The Progenitor Masses of Wolf-Rayet Stars and Luminous Blue Variables Determined from Cluster Turn-Offs
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Limits from the Hubble Space Telescope on a Point Source in SN 1987A
Limits from the Hubble Space Telescope on a Point Source in SN 1987A The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Graves, Genevieve J. M., Peter M. Challis, Roger A. Chevalier, Arlin Crotts, Alexei V. Filippenko, Claes Fransson, Peter Garnavich, et al. 2005. “Limits from the Hubble Space Telescopeon a Point Source in SN 1987A.” The Astrophysical Journal 629 (2): 944–59. https:// doi.org/10.1086/431422. Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:41399924 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA The Astrophysical Journal, 629:944–959, 2005 August 20 # 2005. The American Astronomical Society. All rights reserved. Printed in U.S.A. LIMITS FROM THE HUBBLE SPACE TELESCOPE ON A POINT SOURCE IN SN 1987A Genevieve J. M. Graves,1, 2 Peter M. Challis,2 Roger A. Chevalier,3 Arlin Crotts,4 Alexei V. Filippenko,5 Claes Fransson,6 Peter Garnavich,7 Robert P. Kirshner,2 Weidong Li,5 Peter Lundqvist,6 Richard McCray,8 Nino Panagia,9 Mark M. Phillips,10 Chun J. S. Pun,11,12 Brian P. Schmidt,13 George Sonneborn,11 Nicholas B. Suntzeff,14 Lifan Wang,15 and J. Craig Wheeler16 Received 2005 January 27; accepted 2005 April 26 ABSTRACT We observed supernova 1987A (SN 1987A) with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST ) in 1999 September and again with the Advanced Camera for Surveys (ACS) on the HST in 2003 November. -
Wolf-Rayet Stars in the Small Magellanic Cloud II
A&A 591, A22 (2016) DOI: 10.1051/0004-6361/201527916 Astronomy c ESO 2016 & Astrophysics Wolf-Rayet stars in the Small Magellanic Cloud II. Analysis of the binaries T. Shenar1, R. Hainich1, H. Todt1, A. Sander1, W.-R. Hamann1, A. F. J. Moffat2, J. J. Eldridge3, H. Pablo2, L. M. Oskinova1, and N. D. Richardson4 1 Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany e-mail: [email protected] 2 Département de physique and Centre de Recherche en Astrophysique du Québec (CRAQ), Université de Montréal, CP 6128, Succ. Centre-Ville, Montréal, Québec, H3C 3J7, Canada 3 Department of Physics, University of Auckland, Private Bag, 92019 Auckland, New Zealand 4 Ritter Observatory, Department of Physics and Astronomy, The University of Toledo, Toledo, OH 43606-3390, USA Received 8 December 2015 / Accepted 30 March 2016 ABSTRACT Context. Massive Wolf-Rayet (WR) stars are evolved massive stars (Mi & 20 M ) characterized by strong mass-loss. Hypothetically, they can form either as single stars or as mass donors in close binaries. About 40% of all known WR stars are confirmed binaries, raising the question as to the impact of binarity on the WR population. Studying WR binaries is crucial in this context, and furthermore enable one to reliably derive the elusive masses of their components, making them indispensable for the study of massive stars. Aims. By performing a spectral analysis of all multiple WR systems in the Small Magellanic Cloud (SMC), we obtain the full set of stellar parameters for each individual component. -
The AAVSO DSLR Observing Manual
The AAVSO DSLR Observing Manual AAVSO 49 Bay State Road Cambridge, MA 02138 email: [email protected] Version 1.2 Copyright 2014 AAVSO Foreword This manual is a basic introduction and guide to using a DSLR camera to make variable star observations. The target audience is first-time beginner to intermediate level DSLR observers, although many advanced observers may find the content contained herein useful. The AAVSO DSLR Observing Manual was inspired by the great interest in DSLR photometry witnessed during the AAVSO’s Citizen Sky program. Consumer-grade imaging devices are rapidly evolving, so we have elected to write this manual to be as general as possible and move the software and camera-specific topics to the AAVSO DSLR forums. If you find an area where this document could use improvement, please let us know. Please send any feedback or suggestions to [email protected]. Most of the content for these chapters was written during the third Citizen Sky workshop during March 22-24, 2013 at the AAVSO. The persons responsible for creation of most of the content in the chapters are: Chapter 1 (Introduction): Colin Littlefield, Paul Norris, Richard (Doc) Kinne, Matthew Templeton Chapter 2 (Equipment overview): Roger Pieri, Rebecca Jackson, Michael Brewster, Matthew Templeton Chapter 3 (Software overview): Mark Blackford, Heinz-Bernd Eggenstein, Martin Connors, Ian Doktor Chapters 4 & 5 (Image acquisition and processing): Robert Buchheim, Donald Collins, Tim Hager, Bob Manske, Matthew Templeton Chapter 6 (Transformation): Brian Kloppenborg, Arne Henden Chapter 7 (Observing program): Des Loughney, Mike Simonsen, Todd Brown Various figures: Paul Valleli Clear skies, and Good Observing! Arne Henden, Director Rebecca Turner, Operations Director Brian Kloppenborg, Editor Matthew Templeton, Science Director Elizabeth Waagen, Senior Technical Assistant American Association of Variable Star Observers Cambridge, Massachusetts June 2014 i Index 1. -
Luminous Blue Variables
Review Luminous Blue Variables Kerstin Weis 1* and Dominik J. Bomans 1,2,3 1 Astronomical Institute, Faculty for Physics and Astronomy, Ruhr University Bochum, 44801 Bochum, Germany 2 Department Plasmas with Complex Interactions, Ruhr University Bochum, 44801 Bochum, Germany 3 Ruhr Astroparticle and Plasma Physics (RAPP) Center, 44801 Bochum, Germany Received: 29 October 2019; Accepted: 18 February 2020; Published: 29 February 2020 Abstract: Luminous Blue Variables are massive evolved stars, here we introduce this outstanding class of objects. Described are the specific characteristics, the evolutionary state and what they are connected to other phases and types of massive stars. Our current knowledge of LBVs is limited by the fact that in comparison to other stellar classes and phases only a few “true” LBVs are known. This results from the lack of a unique, fast and always reliable identification scheme for LBVs. It literally takes time to get a true classification of a LBV. In addition the short duration of the LBV phase makes it even harder to catch and identify a star as LBV. We summarize here what is known so far, give an overview of the LBV population and the list of LBV host galaxies. LBV are clearly an important and still not fully understood phase in the live of (very) massive stars, especially due to the large and time variable mass loss during the LBV phase. We like to emphasize again the problem how to clearly identify LBV and that there are more than just one type of LBVs: The giant eruption LBVs or h Car analogs and the S Dor cycle LBVs. -
Fundamental Parameters of Wolf-Rayet Stars VI
Astron. Astrophys. 320, 500–524 (1997) ASTRONOMY AND ASTROPHYSICS Fundamental parameters of Wolf-Rayet stars VI. Large Magellanic Cloud WNL stars? P.A.Crowther and L.J. Smith Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK Received 5 February 1996 / Accepted 26 June 1996 Abstract. We present a detailed, quantitative study of late WN Key words: stars: Wolf-Rayet;mass-loss; evolution; fundamen- (WNL) stars in the LMC, based on new optical spectroscopy tal parameters – galaxies: Magellanic Clouds (AAT, MSO) and the Hillier (1990) atmospheric model. In a pre- vious paper (Crowther et al. 1995a), we showed that 4 out of the 10 known LMC Ofpe/WN9 stars should be re-classified WN9– 10. We now present observations of the remaining stars (except the LBV R127), and show that they are also WNL (WN9–11) 1. Introduction stars, with the exception of R99. Our total sample consists of 17 stars, and represents all but one of the single LMC WN6– Quantitative studies of hot luminous stars in galaxies are im- 11 population and allows a direct comparison with the stellar portant for a number of reasons. First, and probably foremost, parameters and chemical abundances of Galactic WNL stars is the information they provide on the effect of the environment (Crowther et al. 1995b; Hamann et al. 1995a). Previously un- on such fundamental properties as the mass-loss rate and stellar published ultraviolet (HST-FOS, IUE-HIRES) spectroscopy are evolution. In the standard picture (e.g. Maeder & Meynet 1987) presented for a subset of our programme stars. -
The Wolf-Rayet + of Star Binary AB7: a Warmer in the Small Magellanic Cloud+)
The Wolf-Rayet + Of star binary AB7: A Warmer in the Small Magellanic Cloud+) Manfred W. Pakull1) & Luciana Bianchi2) 1) Observatoire de Besançon, 25044 Besançon Cedex, France 2) Osservatorio Astronomico di Turino, 10025 Pino Torinese, Italy Summary Strong nebular Hell λ4686 recombination radiation (λ4686/Ηβ = 0.2) has recently been detected in the bright HII region N76 in the Small Magellanic Cloud by Testor & Pakull (1989). The rather symmetric intensity distribution suggests a nebular morphology which consists of a thick outer shell comprising the He*"1* and H+ ionization fronts and a central region of warm, highly ionized gas which is surrounded by a hollow inner shell. The source of the high nebular ionization is identified with the peculiar Wolf-Rayet + Of star spectroscopic binary AB7. Optical and UV spectra (cf. Figure) show in addition to hydrogen and helium absorption lines and the NIII λλ4634-41 complex from the Of star, only broad He II and weak NVemission lines due to the Wolf-Rayet companion. The absence of other diagnostic features qualifies the evolved component as a rare, high-excitation WN star (WN2 or WN1). Subtracting from the optical spectrum of AB7 suitably scaled spectra of SMC Ο stars up to the point that the absorption lines disappeared, suggests that the WN 1 component contributes about 30 % to the total optical light. ' 4000 4500 5000 5500 °' üoö ' iioö t7Ö5 üoö" Wavelength (A) WAVELENGTH (AI Optical and IUE spectra of the 06 IIIf+ WN1 binary AB 7 From the nebular λ4686 flux and the optical brightness of the WN1 star a black body Zanstra temperature of about 80 000 Κ and a luminosity of 106 Lo are derived. -
MLM 65 Schematic
R1B R2B R3B 20kB C1 20kB C2 20kB C3 NC NC NC R16 47pF R17 47pF R18 47pF 100k 100k 100k GND GND GND +15V +15V +15V 8 8 R19 R20 8 R21 R22 R23 R24 2 C105 180 deg 2 C106 180 deg 2 C107 180 deg 1 1 1 30.1k 30.1k U1A MIC1_L 30.1k 30.1k U2A MIC2_L 30.1k 30.1k U3A MIC3_L 3 3 3 22/16v 22/16v 22/16v 33078 R165 33078 R166 33078 R167 4 4 GND 4 20.0k GND GND 20.0k 20.0k -15V -15V -15V 3 3 3 GND GND GND MIC_1 2 R1A MIC_2 2 R2A MIC_3 2 R3A 20kB C4 20kB C5 20kB C6 1 1 0 deg 1 0 deg 0 deg GND GND GND R25 47pF R26 47pF R27 47pF 100k 100k 100k R28 R29 6 180 deg R30 R31 6 180 deg R32 R33 6 180 deg C108 C109 C110 7 7 7 30.1k 30.1k U1B MIC1_R 30.1k 30.1k U2B MIC2_R 30.1k 30.1k U3B MIC3_R 5 5 5 22/16v 22/16v 22/16v 33078 R168 33078 R169 33078 R170 GND 20.0k GND GND 20.0k 20.0k GND GND GND R4B R5B R6B 20kB C7 20kB C8 20kB C9 NC NC NC R34 47pF R35 47pF R36 47pF 100k 100k 100k GND GND GND +15V +15V +15V 8 8 R37 R38 2 8 180 deg R39 R40 2 180 deg R41 R42 2 180 deg C111 C112 C115 1 1 1 30.1k 30.1k U4A MIC4_L 30.1k 30.1k U5A MIC5_L 30.1k 30.1k U6A MIC6_L 3 3 3 22/16v 22/16v 33078 22/16v R171 33078 R172 33078 R175 4 4 GND 4 GND GND 20.0k 20.0k 20.0k -15V -15V -15V 3 3 3 GND GND GND MIC_4 2 R4A MIC_5 2 R5A MIC_6 2 R6A 20kB C10 20kB C11 20kB C12 1 1 0 deg 1 0 deg 0 deg GND GND GND R43 47pF R44 47pF R45 47pF 100k 100k 100k R46 R47 6 180 deg R48 R49 6 180 deg R50 R51 6 180 deg C113 C114 C116 7 7 7 30.1k 30.1k U4B MIC4_R 30.1k 30.1k U5B MIC5_R 30.1k 30.1k U6B MIC6_R 5 5 5 22/16v 22/16v 22/16v 33078 R173 33078 R174 33078 R176 GND GND GND 20.0k 20.0k 20.0k GND GND GND J1 -
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. -
Stsci Newsletter: 2011 Volume 028 Issue 02
National Aeronautics and Space Administration Interacting Galaxies UGC 1810 and UGC 1813 Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA) 2011 VOL 28 ISSUE 02 NEWSLETTER Space Telescope Science Institute We received a total of 1,007 proposals, after accounting for duplications Hubble Cycle 19 and withdrawals. Review process Proposal Selection Members of the international astronomical community review Hubble propos- als. Grouped in panels organized by science category, each panel has one or more “mirror” panels to enable transfer of proposals in order to avoid conflicts. In Cycle 19, the panels were divided into the categories of Planets, Stars, Stellar Rachel Somerville, [email protected], Claus Leitherer, [email protected], & Brett Populations and Interstellar Medium (ISM), Galaxies, Active Galactic Nuclei and Blacker, [email protected] the Inter-Galactic Medium (AGN/IGM), and Cosmology, for a total of 14 panels. One of these panels reviewed Regular Guest Observer, Archival, Theory, and Chronology SNAP proposals. The panel chairs also serve as members of the Time Allocation Committee hen the Cycle 19 Call for Proposals was released in December 2010, (TAC), which reviews Large and Archival Legacy proposals. In addition, there Hubble had already seen a full cycle of operation with the newly are three at-large TAC members, whose broad expertise allows them to review installed and repaired instruments calibrated and characterized. W proposals as needed, and to advise panels if the panelists feel they do not have The Advanced Camera for Surveys (ACS), Cosmic Origins Spectrograph (COS), the expertise to review a certain proposal. Fine Guidance Sensor (FGS), Space Telescope Imaging Spectrograph (STIS), and The process of selecting the panelists begins with the selection of the TAC Chair, Wide Field Camera 3 (WFC3) were all close to nominal operation and were avail- about six months prior to the proposal deadline. -
The Wolf-Rayet + of Star Binary AB7: a Warmer in the Small Magellanic Cloud+)
The Wolf-Rayet + Of star binary AB7: A Warmer in the Small Magellanic Cloud+) Manfred W. Pakull1) & Luciana Bianchi2) 1) Observatoire de Besançon, 25044 Besançon Cedex, France 2) Osservatorio Astronomico di Turino, 10025 Pino Torinese, Italy Summary Strong nebular Hell λ4686 recombination radiation (λ4686/Ηβ = 0.2) has recently been detected in the bright HII region N76 in the Small Magellanic Cloud by Testor & Pakull (1989). The rather symmetric intensity distribution suggests a nebular morphology which consists of a thick outer shell comprising the He*"1* and H+ ionization fronts and a central region of warm, highly ionized gas which is surrounded by a hollow inner shell. The source of the high nebular ionization is identified with the peculiar Wolf-Rayet + Of star spectroscopic binary AB7. Optical and UV spectra (cf. Figure) show in addition to hydrogen and helium absorption lines and the NIII λλ4634-41 complex from the Of star, only broad He II and weak NVemission lines due to the Wolf-Rayet companion. The absence of other diagnostic features qualifies the evolved component as a rare, high-excitation WN star (WN2 or WN1). Subtracting from the optical spectrum of AB7 suitably scaled spectra of SMC Ο stars up to the point that the absorption lines disappeared, suggests that the WN 1 component contributes about 30 % to the total optical light. ' 4000 4500 5000 5500 °' üoö ' iioö t7Ö5 üoö" Wavelength (A) WAVELENGTH (AI Optical and IUE spectra of the 06 IIIf+ WN1 binary AB 7 From the nebular λ4686 flux and the optical brightness of the WN1 star a black body Zanstra temperature of about 80 000 Κ and a luminosity of 106 Lo are derived. -
ESO Annual Report 2004 ESO Annual Report 2004 Presented to the Council by the Director General Dr
ESO Annual Report 2004 ESO Annual Report 2004 presented to the Council by the Director General Dr. Catherine Cesarsky View of La Silla from the 3.6-m telescope. ESO is the foremost intergovernmental European Science and Technology organi- sation in the field of ground-based as- trophysics. It is supported by eleven coun- tries: Belgium, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Sweden, Switzerland and the United Kingdom. Created in 1962, ESO provides state-of- the-art research facilities to European astronomers and astrophysicists. In pur- suit of this task, ESO’s activities cover a wide spectrum including the design and construction of world-class ground-based observational facilities for the member- state scientists, large telescope projects, design of innovative scientific instruments, developing new and advanced techno- logies, furthering European co-operation and carrying out European educational programmes. ESO operates at three sites in the Ataca- ma desert region of Chile. The first site The VLT is a most unusual telescope, is at La Silla, a mountain 600 km north of based on the latest technology. It is not Santiago de Chile, at 2 400 m altitude. just one, but an array of 4 telescopes, It is equipped with several optical tele- each with a main mirror of 8.2-m diame- scopes with mirror diameters of up to ter. With one such telescope, images 3.6-metres. The 3.5-m New Technology of celestial objects as faint as magnitude Telescope (NTT) was the first in the 30 have been obtained in a one-hour ex- world to have a computer-controlled main posure. -
Gas and Dust in the Magellanic Clouds
Gas and dust in the Magellanic clouds A Thesis Submitted for the Award of the Degree of Doctor of Philosophy in Physics To Mangalore University by Ananta Charan Pradhan Under the Supervision of Prof. Jayant Murthy Indian Institute of Astrophysics Bangalore - 560 034 India April 2011 Declaration of Authorship I hereby declare that the matter contained in this thesis is the result of the inves- tigations carried out by me at Indian Institute of Astrophysics, Bangalore, under the supervision of Professor Jayant Murthy. This work has not been submitted for the award of any degree, diploma, associateship, fellowship, etc. of any university or institute. Signed: Date: ii Certificate This is to certify that the thesis entitled ‘Gas and Dust in the Magellanic clouds’ submitted to the Mangalore University by Mr. Ananta Charan Pradhan for the award of the degree of Doctor of Philosophy in the faculty of Science, is based on the results of the investigations carried out by him under my supervi- sion and guidance, at Indian Institute of Astrophysics. This thesis has not been submitted for the award of any degree, diploma, associateship, fellowship, etc. of any university or institute. Signed: Date: iii Dedicated to my parents ========================================= Sri. Pandab Pradhan and Smt. Kanak Pradhan ========================================= Acknowledgements It has been a pleasure to work under Prof. Jayant Murthy. I am grateful to him for giving me full freedom in research and for his guidance and attention throughout my doctoral work inspite of his hectic schedules. I am indebted to him for his patience in countless reviews and for his contribution of time and energy as my guide in this project.