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The Effect of the Apsidal Motion on the Light Curve of the Close Binary HD 93205 (O3V+O8V)?
A&A 397, 921–925 (2003) Astronomy DOI: 10.1051/0004-6361:20021438 & c ESO 2003 Astrophysics The effect of the apsidal motion on the light curve of the close binary HD 93205 (O3V+O8V)? A. M. van Genderen?? Leiden Observatory, Postbus 9513, 2300 RA Leiden, The Netherlands Received 25 June 2002/Accepted 28 August 2002 Abstract. The 1982–1985 photometry (VBLUW system) of the O3V+O8V close binary HD 93205 has been rediscussed be- cause of new insights into its true nature and orbital changes. By comparing this data set with the one obtained by Antokhina et al. (2000) in 1993, and using the same ephemeris to construct the light curve in the phase diagram, the effect of the apsidal motion became obvious: a phase shift between the two light curves and a small change of the shape. A phase-locked light variationintheL passband (containing the higher Balmer lines) is clearly present in the 1982–1985 data set and is presumably due to absorption if the O8 star is seen through cooler inter-binary gas, e.g. the bow-shock between the two colliding winds. Key words. stars: variables: general – stars: binaries: close – stars: early-type – stars: individual: HD 93205 1. Introduction Sect. 2). So far only the observations in the V band relative to the comparison star were published (Papers I, IX). The phase HD 93205 (O3V+O8V) is the earliest known system for which diagrams of the 1982–1985 and 1993 data sets, the latter from an RV is known, of which the first was presented by Conti & Antokhina et al. -
Binary Star Modeling: a Computational Approach
TCNJ JOURNAL OF STUDENT SCHOLARSHIP VOLUME XIV APRIL 2012 BINARY STAR MODELING: A COMPUTATIONAL APPROACH Author: Daniel Silano Faculty Sponsor: R. J. Pfeiffer, Department of Physics ABSTRACT This paper illustrates the equations and computational logic involved in writing BinaryFactory, a program I developed in Spring 2011 in collaboration with Dr. R. J. Pfeiffer, professor of physics at The College of New Jersey. This paper outlines computational methods required to design a computer model which can show an animation and generate an accurate light curve of an eclipsing binary star system. The final result is a light curve fit to any star system using BinaryFactory. An example is given for the eclipsing binary star system TU Muscae. Good agreement with observational data was obtained using parameters obtained from literature published by others. INTRODUCTION This project started as a proposal for a simple animation of two stars orbiting one another in C++. I found that although there was software that generated simple animations of binary star orbits and generated light curves, the commercial software was prohibitively expensive or not very user friendly. As I progressed from solving the orbits to generating the Roche surface to generating a light curve, I learned much about computational physics. There were many trials along the way; this paper aims to explain to the reader how a computational model of binary stars is made, as well as how to avoid pitfalls I encountered while writing BinaryFactory. Binary Factory was written in C++ using the free C++ libraries, OpenGL, GLUT, and GLUI. A basis for writing a model similar to BinaryFactory in any language will be presented, with a light curve fit for the eclipsing binary star system TU Muscae in the final secion. -
X-Ray Study of Stellar Winds with Suzaku
X-ray Study of Stellar Winds with Suzaku Yoshiaki Hyodo Department of Physics, Graduate School of Science, Kyoto University Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan [email protected] This thesis was submitted to the Department of Physics, Graduate School of Science, Kyoto University on January 5 2009 in partial fulfillment of the requirements for the degree of Doctor of Philosophy in physics. Abstract Stellar winds from massive stars play an important role for dynamical and chemical evolution of galaxies. To evaluate their effects in a galaxy scale, both the total number and the properties of massive stars should be understood. Most massive stars have soft X-ray emission, while some have additional hard emission. Although it is indicated that the binarity is important, the condition for hard X-ray production has not yet been elucidated. Also, some massive star clusters exhibit diffuse (pc scale) X-ray emission, where stellar winds may be depositing energy to the interstellar space. However, previous studies were not able to clarify the origin of the diffuse emission. It is even unclear whether the emission is physically related to the star cluster or not. The X-ray Imaging Spectrometer (XIS) on board Suzaku has a good energy resolution, a low and stable background, and a large effective area, which are suited for narrow-band surveys and spectroscopy of both point-like and extended X-ray emission. Using the XIS, we performed a very deep survey in the direction of the central region of our Galaxy and pointing observations of three well-known star forming regions in our Galaxy (M 17, the Carina Nebula, and the Arches cluster). -
TU Muscae and the Early-Type Overcontact Binaries Dirk Terrell Department of Space Studies, Southwest Research Institute, Boulde
Exotic Stars as Challenges to Evolution ASP Conference Series, Vol. 279, 2002 C. A. Tout and W. Van Hamme, eds. TU Muscae and the Early-type Overcontact Binaries Dirk Terrell Department of Space Studies, Southwest Research Institute, Boulder, CO 80301, USA Abstract. A simultaneous photometric and spectroscopic analysis of the purported early-type overcontact binary TU Muscae is presented. With a well-behaved light curve and a mass ratio far from unity, if TU Mus is indeed an overcontact system, it presents an interesting chal lenge for 3-D stellar evolution codes, like the Djehuty code, that will be applied to early-type overcontact binaries. The analysis shows TU Mus is slightly overcontact and that a detailed treatment of the reflection effect is important for modeling the light curves. 1. Introduction One of the major unresolved issues in close binary star research is the structure and evolution of overcontact binaries.1 After approximately a decade of vigorous research from the late 1960's to the late 1970's, precipitated by Lucy's (1968) seminal paper on the subject, progress on understanding these stars has slowed. There are probably many reasons for this lack of progress, but the main one is that the necessary computing power to model these stars in three dimensions has only recently been developed. A full treatment of overcontact binaries will re quire a 3-D code capable of modeling the hydrodynamics, energy transport, and probably the magnetic fields present. Such a code, called Djehuty, is currently under development at the Lawrence Livermore National Laboratory by Peter Eggleton and his LLNL colleagues, and will be applied to modeling overcontact binaries. -
Atlas Menor Was Objects to Slowly Change Over Time
C h a r t Atlas Charts s O b by j Objects e c t Constellation s Objects by Number 64 Objects by Type 71 Objects by Name 76 Messier Objects 78 Caldwell Objects 81 Orion & Stars by Name 84 Lepus, circa , Brightest Stars 86 1720 , Closest Stars 87 Mythology 88 Bimonthly Sky Charts 92 Meteor Showers 105 Sun, Moon and Planets 106 Observing Considerations 113 Expanded Glossary 115 Th e 88 Constellations, plus 126 Chart Reference BACK PAGE Introduction he night sky was charted by western civilization a few thou - N 1,370 deep sky objects and 360 double stars (two stars—one sands years ago to bring order to the random splatter of stars, often orbits the other) plotted with observing information for T and in the hopes, as a piece of the puzzle, to help “understand” every object. the forces of nature. The stars and their constellations were imbued with N Inclusion of many “famous” celestial objects, even though the beliefs of those times, which have become mythology. they are beyond the reach of a 6 to 8-inch diameter telescope. The oldest known celestial atlas is in the book, Almagest , by N Expanded glossary to define and/or explain terms and Claudius Ptolemy, a Greco-Egyptian with Roman citizenship who lived concepts. in Alexandria from 90 to 160 AD. The Almagest is the earliest surviving astronomical treatise—a 600-page tome. The star charts are in tabular N Black stars on a white background, a preferred format for star form, by constellation, and the locations of the stars are described by charts. -
Observational Evidence for Tidal Interaction in Close Binary Systems, Including Short-Period Extrasolar Planets
Tidal effects in stars, planets and disks M.-J. Goupil and J.-P. Zahn EAS Publications Series, Vol. ?, 2018 OBSERVATIONAL EVIDENCE FOR TIDAL INTERACTION IN CLOSE BINARY SYSTEMS Tsevi Mazeh1 Abstract. This paper reviews the rich corpus of observational evidence for tidal effects, mostly based on photometric and radial-velocity mea- surements. This is done in a period when the study of binaries is being revolutionized by large-scaled photometric surveys that are detecting many thousands of new binaries and tens of extrasolar planets. We begin by examining the short-term effects, such as ellipsoidal variability and apsidal motion. We next turn to the long-term effects, of which circularization was studied the most: a transition period be- tween circular and eccentric orbits has been derived for eight coeval samples of binaries. The study of synchronization and spin-orbit align- ment is less advanced. As binaries are supposed to reach synchroniza- tion before circularization, one can expect finding eccentric binaries in pseudo-synchronization state, the evidence for which is reviewed. We also discuss synchronization in PMS and young stars, and compare the emerging timescale with the circularization timescale. We next examine the tidal interaction in close binaries that are orbited by a third distant companion, and review the effect of pumping the binary eccentricity by the third star. We elaborate on the impact of the pumped eccentricity on the tidal evolution of close binaries residing in triple systems, which may shrink the binary separation. Finally we consider the extrasolar planets and the observational evidence for tidal interaction with their parent stars. -
FAR ULTRAVIOLET SPECTROSCOPIC EXPLORER SPECTROSCOPY of the O Vi RESONANCE DOUBLET in SAND 2 (WO) Paul A
The Astrophysical Journal, 538:L51±L55, 2000 July 20 q 2000. The American Astronomical Society. All rights reserved. Printed in U.S.A. FAR ULTRAVIOLET SPECTROSCOPIC EXPLORER SPECTROSCOPY OF THE O vi RESONANCE DOUBLET IN SAND 2 (WO) Paul A. Crowther,1 A. W. Fullerton,2,3 D. J. Hillier,4 K. Brownsberger,5 L. Dessart,1,6 A. J. Willis,1 O. De Marco,1 M. J. Barlow,1 J. B. Hutchings,7 D. L. Massa,8 D. C. Morton,7 and G. Sonneborn9 Received 2000 March 17; accepted 2000 June 8; published 2000 July 14 ABSTRACT We present Far Ultraviolet Spectroscopic Explorer spectroscopy of Sand 2, an LMC WO-type Wolf-Rayet star, revealing the O vi resonance P Cygni doublet at 1032±1038 AÊ . These data are combined with Hubble Space Telescope Faint Object Spectrograph ultraviolet and Mount Stromlo 2.3 m optical spectroscopy and analyzed using a spherical, non-LTE, line-blanketed code. Our study reveals exceptional stellar parameters: T¤ » 21 Ç 25 21 150,000 K,v` = 4100 km s , log (L/L,,) = 5.3 , andM=1 # 10 M yr , if we adopt a volume ®lling factor » 5 » 10.10 of 10%. Elemental abundances ofC/He 0.7 0.2 and O/He 0.1520.05 by number qualitatively support pre- vious recombination line studies. We con®rm that Sand 2 is more chemically enriched in carbon than LMC WC stars and that it is expected to undergo a supernova explosion within the next5 # 10 4 yr. Subject headings: stars: evolution Ð stars: individual (Sand 2) Ð stars: Wolf-Rayet 1. -
New Observational Results on the Colliding Wind WR+O Binary WR 30A
Wolf-Rayet Phenomena in Massive Stars and Starburst Galaxies Proceedings IAU Symposium No. 193, @1999 IAU K.A. van der Hucht, G. Koenigsberger & P.R.J. Eenens, eds. New observational results on the colliding wind WR+O binary WR 30a Eric Gosset", Pierre Royer I, Gregor Rauw", Jean Manfroid", and Jean-Marie Vreux Institut d'Astrophysique et de Geophsisique, Unioersite de Liege, avenue de Cointe, 5, B-4000 Liege, Belgium 1. Introduction WR 30a (MS 4) was first suspected as a possible Wolf-Rayet star by McConnell & Sanduleak (1970) during a deep objective-prism survey performed around the Carina Nebula region. From subsequent studies, the spectrum turned out to be composite, with a WR component classified W04 (or alternatively WC4, W05 and WC3) and an 0 component classified 04. Niemela (1995) reported the first, and up-to-now unique, radial velocity study for that star. She noticed large variations of C IV A4658 from night to night, suggesting that WR 30a might be a short period binary. A plot of the C IV emission-line velocities versus the He II absorption ones clearly indicates that they are exhibiting opposite binary motions. The apparent velocity amplitudes imply a rather low mass ratio Mwo 4/Mo4 == 0.15, although the radial velocities of the C IV line could be distorted due to line-profile variations. In the present paper, we confirm the binary nature of WR 30a and propose, for the first time, a value for the orbital period of the system: P == 4.62 days. Other orbital parameters are also derived and discussed. -
Arxiv:1008.3235V2 [Astro-Ph.HE] 30 Aug 2010 .Roth M
F ermi Large Area Telescope Observation of a Gamma-ray Source at the Position of Eta Carinae A. A. Abdo1,2, M. Ackermann3, M. Ajello3, A. Allafort3, L. Baldini4, J. Ballet5, G. Barbiellini6,7, D. Bastieri8,9, K. Bechtol3, R. Bellazzini4, B. Berenji3, R. D. Blandford3, E. Bonamente10,11, A. W. Borgland3, A. Bouvier3, T. J. Brandt12,13, J. Bregeon4, A. Brez4, M. Brigida14,15, P. Bruel16, R. Buehler3, T. H. Burnett17, G. A. Caliandro18, R. A. Cameron3, P. A. Caraveo19, S. Carrigan9, J. M. Casandjian5, C. Cecchi10,11, O.¨ C¸elik20,21,22, S. Chaty5, A. Chekhtman1,23, C. C. Cheung1,2, J. Chiang3, S. Ciprini11, R. Claus3, J. Cohen-Tanugi24, L. R. Cominsky25, J. Conrad26,27,28, C. D. Dermer1, F. de Palma14,15, S. W. Digel3, E. do Couto e Silva3, P. S. Drell3, R. Dubois3, D. Dumora29,30, C. Favuzzi14,15, S. J. Fegan16, E. C. Ferrara20, M. Frailis31,32, Y. Fukazawa33, P. Fusco14,15, F. Gargano15, N. Gehrels20, S. Germani10,11, N. Giglietto14,15, F. Giordano14,15, G. Godfrey3, I. A. Grenier5, M.-H. Grondin29,30, J. E. Grove1, L. Guillemot34,29,30, S. Guiriec35, D. Hadasch36, Y. Hanabata33, A. K. Harding20, M. Hayashida3, E. Hays20, A. B. Hill37,38, D. Horan16, R. E. Hughes13, R. Itoh33, M. S. Jackson39,27, G. J´ohannesson3, A. S. Johnson3, W. N. Johnson1, T. Kamae3, H. Katagiri33, J. Kataoka40, M. Kerr17, J. Kn¨odlseder12, M. Kuss4, J. Lande3, L. Latronico4, S.-H. Lee3, M. Lemoine-Goumard29,30, M. Livingstone41, M. Llena Garde26,27, F. Longo6,7, F. Loparco14,15, M. -
A\St Ronomia B Oletín N° 46 La Plata, Buenos Aires, 2003
A sociacion AJrgent ina de ~A\st ronomia Boletín N° 46 La Plata, Buenos Aires, 2003 AsociaciónArgentina, de Astronomía - Boletín 46 i Asociación Argentina de Astronomía Reunión Anual La Plata, Buenos Aires, 22 al 25 de septiembre Organizada por: Facultad de Ciencias Astronómicas y Geofísicas Universidad Nacional de La Plata EDITORES Stella Maris Malaroda Silvia Mabel Galliani 2003 ISSN 0571^3285 AsociaciónArgentina, de Astronomía - Boletín 46 íi Asociación Argentina de Astronomía Fundada en 1958 Personería Jurídica 1421, Prov. de Buenos Aires Asociación Argentina de Astronomía - Boletín 46 iii Comisión Directiva Presidente: Dra. Marta Rovira Vicepresidente: Dr. Diego García Lambas Secretario: Dr. Andrés Piatti Tesorero: Dra. Cristina Cappa Vocal 1: Dr. Sergio Cellone Vocal 2: Dra. Lilia Patricia Bassino Vocal Sup. 1: Dra. Zulema González de López García Vocal Sup. 2: Lie. David Merlo Comisión Revisora de Cuentas Titulares: Dra. Mirta Mosconi Dra. Elsa Giacani Dra. Stella Malaroda Suplentes: Dra. Irene Vega Comité Nacional de Astronomía Secretario: Dr. Adrián Brunini Miembros: Dr. Diego García Lambas Dra. Olga Inés Pintado Lie. Roberto Claudio Gamen Lie. Guillermo Federico Hágele Asociación Argentina de Astronomía - Boletín 46 IV Comité Científico de la Reunión Dr. Roberto Aquilano Dr. Adrián Brunini Dr. Juan José Clariá Dra. Cristina Cappa Dr. Juan Carlos Forte (Presidente) Dr. Daniel Gómez Lie. Carlos López Dra. Stella Malaroda Dra. Mirta Mosconi Comité Organizador Local Lie. María Laura Arias Dr. Pablo Cincotta (Presidente) Lie. Roberto -
Descriptions of Planetary and He1 Iocent R Ic Spacecraft and Investigations
NATIONAL SPACE SCIENCE DATA CENTER WORLD DATA CENTER A for ROCKETS6 AND SATELLITES 88-07 DATA CATALOG SERIES FOR SPACE SCIENCE AND APPLICATIOINS FLIGHT MISSIONS Volume 1A Descriptions of Planetary and He1iocent r ic Spacecraft and Investigations Second Edition March 1988 ~ CATEGORIES PACECRAFT USED FN THIS PLANETARY AND HELIOCENTRIC This category includes probes to the various planets of the solar system and probes designed to make measurements of the characteristics of interplanetary space. Also included are the probes that will pass out of the solar system into interstellar space. NSSDC/WDC-A-R&S 88-07 DATA CATALOG SE:RIES FOR SPACE SCIENCE AND APPLICATIONS FLIGHT MISSIONS Volume 1A DESCRIPTIONS OF P:LANETARY AND HELIOCENTRIC SPACECRAFT AND INVESTIGATIONS Edited By Winifred Sawtell Cameron Robert W. Vostreys Second Edition March 1988 National Space Science Data Center (NSSDC) / World Data Center A for Rc'ckets and Satellites (WDC-A-R&S National Aeronautics and Space Administration Goddard Space Flight Center Greenbelt, Maryland 20771 PREFACE TO THE SECOND EDITION The decision to reprint Volume 1A of the Data Catalog Series for Space Science and Applications Flight Missions was made primarily because it was no longer available when its companion, Volume lB, was completed in April 1987. Although Volume 1A was printed in September 1982, in this second edition no changes were made to the original text, since it described spacecraft and experiments as they actually were durin~qthe acquisition of the data in Volume 1B‘. The only significantarevisionmade in the second edition was the addition of Appendix E, which is an index showing the pages in Volume 1A where one can find descriptions of the spacecraft and experiments corresponding to the data sets described in Volume 1B. -
Third Bodies Or Magentic Activity in Binary Stars ?
TMHMA FUSIKHS, PANEPISTHMIO PATRWN TOMEAS JEWRHTIKHS, UPOLOGISTIKHS FUSIKHS KAI ASTROFUSIKHS EIDIKH EREUNHTIKH ERGASIA GIA TO METAPTUQIAKO DIPLWMA EXEIDIKEUSHS « TrÐta S¸mata ή Μαγνητική Δραστηριόthta se διπλά αστρικά συστήματa ;» KwnstantÐnoc Zèrbac A.M.: 1050804 Epiblèpousa: E.-P. Qristοπούλου, EpÐkourh Καθηγήτρια PanepisthmÐou Patr¸n Πάτρα, 2018 Περιεχόμενα i Περιεχόμενα Katάλοgoc Σχημάτwn . iv Katάλοgoc Piνάκων . xi PerÐlhyh .................................. 1 Abstract ................................... 4 Κεφάλαιo 1 Troχιακά qarakthriστικά dipl¸n sustημάτwn . 6 1.1 To Πρόβλημα twn Δύο Σωμάτwn . 6 1.2 Μορφή Troχιάς . 10 1.2.1 Λύσειc twn Exis¸sewn KÐnhshc . 10 1.2.2 ExÐswsh Troχιάς . 11 1.3 ExÐswsh Kepler ............................. 17 1.3.1 EpÐlush ExÐswshc Kepler ................... 20 1.4 Troχιακά stoiqeÐa . 21 1.4.1 Troχιακή (Fwtομετρική) kai Γωνιακή Φάsh . 23 1.4.2 Kuklikèc kai 'Ekkentrec Troqièc . 24 1.4.3 Sqèsh troqiak¸n stoiqeÐwn me thn oλική sτροφορμή kai e- nèrgeia . 26 BibliografÐa KefalaÐou 1 . 29 Κεφάλαιo 2 Γεωμετρικά qarakthriστικά dipl¸n συστημάτwn 30 2.1 Ενεργό Βαρυτικό Δυναμικό - Δυναμικό Kopal . 31 2.2 Montèlo Roche ............................. 37 2.3 Morfoloγική Taxiνόμηση Dipl¸n Συστημάτwn . 42 2.4 Συστήματa Upeρεπαφής τύπου W UMa . 49 2.4.1 Γενικά Qarakthriστικά . 49 2.4.2 To παράδοξο tou tύπου W ................... 50 2.4.3 Δομή kai Εξελικτικά Σενάρια . 51 2.5 Antαλλαγή kai Metαφορά Μάζας . 55 2.5.1 DeÐkthc AktÐnac - Μάzac . 56 2.5.2 Metαφορά Μάζας (RLOF)................... 62 2.5.3 Ap¸leia Μάζας . 64 BibliografÐa KefalaÐou 2 . 70 Περιεχόμενα ii Κεφάλαιo 3 TrÐta s¸mata ή μαγνητική δραστηριόthta se διπλά αστρικά συστήματa .................... 74 3.1 Eiσαγωγή . 74 3.2 Metabolèc sto διάγραμμα O-C ....................