New Times of Minima of Some Eclipsing Binary Stars
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New CCD Times of Minima of Eclipsing Binary Systems
We present a total of 208 CCD timings for 103 eclipsing binaries.
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A catalogue of eclipsing variables
A new catalogue of 6330 eclipsing variable stars is presented. Thecatalogue was developed from the General Catalogue of Variable Stars(GCVS) and its textual remarks by including recently publishedinformation about classification of 843 systems and making correspondingcorrections of GCVS data. The catalogue1 represents thelargest list of eclipsing binaries classified from observations.
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CCD Minima for Selected Eclipsing Binaries in 2005
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Photoelectric Minima of Selected Eclipsing Binaries and Maxima of Pulsating Stars
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The early-type eclipsing binary V1331 Aql*
We present a spectroscopic and photometric analysis of V1331 Aql, anearly-type eclipsing binary with a quite short period, i.e. 1.364 d.Radial velocity curves of both components were constructed fromhigh-dispersion spectra of this close early B-type system, which are thefirst published spectroscopic measurements of this star. The light curveanalysis is based on new UBV curves. Absolute dimensions of the binarycomponents are derived. The primary mass M1 (=10.1Msolar) and radius are close to the expected ZAMS values fortype B1V. The mass of the secondary component M2 (=5.3Msolar) corresponds to B4IV, but the component is hotter thanexpected for this type. It is oversized and overluminous for such amass, and in this respect is similar to the secondary components ofsemi-detached Algol-like systems. However, it does not completely fillits Roche lobe. A revision of the few other known binaries of comparablespectral type and period and a recalculation of the parameters of AI Cruand V Pup suggests that the detached configuration of V1331 Aql isunique among this group.
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Catalogue of Algol type binary stars
A catalogue of (411) Algol-type (semi-detached) binary stars ispresented in the form of five separate tables of information. Thecatalogue has developed from an earlier version by including more recentinformation and an improved layout. A sixth table lists (1872) candidateAlgols, about which fewer details are known at present. Some issuesrelating to the classification and interpretation of Algol-like binariesare also discussed.Catalogue is only available in electronic form at the CDS via anonymousftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/417/263
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CCD Times of Minima of Some Eclipsing Binaries in 2003
We present CCD observations of minima of 31 eclipsing binaries observedby SAVS sky survey in 2003.
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Beobachtungsergebnisse Bundesdeutsche Arbeitsgemeinschaft fur Veranderlichen Serne e.V.
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CCD Times of Minima of Some Eclipsing Binaries in 2002
We present CCD observations of minima of 11 eclipsing binaries.
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Beobachtungsegebnisse Bundesdeutsche Arbeitsgemainschaft fur Veranderliche Sterne e.V.
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Search for duplicity in periodic variable Be stars
Four Be stars, HR 1960, HR 2968,HR 3237 and HR 3642, selectedaccording to their periodic variations in HIPPARCOS and GENEVAphotometries, were monitored from 1998 until 2001 with the CORALIEspectrograph. Among these stars, two are new spectroscopic binaries andone is a new lambda Eri short period variable. HR 1960 is a lowamplitude (K = 3.4 km s-1) SB1 with a period of 395.48 d inagreement with the photometric prediction. HR 3237 is a short period SB1(P = 5.1526 d). HR 3642 presents some interesting variations inphotometry and spectroscopy: indeed, a mid- and a short-term variationis present with periods of 137.99 d (Hp magnitude) and 1.13028 d (radialvelocity) respectively. The short-term variation, characteristic of thelambda Eri stars, probably implies non-radial pulsations orinhomogeneities in the corotating disc. The last star, HR 2968, is anexcellent photometric binary candidate, but no spectroscopic obviousnessof a companion has been found. Based on observations collected at theSwiss 40 cm, 70 cm and 120 cm telescopes at the European SouthernObservatory (La Silla, Chile) and on data from the ESA HIPPARCOSsatellite. The photometric and radial velocity data are only availablein electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr(130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/385/488 Table 3 is onlyavailable in electronic form at http://www.edpsciences.org
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Beobachtungsergebnisse Bundesdeutsche Arbeitsgemeinschaft fur Veraenderliche Sterne e.V.
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A Search for High-Velocity Be Stars
We present an analysis of the kinematics of Be stars based uponHipparcos proper motions and published radial velocities. We findapproximately 23 of the 344 stars in our sample have peculiar spacemotions greater than 40 km s-1 and up to 102 kms-1. We argue that these high-velocity stars are the resultof either a supernova that disrupted a binary or ejection by closeencounters of binaries in young clusters. Be stars spun up by binarymass transfer will appear as high-velocity objects if there wassignificant mass loss during the supernova explosion of the initiallymore massive star, but the generally moderate peculiar velocities of BeX-ray binaries indicate that the progenitors lose most of their massprior to the supernova (in accordance with model predictions). Binaryformation models for Be stars predict that most systems bypass thesupernova stage (and do not receive runaway velocities) to createultimately Be+white dwarf binaries. The fraction of Be stars spun up bybinary mass transfer remains unknown, since the post-mass transfercompanions are difficult to detect.
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Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics
The Catalogue, available at the Centre de Données Stellaires deStrasbourg, consists of 13 573 records concerning the results obtainedfrom different methods for 7778 stars, reported in the literature. Thefollowing data are listed for each star: identifications, apparentmagnitude, spectral type, apparent diameter in arcsec, absolute radiusin solar units, method of determination, reference, remarks. Commentsand statistics obtained from CADARS are given. The Catalogue isavailable in electronic form at the CDS via anonymous ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcar?J/A+A/367/521
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Stars with the Largest Hipparcos Photometric Amplitudes
A list of the 2027 stars that have the largest photometric amplitudes inHipparcos Photometry shows that most variable stars are all Miras. Thepercentage of variable types change as a function of amplitude. Thiscompilation should also be of value to photometrists looking forrelatively unstudied, but large amplitude stars.
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Catalogue of H-alpha emission stars in the Northern Milky Way
The ``Catalogue of Stars in the Northern Milky Way Having H-alpha inEmission" appears in Abhandlungen aus der Hamburger Sternwarte, Band XIin the year 1997. It contains 4174 stars, range {32degr <= l() II< 214degr , -10degr < b() II < +10degr } having the Hαline in emission. HBH stars and stars of further 99 lists taken from theliterature till the end of 1994 were included in the catalogue. We givethe cross-identification of stars from all lists used. The catalogue isalso available in the Centre de Données, Strasbourg ftp130.79.128.5 or http://cdsweb.u-strasbg.fr and at the HamburgObservatory via internet.
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Variations of the orbital periods in semi-detached binary stars with radiative outer layers
A detailed analysis of the period changes of sixteen semi-detachedbinaries which contain only stars with radiative outer layers(ET-systems) has been performed and their respective O-C diagrams arebrought and discussed. It was found that the course of the periodvariations is monotonic and in some systems the period is even constant.This detailed analysis of extensive sets of timings covering severaldecades brings a strong support to an earlier finding of te[Hall(1989)]{hal89} and develops it further. We show that all systems withthe orbital periods shorter than nine days display constant period orits increase, with the exception of an uncertain case of V 337 Aql. Thecourse of the period variations in TT Aur appears more complex but thecyclic term can be plausibly explained by the third body. A search forgeneral relations between the parameters of the systems and the periodchanges was undertaken. The mass ratio q appears to play a role in theperiod variations. Clear changes in systems with orbital periods shorterthan 9 days were detected only for q>0.4 while constant periods arecommon in systems with q<0.4 in this period range. The sense of thesecular changes in most systems is in accordance with the dominantconservative mass transfer in evolved binary and corresponds to the slowphase. The role of the evolutionary scenarios (case A versus B) and theinfluence of changes of the rotational angular momenta of the componentsare discussed.
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UBV beta Database for Case-Hamburg Northern and Southern Luminous Stars
A database of photoelectric UBV beta photometry for stars listed in theCase-Hamburg northern and southern Milky Way luminous stars surveys hasbeen compiled from the original research literature. Consisting of over16,000 observations of some 7300 stars from over 500 sources, thisdatabase constitutes the most complete compilation of such photometryavailable for intrinsically luminous stars around the Galactic plane.Over 5000 stars listed in the Case-Hamburg surveys still lackfundamental photometric data.
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Catalogue of stars in the northern Milky Way having H-alpha in emission
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The calculation of critical rotational periods in three typical close binary systems based on synchronization theory.
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Measurement and study of rotation in close binary stars (III) Statistical analysis of synchronization.
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Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Subtittle: Radial velocities: The Wilson-Evans-Batten catalogue.
We give a common version of the two catalogues of Mean Radial Velocitiesby Wilson (1963) and Evans (1978) to which we have added the catalogueof spectroscopic binary systems (Batten et al. 1989). For each star,when possible, we give: 1) an acronym to enter SIMBAD (Set ofIdentifications Measurements and Bibliography for Astronomical Data) ofthe CDS (Centre de Donnees Astronomiques de Strasbourg). 2) the numberHIC of the HIPPARCOS catalogue (Turon 1992). 3) the CCDM number(Catalogue des Composantes des etoiles Doubles et Multiples) byDommanget & Nys (1994). For the cluster stars, a precise study hasbeen done, on the identificator numbers. Numerous remarks point out theproblems we have had to deal with.
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Are Contact Binaries Undergoing Thermal Relaxation Oscillations with Contact Discontinuity?
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995AJ....110..782W&db_key=AST
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Measurement and analysis of rotation in close binaries. II. Calculation of synchronism.
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A spectrum synthesis program for binary stars
A new program produces synthetic spectra of binary stars at arbitraryvalues of orbital longitude, including longitudes of partial or completeeclipse. The stellar components may be distorted, either tidally orrotationally, or both. Either or both components may be rotatingnonsynchronously. We illustrate the program performance with two cases:EE Peg, an eclipsing binary with small distortion, and SX Aur, aneclipsing binary that is close to contact.
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Rotation of close binary system components
The rotation of close binary system components is investigated. Theprincipal physical characteristics as well as the equatorial rotationaland the axial and orbital inclinations for 46 close binary systems weredetermined. It is found that the rotation axes of the individual starsin a pair cross the orbital plane under different angles. As a rule, therotation and orbital periods of a vast majority of the systemsinvestigated here do not coincide.
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A Spectrum Synthesis Program for Binary Stars
A new computer program produces synthetic spectra of binary stars atarbitrary values of orbital longitude, including longitudes of partialor complete eclipse. The stellar components may be distorted, eithertidally or rotationally, or both. Either or both components may berotating non-synchronously. We illustrate the program performance withtwo cases: EE Peg, an eclipsing binary with small distortion and SX Aur,an eclipsing binary that is close to contact.
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OB-type binaries: Models versus observations
Recently published models on close binary evolution for massive stars (Mgreater than 5 solar mass) are compared to a set of detached andsemidetached OB binaries. For the majority of the detached systems, wefind good correspondence between theoretical and observedcharacteristics for stars with masses between 4.5 sola mass and 17 solarmass. We explore the origin of semidetached systems, and discussanomalies between models and observed characteristics. An initial massratio of around 0.6 seems to be preffered for this group. Finally, webriefly examine a number of massive (marginal) contact systems. Thelatter systems all seem to evolve according to case A of mass transfer.
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The students' observatory 1935-43 : when Aller measured radial velocities and Popper interpreted stellar spectra, with brief updates on the significance of DQ Her, SN 1937C, alpha Cygni, RY Scuti and the rotation of M 33.
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INHABITED SKY
