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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Minima Kurt Locher 2004-2005
Minima observed 2004..2005 by Kurt Locher visually, not accepted by IBVSas part of BBSAG Bulletin.
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Photoelectric Minima of Selected Eclipsing Binaries and Maxima of Pulsating Stars
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Close binary stars in ob-association regions i. preliminary investigation
We performed a sample of O- and B-eclipsing binary stars inOB-association regions and obtained the preliminary list of 147 binariesin 45 OB-association regions. We tried to elucidate the question whether(or not) the close binaries belong to corresponding OB-associations,from the commonness of their proper motions, radial velocities anddistances. Based on the completeness of the data,the binaries aredevided into three groups and the scheme for calculation of degree ofbelonging of stars to OB-associations is developed. Necessary data arenot available for nine systems and they are given in a specific table.For 12 cases, the binaries project onto the regions of two associations.We show that 33 (22.3%) close binary stars are members, 65 (43.9%) areprobable members and 39 (26.4%) are less probable members of theOB-associations. We find that 11 binaries belong to the Galaxybackground. The comparison of the distributions of orbital periods forthe binaries in OB-associations and for O-, B-binaries of the Galaxybackground shows their considerable differences in the vicinity of thetwo-day period.
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CCD Times of Minima of Selected Eclipsing Binaries
682 CCD minima observations of 259 eclipsing binaries made mainly byauthor are presented. The observed stars were chosen mainly fromcatalogue BRKA of observing programme of BRNO-Variable Star Section ofCAS.
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163. List of Minima Timings of Eclipsing Binaries by BBSAG Observers
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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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Archive of Photometric Plates Obtained at Cluj Astronomical Observatory
The archive of photometric plates obtained at the AstronomicalObservatory of Cluj in the period 1952-1974 is presented. The plateinventory is made within the framework of the Wide-Field Plate Databaseproject. The plates were taken in the regions around 110 variable stars(eclipsing variables and RR Lyrae-type stars), as well as in somecomparison stars regions.
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Photoelectric Minima of Selected Eclipsing Binaries
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162-nd List of Minima Timings of Eclipsing Binaries by BBSAG Observers
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Orbital period study of the Algol-type eclipsing binary system TW Draconis
The century-long times of light minimum of the Algol-type eclipsingbinary star, TW Dra (BD/+64°1077, SpA5V+K2III), are investigated byconsidering a new pattern of period change. Two sudden period increasesand two successive period decreases are discovered to superimpose on arapid secular increase (dP/dt=+4.43×10-6days/year). Thesecular increase may be caused by a dynamical mass transfer from thesecondary to the primary component(dm/dt=6.81×10-7Msolar/year) that is inagreement with the semi-detached configuration of the system and withthe existence of a hot spot and a gaseous stream in the binary system.The irregular period jumps superimposed on the secular increase can beexplained by the structure variation of the K2-type giant viainstabilities of the outer convective layer or via magnetic activitycycles.
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Japan's First Variable Star Observer, Dr. Naozo Ichinohe
This paper gives a brief account of the astronomical career of a pioneerin Japanese astrophysics, Dr. Naozo Ichinohe, 1872-1920.
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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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Survey of Hα Mass Transfer Structures in Classical Algol-Type Binaries
Five years of Hα survey data for 37 ``classical'' Algol-typebinaries are presented. All these systems have primaries with a spectraltype of A or B, have a period of less than 5 days, and are visible inthe Northern Hemisphere. Data were collected with the 1.02 m reflectorat the US Naval Observatory, Flagstaff Station. The survey consists ofover 460 system spectra. Each system was observed at least once duringthe 5 years, with many systems observed several times over severalepochs. Difference profiles are calculated for most spectra by modelingand subtracting the spectrum of the photospheres of the stellarcomponents. We examined each spectrum for the presence of mass transfer,stream-star and stream-disk interaction, a disk or circumstellar bulge,and chromospheric emission. We present information on the prevalence ofmass transfer activity, disk presence, and system states associated withparticular mass transfer structures. We show that no currently publishedstudy, including this one, has enough data for a rigorous statisticalidentification of system states.
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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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CCD Minima of Selected Eclipsing Binaries in 1999
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Do the physical properties of Ap binaries depend on their orbital elements?
We reveal sufficient evidence that the physical characteristics of Apstars are related to binarity. The Ap star peculiarity [represented bythe Δ(V1-G) value and magnetic field strength] diminishes witheccentricity, and it may also increase with orbital period(Porb). This pattern, however, does not hold for largeorbital periods. A striking gap that occurs in the orbital perioddistribution of Ap binaries at 160-600d might well mark a discontinuityin the above-mentioned behaviour. There is also an interestingindication that the Ap star eccentricities are relatively lower thanthose of corresponding B9-A2 normal binaries for Porb>10d.All this gives serious support to the pioneering idea of Abt &Snowden concerning a possible interplay between the magnetism of Apstars and their binarity. Nevertheless, we argue instead in favour ofanother mechanism, namely that it is binarity that affects magnetism andnot the opposite, and suggest the presence of a newmagnetohydrodynamical mechanism induced by the stellar companion andstretching to surprisingly large Porb.
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Is asynchronism in semidetached binary systems real?
We analyze statistical relationships between the parameters ofAlgol-type binaries with asynchronous rotation of the primary componentsand provide observational evidence for denser, more extended gaseousenvelopes in the eclipsing systems of this group. We conclude thatasynchronism of the primary components in such systems is not real. Thelines that are used to determine the rotational velocities of thesecomponents originate mostly in the part of the atmosphere which acquiresan additional angular momentum during the interaction with the gasstream and produces a transient accretion disk near the equatorialplane.
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Hα Spectroscopy of RW Monocerotis
Five years of sparse full-orbit Hα spectroscopy are presented forthe short-period Algol RW Monocerotis. A spectroscopic mass ratio isderived that confirms the published photometric mass ratio. Of the twopublished rotation rates of the primary star, 66 and 260 kms-1, the slower best fits our observations. Hα emissionwas not seen during any of five eclipses, indicating that the secondaryis notstrongly chromospherically active. At every epoch an emissionfeature between the two stars was found, confirming that there iscontinuous mass transfer. However, an accompanying accretion disk wasseen in only two of six observing runs, using out-of-eclipsespectroscopy. Comparing with models, we show how a single out-of-eclipseHα observation can provide information on the mass transferpresence at that epoch. Finally, we see redshifted absorption justbefore and after primary eclipse, consistent with the location andvelocity of a mass transfer stream. However, the Hα absorptionequivalent width (with respect to the out-of-eclipse continuum) fallsproportionally with the primary's visibility between first and secondcontact. This indicates that the stream is projected against the entireface of the primary, a much larger area than predicted by theory.
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Photometric analysis of the neglected eclipsing binary system DL Cygni
DL Cygni is a poorly studied early-type eclipsingbinary system. In this paper we present new Kron-Cousins VR light curvesobtained at Baja Astronomical Observatory in 1998. A detailedphotometric analysis based on these observations was carried out by theuse of the most recent version of the Wilson-Devinney (WD) code. It isfound that the system is likely a strongly interacting semidetached one.We explain the irregularities of the light curves with the presence ofcircumstellar matter. Different solutions are presented according to thesupposed positions of the circumstellar medium. We suspect that thesystem consists of an asynchronously rotating main-sequence primaryspinned up by the infalling gas of the mass losing evolved secondarycomponent. A period study was also carried out. The period seems to belonger than some decades ago. Due to the lack of spectroscopicinformation we can give only a very uncertain estimation on the absoluteparameters of the binary. One of our initial comparison starsGSC 3595-0816 is suspected to be variable.Tables~3a-c are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
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Interaction of Eclipsing Binaries with their Environment
The interaction of eclipsing binary star systems with the mass around(in the form of star, planet, envelope or disk) affects the orbitalperiod of these systems. Thus, the long-term orbital period changes ofeclipsing binaries which can be deduced by using the observed times ofeclipse minima provide a good tool in understanding the interaction ofeclipsing binaries with their environment. In the present contributionmany examples of the orbital period changes of different eclipsingbinaries are presented and interpreted in terms of the interaction withtheir environment.
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Chemical Evolution of Algols
Not Available
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Rotation of Algol binaries - a line profile model applied to observations.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1996MNRAS.283..613M&db_key=AST
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Period Corrections for Eight Eclipsing Binary Stars
AAVSO observations of eight eclipsing stars indicate a discrepancy whencompared to the elements listed in the fourth edition of the GeneralCatalogue of Variable Stars (GCVS) (Kholopov et al. 1985). New periodsfor XZ Aql, AL Cam, R CMa, U CrB, DK Cyg, V704 Cyg, RW Mon, and TX UMahave been calculated.
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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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Quantitative spectral types for 19 Algol secondaries
Time-resolved spectra of 19 short-period Algol-type binary star systemsobtained during total eclipse are used to derive the temperaturespectral class of the mass-losing secondary component. The spectralclassifications employed a quantitative comparison of the strengths ofabsorption features in stars of known spectral class with those of theprogram stars. The luminosity spectral class can not be determined fromthese data, so both main-sequence and giant stars were used for thecomparison. Our spectral types are compared with published types andfound to be generally in good agreement, unless the published types arederived from the light curves. The photometrically determined types aresystematically later than our directly determined types. This effect isshown also to exist in catalogs of Algol parameters.
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Searching for Intrinsic Variations in Eclipsing Binary Stars
Using a database of nearly 4000 visual estimates made by the authorbetween 1967 and 1993, evidence for intrinsic variations on a time scaleof years is sought after 64 eclipsing binary stars. While none is foundfor most stars, certainb objects warrant further investigation.
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Consequences of the star-stream interaction in Algol
The H-alpha line profile of Algol is studied in order to determine thenature of the interaction between the gas stream and the primary.Evidence is found of an asymmetric transient accretion disk with anaverage radius of (1.8 +/-0.2)RA, an electron density greaterthan about 10 exp 10/cu cm, and mass greater than 10 exp -12 solar mass.The trailing side of the disk is wider and denser than the leading side.The present theoretical calculations of the depth of the shock regionproduced when the gas stream strikes the primary indicate that the shockoccurs above the photosphere of the star. The analyses of H-alpha and UVresonance lines show that the circumstellar material in Algol consistsof four components in addition to the gas stream. It is concluded thatthese transient phenomena are all consequences of the impact of the gasstream on the primary star.
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Observations in regions of Cassiopeia, Gemini, and Monoceros with the Glazar space telescope
Observations at 1640 A of regions in Cassiopeia, Gemini, and Monocerosmade with the Glazar space telescope are presented; 7, 11, 13, and 35early-type stars brighter than about 9 mag were detected in the observedregions. The distribution of dust matter in the corresponding regions isstudied. It is determined that companions of HD 4442, 4797, and BD + 62deg 2225 are subdwarfs of sdB - sdO types; the hot companion of HD220102 may be of the type from B8 Ib-II to sdB. It is shown that HD 5233and 261490 are probably embedded in dense circumstellar envelopes.
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INHABITED SKY
