DOCSLIB.ORG

Astrophysics in 2000

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Astrophysics in 2000 UC Irvine UC Irvine Previously Published Works Title Astrophysics in 2000 Permalink https://escholarship.org/uc/item/5272z5d3 Journal Publications of the Astronomical Society of the Pacific, 113(787) ISSN 0004-6280 Authors Trimble, V Aschwanden, MJ Publication Date 2001-09-01 DOI 10.1086/322844 License https://creativecommons.org/licenses/by/4.0/ 4.0 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Publications of the Astronomical Society of the Pacific, 113:1025–1114, 2001 September ᭧ 2001. The Astronomical Society of the Pacific. All rights reserved. Printed in U.S.A. Invited Review Astrophysics in 2000 Virginia Trimble Department of Astronomy, University of Maryland, College Park, MD 20742; and Department of Physics and Astronomy, University of California, Irvine, CA 92697 and Markus J. Aschwanden Lockheed Martin Advanced Technology Center, Solar and Astrophysics Laboratory, Department L9-41, Building 252, 3251 Hanover Street, Palo Alto, CA 94304; [email protected] Received 2001 April 13; accepted 2001 April 13 ABSTRACT. It was a year in which some topics selected themselves as important through the sheer numbers of papers published. These include the connection(s) between galaxies with active central engines and galaxies with starbursts, the transition from asymptotic giant branch stars to white dwarfs, gamma-ray bursters, solar data from three major satellite missions, and the cosmological parameters, including dark matter and very large scale structure. Several sections are oriented around processes—accretion, collimation, mergers, and disruptions—shared by a number of kinds of stars and galaxies. And, of course, there are the usual frivolities of errors, omissions, exceptions, and inventories. 1. INTRODUCTION the Astronomical Society of India, Baltic Astronomy, New As- tronomy, IAU Circulars, and, of course, Publications of the Astrophysics in 2000 is the tenth, and probably last, of its Astronomical Society of the Pacific. On the grounds that even ilk. The predecessors, Astrophysics in 1991, 1992, etc., appear review writers are entitled to an occasional afternoon off, we somewhere near the beginnings of volumes 104 to 112 of PASP have reserved the right to look at Observatory, Journal of the and are cited below as Ap91, Ap92, and so forth. In the in- Royal Astronomical Society of Canada, Monthly Notices of the tervening decade, the number of astronomical words published Astronomical Society of South Africa, Journal of the American per year has increased by something like 50%, a growth that Association of Variable Star Observers, and a few others just is not reflected for some reason in the numbers of papers in- for fun, without systematic recording of their contents. dexed in Astronomy and Astrophysics Abstracts (22,848 in 1989 and 24,406 in 1999), many of them abstracts and con- 1.1. Ave ference presentations. But the time required to read the 5000 or so papers per year appearing in major journals has increased Among the entities to be welcomed this year were the re- proportionally and now exceeds what can be extracted from maining three mirrors, at 8 meters each, of the Very Large the authors’ other responsibilities. Or, from another point of Telescope, the dedications of the Green Bank Telescope and view, at its current rate of expansion of 5% per year, a paper LIGO (no published data from either yet), the opening of the copy of the Astrophysical Journal would close the universe by new Rose Center and Hayden Planetarium at the American 4450. Museum of Natural History (which also seems to have begun The journals scanned were the issues that reached the library a new custom of reviewing such exhibits as if they were books), shelves between 1 October 1999 and 30 September 2000 of the Gruber Prize in Cosmology (first two winners, P. James E. Nature, Physical Review Letters, Science, The Astrophysical Peebles and Allan R. Sandage), and the (apparently successful) Journal (plus Letters and Supplement Series), Monthly Notices launches of Newton-XMM (10 December), Cluster II (in two of the Royal Astronomical Society, Astronomy and Astrophysics lots, 12 July and 9 August), HETE II (a second try at the High (plus Supplements and Reviews), Astronomical Journal (always Energy Transient Explorer, the second adjective referring, we part of the data base, but unaccountably missing from the hope, to the events to be monitored, not to the mission itself), printed list in Ap99), Acta Astronomica, Revista Mexicana As- the Shenzhou “unoccupied orbiter” (21 hours in orbit on 26 tronomia y Astrofisica, Astrophysics and Space Science, As- November), the part of the International Space Station called tronomy Reports, Astronomy Letters, Astrofizica, Astronomi- Zvezda (on 12 July), and ACRIMSat (20 December). About sche Nachrichten, Journal of Astrophysics and Astronomy, 150 Ph.D.’s in astronomy and related subjects were awarded Publications of the Astronomical Society of Japan, Bulletin of in the USA during the year. 1025 1026 TRIMBLE & ASCHWANDEN 1.2. Atque John Wolbach, Philip Keenan, James Cuffey, Harrison Menden- During the year, there were some things that came and went, hall, Samuel Goldstein, Jeffrey Willick, Jerome Korman, Fred- or went and came, so quickly or so often that it was hard to erick Hollander, Jean Heidemann, K. Narahari Rao, James W.- decide whether to say “hello” or “goodbye.” Among these were K. Mark, Edward Dyer, Robert Hjellming, Henk van de Hulst, the radio interferometry satellite HALCA (with about three near- John Simpson, Bill Fastie, Donald Billing, John O’Keefe, Her- failures and rescues), NEAR (which came much NEARer to the bert Friedman, Frank Kerr, Raymond Grenchik, and Joseph We- asteroid Eros in February 2000 than in the previous year), the ber (on the 30th of September, last day of the index year and Pluto-Kuiper Express (which was cancelled, but followed first day of year 5761). quickly by a new Plutonic announcement of opportunity), MIR, 2. SOLAR PHYSICS New Astronomy Reviews (a reincarnation of the old Vistas in Astronomy), and the Iridium set of communications satellites Additional journals scanned for this section were Solar Phys- (which really does deserve to be called Dysprosium). A special ics and the relevant parts of Journal of Geophysical Research, award goes to Voyager 1, which has reached 76 AU from the Geophysical Research Letters, Advances in Space Research, Sun (the furthmost the mind of man has ever set foot, as it Astroparticle Physics,andSpace Science Reviews. The cut-off were) and still hasn’t reached the heliopause. date was set, in some cases, by arrival at the electronically mirrored website of NASA’s Astrophysics Data System rather 1.3. Vale than at library shelves. The usual guidelines pertain to this and the following eleven sections. Focus is on papers published Among the things we lost during the year were the Mars Polar during the reference year. Papers on which the present authors’ Lander and its associated penetrators (declared dead in Decem- names appear are cited only if they have been shown to be ber), the Compton Gamma Ray Observatory (put into a geosta- wrong. And the historical background is cited only occasionally tionary orbit on the ocean floor on 4 June), the NRAO 12-meter and erratically. In this context, it is worth remembering another dish (though closing a ground-based telescope is generally less of the classic sayings of Raymond Arthur Lyttleton. When it irreversible than the space-based case), Astro E (an unsuccessful was pointed out to him that his stationery, unlike the rest of launch on 10 February, continuing the Japanese tradition of never what was used at the Institute of Theoretical Astronomy in losing a named spacecraft), Comet LINEAR (whose brief ap- Cambridge, did not mention that Fred Hoyle was the director, pearance in July as six smaller comets showed that there is his response was, “Well, it doesn’t say he isn’t.” And so, if we intermediate-level structure between dust grains and the nucleus, have failed to say that you were the first to sweep dysprosium to be called cometesimals, if you must), and the Irish Astro- under the carpet, there was no intention to say that you weren’t. nomical Journal, which ceased publication in mid-volume after The following six sections explore the Sun from interior to 50 years. It was a somewhat informal, chatty publication (long heliosphere, inside out. Most of the new observations come edited by Ernst Opik), and its loss is yet another in a sequence from the currently operating space missions, Yohkoh,theSolar of relatively informal publications that have disappeared in recent and Heliospheric Observatory (SoHO), and the Transition Re- years, including Quarterly Journal of the Royal Astronomical gion and Coronal Explorer (TRACE). Society, Astrophysical Letters, and another journal edited for some years by the more blue-pencilled author and not named 2.1. Solar Interior here for fear of legal action. ROSAT collected a small amount of posthumous data between late October and late December 2.1.1. Neutrinos—Do They Care about the Solar Magnetic 1998, spotting az p 4.22 blazar and the highest redshift X-ray Field? absorption to date (Boller et al. 2000). And ASCA succumbed Our knowledge about the solar neutrino problem did not to atmospheric drag on 12 July. make a critical giant leap with century turn (see the Bahcall Our human losses included five staff members of IRAM killed & Davis 2000 Millennium Essay). Although we still are de- in an accident (to whom Cox et al. 2000 is dedicated), Dennis tecting a solar neutrino every other day with the Homestake Sciama (“doktorgrossvater” and even gross gross vater to a num- chlorine detector, the detected capture rate is still a factor of ber of US-based astronomers), Colin Ronan (one of the great three below theoretical predictions.
Load more

Recommended publications
  • The X-Ray Universe 2011
    THE X-RAY UNIVERSE 2011 27 - 30 June 2011 Berlin, Germany A conference organised by the XMM-Newton Science Operations Centre, European Space Astronomy Centre (ESAC), European Space Agency (ESA) ABSTRACT BOOK Oral Communications and Posters Edited by Andy Pollock with the help of Matthias Ehle, Cristina Hernandez, Jan-Uwe Ness, Norbert Schartel and Martin Stuhlinger Organising Committees Scientific Organising Committee Giorgio Matt (Universit`adegli Studi Roma Tre, Italy) Chair Norbert Schartel (XMM-Newton SOC, Madrid, ESA) Co-Chair M. Ali Alpar (Sabanci University, Istanbul, Turkey) Didier Barret (Centre d’Etude Spatiale des Rayonnements, Toulouse, France) Ehud Behar (Technion Israel Institute of Technology, Haifa, Israel) Hans B¨ohringer (MPE, Garching, Germany) Graziella Branduardi-Raymont (University College London-MSSL, Dorking, UK) Francisco J. Carrera (Instituto de F´ısicade Cantabria, Santander, Spain) Finn E. Christensen (Danmarks Tekniske Universitet, Copenhagen, Denmark) Anne Decourchelle (Commissariat `al’´energie atomique et aux ´energies alternatives, Saclay, France) Jan-Willem den Herder (SRON, Utrecht, The Netherlands) Rosario Gonzalez-Riestra (XMM-Newton SOC, Madrid, ESA) Coel Hellier (Keele University, UK) Stefanie Komossa (MPE, Garching, Germany) Chryssa Kouveliotou (NASA/Marshall Space Flight Center, Huntsville, Alabama, USA) Kazuo Makishima (University of Tokyo, Japan) Sera Markoff (University of Amsterdam, The Netherlands) Brian McBreen (University College Dublin, Ireland) Brian McNamara (University of Waterloo, Canada)
    [Show full text]
  • Weak Lensing Galaxy Cluster Field Reconstruction
    Mon. Not. R. Astron. Soc. 000, 1–12 (2012) Printed 14 October 2018 (MN LATEX style file v2.2) Weak Lensing Galaxy Cluster Field Reconstruction E. Jullo1, S. Pires2, M. Jauzac3 & J.-P. Kneib4;1 1Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388, Marseille, France 2Laboratoire AIM, CEA/DSM-CNRS, Université Paris 7 Diderot, IRFU/SAp-SEDI, Service d’Astrophysique, CEA Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette, France 3Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Durban 4041, South Africa 4LASTRO, Ecole polytechnique fédérale de Lausanne, Suisse Released 2013 Xxxxx XX ABSTRACT In this paper, we compare three methods to reconstruct galaxy cluster density fields with weak lensing data. The first method called FLens integrates an inpainting concept to invert the shear field with possible gaps, and a multi-scale entropy denoising proce- dure to remove the noise contained in the final reconstruction, that arises mostly from the random intrinsic shape of the galaxies. The second and third methods are based on a model of the density field made of a multi-scale grid of radial basis functions. In one case, the model parameters are computed with a linear inversion involving a singular value decomposition. In the other case, the model parameters are estimated using a Bayesian MCMC optimization implemented in the lensing software Lenstool. Methods are compared on simulated data with varying galaxy density fields. We pay particular attention to the errors estimated with resampling. We find the multi-scale grid model optimized with MCMC to provide the best results, but at high computational cost, especially when considering resampling.
    [Show full text]
  • Glossary Glossary
    Glossary Glossary Albedo A measure of an object’s reflectivity. A pure white reflecting surface has an albedo of 1.0 (100%). A pitch-black, nonreflecting surface has an albedo of 0.0. The Moon is a fairly dark object with a combined albedo of 0.07 (reflecting 7% of the sunlight that falls upon it). The albedo range of the lunar maria is between 0.05 and 0.08. The brighter highlands have an albedo range from 0.09 to 0.15. Anorthosite Rocks rich in the mineral feldspar, making up much of the Moon’s bright highland regions. Aperture The diameter of a telescope’s objective lens or primary mirror. Apogee The point in the Moon’s orbit where it is furthest from the Earth. At apogee, the Moon can reach a maximum distance of 406,700 km from the Earth. Apollo The manned lunar program of the United States. Between July 1969 and December 1972, six Apollo missions landed on the Moon, allowing a total of 12 astronauts to explore its surface. Asteroid A minor planet. A large solid body of rock in orbit around the Sun. Banded crater A crater that displays dusky linear tracts on its inner walls and/or floor. 250 Basalt A dark, fine-grained volcanic rock, low in silicon, with a low viscosity. Basaltic material fills many of the Moon’s major basins, especially on the near side. Glossary Basin A very large circular impact structure (usually comprising multiple concentric rings) that usually displays some degree of flooding with lava. The largest and most conspicuous lava- flooded basins on the Moon are found on the near side, and most are filled to their outer edges with mare basalts.
    [Show full text]
  • The Evolution of Helium White Dwarfs: Applications to Millisecond
    Pulsar Astronomy — 2000 and Beyond ASP Conference Series, Vol. 3 × 108, 1999 M. Kramer, N. Wex, and R. Wielebinski, eds. The evolution of helium white dwarfs: Applications for millisecond pulsars T. Driebe and T. Bl¨ocker Max-Planck-Institut f¨ur Radioastronomie, Bonn, Germany D. Sch¨onberner Astrophysikalisches Institut Potsdam, Potsdam, Germany 1. White Dwarf Evolution Low-mass white dwarfs with helium cores (He-WDs) are known to result from mass loss and/or exchange events in binary systems where the donor is a low mass star evolving along the red giant branch (RGB). Therefore, He-WDs are common components in binary systems with either two white dwarfs or with a white dwarf and a millisecond pulsar (MSP). If the cooling behaviour of He- WDs is known from theoretical studies (see Driebe et al. 1998, and references therein) the ages of MSP systems can be calculated independently of the pulsar properties provided the He-WD mass is known from spectroscopy. Driebe et al. (1998, 1999) investigated the evolution of He-WDs in the mass range 0.18 < MWD/M⊙ < 0.45 using the code of Bl¨ocker (1995). The evolution of a 1 M⊙-model was calculated up to the tip of the RGB. High mass loss termi- nated the RGB evolution at appropriate positions depending on the desired final white dwarf mass. When the model started to leave the RGB, mass loss was virtually switched off and the models evolved towards the white dwarf cooling branch. The applied procedure mimicks the mass transfer in binary systems. Contrary to the more massive C/O-WDs (MWD ∼> 0.5 M⊙, carbon/oxygen core), whose progenitors have also evolved through the asymptotic giant branch phase, He-WDs can continue to burn hydrogen via the pp cycle along the cooling branch arXiv:astro-ph/9910230v1 13 Oct 1999 down to very low effective temperatures, resulting in cooling ages of the order of Gyr, i.
    [Show full text]
  • Glossary of Acronyms and Definitions
    CASSINI FINAL MISSION REPORT 2018 CASSINI FINAL MISSION REPORT 2019 1 Glossary of Acronyms and Definitions A A/D Analog-to-Digital AACS Attitude and Articulation Control Subsystem AAN Automatic Alarm Notification AB Approved By ABS timed Absolute Timed AC Acoustics AC Alternating Current ACC Accelerometer ACCE Accelerometer Electronics ACCH Accelerometer Head ACE Aerospace Communications & Information Expertise ACE Aerospace Control Environment ACE Air Coordination Element ACE Attitude Control Electronics ACI Accelerometer Interface ACME Antenna Calibration and Measurement Equipment ACP Aerosol Collector Pyrolyzer ACS Attitude Control Subsystem ACT Actuator ACT Automated Command Tracker ACTS Advanced Communications Technology Satellite AD Applicable Document ADAS AWVR Data Acquisition Software ADC Analog-to-Digital Converter ADP Automatic Data Processing AE Activation Energy AEB Agência Espacial Brasileira (Brazilian Space Agency) AF Air Force AFC AACS Flight Computer AFETR Air Force Eastern Test Range AFETRM Air Force Eastern Test Range Manual 2 CASSINI FINAL MISSION REPORT 2019 AFS Atomic Frequency Standard AFT Abbreviated Functional Test AFT Allowable Flight Temperature AFS Andrew File System AGC Automatic Gain Control AGU American Geophysical Union AHSE Assembly, Handling, & Support Equipment AIT Assembly, Integration & Test AIV Assembly, Integration & Verification AKR Auroral Kilometric Radiation AL Agreement Letter AL Aluminum AL Anomalously Large ALAP As Low As Practical ALARA As Low As Reasonably Achievable ALB Automated Link
    [Show full text]
  • Science in the Urantia Papers
    Science ¾ Scientific Validation of the UB z By Denver Pearson z By Phil Calabrese ¾ Seraphic Velocities ¾ Astronomy The Scientific Integrity of the Urantia Book by Denver Pearson As scientifically minded readers first peruse the Urantia Book, it soon occurs to them that many of its statements on the natural sciences conflict with currently held data and theories. In the minds of many this gives rise to doubts about the truthfulness of those statements. Wisdom would lead us to realize that nothing short of perfection is perfect, and anything touched by human hands has fingerprints. This should be our guiding thoughts as we contemplate the accuracy of the scientific content of the Urantia Papers. Several years ago, at the first scientific symposium, it was implied by one of the speakers that the revelation contains errors. This implication is alarming. More recently, at the second symposium held in Oklahoma, an interesting publication named "The Science Content of The Urantia Book" was made available (this document is obtainable from the Brotherhood of Man Library). In this publication is an article entitled "Time Bombs" in which the author suggests that the revelators planted certain inaccurate scientific statements in the book in order to prevent it from becoming a fetish. He states "...the revelators incorporated safeguards in the papers that would form The Urantia Book to diminish the tendency to regard it as an object of worship. What safeguards did they use? Suppose they decided to make sure that mortals reading it understood that some cosmological statements in the book would be found to be inaccurate".
    [Show full text]
  • Dolerites of Svalbard, North-West Barents Sea Shelf: Age, Tectonic Setting and Significance for Geotectonic Interpretation of Th
    RESEARCH/REVIEW ARTICLE Dolerites of Svalbard, north-west Barents Sea Shelf: age, tectonic setting and significance for geotectonic interpretation of the High-Arctic Large Igneous Province Krzysztof Nejbert1, Krzysztof P. Krajewski2, Elz˙bieta Dubin´ ska1 & Zolta´ nPe´ cskay3 1 Institute of Geochemistry, Mineralogy and Petrology, University of Warsaw, Al. Z˙ wirki i Wigury 93, PL-02089 Warsaw, Poland 2 Institute of Geological Sciences, Polish Academy of Sciences, Research Centre in Warsaw, ul. Twarda 51/55, PL-00818 Warsaw, Poland 3 Institute of Nuclear Research, Hungarian Academy of Sciences, Bem te´ r 18/c, HU-4026 Debrecen, Hungary Keywords Abstract Dolerite; geochemistry; petrogenesis; KÁAr whole rock ages; Svalbard; Cretaceous. The dolerites of Svalbard are mineralogically and geochemically homogeneous with geochemical features typical of continental within-plate tholeiites. Their Correspondence geochemistry is similar to tholeiites belonging to a bimodal suite defined as the Krzysztof P. Krajewski, Institute of Geologi- High-Arctic Large Igneous Province (HALIP). KÁAr dating of numerous cal Sciences, Polish Academy of Sciences, dolerites sampled from many locations across Svalbard define a narrow time Research Centre in Warsaw, ul. Twarda 51/ span of this magmatism from 125.593.6 to 78.392.6 Mya. Discrete peaks of 55, PL-00818 Warsaw, Poland. E-mail: [email protected] intensive activity occurred at 115.3, 100.8, 91.3 and 78.5 Mya corresponding to (1) breakup of the continental crust and formation of an initial rift as a result of mantle plume activity, located in the southern part of the Alpha Ridge; (2) magmatic activity related to spreading along the Alpha Ridge that led to the development of the initial oceanic crust and (3) continuation of spreading along the Alpha Ridge and termination of magmatic activity related to HALIP (last two peaks at 91.3 and 78.5 Mya).
    [Show full text]
  • Together We Can Do Great Things Gyda'n Gilydd, Gallwn Wneud
    Together we can do great things Gyda’n gilydd, gallwn wneud pethau mawr Headteacher/Prifathro Mrs S Parry Headteachers Blog Number 136 Blog Prifathro Rhif 5th March 2021 Dear Parents, Guardians and Students/Annwyl Rieni,Gwarchodwyr a Myfyrwyr LHS - the return This week, we received the wonderful news that infection rates in Wales have reduced to a rate that Welsh Government consider it safe for us to formally plan for the staggered return of all students from 15th March. On Monday 8th March I will send our comprehensive plans to all stakeholders to allow everyone to get ready to return. We are reviewing all risk assessments and health and safety processes around the school. As part of this, we will be sending out guidance and resources for the optional use of lateral flow testing for staff and students. Rest assured that we will temper our enthusiasm to get back with our commitment to health and safety. There will be significant additional measures in place. We are preparing all details in preparation to update you on Monday. Patagonia bound on our 100 Heroes Charity and Fitness Event! In the meantime, please do follow the link below to view a very special video message that has been made by the staff of City Hospice to talk about the impact that our 100 Heroes campaign can have on the work that they do. We are really touched to hear from the amazing staff who work at City Hospice. We are making the journey of 12,000km to Patagonia because City Hospice has provided love and care for many members of our community and is close to our heart.
    [Show full text]
  • General Guide to the Science and Cosmos Museum
    General guide to the Science and Cosmos Museum 1 Background: “Tenerife monts” and “Pico” near of Plato crater in the Moon PLANTA TERRAZA Terrace Floor 5 i 2 1 4 6 3 ASCENSOR 4 RELOJ DE SOL ECUATORIAL Elevator Analemmatic sundial i INFORMACIÓN 5 BUSTO PARLANTE Information “AGUSTÍN DE BETANCOURT” Agustín de Betancourt 1 PLAZA “AGUSTÍN DE talking bust BETANCOURT” Agustín de Betancourt 6 ZONA WI-FI Square Wi-Fi zone 2 ANTENA DE RADIOASTRONOMÍA Radioastronomy antenna 3 TELESCOPIO Telescope PLANTA BAJA Ground Floor WC 10 9 8 11 7 1 6 5 4 12 2 3 ASCENSOR Cosmos Lab - Creative Elevator Laboratory 1 EXPOSICIÓN 7 PLANETARIO Exhibition Planetarium 2 TALLER DE DIDÁCTICA 8 SALIDA DE EMERGENCIA Didactic Workshop Emergency exit 3 EFECTOS ÓPTICOS 9 MICROCOSMOS Optical illusions 10 SALÓN DE ACTOS 4 SALA CROMA KEY Assembly hall Chroma Key room 11 EXPOSICIONES TEMPORALES 5 LABERINTO DE ESPEJOS Temporary exhibitions Mirror Labyrinth 12 ZONA DE DESCANSO 6 COSMOS LAB - LABORATORIO Rest zone CREATIVO CONTENIDOS Contents 7 LA TIERRA The Earth 23 EL SOL The Sun 33 EL UNIVERSO The Universe 45 CÓMO FUNCIONA How does it work 72 EL CUERPO HUMANO The human body 5 ¿POR QUÉ PIRÁMIDES? Why pyramids? 1 Sacred places have often been con- ceived of as elevated spaces that draw the believer closer to the divi- nity. For this reason, once architec- tural techniques became sufficiently refined, mosques or cathedrals rai- sed their vaults, minarets, towers and spires to the sky. However, for thousands of years, the formula fa- voured by almost every culture was the pyramid.
    [Show full text]
  • Variable Star Classification and Light Curves Manual
    Variable Star Classification and Light Curves An AAVSO course for the Carolyn Hurless Online Institute for Continuing Education in Astronomy (CHOICE) This is copyrighted material meant only for official enrollees in this online course. Do not share this document with others. Please do not quote from it without prior permission from the AAVSO. Table of Contents Course Description and Requirements for Completion Chapter One- 1. Introduction . What are variable stars? . The first known variable stars 2. Variable Star Names . Constellation names . Greek letters (Bayer letters) . GCVS naming scheme . Other naming conventions . Naming variable star types 3. The Main Types of variability Extrinsic . Eclipsing . Rotating . Microlensing Intrinsic . Pulsating . Eruptive . Cataclysmic . X-Ray 4. The Variability Tree Chapter Two- 1. Rotating Variables . The Sun . BY Dra stars . RS CVn stars . Rotating ellipsoidal variables 2. Eclipsing Variables . EA . EB . EW . EP . Roche Lobes 1 Chapter Three- 1. Pulsating Variables . Classical Cepheids . Type II Cepheids . RV Tau stars . Delta Sct stars . RR Lyr stars . Miras . Semi-regular stars 2. Eruptive Variables . Young Stellar Objects . T Tau stars . FUOrs . EXOrs . UXOrs . UV Cet stars . Gamma Cas stars . S Dor stars . R CrB stars Chapter Four- 1. Cataclysmic Variables . Dwarf Novae . Novae . Recurrent Novae . Magnetic CVs . Symbiotic Variables . Supernovae 2. Other Variables . Gamma-Ray Bursters . Active Galactic Nuclei 2 Course Description and Requirements for Completion This course is an overview of the types of variable stars most commonly observed by AAVSO observers. We discuss the physical processes behind what makes each type variable and how this is demonstrated in their light curves. Variable star names and nomenclature are placed in a historical context to aid in understanding today’s classification scheme.
    [Show full text]
  • Martian Ice How One Neutrino Changed Astrophysics Remembering Two Former League Presidents
    Published by the Astronomical League Vol. 71, No. 3 June 2019 MARTIAN ICE HOW ONE NEUTRINO 7.20.69 CHANGED ASTROPHYSICS 5YEARS REMEMBERING TWO APOLLO 11 FORMER LEAGUE PRESIDENTS ONOMY T STR O T A H G E N P I E G O Contents N P I L R E B 4 . President’s Corner ASTRONOMY DAY Join a Tour This Year! 4 . All Things Astronomical 6 . Full Steam Ahead OCTOBER 5, From 37,000 feet above the Pacific Total Eclipse Flight: Chile 7 . Night Sky Network 2019 Ocean, you’ll be high above any clouds, July 2, 2019 For a FREE 76-page Astronomy seeing up to 3¼ minutes of totality in a PAGE 4 9 . Wanderers in the Neighborhood dark sky that makes the Sun’s corona look Day Handbook full of ideas and incredibly dramatic. Our flight will de- 10 . Deep Sky Objects suggestions, go to: part from and return to Santiago, Chile. skyandtelescope.com/2019eclipseflight www.astroleague.org Click 12 . International Dark-Sky Association on "Astronomy Day” Scroll 14 . Fire & Ice: How One Neutrino down to "Free Astronomy Day African Stargazing Safari Join astronomer Stephen James ̃̃̃Changed a Field Handbook" O’Meara in wildlife-rich Botswana July 29–August 4, 2019 for evening stargazing and daytime PAGE 14 18 . Remembering Two Former For more information, contact: safari drives at three luxury field ̃̃̃Astronomical League Presidents Gary Tomlinson camps. Only 16 spaces available! Astronomy Day Coordinator Optional extension to Victoria Falls. 21 . Coming Events [email protected] skyandtelescope.com/botswana2019 22 . Gallery—Moon Shots 25 . Observing Awards Iceland Aurorae September 26–October 2, 2019 26 .
    [Show full text]
  • Nova Report 2006-2007
    NOVA REPORTNOVA 2006 - 2007 NOVA REPORT 2006-2007 Illustration on the front cover The cover image shows a composite image of the supernova remnant Cassiopeia A (Cas A). This object is the brightest radio source in the sky, and has been created by a supernova explosion about 330 year ago. The star itself had a mass of around 20 times the mass of the sun, but by the time it exploded it must have lost most of the outer layers. The red and green colors in the image are obtained from a million second observation of Cas A with the Chandra X-ray Observatory. The blue image is obtained with the Very Large Array at a wavelength of 21.7 cm. The emission is caused by very high energy electrons swirling around in a magnetic field. The red image is based on the ratio of line emission of Si XIII over Mg XI, which brings out the bi-polar, jet-like, structure. The green image is the Si XIII line emission itself, showing that most X-ray emission comes from a shell of stellar debris. Faintly visible in green in the center is a point-like source, which is presumably the neutron star, created just prior to the supernova explosion. Image credits: Creation/compilation: Jacco Vink. The data were obtained from: NASA Chandra X-ray observatory and Very Large Array (downloaded from Astronomy Digital Image Library http://adil.ncsa.uiuc. edu). Related scientific publications: Hwang, Vink, et al., 2004, Astrophys. J. 615, L117; Helder and Vink, 2008, Astrophys. J. in press.
    [Show full text]