DOCSLIB.ORG

Ultraviolet Astronomy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Ultraviolet Astronomy AccessScience from McGraw-Hill Education Page 1 of 7 www.accessscience.com Ultraviolet astronomy Contributed by: Ana In es´ G omez´ de Castro Publication year: 2014 Study of astronomical objects by means of information obtained from the ultraviolet wavelength range of the electromagnetic spectrum, approximately 10–320 nanometers. The resonance transitions of the most abundant atomic species in the universe are observed in this range up to 6 temperatures as high as 10, K. Molecular gas is also very sensitive to ultraviolet radiation, since the electronic ,+ transitions of the most abundant molecules, including H, 2 , CO, OH, CS, CO, 2 , and C, 2 , are in this range. The number of resonance transitions per 10-nm spectral range is shown in Fig. 1 for the two most abundant molecules, H, 2 and HD, and for the most abundant species in the interstellar medium. It is evident that the ultraviolet range far surpasses the optical range in the density of spectral tracers. Thus, ultraviolet observations are the most sensitive means of detecting and measuring the properties of diffuse matter in the universe over a very wide range of physical conditions, from the warm gas evaporating from extrasolar planets at a few thousand kelvins to the hot gas in the intergalactic medium and in supernova remnants that reaches temperatures of 300,000 K. Moreover, ultraviolet radiation from astronomical sources is a powerful photoionizing agent, fundamental for astrochemistry and the study of the chemical evolution in biogenetic environments, such as the protoplanetary and young planetary disks. See See also: ASTRONOMICAL SPECTROSCOPY . Observatories The ultraviolet spectrum is divided into the extreme-ultraviolet (EUV, 10–90-nm), far-ultraviolet (FUV, 90–200-nm), and near-ultraviolet (NUV, 200–320-nm) ranges. The shorter the wavelength of the radiation, the more it is absorbed, limiting the distances suitable for observation. EUV radiation is heavily absorbed even by the diffuse cloudlets in the interstellar medium, with densities of 10–100 particles per cubic centimeter. Ultraviolet radiation is fully absorbed by the ozone layer in the atmosphere of the Earth; hence, ultraviolet observations are carried out from space. For technological reasons, most of the ultraviolet information about astronomical sources has been obtained in the FUV ∕ NUV range (115–320 nm). See See also: ULTRAVIOLET RADIATION . Ultraviolet astronomy began with instrumentation at high altitudes aboard sounding rockets for brief glimpses of the Sun and stars. In 1972, the S201 experiment was deployed on the lunar surface by the Apollo 16 mission (NASA), chiefly to measure stars brighter than magnitude 10. Some experiments were run from crewed low-Earth platforms, such as the GLAZAR telescope (1988) on board the Mir space station, and the FAUST (Far Ultraviolet Space Telescope) experiment run from the Spacelab-1 space station in 1984; both were equipped with ultraviolet imagers. Over the period 1985–1998, a number of missions were conducted or launched from the space shuttle, AccessScience from McGraw-Hill Education Page 2 of 7 www.accessscience.com WIDTH:DFig. 1 Number of resonance lines per 10 nm in the optical–ultraviolet range. Included are electronic transitions of the two most abundant molecules, H, 2 and HD (the molecule made of an atom of hydrogen and an atom of deuterium), and resonance transitions of other abundant atoms and ions. Also shown are wavelength ranges of the Far Ultraviolet Spectroscopic Explorer (FUSE), the Hubble Space Telescope (HST), and ground-based telescopes. ( Courtesy of FUSE Project, Center for Astrophysical Sciences, The Johns Hopkins University, http: ∕∕ fuse.pha.jhu.edu ∕ educ ∕ bill 697 sci.html ) including the ASTRO missions containing the Hopkins Ultraviolet Telescope, the UltraViolet Imaging Telescope, and the Wisconsin Ultraviolet Photo-Polarimeter Experiment. In addition, ultraviolet spectroscopy at medium and very high resolution was accomplished with the Orbiting and Retrievable Far and Extreme Ultraviolet Spectrometer and the Interstellar Medium Absorption Profile Spectrograph. The scientific data from these missions were acquired over the 7–10-day period that the shuttle orbited the Earth. See See also: SPACE FLIGHT ; SPACE SHUTTLE . By far the majority of ultraviolet astronomy has been carried out from orbiting space telescopes. The first major ultraviolet satellite observatories to be placed in space were the U.S. Orbiting Astronomical Observatories (OAOs). OAO 2 operated from 1968 to 1972 and provided the first full survey of the many kinds of ultraviolet sources in the sky, whereas OAO 3 ( Copernicus ) operated from 1972 to 1980 and obtained high-resolution spectra of bright ultraviolet-emitting stars in order to probe the composition and physical state of intervening interstellar gas and to study the stellar winds of hot stars. A number of smaller satellites, including the European AccessScience from McGraw-Hill Education Page 3 of 7 www.accessscience.com TD 1 and the Dutch ANS, also provided very important survey measurements of the ultraviolet brightnesses of astronomical sources. The InternationalUltraviolet Explorer (IUE), which operated from 1978 to 1996, provided, for the first time, worldwide continuous access to the ultraviolet range to probe the full potential of ultraviolet astronomy. IUE was a collaborative project of NASA, the European Space Agency (ESA), and the United Kingdom Science and Engineering Research Council (SERC). It consisted of a 45-cm-diameter (18-in.) telescope equipped with instrumentation for ultraviolet spectroscopy in the 120–320-nm spectral range. The telescope was in a high-Earth geosynchronous orbit to minimize the contribution from the Earth glow at ultraviolet wavelengths. It was operated in real time, as a ground-based observatory, with two sites: the U.S. site at Goddard Space Flight Center in Maryland and the European site at the Villafranca satellite tracking station in Madrid. The IUE obtained approximately 104,000 ultraviolet spectra of a wide range of astronomical objects, including comets and planets, cool and hot stars, exploding stars, external galaxies, and quasars. The Hubble Space Telescope (HST) was launched into low-Earth orbit in 1990 and was serviced over the years by the shuttle program with missions STS 61 (1993), STS 82 (1997), STS 103 (1999), STS 109 (2002), and STS 125 (2009). The HST is a NASA-led mission with the collaboration of the ESA. The HST is a 2.4-m-aperture (94-in.) telescope equipped with instrumentation for infrared, optical, and ultraviolet astronomy. Instrumentation flown for ultraviolet imaging in the HST has been the Wide-Field Planetary Camera 1 (WF ∕ PC-1, 1990–1993), to obtain images of astronomical objects over a wide field of view; the Faint Objects Camera (FOC, 1990–2002), to take advantage of the superb imaging quality of space observatories over small fields of view; and the Wide Field Planetary Camera 2 (WFPC2, 1994–2010). Currently available instruments for ultraviolet imaging are the Advanced Camera System (ACS), installed in 2002, and the Wide Field Planetary Camera 3 (WFPC3), installed in 2009. WFPC3 has only moderate access to the ultraviolet; it can observe only wavelengths greater than 200 nm. The instrumentation flown in the past for spectroscopy was the Faint Objects Spectrograph (FOS, 1990–1997), for low-resolution spectroscopy and spectropolarimetry of weak ultraviolet sources, and the Goddard High-Resolution Spectrograph (GHRS, 1990–1997), for high-resolution ultraviolet spectroscopy. Currently available instruments are the Space Telescope Imaging Spectrograph (STIS), installed in 1997, and the Cosmic Origins Spectrograph (COS), installed in 2009. See See also: HUBBLE SPACE TELESCOPE . Soon after the HST launch, it was realized that the primary mirror was suffering from spherical aberration. The Corrective Optics Space Telescope Axial Replacement (COSTAR) system was implemented by the STS 61 mission. COSTAR was designed as an optical correction device for light to be focused at the FOC, FOS, and GHRS. It replaced, early in the mission, the High-Speed Photometer (HSP, 1990–1993), built for high-accuracy measurement of rapid photometric variations in the optical and ultraviolet ranges. Instrumentation installed later was built with its own correcting optics. The space shuttle program formally ended on August 31, 2011. No further instruments are planned for the HST . After the last refurbishing mission in 2009, the HST is expected to be fully operational until 2017. AccessScience from McGraw-Hill Education Page 4 of 7 www.accessscience.com In 2003, a NASA-led international mission placed the Galaxy Evolution Explorer (GALEX), a 50-cm-diameter (20-in.) telescope, in a nearly circular orbit at an altitude of 695 km (432 mi) to map the ultraviolet sky. The ◦ telescope provides a very wide field of view of 1.25 diameter, ideally suited for its survey mission. GALEX has run several surveys, the largest being the All-Sky Imaging Survey (AIS). AIS covered 26,000 square degrees of the sky in two ultraviolet bands (134.4–178.6 nm and 177.1–283.1 nm), to limiting magnitudes of 20 and 21, respectively. At shorter wavelengths in the FUV, the Far Ultraviolet Spectroscopic Explorer (FUSE, 1999–2007) was the first mission to explore the 90–120-nm range at high spectral resolution. The satellite was launched into an 800-km (497-mi) low-Earth orbit. One of the primary goals of the mission was to measure the deuterium-to-hydrogen abundance ratio in the Milky Way Galaxy and in the intergalactic medium. The Far Ultraviolet Imaging Spectrograph (FIMS), also known as the Spectroscopy of Plasma Evolution from Astrophysical Radiation (SPEAR) instrument, was launched in South Korea’s first space science satellite (STSAT-1) in late 2003. FIMS ∕ SPEAR was intended to conduct the first large-scale spectral mapping of diffuse cosmic emission in the far ultraviolet (90–175 nm). In 1992, the extreme-ultraviolet window to the universe was opened with the launch of NASA’s Extreme Ultraviolet Explorer (EUVE) satellite, which continued operation until 2001.
Load more

Recommended publications
  • The Status and Future of EUV Astronomy
    The status and future of EUV astronomy M. A. Barstow∗, S. L. Casewell Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH, UK J. B. Holberg Lunar and Planetary Laboratory, 1541 East University Boulevard, Sonett Space Sciences Building, University of Arizona, Tucson, AZ 85721, USA M.P. Kowalski Naval Research Laboratory,4555 Overlook Ave SW Washington, DC 20375, USA Abstract The Extreme Ultraviolet wavelength range was one of the final windows to be opened up to astronomy. Nevertheless, it provides very important diagnostic tools for a range of astronomical objects, although the opacity of the interstellar medium restricts the majority of observations to sources in our own galaxy. This review gives a historical overview of EUV astronomy, describes current instrumental capabilities and examines the prospects for future facilities on small and medium-class satellite platforms. Keywords: Extreme Ultraviolet, Spectroscopy, White Dwarfs, Stellar Coronae, Interstellar Medium 1. Introduction arXiv:1309.2181v1 [astro-ph.SR] 9 Sep 2013 The Extreme Ultraviolet (EUV) nominally spans the wavelength range from 100 to 912 A,˚ although for practical purposes the edges are often some- what indistinct as instrument band-passes may extend short-ward into the soft X-ray or long-ward into the far ultraviolet (far-UV). The production of EUV photons is primarily associated with the existence of hot, 105-107 K gas ∗Corresponding Author: [email protected] Preprint submitted to Advances in Space Research October 29, 2018 in the Universe. Sources of EUV radiation can be divided into two main cat- egories, those where the emission arises from recombination of ions and elec- trons in a hot, optically thin plasma, giving rise to emission line spectra, and objects which are seen by thermal emission from an optically thick medium, resulting in a strong continuum spectrum which may contain features arising from transitions between different energy levels or ionisation stages of sev- eral elements.
    [Show full text]
  • Historian Corner
    Historian Corner - Low Earth Orbit (roughly circular orbit) By Barb Sande - Perigee: 537.0 km (333.7 miles) [email protected] - Apogee: 540.9 km (336.1 miles) - Inclination: 28.47 degrees - Period: 95.42 minutes ANNOUNCEMENT: MARK YOUR CALENDARS!!! HST Mission: th The Titan Panel Discussion in honor of the 15 - On-going optical (near-infrared to UV wavelength) anniversary of the end of the program has been astronomical observations of the universe scheduled for Thursday, October 15 from 1:00 to 3:00 - End of HST mission estimated to be 2030-2040 pm MDT via a Zoom teleconference (virtual panel). - Estimated costs of the HST program (including There are ten volunteers currently enlisted to participate replacement instruments and five servicing missions) in the panel, including Norm Fox, Bob Hansen, Ken = ~ $10 billion – does not include on-going science Zitek, Ralph Mueller, Larry Perkins, Dave Giere, Dennis Connection to Lockheed Martin: Brown, Jack Kimpton, Fred Luhmann, and Samuel - Lockheed Sunnyvale built and integrated the main Lukens. If you want to call into the panel discussion to HST spacecraft and systems hear the roundtable, please RSVP to me at the email - Martin Marietta/Lockheed Martin provided six above (emails only for RSVP, no phone calls). There are external tanks and associated subsystems for the limitations to Zoom attendance for meetings. The shuttle launches supporting the HST program. details of the meeting will be emailed to the attendees - at a later date (Zoom link). Program Profile This 2020 Q3 issue profiles the Hubble Space Telescope (HST) in honor of its 30th anniversary in orbit.
    [Show full text]
  • UV and Infrared Astronomy
    Why Put a Telescope In Space? • Access to light that does not penetrate the atmosphere • No seeing. A telescope can reach the diffraction limit: 1.22 l/D radians Astronomy in Space. I. UV Astronomy Ultraviolet Astronomy 912-3650 Å (Lyman Limit to Balmer jump) • Continuua of hot stars (spectral types O,B,A) • H I Lyman lines (1-n transitions) • Resonance lines of Li-like ions C IV, N V, O VI • H2 Lyman and Werner bands Normal incidence optics • Special UV-reflective coatings The Far Ultraviolet 912 to 1150 Å • Defined by Lyman limit, MgF cutoff at 1150 Å • LiF + Al reflects longward of 1050 Å • SiC reflects at shorter wavelengths The Astronomy Quarterly, Vol. 7, pp. 131-142, 1990 0364-9229f90 $3.00+.00 Printed in the USA. All rights reserved. Copyright (c) 1990 Pergamon Press plc ASTRONOMICAL ADVANTAGES History OFAN • 9/1/1946: Lyman Spitzer EXTRA-TERRESTRIAL OBSERVATORY proposed a Space Telescope in LYMAN SPITZER, Jr. ’ a Report to project Rand This study points out, in a very preliminary way, the results that might be expected from astronomical measurements made with a satellite • 1966: Spitzer (Princeton) vehicle. The discussion is divided into three parts, corresponding to three different assumptions concerning the amount of instrumentation provided. chairs NASA Ad Hoc In the first section it is assumed that no telescope is provided; in the second a 10-&h reflector is assumed; in the third section some of the results Committee on the "Scientific obtainable with a large reflecting telescope, many feet in diameter, and revolving about the earth above the terrestrial atmosphere, are briefly Uses of the Large Space sketched.
    [Show full text]
  • GRAVITY ASTROPHYSICS a Plan for the 1990S
    ULTRAVIOLET, VISIBLE, and GRAVITY ASTROPHYSICS A Plan for the 1990s (NASA-NP-I52) ULTRAVIOLET, N94-24973 VISI3LE, ANO GRAVITY ASTROPHYSICS: A PLAN FOR THE 1990'S (NASA) 76 p Unclas HI190 0207794 ORIGINAL PAGE COLOR PHOTOGRAPH National Aeronautics and Space Administration I-oreword N ASA'sprioritiesOfficefrom oftheSpaceU.S. NationalScience Academyand Applicationsof Sciences.(OSSA)Guidancereceivesto theadviceOSSAon Astrophysicsscientific strategyDivision,and in particular, is provided by dedicated Academy committees, ad hoc study groups and, at 10-year intervals, by broadly mandated astronomy and astrophysics survey committees charged with making recommen- dations for the coming decade. Many of the Academy's recommendations have important implications for the conduct of ultraviolet and visible-light astronomy from space. Moreover, these areas are now poised for an era of rapid growth. Through technological progress, ultraviolet astronomy has already risen from a novel observational technique four decades ago to the mainstream of astronomical research today. Recent developments in space technology and instrumen- tation have the potential to generate comparably dramatic strides in observational astronomy within the next 10 years. In 1989, the Ultraviolet and Visible Astrophysics Branch of the OSSA Astrophysics Division recognized the need for a new, long-range plan that would implement the Academy's recommendations in a way that yielded the most advantageous use of new technology. NASA's Ultraviolet, Visible, and Gravity Astrophysics Management Operations Working Group was asked to develop such a plan for the 1990s. Since the Branch holds programmatic responsibility for space research in gravitational physics and relativity, as well as for ultraviolet and visible-light astrophysics, missions in those areas were also included.
    [Show full text]
  • Observing Photons in Space
    —1— Observing photons in space For the truth of the conclusions of physical science, observation is the supreme court of appeals Sir Arthur Eddington Martin C.E. HuberI, Anuschka PauluhnI and J. Gethyn TimothyII Abstract This first chapter of the book ‘Observing Photons in Space’ serves to illustrate the rewards of observing photons in space, to state our aims, and to introduce the structure and the conventions used. The title of the book reflects the history of space astronomy: it started at the high-energy end of the electromagnetic spectrum, where the photon aspect of the radiation dominates. Nevertheless, both the wave and the photon aspects of this radiation will be considered extensively. In this first chapter we describe the arduous efforts that were needed before observations from pointed, stable platforms, lifted by rocket above the Earth’s atmosphere, became the matter of course they seem to be today. This exemplifies the direct link between technical effort — including proper design, construction, testing and calibration — and some of the early fundamental insights gained from space observations. We further report in some detail the pioneering work of the early space astronomers, who started with the study of γ- and X-rays as well as ultraviolet photons. We also show how efforts to observe from space platforms in the visible, infrared, sub-millimetre and microwave domains developed and led to today’s emphasis on observations at long wavelengths. The aims of this book This book conveys methods and techniques for observing photons1 in space. ‘Observing’ photons implies not only detecting them, but also determining their direction at arrival, their energy, their rate of arrival, and their polarisation.
    [Show full text]
  • Nasa Space Telescope Imaging Technology
    NASA SPACE TELESCOPE IMAGING TECHNOLOGY MISSION FACTS ENABLING TECHNOLOGY > Wide Field and Planetary Camera HUBBLE SPACE TELESCOPE Better understand > Completed more than 1.3 MILLION OBSERVATIONS the age of the universe > Traveled 4+ BILLION MILES on low Earth orbit 4+ > Goddard High Resolution Spectrograph “THE FORERUNNER” BILLION > Discovered that the universe is approximately MILES > High Speed Photometer L3HARRIS ROLE: 13.7 BILLION YEARS OLD > Faint Object Camera & Spectrograph Provided fine guidance and focus control systems and 2.4m backup mirror CHANDRA X-RAY Explain the structure, > Uses X-RAY VISION to detect extremely hot, > High Resolution Camera activity and evolution high-energy regions of space OBSERVATORY > Advanced CCD Imaging Spectrometer of the universe > Flies 200 TIMES HIGHER than Hubble – X-RAY “THE DETECTIVE” VISION > High Energy Transmission more than 1/3 of the way to the moon Grating Spectrometer L3HARRIS ROLE: > Provides data on quasars as they were > Low Energy Transmission Designed, integrated and 10 BILLION YEARS AGO Grating Spectrometer tested imaging system JAMES WEBB Observe distant events > Will be the MOST POWERFUL space telescope ever > Near-Infrared Camera and objects, such as the SPACE TELESCOPE > Will balance between gravity of Earth and sun > Near-Infrared Spectrograph formation of the first 940,000 MILES IN SPACE MOST “THE HISTORIAN” galaxies, stars and POWERFUL > Mid-Infrared Instrument planets in the universe > 6.5-METER MIRROR made of 18 gold-coated > Fine Guidance Sensor/Near InfraRed L3HARRIS
    [Show full text]
  • Instrument Handbook V7.0
    Version 7.0 October 2004 Near Infrared Camera and Multi-Object Spectrometer Instrument Handbook for Cycle 14 Space Telescope Science Institute 3700 San Martin Drive Baltimore, Maryland 21218 [email protected] Operated by the Association of Universities for Research in Astronomy, Inc., for the National Aeronautics and Space Administration User Support For prompt answers to any question, please contact the STScI Help Desk. • E-mail: [email protected] • Phone: (410) 338-1082 (800) 544-8125 (U.S., toll free) World Wide Web Information and other resources are available on the NICMOS World Wide Web site: • URL: http://www.stsci.edu/hst/nicmos Revision History Version Date Editors 1.0 June 1996 D.J. Axon, D. Calzetti, J.W. MacKenty, C. Skinner 2.0 July 1997 J.W. MacKenty, C. Skinner, D. Calzetti, and D.J. Axon 3.0 June 1999 D. Calzetti, L. Bergeron, T. Böker, M. Dickinson, S. Holfeltz, L. Mazzuca, B. Monroe, A. Nota, A. Sivaramakrishnan, A. Schultz, M. Sosey, A. Storrs, A. Suchkov. 4.0 May 2000 T. Böker, L. Bergeron, D. Calzetti, M. Dickinson, S. Holfeltz, B. Monroe, B. Rauscher, M. Regan, A. Sivaramakrishnan, A. Schultz, M. Sosey, A. Storrs 4.1 May 2001 A. Schultz, S. Arribas, L. Bergeron, T. Böker, D. Calzetti, M. Dickinson, S. Holfeltz, B. Monroe, K. Noll, L. Petro, M. Sosey 5.0 October 2002 S. Malhotra, L. Mazzuca, D. Calzetti, S. Arribas, L. Bergeron, T. Böker, M. Dickinson, B. Mobasher, K. Noll, L. Petro, E. Roye, A. Schultz, M. Sosey, C. Xu 6.0 October 2003 E. Roye, K. Noll, S.
    [Show full text]
  • Kepler Press
    National Aeronautics and Space Administration PRESS KIT/FEBRUARY 2009 Kepler: NASA’s First Mission Capable of Finding Earth-Size Planets www.nasa.gov Media Contacts J.D. Harrington Policy/Program Management 202-358-5241 NASA Headquarters [email protected] Washington 202-262-7048 (cell) Michael Mewhinney Science 650-604-3937 NASA Ames Research Center [email protected] Moffett Field, Calif. 650-207-1323 (cell) Whitney Clavin Spacecraft/Project Management 818-354-4673 Jet Propulsion Laboratory [email protected] Pasadena, Calif. 818-458-9008 (cell) George Diller Launch Operations 321-867-2468 Kennedy Space Center, Fla. [email protected] 321-431-4908 (cell) Roz Brown Spacecraft 303-533-6059. Ball Aerospace & Technologies Corp. [email protected] Boulder, Colo. 720-581-3135 (cell) Mike Rein Delta II Launch Vehicle 321-730-5646 United Launch Alliance [email protected] Cape Canaveral Air Force Station, Fla. 321-693-6250 (cell) Contents Media Services Information .......................................................................................................................... 5 Quick Facts ................................................................................................................................................... 7 NASA’s Search for Habitable Planets ............................................................................................................ 8 Scientific Goals and Objectives .................................................................................................................
    [Show full text]
  • Where Are All the Sirius-Like Binary Systems?
    Mon. Not. R. Astron. Soc. 000, 1-22 (2013) Printed 20/08/2013 (MAB WORD template V1.0) Where are all the Sirius-Like Binary Systems? 1* 2 3 4 4 J. B. Holberg , T. D. Oswalt , E. M. Sion , M. A. Barstow and M. R. Burleigh ¹ Lunar and Planetary Laboratory, Sonnett Space Sciences Bld., University of Arizona, Tucson, AZ 85721, USA 2 Florida Institute of Technology, Melbourne, FL. 32091, USA 3 Department of Astronomy and Astrophysics, Villanova University, 800 Lancaster Ave. Villanova University, Villanova, PA, 19085, USA 4 Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK 1st September 2011 ABSTRACT Approximately 70% of the nearby white dwarfs appear to be single stars, with the remainder being members of binary or multiple star systems. The most numerous and most easily identifiable systems are those in which the main sequence companion is an M star, since even if the systems are unresolved the white dwarf either dominates or is at least competitive with the luminosity of the companion at optical wavelengths. Harder to identify are systems where the non-degenerate component has a spectral type earlier than M0 and the white dwarf becomes the less luminous component. Taking Sirius as the prototype, these latter systems are referred to here as ‘Sirius-Like’. There are currently 98 known Sirius-Like systems. Studies of the local white dwarf population within 20 pc indicate that approximately 8 per cent of all white dwarfs are members of Sirius-Like systems, yet beyond 20 pc the frequency of known Sirius-Like systems declines to between 1 and 2 per cent, indicating that many more of these systems remain to be found.
    [Show full text]
  • Division a Fundamental Astronomy NC-‐5 Gravitational Wave
    25/11/14 1 TM LoIs for Commissions: http://www.iau.org/submissions/commissionproposal/list/ Sorted by "Parent Divisions" (or by "Cross-Divisions") Titles may be abridged. Division A Fundamental Astronomy NC-5 Gravitational Wave Astronomy NC-9 Astrometry NC-10 Computational Astrophysics NC-18 Rotation of the Earth NC-23 Dynamical Astronomy NC-26 Solar System Ephemerides NC-30 Fundamental Standards NC-36 Gravitational Lensing NC-46 Time Division B Facitilities, Technologies & Data Science NC-5 Gravitational Wave Astronomy NC-6 Computational Astrophysics NC-10 Computational Astrophysics NC-15 Photometry and Polarimetry NC-19 Ultraviolet Astronomy NC-21 Data and Documentation NC-27 Astronomical Telescopes NC-29 Time Domain Astronomy NC-34 Radio Astronomy NC-35 Optical and IR Interferometry NC-41 Astrostatistics & Astroinformatics NC-42 Laboratory Astrophysics NC-55 Protection of Observatory Sites NC-56 Computational Astrophysics Division C Education, Outreach & Heritage NC-10 Computational Astrophysics NC-11 Astronomy Education & Development NC-20 Astronomical Heritage NC-52 Astronomical Discoveries & Alerts NC-54 Communicating Astronomy NC-57 History of Astronomy Division D High-Energy Phenomena & Fundamental Physics NC-5 Gravitational Wave Astronomy NC-39 Gravitational Wave Astrophysics NC-44 Supernovae NC-53 BH & Evolution of Galaxies Division E Sun & Heliosphere NC-37 Solar Radiation and Structure NC-45 Space Weather etc. NC-49 Solar Activity 25/11/14 2 TM Division F Planetary Systems & Bioastronomy NC-12 Celestial Spectroscopy NC-13 Astrobiology
    [Show full text]
  • Hubble 4Th May 2020
    The Hubble Space Telescope …. and it’s successor …. plus ‘Edwin Hubble, his life and work’ Context - what and where • Solar system • Distances • Stars and Galaxies • The Milky Way • Earliest Light The Solar System The Solar system formed about 5 billion (5 thousand million) years ago. The circumference of Earth is 40,000km (25,000 miles) and of the Moon is 11,000 km (6,800 miles). We are, on average, 93 million miles (150 million kms) from the Sun, and it takes 8 minutes 20 seconds for light from the Sun to reach the Earth. The average distance from the Earth to the Sun is also known as one Astronomical Unit (AU). Astronomical units are usually used to measure distances within our Solar System. The Earth orbits the Sun in one year. One day is the time it takes for the earth to spin round once. Other planets orbit at different rates; eg, Jupiter takes 12 years for one orbit of the Sun; Mars takes 687 days. The Moon orbits around the Earth once every 27.32 days. It is 250 thousand miles (400 thousand km) away, so it takes 1.3 seconds for light to travel from the Moon to us. Every individual star your eyes can see in the night sky is in the Milky Way Galaxy. Our Sun is just one minor star in one Galaxy Distances and times Distances in space are so huge that new measurements are needed. The distance measurement often used is the light-year, the distance that light travels in one year in a vacuum.
    [Show full text]
  • The New and Improved Hubble Space Telescope by Sally Stephens, Astronomical Society of the Pacific
    www.astrosociety.org/uitc No. 26 - Winter 1994 © 1994, Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112. The New and Improved Hubble Space Telescope by Sally Stephens, Astronomical Society of the Pacific The small room at the Space Telescope Science Institute in Baltimore was packed, even though it was the middle of the night. Astronomers and technicians strained to get a good view of the monitor that would soon show them the first picture taken with the newly "fixed" Hubble Space Telescope (HST). At 1:00 a.m., on Dec. 18, 1993, the image was radioed from the telescope to the ground. Tension gave way to cheers and exuberant shouts as the image of a star appeared on the monitor, a star without any of the smeared light astronomers had come to expect from the telescope's flawed main mirror. According to Edward Weiler, Hubble Space Telescope Program Scientist, the HST had not only been fixed, but "fixed beyond our wildest expectations." What Had Happened? The Fix The Repair Mission "The Trouble with Hubble is Over" Crystal-Clear Images Activity: "Name That Angle" What Had Happened? When it was launched in 1990, astronomers expected to use the telescope to see farther into space and with greater clarity than had ever been possible. Circling 580 kilometers (360 miles) above the Earth's surface, the Hubble Space Telescope would float high above our turbulent atmosphere, which blurs the vision of even the largest telescopes on the ground. With the orbiting HST, astronomers hoped to see objects ten times more clearly than possible from the ground.
    [Show full text]