WZ And, a probable contact system with mass ratio very close to unity
We present B and V time-series CCD photometry of the short-periodeclipsing binary WZ And. Eight new epochs of minimum light weredetermined from the observations covering five primary and threesecondary eclipses. Refined period and new ephemeris are given for thesystem based on the photoelectric and CCD photometric times of minimaobtained in the recent 20 years. A period study covering 100 years ornearly 59,000 orbital cycles reveals a cyclic but not periodic behaviorof long-term period variations. Two major period jumps can be indicated.That could be evidence for the existence of a very eccentric third bodyof the eclipsing system. The light curve shows continuous light changesoutside eclipses in both V and B band, indicating that it could be of EWrather EB type. A simultaneous solution of the two light curves wascomputed using the Wilson Devinney code. The solution indicates that WZAnd is in shallow contact with a fill-out factor of 6%. Aphotometric mass ratio of q = 1.00 ± 0.01 was derived for thesystem. Discussions on the period behavior and the probable evolutionarystatus of the system suggest that WZ And could very probably be a newlyformed equal-mass contact system.
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Photoelectric Minima of Selected Eclipsing Binaries and Maxima of Pulsating 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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Times of Minima for Neglected Eclipsing Binaries in 2005
Times of minima obtained at Rolling Hills Observatory during 2005 for anumber of neglected eclipsing binaries are presented.
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The Case for Third Bodies as the Cause of Period Changes in Selected Algol Systems
Many eclipsing binary star systems show long-term variations in theirorbital periods, evident in their O-C (observed minus calculated period)diagrams. With data from the Robotic Optical Transient Search Experiment(ROTSE-I) compiled in the SkyDOT database, New Mexico State University 1m data, and recent American Association of Variable Star Observers(AAVSO) data, we revisit Borkovits and Hegedüs's best-casecandidates for third-body effects in eclipsing binaries: AB And, TV Cas,XX Cep, and AK Her. We also examine the possibility of a third bodyorbiting Y Cam. Our new data support their suggestion that a third bodyis present in all systems except AK Her, as is revealed by thesinusoidal variations of the O-C residuals. Our new data suggest that athird body alone cannot explain the variations seen in the O-C residualsof AK Her. We also provide a table of 143 eclipsing binary systems thathave historical AAVSO O-C data with new values computed from the SkyDOTdatabase.
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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 2003
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Eclipsing Binaries in the Blue Envelope of the Period-Color Diagram
Several interesting close eclipsing binaries in the short-period blueenvelope of the period-color diagram are investigated. Their l O--Cdiagrams are discussed and in several cases new solutions are given.
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On the properties of contact binary stars
We have compiled a catalogue of light curve solutions of contact binarystars. It contains the results of 159 light curve solutions. Theproperties of contact binary stars were studied using the cataloguedata. As is well known since Lucy's (\cite{Lucy68a},b) and Mochnacki's(\cite{Mochnacki81}) studies, primary components transfer their ownenergy to the secondary star via the common envelope around the twostars. This transfer was parameterized by a transfer parameter (ratio ofthe observed and intrinsic luminosities of the primary star). We provethat this transfer parameter is a simple function of the mass andluminosity ratios. We introduced a new type of contact binary stars: Hsubtype systems which have a large mass ratio (q>0.72). These systemsshow behaviour in the luminosity ratio- transfer parameter diagram thatis very different from that of other systems and according to ourresults the energy transfer rate is less efficient in them than in othertypes of contact binary stars. We also show that different types ofcontact binaries have well defined locations on the mass ratio -luminosity ratio diagram. Several contact binary systems do not followLucy's relation (L2/L1 =(M2/M1)0.92). No strict mass ratio -luminosity ratio relation of contact binary stars exists.Tables 2 and 3 are available in electronic form athttp://www.edpsciences.org
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Times of Minima for Neglected Eclipsing Binaries in 2002
We present several CCD minima observations of eclipsing binaries.
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Catalogue of the field contact binary stars
A catalogue of 361 galactic contact binaries is presented. Listedcontact binaries are divided into five groups according to the type andquality of the available observations and parameters. For all systemsthe ephemeris for the primary minimum, minimum and maximum visualbrightness and equatorial coordinates are given. If available,photometric elements, (m1+m2)sin3i,spectral type, parallax and magnitude of the O'Connell effect are alsogiven. Photometric data for several systems are augmented by newobservations. The quality of the available data is assessed and systemsrequiring modern light-curve solutions are selected. Selectedstatistical properties of the collected data are discussed.
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CCD Minima of Selected Eclipsing Binaries in 2000
This report presents minima timings of selected eclipsing binaries
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Coordinates and Identifications for Sonneberg variables on MVS 291-295
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A photometric study of early-type contact binary CT Tauri
We present a photometric analysis of a short period binary system CTTau. New times of minima indicate no period changes over the last 30years. CT Tau is in a quiet evolutionary phase without any trace of massexchange between components. The photometric solution is also presented.We found a dumbbell-shaped configuration of the system with the fill-outfactor close to unity and mass ratio q = 1. The masses, radii, andtemperatures of two components are identical (log M= 0.60, log R = 0.51,and log T = 4.26) and the system is located at the distance dapproximately equals 1.5 kpc.
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The SVS Numbering Series Discontinued
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No Major Period Change for CT Tauri
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New Period of CT Tauri
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Massive close binaries with early-type components, observed characteristics.
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A catalogue of parameters for eclipsing binaries
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Results of BAV observations of variable stars
In this 12th compilation of BAV, results of observations are given fromthe years 1976 and 1977 for 231 observed minima of 58 eclipsingbinaries, 108 maxima of 25 RR Lyrae stars, four maxima of four DeltaCephei stars, and four maxima of one Delta Scuti star.One-hundred-eighty-two results of 23 long-period, semiregular, irregularand RV Tauri stars are also given.
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Infra-red observations of young stars. II. T Tau stars and the ORI population.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973MNRAS.161...97C&db_key=AST
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CT Tauri
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Photographic Proper Motions and the Mean Parallax of RW Aurigae Variables
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Spectral Classifications for 112 Variable Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1960ApJ...131..632H&db_key=AST
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Uber 43 Veranderliche in den Sternbildern Auriga und Taurus.
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Die RW Aurigae-Sterne und ihre Nebenformen
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Variables stars.
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