DOCSLIB.ORG

Taking the Measure of the Universe: Precision Astrometry with SIM

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Taking the Measure of the Universe: Precision Astrometry with SIM Accepted for publication in PASP, January 2008 issue A Preprint typeset using LTEX style emulateapj v. 08/22/09 TAKING THE MEASURE OF THE UNIVERSE: PRECISION ASTROMETRY WITH SIM PLANETQUEST Stephen C. Unwin1, Michael Shao2, Angelle M. Tanner2, Ronald J. Allen3, Charles A. Beichman4, David Boboltz5, Joseph H. Catanzarite2, Brian C. Chaboyer6, David R. Ciardi4, Stephen J. Edberg2, Alan L. Fey5, Debra A. Fischer7, Christopher R. Gelino8, Andrew P. Gould9, Carl Grillmair8, Todd J. Henry10, Kathryn V. Johnston11,12, Kenneth J. Johnston5, Dayton L. Jones2, Shrinivas R. Kulkarni4, Nicholas M. Law4, Steven R. Majewski13, Valeri V. Makarov2, Geoffrey W. Marcy14, David L. Meier2, Rob P. Olling15, Xiaopei Pan2, Richard J. Patterson13, Jo Eliza Pitesky2, Andreas Quirrenbach16, Stuart B. Shaklan2, Edward J. Shaya15, Louis E. Strigari17, John A. Tomsick18,19, Ann E. Wehrle20, and Guy Worthey21 Accepted for publication in PASP, January 2008 issue ABSTRACT Precision astrometry at microarcsecond accuracy has application to a wide range of astrophysical problems. This paper is a study of the science questions that can be addressed using an instrument with flexible scheduling that delivers parallaxes at about 4 microarcsec (µas) on targets as faint as V = 20, and differential accuracy of 0.6 µas on bright targets. The science topics are drawn primarily from the Team Key Projects, selected in 2000, for the Space Interferometry Mission PlanetQuest (SIM PlanetQuest). We use the capabilities of this mission to illustrate the importance of the next level of astrometric precision in modern astrophysics. SIM PlanetQuest is currently in the detailed design phase, having completed in 2005 all of the enabling technologies needed for the flight instrument. It will be the first space-based long baseline Michelson interferometer designed for precision astrometry. SIM will contribute strongly to many astronomical fields including stellar and galactic astrophysics, planetary systems around nearby stars, and the study of quasar and AGN nuclei. Using differential astrometry SIM will search for planets with masses as small as an Earth orbiting in the ‘habitable zone’ around the nearest stars, and could discover many dozen if Earth-like planets are common. It will characterize the multiple-planet systems that are now known to exist, and it will be able to search for terrestrial planets around all of the candidate target stars in the Terrestrial Planet Finder and Darwin mission lists. It will be capable of detecting planets around young stars, thereby providing insights into how planetary systems are born and how they evolve with time. Precision astrometry allows the measurement of accurate dynamical masses for stars in binary systems. SIM will observe significant numbers of very high- and low-mass stars, providing stellar masses to 1%, the accuracy needed to challenge physical models. Using precision proper motion measurements, SIM will probe the Galactic mass distribution, and through studies of tidal tails, the formation and evolution of the Galactic halo. SIM will contribute to cosmology through improved accuracy of the Hubble Constant. With repeated astrometric measurements of the nuclei of active galaxies, SIM will probe the dynamics of accretion disks around supermassive black holes, and the relativistic jets that emerge from them. Subject headings: Extrasolar Planets, Stars, Galaxies, Quasars and Active Galactic Nuclei, Astronom- ical Instrumentation arXiv:0708.3953v2 [astro-ph] 7 Nov 2007 1 Jet Propulsion Laboratory, California Institute of Tech- CT 06459 nology, 4800 Oak Grove Drive, Pasadena, CA 91109; 12 Columbia University, Pupin Physics Laboratories, 550 West [email protected] 2 120th Street, New York, NY 10027 Jet Propulsion Laboratory, California Institute of Technology, 13 University of Virginia, Department of Astronomy, P.O. Box 4800 Oak Grove Drive, Pasadena, CA 91109 3 400325, Charlottesville, VA 22904-4325 Space Telescope Science Institute, 3700 San Martin Drive, 14 University of California, Berkeley, 417 Campbell Hall, Berke- Baltimore, MD 21218 4 ley, CA 94720 Michelson Science Center, California Institute of Technology, 15 University of Maryland, Astronomy Department, 0227 CSS 770 S. Wilson Ave., Pasadena, CA 91125 5 College Park, MD 20742 United States Naval Observatory, 3450 Massachusetts Avenue 16 Landessternwarte Koenigstuhl 12, 69117 Heidelberg, Ger- NW, Washington DC 20392 6 many Department of Physics and Astronomy, 6127 Wilder Labora- 17 University of California at Irvine, Department of Physics and tory, Dartmouth College, Hanover, NH 03755 7 Astronomy, Irvine, CA 92697 Department of Physics and Astronomy, San Francisco State 18 University of California at San Diego, Center for Astrophysics University San Francisco, CA 95064 8 and Space Sciences, 9500 Gilman Drive, La Jolla, CA 92093 Spitzer Science Center, 1200 E. California Blvd., Pasadena, 19 Space Sciences Laboratory, 7 Gauss Way, University of CA 91125 9 California, Berkeley, CA 94720-7450 Department of Astronomy, The Ohio State University, 140 W. 20 Space Science Institute, 4750 Walnut Street, Suite 205, 18th Avenue, Columbus, OH 43210 10 Boulder, CO 80301 Department of Physics and Astronomy, Georgia State Uni- 21 Department of Physics and Astronomy, Washington State versity, Atlanta, GA 30303 11 University, Department of Physics and Astronomy, Webster Hall Van Vleck Observatory, Wesleyan University, Middletown, 1245, Pullman, WA 99164-2814 2 Unwin et al. paper. 1. INTRODUCTION Recommended by the 1990 NRC Decadal Survey Astrometry is perhaps the most fundamental, and old- (Bahcall 1990), SIM PlanetQuest entered its Formulation est of all areas in astronomy, and it remains a corner- Phase (Phase A) in October 1997 and was approved to stone of the field for the twenty-first century. Accurate enter Phase B in August 2003. SIM was again endorsed distances to astronomical objects are essential for de- by the 2000 NRC Decadal Survey (McKee & Taylor riving fundamental quantities like mass and luminosity. 2000) wherein it was assumed that SIM would be com- Photographic astrometry in the nineteenth and twen- pleted, making it unnecessary to rank it against new mis- tieth centuries laid the foundation for our understand- sion recommendations in that report. Technology devel- ing of local stellar populations by identifying the inhab- opment was completed in July 2005 and formally signed itants of the solar neighborhood (Gliese 1969; Luyten off by NASA Headquarters in March 2006 after extensive 1979). The Second US Naval Observatory CCD Astro- external independent review. Having completed nearly graph Catalog (UCAC2) is a CCD-based survey covering all of the Formulation Phase (Phase A/B), SIM is ready most of the sky, with accuracies of 15 70 milliarcsec to enter the Implementation Phase, with mature designs, (mas), depending on brightness (Zacharias− et al. 2004), well understood schedule and cost, and low technical and and utilizing the Hipparcos and Tycho-2 reference frame. cost risk. Unfortunately, there is no official launch date, Recent CCD based astrometry over narrow fields has since budget pressures on NASA’s Science Mission Direc- achieved an accuracy of less than 1 mas in a single mea- torate have resulted in NASA delaying the Implementa- surement (Pravdo et al. 2005). On still smaller scales, tion Phase. Lane & Muterspaugh (2004) have demonstrated 16 This paper covers the expected science contributions microarcsec measurements between the components≃ of a of SIM but does not describe any of the technical details 0.25-arcsecond binary, using the Palomar Testbed Inter- of the instrument or mission. Brief descriptions of the ferometer at 2 µm. CCD parallaxes now achieve typical instrument itself and the supporting technologies may errors of 0.5 mas (Harris et al. 2005). Wide-angle as- be found in several technical papers (Laskin 2006; Marr trometry using ground-based optical and near-IR inter- 2006; Shao 2006). A companion paper (Shao & Nemati, ferometers now reaches 20 mas (Hummel et al. 1994). In in preparation) explains the SIM instrument design, op- the radio range, very long baseline interferometry (VLBI) eration, performance and calibration in more detail. The astrometry of quasars has allowed the creation of a quasi- astrometric performance of SIM is based on an hierar- inertial reference frame, the ICRF (International Celes- chical error budget with more than 1000 terms, and with tial Reference Frame; Ma et al. 1998) with wide-angle key sets of parameters verified in a series of testbeds de- accuracy 0.25 mas. veloped during Formulation Phase. Quoted performance Space-based astrometry has brought about a renais- numbers are current best estimates from the error budget sance in the field. The ESA Hipparcos mission, which and detailed instrument design. operated from 1989-1993, yielded an astrometric cata- The acronym SIM stands for Space Interferometry Mis- log of 118,000 stars down to 12.5 magnitude, with posi- sion. SIM will be the first space-based Michelson inter- tional accuracy of 1 mas for stars brighter than V = 11. ferometer for astrometry. The instrument will operate The European Space Agency (ESA) is now developing in the optical waveband using a 9-m baseline between the Gaia mission as a next generation astrometric survey the apertures. With a global astrometry accuracy of mission (Perryman et al. 2001; Perryman 2002), which is 3 µas for stars brighter than V = 20, it will measure parallaxes and proper motions of stars throughout the expected to develop a catalog
Load more

Recommended publications
  • Hunting Down Stars with Unusual Infrared Properties Using Supervised Machine Learning
    . Magnificent beasts of the Milky Way: Hunting down stars with unusual infrared properties using supervised machine learning Julia Ahlvind1 Supervisor: Erik Zackrisson1 Subject reader: Eric Stempels1 Examiner: Andreas Korn1 Degree project E in Physics { Astronomy, 30 ECTS 1Department of Physics and Astronomy { Uppsala University June 22, 2021 Contents 1 Background 2 1.1 Introduction................................................2 2 Theory: Machine Learning 2 2.1 Supervised machine learning.......................................3 2.2 Classification...............................................3 2.3 Various models..............................................3 2.3.1 k-nearest neighbour (kNN)...................................3 2.3.2 Decision tree...........................................4 2.3.3 Support Vector Machine (SVM)................................4 2.3.4 Discriminant analysis......................................5 2.3.5 Ensemble.............................................6 2.4 Hyperparameter tuning.........................................6 2.5 Evaluation.................................................6 2.5.1 Confusion matrix.........................................6 2.5.2 Precision and classification accuracy..............................7 3 Theory: Astronomy 7 3.1 Dyson spheres...............................................8 3.2 Dust-enshrouded stars..........................................8 3.3 Gray Dust.................................................9 3.4 M-dwarf.................................................. 10 3.5 post-AGB
    [Show full text]
  • Extremely Extended Dust Shells Around Evolved Intermediate Mass Stars: Probing Mass Loss Histories,Thermal Pulses and Stellar Evolution
    EXTREMELY EXTENDED DUST SHELLS AROUND EVOLVED INTERMEDIATE MASS STARS: PROBING MASS LOSS HISTORIES,THERMAL PULSES AND STELLAR EVOLUTION A Thesis presented to the Faculty of the Graduate School at the University of Missouri In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy by BASIL MENZI MCHUNU Dr. Angela K. Speck December 2011 The undersigned, appointed by the Dean of the Graduate School, have examined the dissertation entitled: EXTREMELY EXTENDED DUST SHELLS AROUND EVOLVED INTERMEDIATE MASS STARS PROBING MASS LOSS HISTORIES, THERMAL PULSES AND STELLAR EVOLUTION USING FAR-INFRARED IMAGING PHOTOMETRY presented by Basil Menzi Mchunu, a candidate for the degree of Doctor of Philosophy and hereby certify that, in their opinion, it is worthy of acceptance. Dr. Angela K. Speck Dr. Sergei Kopeikin Dr. Adam Helfer Dr. Bahram Mashhoon Dr. Haskell Taub DEDICATION This thesis is dedicated to my family, who raised me to be the man I am today under challenging conditions: my grandfather Baba (Samuel Mpala Mchunu), my grandmother (Ma Magasa, Nonhlekiso Mchunu), my aunt Thembeni, and my mother, Nombso Betty Mchunu. I would especially like to thank my mother for all the courage she gave me, bringing me chocolate during my undergraduate days to show her love when she had little else to give, and giving her unending support when I was so far away from home in graduate school. She passed away, when I was so close to graduation. To her, I say, ′′Ulale kahle Macingwane.′′ I have done it with the help from your spirit and courage. I would also like to thank my wife, Heather Shawver, and our beautiful children, Rosemary and Brianna , for making me see life with a new meaning of hope and prosperity.
    [Show full text]
  • Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects
    Juliana Crestani Ribeiro de Souza Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects Porto Alegre 2017 Juliana Crestani Ribeiro de Souza Spatial Distribution of Galactic Globular Clusters: Distance Uncertainties and Dynamical Effects Dissertação elaborada sob orientação do Prof. Dr. Eduardo Luis Damiani Bica, co- orientação do Prof. Dr. Charles José Bon- ato e apresentada ao Instituto de Física da Universidade Federal do Rio Grande do Sul em preenchimento do requisito par- cial para obtenção do título de Mestre em Física. Porto Alegre 2017 Acknowledgements To my parents, who supported me and made this possible, in a time and place where being in a university was just a distant dream. To my dearest friends Elisabeth, Robert, Augusto, and Natália - who so many times helped me go from "I give up" to "I’ll try once more". To my cats Kira, Fen, and Demi - who lazily join me in bed at the end of the day, and make everything worthwhile. "But, first of all, it will be necessary to explain what is our idea of a cluster of stars, and by what means we have obtained it. For an instance, I shall take the phenomenon which presents itself in many clusters: It is that of a number of lucid spots, of equal lustre, scattered over a circular space, in such a manner as to appear gradually more compressed towards the middle; and which compression, in the clusters to which I allude, is generally carried so far, as, by imperceptible degrees, to end in a luminous center, of a resolvable blaze of light." William Herschel, 1789 Abstract We provide a sample of 170 Galactic Globular Clusters (GCs) and analyse its spatial distribution properties.
    [Show full text]
  • Habitability on Local, Galactic and Cosmological Scales
    Habitability on local, Galactic and cosmological scales Luigi Secco1 • Marco Fecchio1 • Francesco Marzari1 Abstract The aim of this paper is to underline con- detectable studying our site. The Climatic Astronom- ditions necessary for the emergence and development ical Theory is introduced in sect.5 in order to define of life. They are placed at local planetary scale, at the circumsolar habitable zone (HZ) (sect.6) while the Galactic scale and within the cosmological evolution, translation from Solar to extra-Solar systems leads to a as pointed out by the Anthropic Cosmological Princi- generalized circumstellar habitable zone (CHZ) defined ple. We will consider the circumstellar habitable zone in sect.7 with some exemplifications to the Gliese-667C (CHZ) for planetary systems and a Galactic Habitable and the TRAPPIST-1 systems; some general remarks Zone (GHZ) including also a set of strong cosmologi- follow (sect.8). A first conclusion related to CHZ is cal constraints to allow life (cosmological habitability done moving toward GHZ and COSH (sect.9). The (COSH)). Some requirements are specific of a single conditions for the development of life are indeed only scale and its related physical phenomena, while others partially connected to the local scale in which a planet are due to the conspired effects occurring at more than is located. A strong interplay between different scales one scale. The scenario emerging from this analysis is exists and each single contribution to life from individ- that all the habitability conditions here detailed must ual scales is difficult to be isolated. However we will at least be met.
    [Show full text]
  • Jpc-Final-Program.Pdf
    49th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit (JPC) Advancing Propulsion Capabilities in a New Fiscal Reality 14–17 July 2013 San Jose Convention Center 11th International Energy Conversion San Jose, California Engineering Conference (IECEC) FINAL PROGRAM www.aiaa.org/jpc2013 www.iecec.org #aiaaPropEnergy www.aiaa.org/jpc2013 • www.iecec.org 1 #aiaaPropEnergy GET YOUR CONFERENCE INFO ON THE GO! Download the FREE Conference Mobile App FEATURES • Browse Program – View the program at your fingertips • My Itinerary – Create your own conference schedule • Conference Info – Including special events • Take Notes – Take notes during sessions • Venue Map – San Jose Convention Center • City Map – See the surrounding area • Connect to Twitter – Tweet about what you’re doing and who you’re meeting with #aiaaPropEnergy HOW TO DOWNLOAD Any version can be run without an active Internet connection! You can also sync an Compatible with itinerary you created online with the app by entering your unique itinerary name. iPhone/iPad, MyItinerary Mobile App MyItinerary Web App Android, and • For optimal use, we recommend • For optimal use, we recommend: rd BlackBerry! iPhone 3GS, iPod Touch (3 s iPhone 3GS, iPod Touch (3rd generation), iPad iOS 4.0, or later generation), iPad iOS 4.0, • Download the MyItinerary app by or later searching for “ScholarOne” in the s Most mobile devices using Android App Store directly from your mobile 2.2 or later with the default browser device. Or, access the link below or scan the QR code to access the iTunes s BlackBerry Torch or later device Sponsored by: page for the app.
    [Show full text]
  • Ghost Imaging of Space Objects
    Ghost Imaging of Space Objects Dmitry V. Strekalov, Baris I. Erkmen, Igor Kulikov, and Nan Yu Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099 USA NIAC Final Report September 2014 Contents I. The proposed research 1 A. Origins and motivation of this research 1 B. Proposed approach in a nutshell 3 C. Proposed approach in the context of modern astronomy 7 D. Perceived benefits and perspectives 12 II. Phase I goals and accomplishments 18 A. Introducing the theoretical model 19 B. A Gaussian absorber 28 C. Unbalanced arms configuration 32 D. Phase I summary 34 III. Phase II goals and accomplishments 37 A. Advanced theoretical analysis 38 B. On observability of a shadow gradient 47 C. Signal-to-noise ratio 49 D. From detection to imaging 59 E. Experimental demonstration 72 F. On observation of phase objects 86 IV. Dissemination and outreach 90 V. Conclusion 92 References 95 1 I. THE PROPOSED RESEARCH The NIAC Ghost Imaging of Space Objects research program has been carried out at the Jet Propulsion Laboratory, Caltech. The program consisted of Phase I (October 2011 to September 2012) and Phase II (October 2012 to September 2014). The research team consisted of Drs. Dmitry Strekalov (PI), Baris Erkmen, Igor Kulikov and Nan Yu. The team members acknowledge stimulating discussions with Drs. Leonidas Moustakas, Andrew Shapiro-Scharlotta, Victor Vilnrotter, Michael Werner and Paul Goldsmith of JPL; Maria Chekhova and Timur Iskhakov of Max Plank Institute for Physics of Light, Erlangen; Paul Nu˜nez of Coll`ege de France & Observatoire de la Cˆote d’Azur; and technical support from Victor White and Pierre Echternach of JPL.
    [Show full text]
  • Information Bulletin on Variable Stars
    COMMISSIONS AND OF THE I A U INFORMATION BULLETIN ON VARIABLE STARS Nos November July EDITORS L SZABADOS K OLAH TECHNICAL EDITOR A HOLL TYPESETTING K ORI ADMINISTRATION Zs KOVARI EDITORIAL BOARD L A BALONA M BREGER E BUDDING M deGROOT E GUINAN D S HALL P HARMANEC M JERZYKIEWICZ K C LEUNG M RODONO N N SAMUS J SMAK C STERKEN Chair H BUDAPEST XI I Box HUNGARY URL httpwwwkonkolyhuIBVSIBVShtml HU ISSN COPYRIGHT NOTICE IBVS is published on b ehalf of the th and nd Commissions of the IAU by the Konkoly Observatory Budap est Hungary Individual issues could b e downloaded for scientic and educational purp oses free of charge Bibliographic information of the recent issues could b e entered to indexing sys tems No IBVS issues may b e stored in a public retrieval system in any form or by any means electronic or otherwise without the prior written p ermission of the publishers Prior written p ermission of the publishers is required for entering IBVS issues to an electronic indexing or bibliographic system to o CONTENTS C STERKEN A JONES B VOS I ZEGELAAR AM van GENDEREN M de GROOT On the Cyclicity of the S Dor Phases in AG Carinae ::::::::::::::::::::::::::::::::::::::::::::::::::: : J BOROVICKA L SAROUNOVA The Period and Lightcurve of NSV ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::: W LILLER AF JONES A New Very Long Period Variable Star in Norma ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::::: EA KARITSKAYA VP GORANSKIJ Unusual Fading of V Cygni Cyg X in Early November :::::::::::::::::::::::::::::::::::::::
    [Show full text]
  • Astrometrically Registered Maps of H2O and Sio Masers Toward VX Sagittarii
    ARTICLE DOI: 10.1038/s41467-018-04767-8 OPEN Astrometrically registered maps of H2O and SiO masers toward VX Sagittarii Dong-Hwan Yoon1,2, Se-Hyung Cho2,3, Youngjoo Yun2, Yoon Kyung Choi2, Richard Dodson4, María Rioja4,5, Jaeheon Kim6, Hiroshi Imai7, Dongjin Kim3, Haneul Yang1,2 & Do-Young Byun2 The supergiant VX Sagittarii is a strong emitter of both H2O and SiO masers. However, previous VLBI observations have been performed separately, which makes it difficult to 1234567890():,; spatially trace the outward transfer of the material consecutively. Here we present the astrometrically registered, simultaneous maps of 22.2 GHz H2O and 43.1/42.8/86.2/129.3 GHz SiO masers toward VX Sagittarii. The H2O masers detected above the dust-forming layers have an asymmetric distribution. The multi-transition SiO masers are nearly circular ring, suggesting spherically symmetric wind within a few stellar radii. These results provide the clear evidence that the asymmetry in the outflow is enhanced after the smaller molecular gas clump transform into the inhomogeneous dust layers. The 129.3 GHz maser arises from the outermost region compared to that of 43.1/42.8/86.2 GHz SiO masers. The ring size of the 129.3 GHz maser is maximized around the optical maximum, suggesting that radiative pumping is dominant. 1 Astronomy Program, Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea. 2 Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Korea. 3 Department of Astronomy, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.
    [Show full text]
  • THE KINEMATICS and AGES of STARS in GLIESE's CATALOGUE 1. Introduction This Contribution Gives Some Results on the Kinematics An
    THE KINEMATICS AND AGES OF STARS IN GLIESE'S CATALOGUE R. WIELEN Astronomisches Rechen-Institut, Heidelberg, F.R.G. 1. Introduction This contribution gives some results on the kinematics and ages of stars near the Sun. These results are mainly based on the catalogue of nearby stars compiled by Gliese (1957, 1969 and minor recent modifications). Table I shows the number of objects under consideration. While the old catalogue (1957) contained only stars with distances r up to 20 pc, the new edition (1969) includes many stars with slightly larger distances. In Table I, a 'system' is either a single star or a binary or a multiple system. The number of systems with known space velocities nearer than 20 pc has increased by about 30% from 1957 to 1969. The first edition of Gliese's catalogue (1957) has been analyzed in detail by Gliese (1956) and von Hoerner (1960). TABLE I Gliese's Catalogue of Nearby Stars Number Edition 1969 1957 All j-s=20pc r<20 pc Stars 1890 1277 1095 Systems 1529 1036 916 Systems with known space velocity 1131 770 598 Although Gliese's catalogue is the most complete collection of stars within 20 pc, this sample of stars is severely biased by selection effects and is not fully representative for all the nearby stars. Only the stars brighter than M„~ +7 are almost completely known within 20 pc. For the fainter stars, the following selection effects occur: (a) The southern sky is deficient in detected faint nearby stars; (b) Since most of the faint nearby stars are found by their high proper motions, the sample is deficient in stars with small tangential components of their space velocities (measured with respect to the Sun); (c) Due to incomplete detection, the apparent space density of faint stars decreases rapidly with increasing distance r, and this effect becomes stronger with increasing M„.
    [Show full text]
  • CSIRO Australia Telescope National Facility
    ASTRONOMY AND SPACE SCIENCE www.csiro.au CSIRO Australia Telescope National Facility Annual Report 2014 CSIRO Australia Telescope National Facility Annual Report 2014 ISSN 1038-9554 This is the report of the CSIRO Australia Telescope National Facility for the calendar year 2014, approved by the Australia Telescope Steering Committee. Editor: Helen Sim Designer: Angela Finney, Art when you need it Cover image: An antenna of the Australia Telescope Compact Array. Credit: Michael Gal Inner cover image: Children and a teacher from the Pia Wadjarri Remote Community School, visiting CSIRO's Murchison Radio-astronomy Observatory in 2014. Credit: CSIRO ii CSIRO Australia Telescope National Facility – Annual Report 2014 Contents Director’s Report 2 Chair’s Report 4 The ATNF in Brief 5 Performance Indicators 17 Science Highlights 23 Operations 35 Observatory and Project Reports 43 Management Team 53 Appendices 55 A: Committee membership 56 B: Financial summary 59 C: Staff list 60 D: Observing programs 65 E: PhD students 73 F: PhD theses 74 G: Publications 75 H: Abbreviations 84 1 Director’s Report Credit: Wheeler Studios Wheeler Credit: This year has seen some very positive an excellent scorecard from the Australia Dr Lewis Ball, Director, Australia results achieved by the ATNF staff, as well Telescope Users Committee. Telescope National Facility as some significant challenges. We opened We began reducing CSIRO expenditure a new office in the Australian Resources on the Mopra telescope some five years Research Centre building in Perth, installed ago. This year’s funding cut pushed us to phased-array feeds (PAFs) on antennas of take the final step along this path, and we our Australian SKA Pathfinder (ASKAP), and will no longer support Mopra operations collected data with a PAF-equipped array for using CSIRO funds after the end of the 2015 the first time ever in the world.
    [Show full text]
  • AU25: 2, 3, 4.. 50 Estrellas
    ars universalis 2, 3, 4… 50 ESTRELLAS Vexilología (II): arte y ciencia de las banderas, pendones y estandartes. De arriba a abajo y de izquierda a derecha, banderas de Australia, Bosnia y Herzegovina, Burundi, Cabo Verde, China (primera columna), Dominica, Guinea Ecuatorial, Granada, Honduras, Micronesia (segunda columna), Nueva Zelanda, Panamá, Papúa Nueva Guinea, San Cristóbal y Nieves, Samoa (tercera columna), Santo Tomé y Príncipe, Eslovenia, Islas Salomón, Siria, Tayikistán (cuarta columna), Tuvalu, Estados Unidos de América y Venezuela (quinta columna). (Cortesía del autor) ste segundo artículo de Nueva Guinea, Samoa y las Islas tralia, Nueva Zelanda, Papúa la serie astrovexilológi- Salomón. Seis las de Australia y Nueva Guinea y Samoa. Las cua- ca está dedicado a veinti- Guinea Ecuatorial (en el escudo tro estrellas en la bandera de trés banderas con dos o de armas). Siete las de Grana- Nueva Zelanda son rojas y file- E 01+02 más estrellas. Dos mullets tienen da y Tayikistán (una estrella so- teadas en blanco: Ácrux ( las banderas de Panamá, San bre cada una de las siete monta- Crucis, B0.5 IV+B1 V, V = 0,76 Cristóbal y Nieves (Saint Kitts ñas con jardines de orquídeas). mag.), Mimosa ( Crucis, 훼B1 IV, and Nevis), Santo Tomé y Prín- Ocho las de Bosnia y Herzego- V = 1,25 mag.), Gacrux ( Cru- cipe y Siria, que representan los vina (en realidad, siete estrellas cis, M3.5 III, V = 훽1,64 mag.) e partidos conservadores y los li- enteras y dos medias, en una su- Imai ( Crucis, B2 IV, V =훾 2,79 berales, dos parejas de islas y la cesión supuestamente infinita; mag.).
    [Show full text]
  • Small Wonders: Ophiuchus
    Page 1 of 13 Small Wonders: Ophiuchus Small Wonders: Ophiuchus A monthly sky guide for the beginning to intermediate amateur astronomer Tom Trusock - 06/09 Barnard 72 (The Snake Nebula) - One of the many dark nebulae in Ophiuchus: Contributed by Hunter Wilson Tom Trusock June 2009 Page 2 of 13 Small Wonders: Ophiuchus This massive constellation culminates around midnight on June 12th and for me, has always been the harbinger of Summer. As with many constellations, it's mythology is somewhat mixed, but the most prevalent mythos is it's association with Aesculapius, surgeon aboard Jason's Argo. I've been an amateur astronomer for decades now, but I'm still awed by the sheer size of this constellation. Bordered on the north by Hercules and the south by Scorpius and Sagittarius, it reaches from +14 to just beneath -30 declination, and covers nearly three hours in right ascension and splits Serpens neatly in two. Widefield Finder Chart - Looking South, early June around 12pm. It's brightest star is 2nd magnitude Rasalhague located at the top of the constellations distinctive bell shape. The most interesting star within it's borders is probably the mag 9.5 red dwarf named Barnard's Star. Discovered in 1916 by E. E. Barnard, it's six light years away (making it the second closest star) and has a proper motion in our sky of one degree every 350 years. Barnard's star is approaching us rapidly – around 87 miles per second – and will reach closest approach of 3.8 light years around 8000 years from now.
    [Show full text]