NOTE.—For Action on Bills and Resolutions See History of Bills and Resolutions
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
1993Apjs ... 86. .293D the Astrophysical Journal Supplement
The Astrophysical Journal Supplement Series, 86:293-306, 1993 May .293D © 1993. The American Astronomical Society. All rights reserved. Printed in U.S.A. 86. ... OBSERVATIONS OF THE Ca n INFRARED TRIPLET IN CHROMOSPHERICALLY ACTIVE 1993ApJS SINGLE AND BINARY STARS Robert C. Dempsey1 Joint Institute for Laboratory Astrophysics, University of Colorado, Campus Box 440, Boulder CO 80309 Bernard W. Bopp1 Ritter Observatory, The University of Toledo, 2801 West Bancroft, Toledo, OH 43606 Gregory W. Henry Center for Excellence in Information Systems, Tennessee State University, 330 10th Avenue North, Nashville, TN 32703 AND Douglas S. Hall Dyer Observatory, Vanderbilt University, Nashville, TN 37235 Received 1992 August 5; accepted 1992 October 16 ABSTRACT Spectroscopic observations of the Ca n infrared triplet (XX 8498, 8542, 8662) have been obtained for 45 stars which are known or suspected to be chromosphericaUy active. The sample includes both single and binary stars of spectral types from F2 to M5 spanning luminosity classes III, IV, and V. Several different types of activity diagnostics were measured and their relative merits are discussed. Dependence of chromospheric emission upon rotation period, luminosity, temperature, and duplicity are analyzed. Synchronous binaries show a slight trend of increased emission with decreasing period while the asynchronous binaries show abnormally high activity levels for their rotation periods. Several stars exhibit rotationally modulated emission which is anticorrelated with the stellar brightness. Finally, estimates of chromospheric energy losses are presented with the result that the total loss in the infrared triplet is about twice that of the H and K Unes. Subject headings: infrared: stars — stars: chromospheres — stars: late-type 1. -
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 ::::::::::::::::::::::::::::::::::::::: -
Publications Et Communications De Florentin Millour (Février 2016) H-Index 21, Total : 130 Publications Dont 53 À Comité De Lecture
Publications et communications de Florentin Millour (Février 2016) h-index 21, total : 130 publications dont 53 à comité de lecture. Articles dans des revues à comité de lecture, thèse 2015 1. Mourard, D., ..., Millour, F. ; et al., . (2015, A&A, 577, 51) Spectral and spatial imaging of the Be+sdO binary Phi Persei 2014 2. Chesneau, O. ; Millour, F. ; de Marco, O. et al., . (2014, A&A, 569, 3) V838 Monocerotis : the central star and its environment a decade after outburst 3. Chesneau, O. ; Millour, F. ; de Marco, O. et al., . (2014, A&A, 569, 4) The RCB star V854 Centauri is surrounded by a hot dusty shell 4. Chesneau, O. ; Meilland, A. ; Chapellier, E. ; Millour, F. ; et al., . (2014, A&A, 563, A71) The yellow hypergiant HR 5171 A : Resolving a massive interacting binary in the common envelope phase. 5. Domiciano de Souza, A. ; Kervella, P. ; Moser Faes, D. et al. (2014, A&A, 569, 10) The environment of the fast rotating star Achernar. III. Photospheric parameters revealed by the VLTI 6. Hadjara, M. ; Domiciano de Souza, A. ; Vakili, F. et al. (2014, A&A, 569, 45) Beyond the diraction limit of optical/IR interferometers. II. Stellar parameters of rotating stars from dierential phases 7. Schutz, A. ; Vannier, M. ; Mary, D. et al. (2014, A&A, 565, 88) Statistical characterisation of polychromatic absolute and dierential squared visibilities obtained from AMBER/VLTI instrument 2013 8. Millour, F. ; Meilland, A. ; Stee, P. & Chesneau, O. (2013, LNP, 857, 149) Interactions in Massive Binary Stars as Seen by Interferometry 9. Stee, P. ; Meilland, A. -
International Astronomical Union Commission 42 BIBLIOGRAPHY of CLOSE BINARIES No. 93
International Astronomical Union Commission 42 BIBLIOGRAPHY OF CLOSE BINARIES No. 93 Editor-in-Chief: C.D. Scarfe Editors: H. Drechsel D.R. Faulkner E. Kilpio E. Lapasset Y. Nakamura P.G. Niarchos R.G. Samec E. Tamajo W. Van Hamme M. Wolf Material published by September 15, 2011 BCB issues are available via URL: http://www.konkoly.hu/IAUC42/bcb.html, http://www.sternwarte.uni-erlangen.de/pub/bcb or http://www.astro.uvic.ca/∼robb/bcb/comm42bcb.html The bibliographical entries for Individual Stars and Collections of Data, as well as a few General entries, are categorized according to the following coding scheme. Data from archives or databases, or previously published, are identified with an asterisk. The observation codes in the first four groups may be followed by one of the following wavelength codes. g. γ-ray. i. infrared. m. microwave. o. optical r. radio u. ultraviolet x. x-ray 1. Photometric data a. CCD b. Photoelectric c. Photographic d. Visual 2. Spectroscopic data a. Radial velocities b. Spectral classification c. Line identification d. Spectrophotometry 3. Polarimetry a. Broad-band b. Spectropolarimetry 4. Astrometry a. Positions and proper motions b. Relative positions only c. Interferometry 5. Derived results a. Times of minima b. New or improved ephemeris, period variations c. Parameters derivable from light curves d. Elements derivable from velocity curves e. Absolute dimensions, masses f. Apsidal motion and structure constants g. Physical properties of stellar atmospheres h. Chemical abundances i. Accretion disks and accretion phenomena j. Mass loss and mass exchange k. Rotational velocities 6. Catalogues, discoveries, charts a. -
On X-Ray Variability in Active Binary Stars
ApJ, in press On X-ray Variability in Active Binary Stars Vinay Kashyap1 and Jeremy J. Drake2 1Harvard-Smithsonian Center for Astrophysics, MS-83, 60 Garden Street, Cambridge, MA 02138 2Harvard-Smithsonian Center for Astrophysics, MS-3, 60 Garden Street, Cambridge, MA 02138 ABSTRACT We have compared the X-ray emissions of active binary stars observed at various epochs by the Einstein and ROSAT satellites in order to investigate the nature of their X-ray variability. The main aim of this work is to determine whether or not active binaries exhibit long-term variations in X-ray emission, perhaps analogous to the observed cyclic behavior of solar magnetic activity. We find that, while the mean level of emission of the sample remains steady, comparison of different ROSAT observations of the same stars shows significant variation on timescales ∼< 2 yr, with an “effective ∆I variability” I = 0.32 ± 0.04, where I and ∆I represent the mean, and variation from the mean, emission, respectively. A comparison of ROSAT All-Sky Survey and later pointed observations with earlier observations of the same stars carried out with ∆I Einstein yields only marginal evidence for a larger variation ( I = 0.38 ± 0.04 for Einstein vs. ROSAT All-Sky Survey and 0.46 ± 0.05 for Einstein vs. ROSAT pointed) at these longer timescales (∼ 10 yr), indicating the possible presence of a long-term component to the variability. arXiv:astro-ph/9905109v1 10 May 1999 Whether this long-term component is due to the presence of cyclic variability cannot be decided on the basis of existing data. -
Gum 48D: an Evolved HII Region with Ongoing Star Formation
Gum 48d: an evolved HII region with ongoing star formation J.L. Karr Academia Sinica Institute of Astronomy and Astrophysics, Taipei, Taiwan, ROC P. Manoj Department of Physics and Astronomy, University of Rochester, NY N. Ohashi Academia Sinica Institute of Astronomy and Astrophysics, Taipei, Taiwan, ROC ABSTRACT High mass star formation and the evolution of HII regions have a substantial impact on the morphology and star formation history of molecular clouds. The HII region Gum 48d, located in the Centaurus Arm at a distance of 3.5 kpc, is an old, well evolved HII region whose ionizing stars have moved off the main sequence. As such, it represents a phase in the evolution of HII regions that is less well studied than the earlier, more energetic, main sequence phase. In this paper we use multi-wavelength archive data from a variety of sources to perform a detailed study of this interesting region. Morphologically, Gum 48d displays a ring-like faint HII region associated with diffuse emission from the associated PDR, and is formed from part of a large, massive molecular cloud complex. There is extensive ongoing star formation in the region, at scales ranging from low to high mass, which is consistent with triggered star formation scenarios. We investigate the dynamical history and evolution of this region, and conclude that arXiv:0903.0934v1 [astro-ph.GA] 5 Mar 2009 the original HII region was once larger and more energetic than the faint region currently seen. The proposed history of this molecular cloud complex is one of multiple, linked generations of star formation, over a period of 10 Myr. -
508-764-2554 Like to Embrace Rather Than Avoid
PROUD MEDIA SPONSOR OF SOUTHBRIDGE AREA RELAY FOR LIFE! SERVING OUR READERS SINCE 1923 WEDNESDAY , M AY 13, 2009 (508) 764-4325/VISIT US AT: www.theheartofmassachusetts.com Newsstand: 60 cents TODAY’S QUOTE A busy June ballot CANDIDATES FOR COUNCIL HEAD LIST “My closest relation 10 BY GUS STEEVES is myself.” NEWS STAFF WRITER SOUTHBRIDGE — For the — Terence last several elections, Southbridge has bucked the tendency of local races to be TOMORROW’S fairly humdrum. This year T ’ is no exception. WEATHER In fact, the June 30 ballot promises to be the most crowded in recent years. Ten people are running for three seats on the Town Council, five for two school committee seats, and two for town clerk. While many names on the list are repeat candidates, there are several new faces. “This is the first [annual election] where pretty much everybody who pulled out papers returned them,” said Showers Town Clerk Madaline High 64 Daoust. “Maybe we’ll get a Low 53 lot more people to come out VFW AWARDS NIGHT to vote.” In fact, just one person, INNING Shawn Kelley photo W INNING who took out papers for Bay all the candidates last night File photo LOTTERY SOUTHBRIDGE — VFW Man of the Year — Southbridge Police Path School Committee, did in an effort to sample the dif- Poll workers go over absentee bal- Chief Daniel Charette — sits with his wife, Kathleen, and son not return them, leaving that ferent views at issue this lots at West Street School to veri- NUMBERS Jacob, 12, at the group’s 63rd annual testimonial banquet seat without a candidate. -