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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 ::::::::::::::::::::::::::::::::::::::: -
Spectroscopy of Variable Stars
Spectroscopy of Variable Stars Steve B. Howell and Travis A. Rector The National Optical Astronomy Observatory 950 N. Cherry Ave. Tucson, AZ 85719 USA Introduction A Note from the Authors The goal of this project is to determine the physical characteristics of variable stars (e.g., temperature, radius and luminosity) by analyzing spectra and photometric observations that span several years. The project was originally developed as a The 2.1-meter telescope and research project for teachers participating in the NOAO TLRBSE program. Coudé Feed spectrograph at Kitt Peak National Observatory in Ari- Please note that it is assumed that the instructor and students are familiar with the zona. The 2.1-meter telescope is concepts of photometry and spectroscopy as it is used in astronomy, as well as inside the white dome. The Coudé stellar classification and stellar evolution. This document is an incomplete source Feed spectrograph is in the right of information on these topics, so further study is encouraged. In particular, the half of the building. It also uses “Stellar Spectroscopy” document will be useful for learning how to analyze the the white tower on the right. spectrum of a star. Prerequisites To be able to do this research project, students should have a basic understanding of the following concepts: • Spectroscopy and photometry in astronomy • Stellar evolution • Stellar classification • Inverse-square law and Stefan’s law The control room for the Coudé Description of the Data Feed spectrograph. The spec- trograph is operated by the two The spectra used in this project were obtained with the Coudé Feed telescopes computers on the left. -
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. -
High Resolution
IN THIS ISSUE: H NEWS AND ANNOUNCEMENTS KRISTINE LARSEN: OBSERVER, EDUCATOR, VOLUNTEER, AND COUNCILOR . 5 HAVE YOU SEEN THIS TELESCopE? . 5 50 YEARS WITH THE AAVSO . 6 SCENES FROM THE 2014 ANNUAL MEETING . 8 AWARDS AND HONORS foR 2014 . 9 ISSUE NO. 63 JANUARY 2015 WWW.AAVSO.ORG H ALSO SCIENCE SUMMARY: AAVSO IN PRINT . 13 TALKING ABOUT THE AAVSO . 14 IN MEMORIAM . 14 STARS AT THE EDGE . 17 INVESTIGATING IR LIGHT LEAKS IN OPTEC B-BAND FILTERS . 18 Complete table of contents on page 2 AAVSONewsletter SINCE 1911... The AAVSO is an international non-profit organization of variable star observers whose mission is: to observe and analyze variable stars; to collect and archive observations for FROM THE worldwide access; and to forge strong collaborations and mentoring between amateurs and professionals that promote both scientific research DIRECTOR’S DESK and education on variable sources. ARNE A. HENDEN (HQA) he holiday season Changes have taken place with the AAVSOnet T is upon us again. robotic telescope network. A new camera was PRESIDENT’S MESSAGE This means a lull in the purchased for BSM_NM, and its original camera JENO SOKOLOSKI workload at the AAVSO moved to BSM_HQ. A new MoonLite focuser as staff members take was sent to BSM_South. New filters and gratings Introducing our incoming vacations to visit family were purchased. BSM_Berry is nearing “first Director, Dr. Stella Kafka and friends. It also gives light” in Perth at Greg Bolt’s house. The queues me a chance to reflect on are being reviewed to remove completed objects, hen AAVSO’s incoming the past year, with its many with new projects being implemented. -
Carbon Stars T. Lloyd Evans
J. Astrophys. Astr. (2010) 31, 177–211 Carbon Stars T. Lloyd Evans SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS, UK. e-mail: [email protected] Received 2010 July 19; accepted 2010 October 18 Abstract. In this paper, the present state of knowledge of the carbon stars is discussed. Particular attention is given to issues of classification, evolution, variability, populations in our own and other galaxies, and circumstellar material. Key words. Stars: carbon—stars: evolution—stars: circumstellar matter —galaxies: magellanic clouds. 1. Introduction Carbon stars have been reviewed on several previous occasions, most recently by Wallerstein & Knapp (1998). A conference devoted to this topic was held in 1996 (Wing 2000) and two meetings on AGB stars (Le Bertre et al. 1999; Kerschbaum et al. 2007) also contain much on carbon stars. This review emphasizes develop- ments since 1997, while paying particular attention to connections with earlier work and to some of the important sources of concepts. Recent and ongoing develop- ments include surveys for carbon stars in more of the galaxies of the local group and detailed spectroscopy and infrared photometry for many of them, as well as general surveys such as 2MASS, AKARI and the Sirius near infrared survey of the Magel- lanic Clouds and several dwarf galaxies, the Spitzer-SAGE mid-infrared survey of the Magellanic Clouds and the current Herschel infrared satellite project. Detailed studies of relatively bright galactic examples continue to be made by high-resolution spectroscopy, concentrating on abundance determinations using the red spectral region, and infrared and radio observations which give information on the history of mass loss. -
Appendix: Spectroscopy of Variable Stars
Appendix: Spectroscopy of Variable Stars As amateur astronomers gain ever-increasing access to professional tools, the science of spectroscopy of variable stars is now within reach of the experienced variable star observer. In this section we shall examine the basic tools used to perform spectroscopy and how to use the data collected in ways that augment our understanding of variable stars. Naturally, this section cannot cover every aspect of this vast subject, and we will concentrate just on the basics of this field so that the observer can come to grips with it. It will be noticed by experienced observers that variable stars often alter their spectral characteristics as they vary in light output. Cepheid variable stars can change from G types to F types during their periods of oscillation, and young variables can change from A to B types or vice versa. Spec troscopy enables observers to monitor these changes if their instrumentation is sensitive enough. However, this is not an easy field of study. It requires patience and dedication and access to resources that most amateurs do not possess. Nevertheless, it is an emerging field, and should the reader wish to get involved with this type of observation know that there are some excellent guides to variable star spectroscopy via the BAA and the AAVSO. Some of the workshops run by Robin Leadbeater of the BAA Variable Star section and others such as Christian Buil are a very good introduction to the field. © Springer Nature Switzerland AG 2018 M. Griffiths, Observer’s Guide to Variable Stars, The Patrick Moore 291 Practical Astronomy Series, https://doi.org/10.1007/978-3-030-00904-5 292 Appendix: Spectroscopy of Variable Stars Spectra, Spectroscopes and Image Acquisition What are spectra, and how are they observed? The spectra we see from stars is the result of the complete output in visible light of the star (in simple terms). -
Variable Star Section Circular 70
The B ritish Astronomical Association VARIABLE STAR SECTION APRIL CIRCULAR 70 1990 ISSN 0267-9272 Office: Burlington House, Piccadilly, London, W1V 9AG VARIABLE STAR SECTION CIRCULAR 70 CONTENTS Doug Saw 1 Gordon Patson 1 Jack Ells 1 Changes in Administrative Arrangements 1 SS Computerization - Appeal for an Organizer 2 Submission of VSS Observations 2 Under-observed Stars in 1989 - Melvyn Taylor 3 Binocular Programme Priority List - John Isles 7 For Sale 8 Unusual Carbon Stars 9 Two Symbiotic Stars 13 Forthcoming VSS Report: W Cygni 14 Minima of Eclipsing Binaries, 1987 16 Preliminary Light-curves and Reports on 4 Stars 22 (Omicron Cet, R CrB, CH Cyg, R Set) Editorial Note 26 Five Semiregular Variables, 1974-87 - Ian Middlemist 26 (TZ Cas, ST Cep, S Dra, U Lac, Y UMa) Algols and Amateurs 34 AAVSO Meeting, Brussels 1990 July 24-28 36 Charts: AXPer/UV Aur 15 ST Cep / S Dra 32 U Lac / Y UMa 32 Professional-Amateur Liason Committee centre pages Newsletter No. 3 Observing with Amateurs’ Telescopes i Availability of Visual Data ii Meeting of Photoelectric Photometry iii AAVSO Meeting, Brussels, 1990 July 24-28 iv Printed by Castle Printers of Wittering Doug Saw It is with deep regret that we announce the death on 1990 March 6 of Doug Saw, Deputy Director and past Director and Secretary of the Section. Doug’s contribution to the Section has been exceptional, most particularly in his handling of untold thousands of observations over many years. Although in poor health recently, he continued with the administrative work until very shortly before his death. -
Further Observations of the Lambda 10830 He Line in Stars and Their Significance As a Measure of Stellar Activity
General Disclaimer One or more of the Following Statements may affect this Document This document has been reproduced from the best copy furnished by the organizational source. It is being released in the interest of making available as much information as possible. This document may contain data, which exceeds the sheet parameters. It was furnished in this condition by the organizational source and is the best copy available. This document may contain tone-on-tone or color graphs, charts and/or pictures, which have been reproduced in black and white. This document is paginated as submitted by the original source. Portions of this document are not fully legible due to the historical nature of some of the material. However, it is the best reproduction available from the original submission. Produced by the NASA Center for Aerospace Information (CASI) or I CALIFORNIA INSTITUTE OF TECHNOLOGY BIG BEAR SOLA R OBSERVATORY HALE OBSERVATORIES 4 I r -b cb c^ a y CNN (NASA-CR-145974) FURTHER CBSEPVATIONS CF N76-14992 THE LAMEDA 1083u He LING, IN STARS AND THEIR SIGNIFIC!NCE AS A MEAEURE OF STELLAR ACTIVITY (dale CbseEvatories, Pasadena, Unclas Calif.) 28 p HC $4.('. CSCL J3A G3;89 1,7726 t I FURTHER OBSERVATIONS OF THE XZ0830 HE LINE IN STARS AND THEIR SIGNIFICANCE AS A MEASURE OF STELLAR ACTIVITY H. Zirin HALE OBSERVATORIES CARNEGIE INSTITUTION OF WASHINGTON CALIFORNIA INSTITUTE OF TECHNOLOGY BBSO #0150 November, 1975 ABSTRACT Measurements of the x10830 He line in 198 stars are given, f along with data on other features in that spectral range. Nearly 80% of all G and K stars show some 110830; of these, half are variable and 1/4 show emission. -
David Stevenson the Complex Lives of Star Clusters Astronomers’ Universe
David Stevenson The Complex Lives of Star Clusters Astronomers’ Universe More information about this series at http://www.springer.com/series/6960 David Stevenson The Complex Lives of Star Clusters David Stevenson Sherwood , UK ISSN 1614-659X ISSN 2197-6651 (electronic) Astronomers’ Universe ISBN 978-3-319-14233-3 ISBN 978-3-319-14234-0 (eBook) DOI 10.1007/978-3-319-14234-0 Library of Congress Control Number: 2015936043 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2015 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifi cally the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfi lms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specifi c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Cover photo of the Orion Nebula M42 courtesy of NASA Spitzer Printed on acid-free paper Springer International Publishing AG Switzerland is part of Springer Science+Business Media (www.springer.com) For my late mother, Margaret Weir Smith Stevenson Pref ace Stars are fairly social beasts. -
Late Stages of Stellar Evolution*
Late stages of Stellar Evolution £ Joris A.D.L. Blommaert ([email protected]) Instituut voor Sterrenkunde, K.U. Leuven, Celestijnenlaan 200B, B-3001 Leuven, Belgium Jan Cami NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035, USA Ryszard Szczerba N. Copernicus Astronomical Center, Rabia´nska 8, 87-100 Toru´n, Poland Michael J. Barlow Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, U.K. Abstract. A large fraction of ISO observing time was used to study the late stages of stellar evolution. Many molecular and solid state features, including crystalline silicates and the rota- tional lines of water vapour, were detected for the first time in the spectra of (post-)AGB stars. Their analysis has greatly improved our knowledge of stellar atmospheres and circumstel- lar environments. A surprising number of objects, particularly young planetary nebulae with Wolf-Rayet central stars, were found to exhibit emission features in their ISO spectra that are characteristic of both oxygen-rich and carbon-rich dust species, while far-IR observations of the PDR around NGC 7027 led to the first detections of the rotational line spectra of CH and CH· . Received: 18 October 2004, Accepted: 2 November 2004 1. Introduction ISO (Kessler et al., 1996, Kessler et al., 2003) has been tremendously impor- tant in the study of the final stages of stellar evolution. A substantial fraction of ISO observing time was used to observe different classes of evolved stars. IRAS had already shown the strong potential to discover many evolved stars with circumstellar shells in the infrared wavelength range. -
Submillimeter Array Newsletter Number 32, July 2021 CONTENTS from T H E DIR EC TOR
Submillimeter Array Newsletter Number 32, July 2021 CONTENTS FROM T H E DIR EC TOR 1 From the Director Dear SMA Newsletter readers, SCIENCE HIGHLIGHTS: This past year has been a difficult year, and maintaining SMA operations to the highest standard 2 Multi-epoch SMA Observations of the L1448C(N) ProtostellarJet has been, and continues to be, challenging. Since the onset of the pandemic more than a year ago, in common with many organizations, performing certain routine maintenance tasks and 5 Resolved Measurements of GMCs in M31: CO Isotopologues effecting repairs to damaged or failing equipment became infeasible in part due to safety and the Dust restrictions implemented for staff working in close proximity. As a result, the SMA has not been able to sustain science observations with the full eight-element array for some time. While we bk The Nature of 500 micron Risers I: SMA Observations currently have only six antennas in the array, with two antennas off-line with antenna drive-system issues, we have imposed modifications to observing strategy, coupled with TECHNICAL HIGHLIGHTS: postponing the most demanding high fidelity, high resolution observations, which has enabled science observations to continue. bo Development of a Silicon-chip-based Waveguide Directional Coupler for The antenna drive-system issues are well understood, and I am confident that the dedicated the wSMA staff at the observatory site will resolve the current issues in the next several weeks. As a bs MIR Update result, the SMA call for proposals will offer the full-range of observation types for the upcoming 2021B semester (deadline of 16 September). -
The Agb Newsletter
THE AGB NEWSLETTER An electronic publication dedicated to Asymptotic Giant Branch stars and related phenomena Official publication of the IAU Working Group on Red Giants and Supergiants No. 286 — 2 May 2021 https://www.astro.keele.ac.uk/AGBnews Editors: Jacco van Loon, Ambra Nanni and Albert Zijlstra Editorial Board (Working Group Organising Committee): Marcelo Miguel Miller Bertolami, Carolyn Doherty, JJ Eldridge, Anibal Garc´ıa-Hern´andez, Josef Hron, Biwei Jiang, Tomasz Kami´nski, John Lattanzio, Emily Levesque, Maria Lugaro, Keiichi Ohnaka, Gioia Rau, Jacco van Loon (Chair) Editorial Dear Colleagues, It is our pleasure to present you the 286th issue of the AGB Newsletter. A healthy 30 postings are sure to keep you inspired. Now that the Leuven workshop has happened, we are gearing up to the IAU-sponsored GAPS 2021 virtual discussion meeting aimed to lay out a roadmap for cool evolved star research: we have got an exciting line-up of new talent as well as seasoned experts introducing the final session – all are encouraged to contribute to the meeting through 5-minute presentations or live discussion and the White Paper that will follow (see announcement at the back). Those interested in the common envelope process will no doubt consider attending the CEPO 2021 virtual meeting on this topic organised at the end of August / star of September. Great news on the job front: there are Ph.D. positions in Bordeaux, postdoc positions in Warsaw and another one in Nice. Thanks to Josef Hron and P´eter Abrah´am´ for ensuring the continuation of the Fizeau programme for exchange in the field of interferometry.