data Warehouse is platform-independent from an office environment using commercial standards (Unix, Windows98/NT). The latest Internet technology is used to reach the HST engineering community. A WEB-based user interface allows easy access to the data archives. This paper will provide a CCS system overview and will illustrate some of the CCS telemetry capabilities: in particular the use of the new Telemetry Archiving System. Vision 20001 is an ambitious project, but one that is well under way. It will allow the HST program to realize reduced operations costs for the Third Servicing Mission and beyond.

  17. The Coma - Leo I Distance Ratio and the Hubble Constant

    E-print Network

    Michael D. Gregg

    1997-03-05

    The diameter - velocity dispersion relation in B, V, and K for three early-type galaxies in the Leo I (M96) group is derived from published photometry and kinematic data. The relations in all three colors have slopes which agree well with those for the Coma cluster. The RMS scatter of the Leo I galaxies in each color is extremely small, consistent with the group's compactness. These relations yield estimates of the Coma-Leo I distance ratio of 9.01 +/- 0.51, 8.77 +/- 0.43, and 8.82 +/- 0.31, respectively, with a weighted mean of 8.84 +/- 0.23. The general agreement among the three colors indicates that the early-type galaxies in Leo I and Coma have similar stellar populations. The Coma-Leo I distance ratio coupled with estimates of the absolute distance to the Leo I group allows the Hubble constant to be determined, free of the uncertainties which arise when working with the Virgo cluster. Several high quality distance estimates are available from a variety of techniques: Cepheids in M96 (Tanvir et al. 1995) and M95 (Graham et al. 1997), surface brightness fluctuations (Tonry et al. 1997), planetary nebulae luminosity functions (Ciardullo et al. 1993), and the luminosity of the red giant branch tip (Sakai, Freedman, & Madore 1996). Adopting a cosmic recession velocity of the Coma cluster in the microwave background frame of 7200 +/- 300 km/s, these distance estimates lead to values of the Hubble constant ranging from 70 to 81 km/s/Mpc, with an unweighted mean of 75 +/- 6 km/s/Mpc.

  18. Hubble Space Telescope Image: Planetary Nebula IC 4406

    NASA Technical Reports Server (NTRS)

    2001-01-01

    This Hubble Space Telescope image reveals a rainbow of colors in this dying star, called IC 446. Like many other so-called planetary nebulae, IC 4406 exhibits a high degree of symmetry. The nebula's left and right halves are nearly mirror images of the other. If we could fly around IC 446 in a spaceship, we would see that the gas and dust form a vast donut of material streaming outward from the dying star. We do not see the donut shape in this photograph because we are viewing IC 4406 from the Earth-orbiting HST. From this vantage point, we are seeing the side of the donut. This side view allows us to see the intricate tendrils of material that have been compared to the eye's retina. In fact, IC 4406 is dubbed the 'Retina Nebula.' The donut of material confines the intense radiation coming from the remnant of the dying star. Gas on the inside of the donut is ionized by light from the central star and glows. Light from oxygen atoms is rendered blue in this image; hydrogen is shown as green, and nitrogen as red. The range of color in the final image shows the differences in concentration of these three gases in the nebula. This image is a composite of data taken by HST's Wide Field Planetary Camera 2 in June 2001 and in January 2002 by Bob O'Dell (Vanderbilt University) and collaborators, and in January by the Hubble Heritage Team (STScI). Filters used to create this color image show oxygen, hydrogen, and nitrogen gas glowing in this object.

  19. The Production Rate and Employment of Ph.D. Astronomers

    NASA Astrophysics Data System (ADS)

    Metcalfe, Travis S.

    2007-05-01

    As in many sciences, the production rate of new Ph.D. astronomers is decoupled from the global demand for trained scientists. As noted by Thronson (1991, PASP, 103, 90), overproduction appears to be built into the system, making the mathematical formulation of surplus astronomer production similar to that for industrial pollution models -- an unintended side effect of the process. Following Harris (1994, ASP Conf., 57, 12), I document the production of Ph.D. astronomers from 1990 to 2005 using the online Dissertation Abstracts database. To monitor the changing patterns of employment, I examine the number of postdoctoral, tenure-track, and other jobs advertised in the AAS Job Register during this same period. Although the current situation is clearly unsustainable, it was much worse a decade ago with nearly 7 new Ph.D. astronomers in 1995 for every new tenure-track job. While the number of new permanent positions steadily increased throughout the late 1990's, the number of new Ph.D. recipients gradually declined. After the turn of the century, the production of new astronomers leveled off, but new postdoctoral positions grew dramatically. There has also been recent growth in the number of non-tenure-track lecturer, research, and support positions. This is just one example of a larger cultural shift to temporary employment that is happening throughout society -- it is not unique to astronomy.

  20. Astronomical Observatory of Belgrade from 1956 to 1975

    NASA Astrophysics Data System (ADS)

    Radovanac, M.

    2010-06-01

    Although the present monograph "Astronomical Observatory of Belgrade from 1956 to 1975" is an independent work, it is in fact a continuation of the work done by the author and published in the series of the Publications of the Astronomical Society "Rudjer Boskovic" under the title "Astronomical Observatory of Belgrade from 1945 to 1955" in the Proceedings of the conference "Development of Astronomy among Serbs III", no. 6, pp. 55-200 in 2005; that manuscript in turn is an extension of the earlier paper (written together with Luka C. Popovic) and published in the series of the Publications of Astronomical Observatory of Belgrade "Development of Astronomy among Serbs II", no. 72, pp. 133-145 in 2002. Thus the three papers constitute a detailed review of the work of the Astronomical Observatory of Belgrade in the period of 35 years (of the total of 122 years) of its relatively recent history, from 1940 to 1975; this review is prepared using the archive material: general type of documents, notes of various meetings, especially the meetings of the Council of the Observatory, Scientific council and work plans, reports, correspondence, etc.

  1. Astronomical Data Analysis, 6th conf., 37 May 2010, Monastir, Tunisia MULTIVARIATE EVOLUTIONARY

    E-print Network

    Astronomical Data Analysis, 6th conf., 3­7 May 2010, Monastir, Tunisia MULTIVARIATE EVOLUTIONARY to understand their 1 #12; Astronomical Data Analysis, 6th conf., 3­7 May 2010, Monastir, Tunisia relationships

  2. Project of space research and technology center in Engelhardt astronomical observatory

    NASA Astrophysics Data System (ADS)

    Nefedyev, Y.; Gusev, A.; Sherstukov, O.; Kascheev, R.; Zagretdinov, R.

    2012-09-01

    Today on the basis of Engelhardt astronomical observatory (EAO) is created Space research and technology center as consistent with Program for expansion of the Kazan University. The Centre has the following missions: • EDUCATION • SCIENCE • ASTRONOMICAL TOURISM

  3. Copyright 2012 Software Bisque, Inc. All rights reserved. TheSkyX Professional and Serious Astronomer

    E-print Network

    Astronomical Algorithms Software, © 1991 by Jeffrey Sax, and option to the book Astronomical Algorithms by Jean.fr). Mac and the Mac logo are trademarks of Apple Computer, Inc., registered in the U.S. and other ...............................................................................................16 Mac

  4. Astronomer R.G. Chandra: In the Light of His Anglo-American Connection

    NASA Astrophysics Data System (ADS)

    Ray, Saibal; Nath Biswas, Sudhindra; Mukhopadhyay, Utpal

    2014-09-01

    In the present paper we have presented some documents to reveal the longstanding relationship of Indian amateur astronomer R.G. Chandra with the British Astronomical Association and American Association of Variable Star Observers.

  5. Astronomical and Cosmological Aspects of Maya Architecture and Urbanism

    NASA Astrophysics Data System (ADS)

    Šprajc, I.

    2009-08-01

    Archaeoastronomical studies carried out so far have shown that the orientations in the ancient Maya architecture were, like elsewhere in Mesoamerica, largely astronomical, mostly referring to sunrises and sunsets on particular dates and allowing the use of observational calendars that facilitated a proper scheduling of agricultural activities. However, the astronomical alignments cannot be understood in purely utilitarian terms. Since the repeatedly occurring directions are most consistently incorporated in monumental architecture of civic and ceremonial urban cores, they must have had an important place in religion and worldview. The characteristics of urban layouts, as well as architectural and other elements associated with important buildings, reveal that the Maya architectural and urban planning was dictated by a complex set of rules, in which astronomical considerations related to practical needs were embedded in a broader framework of cosmological concepts substantiated by political ideology.

  6. Multiplexed astronomical images: advantages, method, and prototype instrument

    NASA Astrophysics Data System (ADS)

    Ben-Ami, Sagi; Zackay, Barak; Rubin, Adam; Sagiv, Ilan; Gal-Yam, Avishay; Ofek, Eran O.

    2014-08-01

    In some optical systems in which a large field of view (and hence a large detector) is required, it is the detector which drives the total system cost. We propose a concept, and demonstrate an optical system, for an astronomical multiplexer. The instrument projects different portions of the telescope focal plane into a single (possibly) small detector without changing the original plate scale of the image. The resulting image is a superposition of the different portions of the field of view. Since in most cases astronomical images are sparse, photometric measurements can be done directly on the combined images for most objects in the field. We discuss an outline of the concept of multiplexing, in terms of its signal-to-noise properties, and multiplexed image reconstruction algorithm. Furthermore, we present an optical design for an astronomical multiplexer we recently constructed along with some first light images.

  7. Astronomical relativistic reference systems with multipolar expansion: the global one

    E-print Network

    Yi Xie

    2014-07-07

    With rapid development of techniques for astronomical observations, the precision of measurements has been significantly increasing. Theories of astronomical relativistic reference systems, which are the foundation for processing and interpreting these data now and in the future, may require extensions to satisfy the needs of these trends. Besides building a framework compatible with alternative theories of gravity and the pursuit of higher order post-Newtonian approximation, it will also be necessary to make the first order post-Newtonian multipole moments of celestial bodies be explicitly expressed in the astronomical relativistic reference systems. This will bring some convenience into modeling the observations and experiments and make it easier to distinguish different contributions in measurements. As the first step, the global solar system reference system is multipolarly expanded and the post-Newtonian mass and spin moments are shown explicitly in the metric which describes the coordinates of the system. The full expression of the global metric is given.

  8. Planetariums, The Great Messengers of the Astronomical Research

    NASA Astrophysics Data System (ADS)

    Acker, A.

    2005-12-01

    A close partnership between planetariums and astronomers allows the public better access to the results of the astronomical research through high quality audiovisual tools. The French-speaking planetariums have shared their areas of expertise, their different approaches and techniques and their resources since 1984. They created the Association of French Language Planetariums (APLF) in 1989, with a head office located at the Observatory/University of Strasbourg in collaboration with teachers and astronomers. The French Planetariums welcome ~1,300,000 visitors per year, 65 % of which come from schools. APLF comprises about thirty fixed structures, 70 small and portable planetariums, and ten French-speaking Planetariums: Brussels and Genk (Belgium), Brescia (Italy), Lafayette (the USA), Lucerne (Swiss), Montreal (Canada), Tunis. APLF wish to develop planetariums in France and beyond in order to diffuse scientific knowledge towards a large audience and especially towards young people.

  9. Tests of commercial colour CMOS cameras for astronomical applications

    NASA Astrophysics Data System (ADS)

    Pokhvala, S. M.; Reshetnyk, V. M.; Zhilyaev, B. E.

    2013-12-01

    We present some results of testing commercial colour CMOS cameras for astronomical applications. Colour CMOS sensors allow to perform photometry in three filters simultaneously that gives a great advantage compared with monochrome CCD detectors. The Bayer BGR colour system realized in colour CMOS sensors is close to the astronomical Johnson BVR system. The basic camera characteristics: read noise (e^{-}/pix), thermal noise (e^{-}/pix/sec) and electronic gain (e^{-}/ADU) for the commercial digital camera Canon 5D MarkIII are presented. We give the same characteristics for the scientific high performance cooled CCD camera system ALTA E47. Comparing results for tests of Canon 5D MarkIII and CCD ALTA E47 show that present-day commercial colour CMOS cameras can seriously compete with the scientific CCD cameras in deep astronomical imaging.

  10. The Hubble Education and Public Outreach Program: Best Practices and Lessons Learned

    NASA Astrophysics Data System (ADS)

    Eisenhamer, B.; Jirdeh, H.; Knisely, L.; McCallister, D.; Ryer, H.; Smith, D.

    2014-07-01

    This paper highlights examples of best practices and lessons learned from the Hubble EPO program. Scientists and educators work side-by-side to identify the aspects of cutting-edge Hubble discoveries, data, and technology most relevant to STEM education and public understanding of science. The strategy has allowed us to bring Hubble science to the EPO community on a national scale. On this journey, we have identified and refined best practices and lessons learned in program staffing, meeting audience needs, translating cutting-edge science for a variety of diverse audiences, and achieving national reach.

  11. All-Sky brightness monitoring of light pollution with astronomical methods

    Microsoft Academic Search

    O. Rabaza; D. Galadí-Enríquez; A. Espín Estrella; F. Aznar Dols

    2010-01-01

    This paper describes a mobile prototype and a protocol to measure light pollution based on astronomical methods. The prototype takes three all-sky images using BVR filters of the Johnson-Cousins astronomical photometric system. The stars are then identified in the images of the Hipparcos and General Catalogue of Photometric Data II astronomical catalogues, and are used as calibration sources. This method

  12. An astronomical polarity timescale for the late middle Miocene based on cyclic continental sequences

    E-print Network

    Utrecht, Universiteit

    An astronomical polarity timescale for the late middle Miocene based on cyclic continental an astronomically tuned polarity timescale for the late middle Miocene based on a cyclic shallow lacustrine, cyclostratigraphy, astronomical timescale, orbital forcing, Miocene Citation: Abdul Aziz, H., W. Krijgsman, F. J

  13. Night Sky Network: A partnership with NASA, the ASP and Astronomical League

    Microsoft Academic Search

    S. Chippindale; M. Berendsen

    2003-01-01

    In 2002, the Astronomical Society of the Pacific (ASP) surveyed amateur astronomers to determine their views and experiences with public outreach. The ultimate goal was to discover methods to support amateur astronomers in their outreach efforts. The survey discovered that they are looking for ready-made, themed materials, training in astronomy content and presentation skills, mentoring, and networking to enhance their

  14. The Research Tools of the Virtual Astronomical Observatory

    NASA Astrophysics Data System (ADS)

    Hanisch, Robert J.; Berriman, G. B.; Lazio, T. J.; Project, VAO

    2013-01-01

    Astronomy is being transformed by the vast quantities of data, models, and simulations that are becoming available to astronomers at an ever-accelerating rate. The U.S. Virtual Astronomical Observatory (VAO) has been funded to provide an operational facility that is intended to be a resource for discovery and access of data, and to provide science services that use these data. Over the course of the past year, the VAO has been developing and releasing for community use five science tools: 1) "Iris", for dynamically building and analyzing spectral energy distributions, 2) a web-based data discovery tool that allows astronomers to identify and retrieve catalog, image, and spectral data on sources of interest, 3) a scalable cross-comparison service that allows astronomers to conduct pair-wise positional matches between very large catalogs stored remotely as well as between remote and local catalogs, 4) time series tools that allow astronomers to compute periodograms of the public data held at the NASA Star and Exoplanet Database (NStED) and the Harvard Time Series Center, and 5) A VO-aware release of the Image Reduction and Analysis Facility (IRAF) that provides transparent access to VO-available data collections and is SAMP-enabled, so that IRAF users can easily use tools such as Aladin and Topcat in conjuction with IRAF tasks. Additional VAO services will be built to make it easy for researchers to provide access to their data in VO-compliant ways, to build VO-enabled custom applications in Python, and to respond generally to the growing size and complexity of astronomy data. Acknowledgements: The Virtual Astronomical Observatory (VAO) is managed by the VAO, LLC, a non-profit company established as a partnership of the Associated Universities, Inc. and the Association of Universities for Research in Astronomy, Inc. The VAO is sponsored by the National Science Foundation and the National Aeronautics and Space Administration.

  15. HUBBLE UNCOVERS DUST DISK AROUND A MASSIVE BLACK HOLE

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Resembling a gigantic hubcap in space, a 3,700 light-year-diameter dust disk encircles a 300 million solar-mass black hole in the center of the elliptical galaxy NGC 7052. The disk, possibly a remnant of an ancient galaxy collision, will be swallowed up by the black hole in several billion years. Because the front end of the disk eclipses more stars than the back, it appears darker. Also, because dust absorbs blue light more effectively than red light, the disk is redder than the rest of the galaxy (this same phenomenon causes the Sun to appear red when it sets in a smoggy afternoon). This NASA Hubble Space Telescope image was taken with the Wide Field and Planetary Camera 2, in visible light. Details as small as 50 light-years across can be seen. Hubble's Faint Object Spectrograph (replaced by the STIS spectrograph in 1997) was used to observe hydrogen and nitrogen emission lines from gas in the disk. Hubble measurements show that the disk rotates like an enormous carousel, 341,000 miles per hour (155 kilometers per second) at 186 light-years from the center. The rotation velocity provides a direct measure of the gravitational force acting on the gas by the black hole. Though 300 million times the mass of our Sun, the black hole is still only 0.05 per cent of the total mass of the NGC 7052 galaxy. Despite its size, the disk is 100 times less massive than the black hole. Still, it contains enough raw material to make three million sun-like stars. The bright spot in the center of the disk is the combined light of stars that have crowded around the black hole due to its strong gravitational pull. This stellar concentration matches theoretical models linking stellar density to a central black hole's mass. NGC 7052 is a strong source of radio emission and has two oppositely directed `jets' emanating from the nucleus. (The jets are streams of energetic electrons moving in a strong magnetic field and unleashing radio energy). Because the jets in NGC 7052 are not perpendicular to the disk, it may indicate that the black hole and the dust disk in NGC 7052 do not have a common origin. One possibility is that the dust was acquired from a collision with a small neighboring galaxy, after the black hole had already formed. NGC 7052 is located in the constellation of Vulpecula, 191 million light-years from Earth. Credit: Roeland P. van der Marel (STScI), Frank C. van den Bosch (Univ. of Washington), and NASA. A caption and image files are available via the Internet at http://oposite.stsci.edu/pubinfo/1998/22.html.

  16. Astronomical Publication Rates in the US, UK, and Europe

    NASA Astrophysics Data System (ADS)

    Abt, Helmut A.

    I explored the growth of astronomical research in the US, UK, and four productive European countries to see if there has been any leveling off. I counted pages in the four major astronomical journals, and corrected for format changes and for contributions from other countries. The four European countries were France, Germany, Italy, and the Netherlands. In each area there has been no reduction in output. However, the data show that the UK lags behind the US by 10 ± 1 years and the four European countries lag the US by 12 ± 1 years.

  17. Use of Astronomical Literature - A Report on Usage Patterns

    E-print Network

    Edwin A. Henneken; Michael J. Kurtz; Alberto Accomazzi; Carolyn S. Grant; Donna Thompson; Elizabeth Bohlen; Stephen S. Murray

    2008-10-03

    In this paper we present a number of metrics for usage of the SAO/NASA Astrophysics Data System (ADS). Since the ADS is used by the entire astronomical community, these are indicative of how the astronomical literature is used. We will show how the use of the ADS has changed both quantitatively and qualitatively. We will also show that different types of users access the system in different ways. Finally, we show how use of the ADS has evolved over the years in various regions of the world. The ADS is funded by NASA Grant NNG06GG68G.

  18. Double stars: a synergy between amateur and professional astronomers

    NASA Astrophysics Data System (ADS)

    Agati, Jean-Louis; Bonneau, Daniel; Caille, Sébastien; Couteau, Paul; Debackère, André; Dommanget, Jean; Durand, Pierre; Gili, René; Losse, Florent; Manté, René; Mauroy, Florence; Morlet, Guy; Salaman, Maurice; Soulié, Edgar; Thorel, Jean-Claude; Thorel, Yvonne; Verhas, Pierre

    2011-06-01

    In the field of visual double stars, a long term follow-up is required, since their orbital periods may reach several centuries. Created in 1981 within the Société Astronomique de France (SAF) with the support of the late Paul Muller (1910-2000), the Commission des Etoiles Doubles provides the framework for the necessary collaboration between professional and amateur astronomers, through generations. The late Dr. Paul Baize (1901-1995) was a model for its members. Several professional astronomers became scientific advisors of the Commission and have guided many works made by amateurs.

  19. Hubble Space Telescope Imaging of Brightest Cluster Galaxies

    NASA Astrophysics Data System (ADS)

    Laine, Seppo; van der Marel, Roeland P.; Lauer, Tod R.; Postman, Marc; O'Dea, Christopher P.; Owen, Frazer N.

    2003-02-01

    We used the Hubble Space Telescope Wide Field Planetary Camera 2 to obtain I-band images of the centers of 81 brightest cluster galaxies (BCGs), drawn from a volume-limited sample of nearby BCGs. The images show a rich variety of morphological features, including multiple or double nuclei, dust, stellar disks, point-source nuclei, and central surface brightness depressions. High-resolution surface brightness profiles could be inferred for 60 galaxies. Of those, 88% have well-resolved cores. The relationship between core size and galaxy luminosity for BCGs is indistinguishable from that of Faber et al. (published in 1997, hereafter F97) for galaxies within the same luminosity range. However, the core sizes of the most luminous BCGs fall below the extrapolation of the F97 relationship rb~L1.15V. A shallower relationship, rb~L0.72V, fits both the BCGs and the core galaxies presented in F97. Twelve percent of the BCG sample lacks a well-resolved core; all but one of these BCGs have ``power law'' profiles. Some of these galaxies have higher luminosities than any power-law galaxy identified by F97 and have physical upper limits on rb well below the values observed for core galaxies of the same luminosity. These results support the idea that the central structure of early-type galaxies is bimodal in its physical properties but also suggest that there exist high-luminosity galaxies with power-law profiles (or unusually small cores). The BCGs in the latter category tend to fall at the low end of the BCG luminosity function and tend to have low values of the quantity ? (the logarithmic slope of the metric luminosity as a function of radius, at 10 kpc). Since theoretical calculations have shown that the luminosities and ?-values of BCGs grow with time as a result of accretion, this suggests a scenario in which elliptical galaxies evolve from power-law profiles to core profiles through accretion and merging. This is consistent with theoretical scenarios that invoke the formation of massive black hole binaries during merger events. More generally, the prevalence of large cores in the great majority of BCGs, which are likely to have experienced several generations of galaxy merging, underscores the role of a mechanism that creates and preserves cores in such merging events. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with proposal 8683.

  20. The 2012 Hubble Ultra Deep Field (UDF12): Observational Overview

    NASA Astrophysics Data System (ADS)

    Koekemoer, Anton M.; Ellis, Richard S.; McLure, Ross J.; Dunlop, James S.; Robertson, Brant E.; Ono, Yoshiaki; Schenker, Matthew A.; Ouchi, Masami; Bowler, Rebecca A. A.; Rogers, Alexander B.; Curtis-Lake, Emma; Schneider, Evan; Charlot, Stephane; Stark, Daniel P.; Furlanetto, Steven R.; Cirasuolo, Michele; Wild, V.; Targett, T.

    2013-11-01

    We present the 2012 Hubble Ultra Deep Field campaign (UDF12), a large 128 orbit Cycle 19 Hubble Space Telescope program aimed at extending previous Wide Field Camera 3 (WFC3)/IR observations of the UDF by quadrupling the exposure time in the F105W filter, imaging in an additional F140W filter, and extending the F160W exposure time by 50%, as well as adding an extremely deep parallel field with the Advanced Camera for Surveys (ACS) in the F814W filter with a total exposure time of 128 orbits. The principal scientific goal of this project is to determine whether galaxies reionized the universe; our observations are designed to provide a robust determination of the star formation density at z >~ 8, improve measurements of the ultraviolet continuum slope at z ~ 7-8, facilitate the construction of new samples of z ~ 9-10 candidates, and enable the detection of sources up to z ~ 12. For this project we committed to combining these and other WFC3/IR imaging observations of the UDF area into a single homogeneous dataset to provide the deepest near-infrared observations of the sky. In this paper we present the observational overview of the project and describe the procedures used in reducing the data as well as the final products that were produced. We present the details of several special procedures that we implemented to correct calibration issues in the data for both the WFC3/IR observations of the main UDF field and our deep 128 orbit ACS/WFC F814W parallel field image, including treatment for persistence, correction for time-variable sky backgrounds, and astrometric alignment to an accuracy of a few milliarcseconds. We release the full, combined mosaics comprising a single, unified set of mosaics of the UDF, providing the deepest near-infrared blank-field view of the universe currently achievable, reaching magnitudes as deep as AB ~ 30 mag in the near-infrared, and yielding a legacy dataset on this field.

  1. THE 2012 HUBBLE ULTRA DEEP FIELD (UDF12): OBSERVATIONAL OVERVIEW

    SciTech Connect

    Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Ellis, Richard S.; Schenker, Matthew A. [Department of Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); McLure, Ross J.; Dunlop, James S.; Bowler, Rebecca A. A.; Rogers, Alexander B.; Curtis-Lake, Emma; Cirasuolo, Michele; Wild, V.; Targett, T. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ (United Kingdom); Robertson, Brant E.; Schneider, Evan; Stark, Daniel P. [Department of Astronomy and Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Ono, Yoshiaki; Ouchi, Masami [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa City, Chiba 277-8582 (Japan); Charlot, Stephane [UPMC-CNRS, UMR7095, Institut d'Astrophysique de Paris, F-75014, Paris (France); Furlanetto, Steven R. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)

    2013-11-01

    We present the 2012 Hubble Ultra Deep Field campaign (UDF12), a large 128 orbit Cycle 19 Hubble Space Telescope program aimed at extending previous Wide Field Camera 3 (WFC3)/IR observations of the UDF by quadrupling the exposure time in the F105W filter, imaging in an additional F140W filter, and extending the F160W exposure time by 50%, as well as adding an extremely deep parallel field with the Advanced Camera for Surveys (ACS) in the F814W filter with a total exposure time of 128 orbits. The principal scientific goal of this project is to determine whether galaxies reionized the universe; our observations are designed to provide a robust determination of the star formation density at z ?> 8, improve measurements of the ultraviolet continuum slope at z ? 7-8, facilitate the construction of new samples of z ? 9-10 candidates, and enable the detection of sources up to z ? 12. For this project we committed to combining these and other WFC3/IR imaging observations of the UDF area into a single homogeneous dataset to provide the deepest near-infrared observations of the sky. In this paper we present the observational overview of the project and describe the procedures used in reducing the data as well as the final products that were produced. We present the details of several special procedures that we implemented to correct calibration issues in the data for both the WFC3/IR observations of the main UDF field and our deep 128 orbit ACS/WFC F814W parallel field image, including treatment for persistence, correction for time-variable sky backgrounds, and astrometric alignment to an accuracy of a few milliarcseconds. We release the full, combined mosaics comprising a single, unified set of mosaics of the UDF, providing the deepest near-infrared blank-field view of the universe currently achievable, reaching magnitudes as deep as AB ? 30 mag in the near-infrared, and yielding a legacy dataset on this field.

  2. Hubble Provides Infrared View of Jupiter's Moon, Ring, and Clouds

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Probing Jupiter's atmosphere for the first time, the Hubble Space Telescope's new Near Infrared Camera and Multi-Object Spectrometer (NICMOS) provides a sharp glimpse of the planet's ring, moon, and high-altitude clouds.

    The presence of methane in Jupiter's hydrogen- and helium-rich atmosphere has allowed NICMOS to plumb Jupiter's atmosphere, revealing bands of high-altitude clouds. Visible light observations cannot provide a clear view of these high clouds because the underlying clouds reflect so much visible light that the higher level clouds are indistinguishable from the lower layer. The methane gas between the main cloud deck and the high clouds absorbs the reflected infrared light, allowing those clouds that are above most of the atmosphere to appear bright. Scientists will use NICMOS to study the high altitude portion of Jupiter's atmosphere to study clouds at lower levels. They will then analyze those images along with visible light information to compile a clearer picture of the planet's weather. Clouds at different levels tell unique stories. On Earth, for example, ice crystal (cirrus) clouds are found at high altitudes while water (cumulus) clouds are at lower levels.

    Besides showing details of the planet's high-altitude clouds, NICMOS also provides a clear view of the ring and the moon, Metis. Jupiter's ring plane, seen nearly edge-on, is visible as a faint line on the upper right portion of the NICMOS image. Metis can be seen in the ring plane (the bright circle on the ring's outer edge). The moon is 25 miles wide and about 80,000 miles from Jupiter.

    Because of the near-infrared camera's narrow field of view, this image is a mosaic constructed from three individual images taken Sept. 17, 1997. The color intensity was adjusted to accentuate the high-altitude clouds. The dark circle on the disk of Jupiter (center of image) is an artifact of the imaging system.

    This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

  3. HUBBLE SPIES GIANT STAR CLUSTERS NEAR GALACTIC CENTER

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Penetrating 25,000 light-years of obscuring dust and myriad stars, NASA's Hubble Space Telescope has provided the clearest view yet of a pair of the largest young clusters of stars inside our Milky Way galaxy, located less than 100 light-years from the very center of the Galaxy. Having the equivalent mass greater than 10,000 stars like our sun, the monster clusters are ten times larger than typical young star clusters scattered throughout our Milky Way. Both clusters are destined to be ripped apart in just a few million years by gravitational tidal forces in the Galaxy's core. But in the brief time they are around, they shine more brightly than any other star cluster in the Galaxy. Arches cluster (left): The more compact Arches cluster is so dense, over 100,000 of its stars would fill a spherical region in space whose radius is the distance between the Sun and its nearest neighbor, the star Alpha Centauri, 4.3 light-years away. At least 150 of its stars are among the brightest ever seen in the Galaxy. Quintuplet cluster (right): This 4-million-year-old cluster is more dispersed than the Arches cluster. It has stars on the verge of blowing up as supernovae. It is the home of the brightest star seen in the Galaxy, called the Pistol star. Both pictures were taken in infrared light by Hubble's NICMOS camera in September 1997. The false colors correspond to infrared wavelengths. The galactic center stars are white, the red stars are enshrouded in dust or behind dust, and the blue stars are foreground stars between us and the Milky Way's center. The clusters are hidden from direct view behind black dust clouds in the constellation Sagittarius. If the clusters could be seen from Earth they would appear to the naked eye as a pair of third magnitude 'stars,' 1/6th of a full moon's diameter apart. Credit: Don Figer (Space Telescope Science Institute) and NASA

  4. Astronomers Detect Powerful Bursting Radio Source Discovery Points to New Class of Astronomical Objects

    NASA Astrophysics Data System (ADS)

    2005-03-01

    Astronomers at Sweet Briar College and the Naval Research Laboratory (NRL) have detected a powerful new bursting radio source whose unique properties suggest the discovery of a new class of astronomical objects. The researchers have monitored the center of the Milky Way Galaxy for several years and reveal their findings in the March 3, 2005 edition of the journal, “Nature”. This radio image of the central region of the Milky Way Galaxy holds a new radio source, GCRT J1745-3009. The arrow points to an expanding ring of debris expelled by a supernova. CREDIT: N.E. Kassim et al., Naval Research Laboratory, NRAO/AUI/NSF Principal investigator, Dr. Scott Hyman, professor of physics at Sweet Briar College, said the discovery came after analyzing some additional observations from 2002 provided by researchers at Northwestern University. “"We hit the jackpot!” Hyman said referring to the observations. “An image of the Galactic center, made by collecting radio waves of about 1-meter in wavelength, revealed multiple bursts from the source during a seven-hour period from Sept. 30 to Oct. 1, 2002 — five bursts in fact, and repeating at remarkably constant intervals.” Hyman, four Sweet Briar students, and his NRL collaborators, Drs. Namir Kassim and Joseph Lazio, happened upon transient emission from two radio sources while studying the Galactic center in 1998. This prompted the team to propose an ongoing monitoring program using the National Science Foundation’s Very Large Array (VLA) radio telescope in New Mexico. The National Radio Astronomy Observatory, which operates the VLA, approved the program. The data collected, laid the groundwork for the detection of the new radio source. “Amazingly, even though the sky is known to be full of transient objects emitting at X- and gamma-ray wavelengths,” NRL astronomer Dr. Joseph Lazio pointed out, “very little has been done to look for radio bursts, which are often easier for astronomical objects to produce.” The team has monitored the Galactic center for new transient sources and for variability in approximately 250 known sources, but the five bursts from the new radio source, named GCRT J1745-3009, were by far the most powerful seen. The five bursts were of equal brightness, with each lasting about 10 minutes, and occurring every 77 minutes. The source of the bursts is transient Hyman noted. “It has not been detected since 2002 nor is it present on earlier images.” Although the exact nature of the object remains a mystery, the team members currently believe that GCRT J1745-3009 is either the first member of a new class of objects or an unknown mode of activity of a known source class. One important clue to understanding the origin of the radio bursts is that the emission appears to be “coherent,” Hyman said. “There are very few classes of coherent emitters in the universe. Natural astronomical masers — the analog of laser emission at microwave wavelengths — are one class of coherent sources, but these emit in specific wavelengths. In contrast, the new transient’s bursts were detected over a relatively large bandwidth.” The new radio source is located below the expanding ring of debris of this supernova remnant. The plot illustrates the radio light curve of the five detected bursts occurring every 77 minutes. “In addition to these intriguing properties, NRL astronomer Dr. Paul Ray and colleague, Dr. Craig Markwardt of NASA’s Goddard Space Flight Center, have searched the source for X-ray emission but have not found any convincing evidence. “The non-detection of X-ray emission is intriguing,” Ray said. “Many sources that emit transient X-ray flares, such as black hole binary star systems, also have associated radio emission. If upon further observations, X-ray emission is definitively detected or ruled out, this will be a significant help in understanding the nature of this remarkable source.” “Needless to say, the discovery of these transients has been very exciting for our students,” Hyman added. Participating in this research

  5. On the Astronomical Knowledge and Traditions of Aboriginal Australians

    NASA Astrophysics Data System (ADS)

    Hamacher, Duane W.

    2011-12-01

    Historian of science David Pingree defines science in a broad context as the process of systematically explaining perceived or imaginary phenomena. Although Westerners tend to think of science being restricted to Western culture, I argue in this thesis that astronomical scientific knowledge is found in Aboriginal traditions. Although research into the astronomical traditions of Aboriginal Australians stretches back for more than 150 years, it is relatively scant in the literature. We do know that the sun, moon, and night sky have been an important and inseparable component of the landscape to hundreds of Australian Aboriginal groups for thousands (perhaps tens-of-thousands) of years. The literature reveals that astronomical knowledge was used for time keeping, denoting seasonal change and the availability of food sources, navigation, and tidal prediction. It was also important for rituals and ceremonies, birth totems, marriage systems, cultural mnemonics, and folklore. Despite this, the field remains relatively unresearched considering the diversity of Aboriginal cultures and the length of time people have inhabited Australia (well over 40,000 years). Additionally, very little research investigating the nature and role of transient celestial phenomena has been conducted, leaving our understanding of Indigenous astronomical knowledge grossly incomplete. This thesis is an attempt to overcome this deficiency, with a specific focus on transient celestial phenomena. My research, situated in the field of cultural astronomy, draws from the sub-disciplines of archaeoastronomy, ethnoastronomy, historical astronomy, and geomythology. This approach incorporates the methodologies and theories of disciplines in the natural sciences, social sciences, and humanities. This thesis, by publication, makes use of archaeological, ethnographic, and historical records, astronomical software packages, and geographic programs to better understand the ages of astronomical traditions and the role and nature of eclipses, comets, meteors, impact events, and certain variable stars. I also test the hypothesis that certain types of stone arrangements have preferred orientations that probably relate to astronomical phenomena. This research shows that Aboriginal astronomical traditions explain the motions of celestial bodies and the relationship between events in the sky and events on Earth. I explore how Aboriginal people perceived and made use of particular astronomical phenomena, such as meteors and comets, and show that Aboriginal people made careful observations of the motions of celestial bodies. I provide evidence that Aboriginal people noticed the change in brightness of particular stars, described the kinematics of eclipses, explained how lunar phases are related to ocean tides, and acknowledged the relationship between meteors, meteorites, impact events, and impact craters. I then show that linear stone arrangements in New South Wales have a preferred orientation to the cardinal points and explore astronomical reasons for this. In the Appendix, I include biographical details of William Edward Stanbridge, one of the first people to write in depth about Aboriginal astronomical traditions, which were compiled from historic records.

  6. Resolving Sirius-like binaries with the Hubble Space Telescope

    E-print Network

    M. A. Barstow; Howard E. Bond; M. R. Burleigh; J. B. Holberg

    2000-10-31

    We present initial results from a Hubble Space Telescope ultraviolet imaging survey of stars known to have hot white-dwarf companions which are unresolved from the ground. The hot companions, discovered through their EUV or UV emission, are hidden by the overwhelming brightnesses of the primary stars at visible wavelengths. Out of 17 targets observed, we have resolved eight of them with the Wide Field Planetary Camera~2, using various ultraviolet filters. Most of the implied orbital periods for the resolved systems are hundreds to thousands of years, but in at least three cases (56 Persei, zeta Cygni, and REJ1925-566) it shouldbe possible to detect the orbital motions within the next few years, and they may eventually yield new dynamically determined masses for the white-dwarf components. The 56 Persei and 14 Aurigae systems are found to be quadruple and quintuple, respectively, including the known optical components as well as the newly resolved white-dwarf companions. The mild barium star zeta Cygni, known to have an 18 year spectroscopic period, is marginally resolved. All of these new resolved Sirius-type binaries will be useful in determining gravitational redshifts and masses of the white-dwarf components.

  7. HUBBLE SPACE TELESCOPE (HST) IMAGERY OF THE 30 DORADUS NEBULA

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Hubble Space Telescope (HST) images of the 30 Doradus Nebula show its remarkable cluster of tightly-packed young stars 160,000 light years from Earth in the large Magellanic cloud galaxy. Panel A is a portion of a image made with the HST Wide Field Planetary Camera (WFPC). WFPC photographed four adjoining sky regions simultaneously which are assembled in this mosaic. Panel B is an enlargement of the central portion of the HST image which was made in violet light. It shows the compact star cluster R136, which consists of very hot and massive young stars. The star images have bright cores that are only 0.1 arc seconds wide, allowing many more stars to be distinguished than in previous ground-based telescopic photos. Panel C is a photograph of the same region as Panel B, obtained with the Max Planck 2.2 meter telescope at the European Southern Observatory in Chile. The star images are 0.6 arc seconds wide. Panel D shows how computer processing of the HST image in Panel B has sharpened its

  8. Diffuse Dark and Bright Objects in the Hubble Deep Field

    E-print Network

    Changbom Park; Juhan Kim

    1997-12-03

    In the Hubble Deep Field (HDF) we have identified candidate regions where primordial galaxies might be forming. These regions are identified from negative or positive peaks in the difference maps obtained from the HDF maps smoothed over 0.8'' and 4''. They have apparent V magnitudes typically between 29 and 31 (missing flux below the local average level for the dark objects). The identified objects are shown to be real by two ways. First, the cross-correlations of these peaks detected in different filters are strong. Second, their auto-correlation functions indicate that these faint diffuse objects are self-clustered. The subset of objects dark in the F450W and F606W bandpasses, but bright in F814W, also shows stronger correlation compared to the whole dark sample. This further supports that our samples are indeed physical objects. The amplitude and slope of the angular correlation function of the bright objects indicates that these objects are ancestors of the present nearby bright galaxies. We have inspected individual bright objects and noted that they have several tiny spots embedded in extended backgrounds. They are likely to be the primordial galaxies at high redshifts in the process of active star formation and merging. Our subset of dark objects is thought to be the `intergalactic dark clouds' he blocking the background far UV light (at the rest frame) at high redshifts instead of empty spaces between the first galaxies at the edge of the universe of galaxies.

  9. Hubble Space Telescope Imaging Polarimetry of eta Carinae

    NASA Astrophysics Data System (ADS)

    Schulte-Ladbeck, R. E.; Pasquali, A.; Clampin, M.; Nota, A.; Hillier, D. J.; Lupie, O. L.

    1999-09-01

    Linear polarization measurements have been a key to our understanding of the massive star system eta Carinae and its surrounding Homunculus nebula. We here present the results of (linear) polarimetric imaging of eta Carinae in the V band (F555W) with the Hubble Space Telescope's Wide Field Planetary Camera 2 (HST/WFPC2). The data agree well with previous ground-based measurements of the large-scale polarization across the Homunculus, allowing us to confirm that it is primarily a reflection nebula. The HST observations add information on the variation of the polarization across the lobes on small spatial scales. We provide measurements of the polarization in a variety of structures such as the jet, the skirt, the paddle, the southern ridge, and the spot, and discuss the properties of the polarization of the Homunculus on large and small spatial scales. Using a simple Mie-scattering model, we argue that of three previously proposed geometries for the three-dimensional structure of the Homunculus only the double-flask geometry represents a dust distribution which is consistent with our polarization map.

  10. Hubble Space Telescope nickel-hydrogen flight spare battery test

    NASA Technical Reports Server (NTRS)

    Brewer, Jeffrey C.; Whitt, Thomas H.

    1991-01-01

    For several years, MSFC has been engaged in a series of battery tests in support of the Hubble Space Telescope (HST) Program. Now that the HST is in orbit, many of these tests will continue in order to give those responsible for the HST a reasonable prediction on the performance of the flight batteries. These tests will also be a source of needed low earth orbit (LEO) data for nickel hydrogen (Ni-H2) batteries and cells. One of the tests currently in progress at MSFC is a mission simulation test on a 22-cell Ni-H2 battery. This battery is composed of spare cells taken from the lot of cells out of which the Flight Spare Module was assembled. This module is one of two modules launched on the HST. This battery has been on test since Jun. 1989 and has completed nearly 8000 LEO cycles. A series of characterization tests were run prior to the start of the mission simulation and a launch scenario test was run in Feb. and Mar. 1990 to test the behavior of the cells through a simulated launch. The results from these tests as well as the overall performance of the battery as it continues to cycle are reported.

  11. Active Optics and Coronography with the Hubble Space Telescope

    E-print Network

    Fabien Malbet; Michael Shao; Jeffrey Yu

    1994-04-12

    In the field of planet and proto-planetary disk detection, achieving high angular resolution and high dynamic range is a necessity. Coronography coupled with adaptive optics on Hubble Space Telescope is a way to get both good spatial resolution and high dynamic range. However, because of the residual figure errors on the primary and on the secondary, HST has a scattered light level that prevents it from detecting extra-solar planets. Our simulations show that by using an active mirror (400-1000 actuators) in the optical path of HST with adaptive optics, we can correct the mirror errors and decrease the scattering level by a factor $10^{2}$ (from $10^{-4}$ to $10^{-6}$ fainter than the star). Furthermore, by controlling the spatial frequencies of the active mirror with a {\\em dark hole\\/} algorithm we can decrease the scattering level in image zones where planet detection is likely. Using this technique, we have succeeded in decreasing the scattering level to $3\\times 10^{-8}$ of the star intensity within 1 arcsec from the central star. This will allow the detection of a Jupiter-like planet $10^{-9}$ times dimmer than the central star located 10 pc away in 1 hour of integration time with a signal-to-noise ratio of 5. This paper describes the method used to determine the actuator strokes applied to a deformable mirror to achieve planet detection and the design of a coronograph which implements this novel technique.

  12. Hubble Space Telescope solar cell module thermal cycle test

    NASA Technical Reports Server (NTRS)

    Douglas, Alexander; Edge, Ted; Willowby, Douglas; Gerlach, Lothar

    1992-01-01

    The Hubble Space Telescope (HST) solar array consists of two identical double roll-out wings designed after the Hughes flexible roll-up solar array (FRUSA) and was developed by the European Space Agency (ESA) to meet specified HST power output requirements at the end of 2 years, with a functional lifetime of 5 years. The requirement that the HST solar array remain functional both mechanically and electrically during its 5-year lifetime meant that the array must withstand 30,000 low Earth orbit (LEO) thermal cycles between approximately +100 and -100 C. In order to evaluate the ability of the array to meet this requirement, an accelerated thermal cycle test in vacuum was conducted at NASA's Marshall Space Flight Center (MSFC), using two 128-cell solar array modules which duplicated the flight HST solar array. Several other tests were performed on the modules. The thermal cycle test was interrupted after 2,577 cycles, and a 'cold-roll' test was performed on one of the modules in order to evaluate the ability of the flight array to survive an emergency deployment during the dark (cold) portion of an orbit. A posttest static shadow test was performed on one of the modules in order to analyze temperature gradients across the module. Finally, current in-flight electrical performance data from the actual HST flight solar array will be tested.

  13. Astrometry of the omega Centauri Hubble Space Telescope Calibration Field

    NASA Technical Reports Server (NTRS)

    Mighell, Kenneth J.

    2000-01-01

    Astrometry, on the International Celestial Reference Frame (epoch J2000.0), is presented for the Walker (1994, PASP, 106, 828) stars in the omega Centauri (=NGC 5139=C 1323-1472) Hubble Space Telescope Wide Field/Planetary Camera (WF/PC) calibration field of Harris et al. (1993, AJ, 105, 1196). Harris et al. stars were first identified on a WFPC2 observation of the omega Cen HST calibration field. Relative astrometry of the Walker stars in this field was then obtained using Walker's CCD positions and astrometry derived using the STSDAS METRIC task on the positions of the Harris et al. stars on the WFPC2 observation. Finally, the relative astrometry, which was based on the HST Guide Star Catalog, is placed on the International Celestial Reference Frame with astrometry from the USNO-A2.0 catalog. An ASCII text version of the astrometric data of the Walker stars in the omega Cen HST calibration field is available electronically in the online version of the article.

  14. Hubble space telescope calspec flux standards: Sirius (and Vega)

    SciTech Connect

    Bohlin, R. C., E-mail: bohlin@stsci.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2014-06-01

    The Space Telescope Imaging Spectrograph (STIS) has measured the flux for Sirius from 0.17 to 1.01 ?m on the Hubble Space Telescope (HST) White Dwarf scale. Because of the cool debris disk around Vega, Sirius is commonly recommended as the primary IR flux standard. The measured STIS flux agrees well with predictions of a special Kurucz model atmosphere, adding confidence to the modeled IR flux predictions. The IR flux agrees to 2%-3% with respect to the standard template of Cohen and to 2% with the Midcourse Space Experiment absolute flux measurements in the mid-IR. A weighted average of the independent visible and mid-IR absolute flux measures implies that the monochromatic flux at 5557.5 Å (5556 Å in air) for Sirius and Vega, respectively, is 1.35 × 10{sup –8} and 3.44 × 10{sup –9} erg cm{sup –2} s{sup –1} Å{sup –1} with formal uncertainties of 0.5%. Contrary to previously published conclusions, the Hipparcos photometry offers no support for the variability of Vega. Pulse pileup severely affects the Hp photometry for the brightest stars.

  15. Utility of observational Hubble parameter data on dark energy evolution

    E-print Network

    Meng, Xiao-Lei; Li, Shi-Yu; Zhang, Tong-Jie

    2015-01-01

    Aiming at exploring the nature of dark energy, we use thirty-six observational Hubble parameter data (OHD) in the redshift range $0 \\leqslant z \\leqslant 2.36$ to make a cosmological model-independent test of the two-point $Omh^2(z_{2};z_{1})$ diagnostic. In $\\Lambda$CDM, we have $Omh^2 \\equiv \\Omega_{m}h^2$, where $\\Omega_{m}$ is the matter density parameter at present. We bin all the OHD into four data points to mitigate the observational contaminations. By comparing with the value of $\\Omega_{m}h^2$ which is constrained tightly by the Planck observations, our results show that in all six testing pairs of $Omh^2$ there are two testing pairs are consistent with $\\Lambda$CDM at $1\\sigma$ confidence level (CL), whereas for another two of them $\\Lambda$CDM can only be accommodated at $2\\sigma$ CL. Particularly, for remaining two pairs, $\\Lambda$CDM is not compatible even at $2\\sigma$ CL. Therefore it is reasonable that although deviations from $\\Lambda$CDM exist for some pairs, cautiously, we cannot rule out th...

  16. Hubble Servicing Challenges Drive Innovation of Shuttle Rendezvous Techniques

    NASA Technical Reports Server (NTRS)

    Goodman, John L.; Walker, Stephen R.

    2009-01-01

    Hubble Space Telescope (HST) servicing, performed by Space Shuttle crews, has contributed to what is arguably one of the most successful astronomy missions ever flown. Both nominal and contingency proximity operations techniques were developed to enable successful servicing, while lowering the risk of damage to HST systems, and improve crew safety. Influencing the development of these techniques were the challenges presented by plume impingement and HST performance anomalies. The design of both the HST and the Space Shuttle was completed before the potential of HST contamination and structural damage by shuttle RCS jet plume impingement was fully understood. Relative navigation during proximity operations has been challenging, as HST was not equipped with relative navigation aids. Since HST reached orbit in 1990, proximity operations design for servicing missions has evolved as insight into plume contamination and dynamic pressure has improved and new relative navigation tools have become available. Servicing missions have provided NASA with opportunities to gain insight into servicing mission design and development of nominal and contingency procedures. The HST servicing experiences and lessons learned are applicable to other programs that perform on-orbit servicing and rendezvous, both human and robotic.

  17. Hubble Hatches Image of Rotten Egg Nebula Shocks

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Some 5,000 light years (2,900 trillion miles) from Earth, in the constellation Puppis, is the 1.4 light years (more than 8 trillion miles) long Calabash Nebula, referred to as the Rotten Egg Nebula because of its sulfur content which would produce an awful odor if one could smell in space. This image of the nebula captured by NASA's Hubble Space Telescope (HST) depicts violent gas collisions that produced supersonic shock fronts in a dying star. Stars, like our sun, will eventually die and expel most of their material outward into shells of gas and dust These shells eventually form some of the most beautiful objects in the universe, called planetary nebulae. The yellow in the image depicts the material ejected from the central star zooming away at speeds up to one and a half million kilometers per hour (one million miles per hour). Due to the high speeds of the gas, shock-fronts are formed on impact and heat the surrounding gas. Although computer calculations have predicted the existence and structure of such shocks for some time, previous observations have not been able to prove the theory.

  18. Hubble Space Telescope Bi-Stem Thermal Shield Analyses

    NASA Technical Reports Server (NTRS)

    Finlay, Katherine A.

    2004-01-01

    The Hubble Space Telescope (HST) was launched April 24, 1990, and was deployed April 25 into low Earth orbit (LEO). It was soon discovered that the metal poles holding the solar arrays were expanding and contracting as the telescope orbited the Earth passing between the sunlight and the Earth s shadow. The expansion and contraction, although very small, was enough to cause the telescope to shake because of thermal-induced jitters, a detrimental effect when trying to take pictures millions of miles away. Therefore, the European Space Agency (ESA, the provider of the solar arrays) built new solar arrays (SA-11) that contained bi-stem thermal shields which insulated the solar array metal poles. These thermal shields were made of 2 mil thick aluminized-Teflon fluorinated ethylene propylene (FEP) rings fused together into a circular bellows shape. The new solar arrays were put on the HST during an extravehicular activity (EVA), also called an astronaut space walk, during the first servicing mission (SM1) in December 1993. An on-orbit photograph of the HST with the SA-11, and a close up of the bellows-like structure of the thermal shields is provided in Figure 1.

  19. SHIELD: Distance Estimates from Hubble Space Telescope Imaging

    NASA Astrophysics Data System (ADS)

    Cave, Ian; Cannon, J. M.; Larson, E.; Marshall, M.; Moody, S.; Adams, E. A.; Dolphin, A. E.; Elson, E. C.; Giovanelli, R.; Haynes, M. P.; McQuinn, K. B.; Ott, J.; Saintonge, A.; Salzer, J. J.; Skillman, E. D.

    2013-01-01

    The Survey of HI in Extremely Low-mass Dwarfs (SHIELD) is an ongoing study of twelve galaxies with HI masses between 106 and 107 Solar masses, detected by the Arecibo Legacy Fast ALFA (ALFALFA) survey. Here we present new Hubble Space Telescope (HST) imaging of the SHIELD galaxies. The primary goal is to determine the distance of each galaxy. We apply two techniques to measure the apparent magnitude of the tip of the red giant branch (TRGB) feature in the HST color magnitude diagrams. First, a custom designed edge detection filter was written to determine the TRGB magnitude based on a user-selected region of the color magnitude diagram. Second, we apply the maximum likelihood technique implemented in the "TRGBtool" software package (Makarov et al. 2006). In addition to the distances based on the TRGB feature, we also use the MATCH software (Dolphin 2002) to determine the best-fit distance based on the overall CMD morphology. We compare these distance estimates for all members of the SHIELD galaxies, and present a final table of distances that is used in each of the companion SHIELD presentations.

  20. A Mechanical Cryogenic Cooler for the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Jedrich, Nicholas; Zimbelman, Darell; Swift, Walter; Dolan, Francis; Brumfield, Mark (Technical Monitor)

    2002-01-01

    This paper presents a description of the Hubble Space Telescope (HST) Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) Cryo Cooler (NCC), the cutting edge technology involved, its evolution, performance, and future space applications. The NCC is the primary hardware component of the NICMOS Cooling System comprised of the NCC, an Electronics Support Module, a Capillary Pumped Loop/Radiator, and associated interface harnessing. The system will be installed during extravehicular activities on HST during Servicing Mission 3B scheduled for launch in February 2002. The NCC will be used to revive the NICMOS instrument, which experienced a reduced operational lifetime due to an internal thermal short in its dewar structure, and restore HST scientific infrared capability to operational status. The NCC is a state-of-the-art reverse Turbo-Brayton cycle cooler employing gas bearing micro turbo machinery, driven by advanced power conversion electronics, operating at speeds up to 7300 revolutions per second (rps) to remove heat from the NICMOS instrument.

  1. SHUCS: the Snapshot Hubble U-band Cluster Survey

    NASA Astrophysics Data System (ADS)

    Konstantopoulos, Iraklis; SHUCS Collaboration

    2012-01-01

    Star clusters represent a step in the star formation hierarchy above individual stars. As such, they maintain a link to the overall star formation in any galaxy, while their brightness turns them into beacons of star formation in systems out to 100 Mpc. The study of extra-galactic star clusters and their populations has undergone a revival since the launch of HST. However, their use as direct tracers of star formation depends on understanding fundamental laws that regulate the fraction of stars that form in clusters, as well as those that govern the destruction of star clusters. The Snapshot Hubble U-band Cluster Survey (SHUCS) is designed to take a few steps in that direction. By completing the UBVI baseline for galaxies with existing archival BVI coverage, we will derive the ages, masses and luminosities of thousands of clusters in 22 galaxies. This way we will be able to rule out theories and empirical scenarios regarding the formation and destruction of star clusters, and the role of environment in these processes. This talk will present a description of the survey and its many goals, and go through some first results.

  2. Hubble flows and gravitational potentials in observable Universe

    SciTech Connect

    Eingorn, Maxim; Zhuk, Alexander, E-mail: maxim.eingorn@gmail.com, E-mail: ai.zhuk2@gmail.com [Astronomical Observatory, Odessa National University, Street Dvoryanskaya 2, Odessa 65082 (Ukraine)

    2012-09-01

    In this paper, we consider the Universe deep inside of the cell of uniformity. At these scales, the Universe is filled with inhomogeneously distributed discrete structures (galaxies, groups and clusters of galaxies), which disturb the background Friedmann model. We propose mathematical models with conformally flat, hyperbolic and spherical spaces. For these models, we obtain the gravitational potential for an arbitrary number of randomly distributed inhomogeneities. In the cases of flat and hyperbolic spaces, the potential is finite at any point, including spatial infinity, and valid for an arbitrary number of gravitating sources. For both of these models, we investigate the motion of test masses (e.g., dwarf galaxies) in the vicinity of one of the inhomogeneities. We show that there is a distance from the inhomogeneity, at which the cosmological expansion prevails over the gravitational attraction and where test masses form the Hubble flow. For our group of galaxies, it happens at a few Mpc and the radius of the zero-acceleration sphere is of the order of 1 Mpc, which is very close to observations. Outside of this sphere, the dragging effect of the gravitational attraction goes very fast to zero.

  3. A simple method of determining the Hubble constant

    E-print Network

    Yi-Ping Qin

    2000-05-30

    Bidirectional relativistic proper motions of radio components of nearby extragalactic sources give a strong constraint on the determination of the Hubble constant $H_0$. Under the assumption that the real velocity of radio components of extragalactic sources is not less than that of Galactic sources, the value of $H_0$ can be estimated at a high level of accuracy. The assumption is reasonable due to the general belief that the activity in the core of galaxies must be more powerful than that of stars. This method is simple and with only one uncertainty --- the real velocity of components. This uncertainty is related to the value of the real velocity of componenets of Galactic sources and the latter is always well-determined (note that the determination is independent of $H_0$ and the distance of Galactic sources can be directly measured at a rather high level of accuracy). Hopefully the method will play an important role in future research to fix the value of $H_0$. With the data of the three sources available so far and the assumption that the real velocity of componenets of at least one of the sources is not less than a known velocity of componenets of a Galactic source, the constant is estimated to be within $27.08kms^{-1}Mpc^{-1} < H_0 \\leq 53.15kms^{-1}Mpc^{-1}$ with this method.

  4. Hubble Space Telescope CALSPEC Flux Standards: Sirius (and Vega)

    NASA Astrophysics Data System (ADS)

    Bohlin, R. C.

    2014-06-01

    The Space Telescope Imaging Spectrograph (STIS) has measured the flux for Sirius from 0.17 to 1.01 ?m on the Hubble Space Telescope (HST) White Dwarf scale. Because of the cool debris disk around Vega, Sirius is commonly recommended as the primary IR flux standard. The measured STIS flux agrees well with predictions of a special Kurucz model atmosphere, adding confidence to the modeled IR flux predictions. The IR flux agrees to 2%-3% with respect to the standard template of Cohen and to 2% with the Midcourse Space Experiment absolute flux measurements in the mid-IR. A weighted average of the independent visible and mid-IR absolute flux measures implies that the monochromatic flux at 5557.5 Å (5556 Å in air) for Sirius and Vega, respectively, is 1.35 × 10-8 and 3.44 × 10-9 erg cm-2 s-1 Å-1 with formal uncertainties of 0.5%. Contrary to previously published conclusions, the Hipparcos photometry offers no support for the variability of Vega. Pulse pileup severely affects the Hp photometry for the brightest stars.

  5. Cosmological Constraints from Hubble Parameter on f(R) Cosmologies

    E-print Network

    Carvalho, F C; Alcaniz, J S; Santos, J

    2008-01-01

    Modified $f(R)$ gravity in the Palatini approach has been presently applied to Cosmology as a realistic alternative to dark energy. In this concern, a number of authors have searched for observational constraints on several $f(R)$ gravity functional forms using mainly data of type Ia supenovae (SNe Ia), Cosmic Microwave Background ({\\rm CMB}) radiation and Large Scale Structure ({\\rm LSS}). In this paper, by considering a homogeneous and isotropic flat universe, we use determinations of the Hubble function $H(z)$, which are based on differential age method, to place bounds on the free parameters of the $f(R) = R - \\beta/R^{n}$ functional form. We also combine the $H(z)$ data with constraints from Baryon Acoustic Oscillations ({\\rm BAO}) and {\\rm CMB} measurements, obtaining ranges of values for $n$ and $\\beta$ in agreement with other independent analyses. We find that, for some intervals of $n$ and $\\beta$, models based on $f(R) = R - \\beta/R^{n}$ gravity in the Palatini approach, unlike the metric formalism,...

  6. Cosmological Constraints from Hubble Parameter on f(R) Cosmologies

    E-print Network

    F. C. Carvalho; E. M. Santos; J. S. Alcaniz; J. Santos

    2008-11-10

    Modified $f(R)$ gravity in the Palatini approach has been presently applied to Cosmology as a realistic alternative to dark energy. In this concern, a number of authors have searched for observational constraints on several $f(R)$ gravity functional forms using mainly data of type Ia supenovae (SNe Ia), Cosmic Microwave Background ({\\rm CMB}) radiation and Large Scale Structure ({\\rm LSS}). In this paper, by considering a homogeneous and isotropic flat universe, we use determinations of the Hubble function $H(z)$, which are based on differential age method, to place bounds on the free parameters of the $f(R) = R - \\beta/R^{n}$ functional form. We also combine the $H(z)$ data with constraints from Baryon Acoustic Oscillations ({\\rm BAO}) and {\\rm CMB} measurements, obtaining ranges of values for $n$ and $\\beta$ in agreement with other independent analyses. We find that, for some intervals of $n$ and $\\beta$, models based on $f(R) = R - \\beta/R^{n}$ gravity in the Palatini approach, unlike the metric formalism, can produce the sequence of radiation-dominated, matter-dominated, and accelerating periods without need of dark energy.

  7. Hubble Telescope Detects 'Sunscreen' Layer on Distant Planet - Duration: 21 seconds.

    NASA Video Gallery

    Using NASA’s Hubble Telescope, scientists detected a stratosphere on the planet WASP-33b. A stratosphere occurs when molecules in the atmosphere absorb ultraviolet and visible light from the star. ...

  8. Ending Hubble's Troubles. A Product Service Job Succeeds 357 Miles in Space. Resources in Technology.

    ERIC Educational Resources Information Center

    Deal, Walter E., III; And Others

    1995-01-01

    Provides information on the problems with the Hubble Space Telescope and how the National Aeronautics and Space Administration is trying to fix it. Includes a student quiz and possible student outcomes. (JOW)

  9. Hubble Space Telescope: The GO and GTO Observing Programs. Version 1.0

    NASA Technical Reports Server (NTRS)

    Saha, Abhijit

    1990-01-01

    Selected information from the current Hubble Space Telescope (HST) science programs for the Guaranteed Time Observers (GTO's) and General Observers (GO's) is presented. Included are program abstracts, detailed listings of specific targets, and exposure information.

  10. Back to Basics: Naked-Eye Astronomical Observation

    ERIC Educational Resources Information Center

    Barclay, Charles

    2003-01-01

    For pupils of both sexes and all ages from about six upwards, the subject of Astronomy holds many fascinations--the rapid changes in knowledge, the large resource of available IT packages and above all the beautiful pictures from Hubble and the large Earth-based telescopes. This article, however, stresses the excitement and importance of naked-eye…

  11. World's fastest and most sensitive astronomical camera

    NASA Astrophysics Data System (ADS)

    2009-06-01

    The next generation of instruments for ground-based telescopes took a leap forward with the development of a new ultra-fast camera that can take 1500 finely exposed images per second even when observing extremely faint objects. The first 240x240 pixel images with the world's fastest high precision faint light camera were obtained through a collaborative effort between ESO and three French laboratories from the French Centre National de la Recherche Scientifique/Institut National des Sciences de l'Univers (CNRS/INSU). Cameras such as this are key components of the next generation of adaptive optics instruments of Europe's ground-based astronomy flagship facility, the ESO Very Large Telescope (VLT). ESO PR Photo 22a/09 The CCD220 detector ESO PR Photo 22b/09 The OCam camera ESO PR Video 22a/09 OCam images "The performance of this breakthrough camera is without an equivalent anywhere in the world. The camera will enable great leaps forward in many areas of the study of the Universe," says Norbert Hubin, head of the Adaptive Optics department at ESO. OCam will be part of the second-generation VLT instrument SPHERE. To be installed in 2011, SPHERE will take images of giant exoplanets orbiting nearby stars. A fast camera such as this is needed as an essential component for the modern adaptive optics instruments used on the largest ground-based telescopes. Telescopes on the ground suffer from the blurring effect induced by atmospheric turbulence. This turbulence causes the stars to twinkle in a way that delights poets, but frustrates astronomers, since it blurs the finest details of the images. Adaptive optics techniques overcome this major drawback, so that ground-based telescopes can produce images that are as sharp as if taken from space. Adaptive optics is based on real-time corrections computed from images obtained by a special camera working at very high speeds. Nowadays, this means many hundreds of times each second. The new generation instruments require these corrections to be done at an even higher rate, more than one thousand times a second, and this is where OCam is essential. "The quality of the adaptive optics correction strongly depends on the speed of the camera and on its sensitivity," says Philippe Feautrier from the LAOG, France, who coordinated the whole project. "But these are a priori contradictory requirements, as in general the faster a camera is, the less sensitive it is." This is why cameras normally used for very high frame-rate movies require extremely powerful illumination, which is of course not an option for astronomical cameras. OCam and its CCD220 detector, developed by the British manufacturer e2v technologies, solve this dilemma, by being not only the fastest available, but also very sensitive, making a significant jump in performance for such cameras. Because of imperfect operation of any physical electronic devices, a CCD camera suffers from so-called readout noise. OCam has a readout noise ten times smaller than the detectors currently used on the VLT, making it much more sensitive and able to take pictures of the faintest of sources. "Thanks to this technology, all the new generation instruments of ESO's Very Large Telescope will be able to produce the best possible images, with an unequalled sharpness," declares Jean-Luc Gach, from the Laboratoire d'Astrophysique de Marseille, France, who led the team that built the camera. "Plans are now underway to develop the adaptive optics detectors required for ESO's planned 42-metre European Extremely Large Telescope, together with our research partners and the industry," says Hubin. Using sensitive detectors developed in the UK, with a control system developed in France, with German and Spanish participation, OCam is truly an outcome of a European collaboration that will be widely used and commercially produced. More information The three French laboratories involved are the Laboratoire d'Astrophysique de Marseille (LAM/INSU/CNRS, Université de Provence; Observatoire Astronomique de Marseille Prov

  12. Ultraviolet Galaxy Counts from STIS Observations of the Hubble Deep Fields1

    Microsoft Academic Search

    Jonathan P. Gardner; Thomas M. Brown; Henry C. Ferguson

    We present galaxy counts in the near-ultraviolet (NUV; 2365ûA) and far- ultraviolet (FUV; 1595ûA) obtained from Space Telescope Imaging Spectrograph (STIS) observations of portions of the Hubble Deep Field North (HDFN), the Hubble Deep Field South (HDFS), and a parallel field near the HDFN. All three fields have deep (AB>29) optical imaging, and we determine magnitudes by taking the ultraviolet

  13. Ultraviolet Galaxy Counts from STIS Observations of the Hubble Deep Fields

    Microsoft Academic Search

    Jonathan P. Gardner; Thomas M. Brown; Henry C. Ferguson

    2000-01-01

    We present galaxy counts in the near-ultraviolet (NUV; 2365\\\\AA) and far-ultraviolet (FUV; 1595\\\\AA) obtained from Space Telescope Imaging Spectrograph (STIS) observations of portions of the Hubble Deep Field North (HDFN), the Hubble Deep Field South (HDFS), and a parallel field near the HDFN. All three fields have deep (AB$>$29) optical imaging, and we determine magnitudes by taking the ultraviolet flux

  14. Ultraviolet Galaxy Counts from Space Telescope Imaging Spectrograph Observations of the Hubble Deep Fields

    Microsoft Academic Search

    Jonathan P. Gardner; Thomas M. Brown; Henry C. Ferguson

    2000-01-01

    We present galaxy counts in the near-ultraviolet (NUV; 2365 Å) and far-ultraviolet (FUV; 1595 Å) obtained from Space Telescope Imaging Spectrograph observations of portions of the Hubble Deep Field-North (HDF-N), the Hubble Deep Field-South (HDF-S), and a parallel field near the HDF-N. All three fields have deep (AB>29) optical imaging, and we determine magnitudes by taking the ultraviolet flux detected

  15. Near-UV Sources in the Hubble Ultra Deep Field: The Catalog

    Microsoft Academic Search

    Elysse N. Voyer; Duilia F. de Mello; Brian Siana; Jonathan P. Gardner; Cori Quirk; Harry I. Teplitz

    2009-01-01

    The catalog from the first high resolution U-band image of the Hubble Ultra\\u000aDeep Field, taken with Hubble's Wide Field Planetary Camera 2 through the F300W\\u000afilter, is presented. We detect 96 U-band objects and compare and combine this\\u000acatalog with a Great Observatories Origins Deep Survey (GOODS) B-selected\\u000acatalog that provides B, V, i, and z photometry, spectral types,

  16. Measurement of Hubble constant: Non-Gaussian Errors in HST key project data

    E-print Network

    Singh, Meghendra; Pandey, Ashwini

    2015-01-01

    Random errors in any data set are expected to follow the Gaussian distribution with zero mean. We propose an elegant method based on Kolmogorov-Smirnov statistic to test the above and apply it on the measurement of Hubble constant which determines the expansion rate of the Universe. The measurements were made using Hubble Space Telescope. Our analysis shows that the errors in the above measurement are non-Gaussian.

  17. Star Witness News: The Hubble Space Telescope--Time Machine to the Galaxies

    NSDL National Science Digital Library

    This news story details the deepest visible light observations of the early universe. This information can be used to introduce the idea that galaxies change over time and to help students realize the vastness of space. This selection is an adaptation of the HubbleSite press release: Hubble's Deepest View Ever of the Universe Unveils Earliest Galaxies. The article is from the Amazing Space science newspaper, The Star Witness, which can be used as a science content reading.

  18. Paired and Interacting Galaxies: International Astronomical Union Colloquium No. 124

    NASA Technical Reports Server (NTRS)

    Sulentic, Jack W. (editor); Keel, William C. (editor); Telesco, C. M. (editor)

    1990-01-01

    The proceedings of the International Astronomical Union Colloquium No. 124, held at the University of Alabama at Tuscaloosa, on December 4 to 7, are given. The purpose of the conference was to describe the current state of theoretical and observational knowledge of interacting galaxies, with particular emphasis on galaxies in pairs.

  19. MaRTA: A low-cost astronomical robotic facility

    NASA Astrophysics Data System (ADS)

    Salto, J. L.

    2014-12-01

    Marta (Maciarol Robotic Telescopes Array) is planned as a facility that allows its components work together or individually in astronomical tasks using telescopes with modest apertures and CCDs and other commercial devices fitting in a low-cost budget. With this equipment, we are able to obtain scientific data while operating remotely, in robotic or automatic mode.

  20. Infrared band strengths: Laboratory techniques and applications to astronomical observations

    NASA Astrophysics Data System (ADS)

    Gerakines, P. A.

    2002-09-01

    Whenever an abundance measurement is derived by way of infrared spectroscopy, it will typically make use of a laboratory-obtained conversion factor between the size of an IR absorption feature and the (column) density of the molecule under study. This factor is usually called the "absolute absorption intensity" by a chemist or the "band strength" by a typical IR astronomer. Band strengths have been studied in chemistry since the 1950s, and the commonly quoted "accuracy to with a factor of ten" historically required of astronomical calculations has not required much new input into this area. Today, however, astronomical measurements require much higher precision, and it is time for IR astronomers to ask more of laboratory measurements and to understand when and why to use IR band strengths in a more appropriate manner. The history, interpretation, measurement, and common astrophysical applications of infrared band strengths will be discussed. The "secrets" of the laboratory techniques involved in their measurement are described, and a compilation of results from the literature is given along with some new results. Typical astrophysical applications and appropriate uses will also be discussed. Common misconceptions are confronted and two challenges are presented: (i) to the laboratory astrophysics community to produce and advertise accurate values with caveats when necessary, and (ii) to the observational community to use the most appropriate results for the environment under study.