1 Amateur Astronomers and the New Golden Age of Cataclysmic Variable
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Multiwavelength Observations of Accretion in Low-Mass X-Ray Binary Systems Robert I
1 Multiwavelength Observations of Accretion in Low-Mass X-ray Binary Systems Robert I. Hynesa Abstract This work is intended to provide an introduction to multiwavelength observations of low-mass X-ray binaries and the techniques used to ana- lyze and interpret their data. The focus will primarily be on ultraviolet, optical, and infrared observations and their connections to other wave- lengths. The topics covered include: outbursts of soft X-ray transients, accretion disk spectral energy distributions, orbital lightcurves in lumi- nous and quiescent states, super-orbital and sub-orbital variability, line spectra, system parameter determinations, and echo-mapping and other rapid correlated variability. 1.1 Introduction The first X-ray binary to be observed and identified as such was Scorpius X-1 (Giacconi et al., 1962), although several other systems were known as optical stars or novae before this. Within a few years, optical and radio counterparts to Sco X-1 were discovered (Sandage et al., 1966; Andrew and Purton, 1968), and the topic has remained multiwavelength in nature since then. This work is intended to provide an introduction to some of the obser- vational characteristics of X-ray binaries suitable for a graduate student or an advanced undergraduate. My aim was to produce a primer for someone relatively new to the field rather than a comprehensive review. Where appropriate I will also discuss techniques for analysis and inter- a Louisiana State University, Department of Physics and Astronomy, 202 arXiv:1010.5770v1 [astro-ph.HE] 27 Oct 2010 Nicholson Hall, Tower Drive, Baton Rouge, LA 70803, USA 2 R. -
Unknown Amorphous Carbon II. LRS SPECTRA the Sample Consists Of
Table I A summary of the spectral -features observed in the LRS spectra of the three groups o-f carbon stars. The de-finition o-f the groups is given in the text. wavelength Xmax identification Group I B - 12 urn E1 9.7 M™ Silicate 12 - 23 jim E IB ^m Silicate Group II < 8.5 M"i A C2H2 CS? 12 - 16 f-i/n A 13.7 - 14 Mm C2H2 HCN? 8 - 10 Mm E 8.6 M"i Unknown 10 - 13 Mm E 11.3 - 11 .7 M«> SiC Group III 10 - 13 MJn E 11.3 - 11 .7 tun SiC B - 23 Htn C Amorphous carbon 1 The letter in this column indicates the nature o-f the -feature: A = absorption; E = emission; C indicates the presence of continuum opacity. II. LRS SPECTRA The sample consists of 304 carbon stars with entries in the LRS catalog (Papers I-III). The LRS spectra have been divided into three groups. Group I consists of nine stars with 9.7 and 18 tun silicate features in their LRS spectra pointing to oxygen-rich dust in the circumstellar shell. These sources are discussed in Paper I. The remaining stars all have spectra with carbon-rich dust features. Using NIR photometry we have shown that in the group II spectra the stellar photosphere is the dominant continuum. The NIR color temperature is of the order of 25OO K. Paper II contains a discussion of sources with this class of spectra. The continuum in the group III spectra is probably due to amorphous carbon dust. -
Star Maps: Where Are the Black Holes?
BLACK HOLE FAQ’s 1. What is a black hole? A black hole is a region of space that has so much mass concentrated in it that there is no way for a nearby object to escape its gravitational pull. There are three kinds of black hole that we have strong evidence for: a. Stellar-mass black holes are the remaining cores of massive stars after they die in a supernova explosion. b. Mid-mass black hole in the centers of dense star clusters Credit : ESA, NASA, and F. Mirabel c. Supermassive black hole are found in the centers of many (and maybe all) galaxies. 2. Can a black hole appear anywhere? No, you need an amount of matter more than 3 times the mass of the Sun before it can collapse to create a black hole. 3. If a star dies, does it always turn into a black hole? No, smaller stars like our Sun end their lives as dense hot stars called white dwarfs. Much more massive stars end their lives in a supernova explosion. The remaining cores of only the most massive stars will form black holes. 4. Will black holes suck up all the matter in the universe? No. A black hole has a very small region around it from which you can't escape, called the “event horizon”. If you (or other matter) cross the horizon, you will be pulled in. But as long as you stay outside of the horizon, you can avoid getting pulled in if you are orbiting fast enough. 5. What happens when a spaceship you are riding in falls into a black hole? Your spaceship, along with you, would be squeezed and stretched until it was torn completely apart as it approached the center of the black hole. -
NL 2011-2 Backup
Newsletter 2011-3 August 2011 www.variablestarssouth.org Hawkes Bay Astronomical Society members at the site of their partially completed Pukerangi roll-off observatory. Photo by Graham Palmer and provided by Col Bembrick. Col’s recollections of the 2011 RASNZ conference hosted by the Hawkes Bay Astronomical Society appear on page 11. Contents From the director - Tom Richards ........................................................................................................................... 2 Variables from Linden – Towards the Hub - Alan Plummer ................................................................. 4 BL Telescopii - Observations of the 2011 eclipse - Peter F Williams ............................................ 7 A DSLR bright Cepheid project - Can you help? - Stan Walker ........................................................ 9 RASNZ Conference Napier, 2011 - Col Bembrick ................................................................................... 11 Recurrent Novae - Stan Walker .............................................................................................................................. 13 Southern Binaries DSLR Project - Mark Blackford .................................................................................. 17 Equatorial Eclipsing Binaries Project - Tom Richards ............................................................................ 19 SPADES Report - Tom Richards ........................................................................................................................... -
The Nova-Like Nebular Optical Spectrum of V404 Cygni at The
MNRAS 000, i–xvi (2016) Preprint 4 October 2018 Compiled using MNRAS LATEX style file v3.0 The nova-like nebular optical spectrum of V404 Cygni at the beginning of the 2015 outburst decay Farid Rahoui1,2⋆, J. A. Tomsick3, P. Gandhi4, P. Casella5, F. Furst¨ 6, L. Natalucci7, A. Rossi8, A. W. Shaw4, V. Testa5, and D. J. Walton6 1European Southern Observatory, K. Schwarzschild-Str. 2, 85748 Garching bei Munchen,¨ Germany 2Department of Astronomy, Harvard University, 60 Garden street, Cambridge, MA 02138, USA 3Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450, USA 4Department of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ, UK 5INAF-OA Roma, Via Frascati 33, I-00078 Monteporzio Catone, Italy 6California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA 7Istituto di Astrofisica e Planetologia Spaziali, INAF, Via Fosso del Cavaliere 100, I-00133 Roma, Italy 8INAF-IASF Bologna, Area della Ricerca CNR, via Gobetti 101, I–40129 Bologna, Italy Accepted XXX. Received YYY; in original form ZZZ ABSTRACT We report on FORS2 optical spectroscopy of the black hole X-ray binary V404 Cygni, performed at the very beginning of its 2015 outburst decay, complemented by quasi- simultaneous Swift X-ray and ultra-violet as well as REM near-infrared observations. Its peculiar spectrum is dominated by a wealth of emission signatures of H i, He i, and higher ionisation species, in particular Fe ii. The spectral features are divided between broad red-shifted and narrow stationary varieties, the latter being emitted in the outer regions. -
Dramatic Change in the Boundary Layer in the Symbiotic Recurrent
Astronomy & Astrophysics manuscript no. tcrb˙submitted˙to˙arxiv © ESO 2018 July 4, 2018 Dramatic change in the boundary layer in the symbiotic recurrent nova T Coronae Borealis. G. J. M. Luna,1,2,3, K. Mukai,4,5 J. L. Sokoloski,6 T. Nelson,7 P. Kuin,8 A. Segreto,9 G. Cusumano,9 M. Jaque Arancibia,10,11 and N. E. Nu˜nez,11 1 CONICET-Universidad de Buenos Aires, Instituto de Astronom´ıa y F´ısica del Espacio, (IAFE), Av. Inte. G¨uiraldes 2620, C1428ZAA, Buenos Aires, Argentina e-mail: [email protected] 2 Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina 3 Universidad Nacional Arturo Jauretche, Av. Calchaqu´ı6200, F. Varela, Buenos Aires, Argentina 4 CRESST and X-ray Astrophysics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA 5 Department of Physics, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA 6 Columbia Astrophysics Lab 550 W120th St., 1027 Pupin Hall, MC 5247 Columbia University, New York, New York 10027, USA 7 Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 8 University College London, Mullard Space Science Laboratory, Holmbury St. Mary, Dorking, RH5 6NT, U.K. 9 INAF - Istituto di Astrofisica Spaziale e Fisica Cosmica, Via U. La Malfa 153, I-90146 Palermo, Italy 10 Departamento de F´ısica y Astronom´ıa, Universidad de La Serena, Av. Cisternas 1200, La Serena, Chile. 11 Instituto de Ciencias Astron´omicas, de la Tierra y del Espacio (ICATE-CONICET), Av. Espa˜na Sur 1512, J5402DSP, San Juan, Argentina ABSTRACT A sudden increase in the rate at which material reaches the most internal part of an accretion disk, i.e. -
The Planets for 1955 24 Eclipses, 1955 ------29 the Sky and Astronomical Phenomena Month by Month - - 30 Phenomena of Jupiter’S S a Te Llite S
THE OBSERVER’S HANDBOOK FOR 1955 PUBLISHED BY The Royal Astronomical Society of Canada C. A. C H A N T, E d ito r RUTH J. NORTHCOTT, A s s is t a n t E d ito r DAVID DUNLAP OBSERVATORY FORTY-SEVENTH YEAR OF PUBLICATION P r i c e 50 C e n t s TORONTO 13 Ross S t r e e t Printed for th e Society By the University of Toronto Press THE ROYAL ASTRONOMICAL SOCIETY OF CANADA The Society was incorporated in 1890 as The Astronomical and Physical Society of Toronto, assuming its present name in 1903. For many years the Toronto organization existed alone, but now the Society is national in extent, having active Centres in Montreal and Quebec, P.Q.; Ottawa, Toronto, Hamilton, London, and Windsor, Ontario; Winnipeg, Man.; Saskatoon, Sask.; Edmonton, Alta.; Vancouver and Victoria, B.C. As well as nearly 1000 members of these Canadian Centres, there are nearly 400 members not attached to any Centre, mostly resident in other nations, while some 200 additional institutions or persons are on the regular mailing list of our publications. The Society publishes a bi-monthly J o u r n a l and a yearly O b s e r v e r ’s H a n d b o o k . Single copies of the J o u r n a l are 50 cents, and of the H a n d b o o k , 50 cents. Membership is open to anyone interested in astronomy. Annual dues, $3.00; life membership, $40.00. -
Arxiv:Astro-Ph/0204354 V1 20 Apr 2002 1 DI Ilb Netdb Adlater) Hand by Inserted Be Will (DOI: Astrophysics & Astronomy H Uecn Dnicto Fi O a Confusing
Astronomy & Astrophysics manuscript no. June 3, 2005 (DOI: will be inserted by hand later) Recurrent Nova IM Normae Taichi Kato1, Hitoshi Yamaoka2, William Liller3, and Berto Monard4 1 Department of Astronomy, Kyoto University, Kyoto 606-8502, Japan 2 Faculty of Science, Kyushu University, Fukuoka 810-8560, Japan 3 Center for Nova Studies, Casilla 5022 Renaca, Vi˜na del Mar, Chile 4 Bronberg Observatory, PO Box 11426, Tiegerpoort 0056, South Africa Received / accepted Abstract. We detected the second historical outburst of the 1920 nova IM Nor. Accurate astrometry of the outbursting object revealed the true quiescent counterpart having a magnitude of R=17.0 mag and B=18.0 mag. We show that the quiescent counterpart shows a noticeable variation. From the comparison of light curves and spectroscopic signatures, we propose that IM Nor and CI Aql comprise a new class of recurrent novae bearing some characteristics similar to those of classical novae. We interpret that the noticeable quiescent variation can be a result of either high orbital inclination, which may be also responsible for the low quiescent brightness, or the presence of high/low states. If the second possibility is confirmed by future observations, IM Nor becomes the first recurrent nova showing state changes in quiescence. Such state changes may provide a missing link between recurrent novae and supersoft X-ray sources. Key words. novae, cataclysmic variables — Stars: individual (IM Nor) 1. Introduction nal studies, Duerbeck (1987) reported the remeasured po- sition of the nova, and different candidates for the qui- IM Nor was originally discovered as a possible nova in 1920 escent counterpart, whose exact identification remained by I. -
A Review of the Disc Instability Model for Dwarf Novae, Soft X-Ray Transients and Related Objects a J.M
A review of the disc instability model for dwarf novae, soft X-ray transients and related objects a J.M. Hameury aObservatoire Astronomique de Strasbourg ARTICLEINFO ABSTRACT Keywords: I review the basics of the disc instability model (DIM) for dwarf novae and soft-X-ray transients Cataclysmic variable and its most recent developments, as well as the current limitations of the model, focusing on the Accretion discs dwarf nova case. Although the DIM uses the Shakura-Sunyaev prescription for angular momentum X-ray binaries transport, which we know now to be at best inaccurate, it is surprisingly efficient in reproducing the outbursts of dwarf novae and soft X-ray transients, provided that some ingredients, such as irradiation of the accretion disc and of the donor star, mass transfer variations, truncation of the inner disc, etc., are added to the basic model. As recently realized, taking into account the existence of winds and outflows and of the torque they exert on the accretion disc may significantly impact the model. I also discuss the origin of the superoutbursts that are probably due to a combination of variations of the mass transfer rate and of a tidal instability. I finally mention a number of unsolved problems and caveats, among which the most embarrassing one is the modelling of the low state. Despite significant progresses in the past few years both on our understanding of angular momentum transport, the DIM is still needed for understanding transient systems. 1. Introduction tems using Doppler tomography techniques (Steeghs et al. 1997; Marsh and Horne 1988; see also Marsh and Schwope Dwarf novae (DNe) are cataclysmic variables (CV) that 2016 for a recent review). -
Bulletin Issue 29 Spring 2018 New Series by Paul Haley Begins in This Issue: 19Th Century Observatories 2018 Sha Spring Conference
BULLETIN ISSUE 29 SPRING 2018 NEW SERIES BY PAUL HALEY BEGINS IN THIS ISSUE: 19TH CENTURY OBSERVATORIES 2018 SHA SPRING CONFERENCE The first talk is at 1015 and the Saturday 21st April 2018 The conference registraon is morning session ends at 1215 Instute of Astronomy, between 0930 and 1000 at which for lunch. The lunch break is University of Cambridge me refreshments are available unl 1330. An on-site lunch Madingley Road, Cambridge in the lecture theatre. The will be available (£5.00) BUT CB3 0HA conference starts at 1000 with a MUST BE PRE-ORDERED. There welcome by the SHA Chairman are no nearby eang places. Bob Bower introduces the There is a break for refreshments Aer the break there is the aernoon session at 1330 then from 1530 to 1600 when Tea/ final talk. The aernoon there are two one-hour talks. Coffee and biscuits will be session will end at 5 p.m. and provided. the conference will then close. 10 00 - 1015 10 15 - 1115 1115 - 1215 SHA Chairman Bob Bower Carolyn Kennett and Brian Sheen Kevin Kilburn Welcomes delegates to Ancient Skies and the Megaliths Forgotten Star Atlas the Instute of of Cornwall Astronomy for the SHA 2018 Archeoastronomy in Cornwall The 18th Century unpublished Spring Conference Past and Present Uranographia Britannica by Dr John Bevis 13 30 - 1430 14 30 - 1530 16 00 – 17 00 Nik Szymanek Kenelm England Jonathan Maxwell The Road to Modern Berkshire Astronomers 5000 BC Some lesser known aspects Astrophotography to AD 2018 regarding the evolution of The pioneering days of Some topics on astronomers and refracting telescopes: from early astrophotographers, observations made from Lippershey's spectacle lens to the up to modern times Berkshire since pre-historic Apochromats times until last week An insight into the development of 2 the refracting telescope In this Issue BOOK SALE AT THE 2017 AGM Digital Bulletin The Digital Bulletin provides extra content and links when viewing the 4 Bulletin as a PDF. -
The Astronomy of Sir John Herschel
Introduction m m m m m m m m m m m Herschel’s Stars The Stars flourish, and in spite of all my attempts to thin them and . stuff them in my pockets, continue to afford a rich harvest. John Herschel to James Calder Stewart, July 17, 1834 n 2017, TRAPPIST-1, a red dwarf star forty light years from Earth, made headlines as the center of a system with not one or two but Iseven potentially habitable exoplanets.1 This dim, nearby star offers only the most recent example of verification of the sort of planetary system common in science fiction: multiple temperate, terrestrial worlds within a single star’s family of planets. Indeed, this discovery followed the an- nouncement only a few years earlier of the very first Earth-sized world orbiting within the habitable zone of its star, Kepler-186, five hundred light years from Earth.2 Along with other ongoing surveys and advanced instruments, the Kepler mission, which recently added an additional 715 worlds to a total of over five thousand exoplanet candidates, is re- vealing a universe in which exoplanets proliferate, Earth-like worlds are common, and planets within the habitable zone of their host star are far from rare.3 Exoplanetary astronomy has developed to the point that as- tronomers can not only detect these objects but also describe the phys- ical characteristics of many with a high degree of confidence and pre- cision, gaining information on their composition, atmospheric makeup, temperature, and even weather patterns. 3 © 2018 University of Pittsburgh Press. All rights reserved. -
Interacting Binaries No
Interacting Binaries No. 16, June 6, 2003 An Electronic Newsletter Editors: Boris T. Gansic¨ ke Dept. of Physics & Astronomy, University of Southampton, Southampton SO17 1BJ, UK Jens Kube Stiftung Alfred-Wegener-Institut fur¨ Polar- und Meeresforschung, Koldewey-Station, N-9173 Ny-Alesund,˚ Norway [email protected], http://astrocat.org/ibnews Contents 1 Editorial 2 2 Abstracts of refereed papers 3 – 1RXS J062518.2+733433: A new intermediate polar Araujo-Betancor et al. 3 – RX J0042.3+4115: a stellar mass black hole binary identified in M31 Barnard et al. 3 – Physical changes during Z-track movement in Sco X-1 on the flaring branch Barnard et al. 4 – Anomalous ultraviolet line flux ratios in the cataclysmic variables 1RXS J232953.9+062814, CE315, BZ UMa and EY Cyg observed with HST/STIS Gansic¨ ke et al. 4 – A new evolutionary channel for Type Ia supernovae King et al. 5 – CVcat: an interactive database on cataclysmic variables Kube et al. 5 – The Fe XXII I(11.92 A)/I(11.77˚ A)˚ Density Diagnostic Applied to the Chandra High Energy Trans- mission Grating Spectrum of EX Hydrae Mauche et al. 5 – The formation of the coronal flow/ADAF Meyer-Hofmeister & Meyer . 6 – The Origin of Soft X-rays in DQ Herculis Mukai et al. 6 – Looking for Dust and Molecules in Nova V4743 Sagittarii Nielbock & Schmidtobreick . 6 – Ultraviolet Spectra of CV Accretion Disks with Non-Steady T(r) Laws Orosz & Wade . 7 – On resonance line profiles predicted by radiation driven disk wind models. Proga . 7 – The emission distribution in RR Pictoris Schmidtobreick et al.