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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Precise CCD Times of Minima of Selected Eclipsing Binaries
We present 135 precise CCD minima timings for 93 eclipsing binariesobtained at Ondrejov observatory during 2003-2004.
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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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Photoelectric Minima of Selected Eclipsing Binaries and Maxima of Pulsating Stars
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New Times of Minima of Eclipsing Binary Stars
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Photoelectric Minima of Some Eclipsing Binary Stars
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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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Photometric Analyses of the Contact Binaries FZ Orionis and AH Tauri
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CCD Minima for Selected Eclipsing Binaries in 2003
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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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162-nd List of Minima Timings of Eclipsing Binaries by BBSAG Observers
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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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Period Studies of Some Neglected Close Binaries: EP Andromedae, V724 Aquilae, SS Comae, AM Eridani, FZ Orionis, BY Pegasi, EQ Tauri, and NO Vulpeculae
Orbital period changes of eight neglected short-period close binaries,EP And, V724 Aql, SS Com, AM Eri, FZ Ori, BY Peg, EQ Tau, and NO Vul,are presented based on the analysis of their O-C observations. It isfound that the periods of BY Peg and EQ Tau are decreasing at rates ofdP/dt=-1.67×10-7 and -1.72×10-7 dayyr-1, respectively, while the orbital periods of SS Com andAM Eri show secular increase at rates ofdP/dt=+5.91×10-7 and +4.39×10-7 dayyr-1. Weak evidence also indicates that the orbital period ofEP And is increasing. For FZ Ori, the decrease rate of orbital period isrevised. For the other two systems, V724 Aql and NO Vul, their O-C curvecan be described by a sudden period decrease or a continuous perioddecrease; further investigation is needed. The period changes of theeight systems can be explained by mass transfer between the twocomponents and/or mass and angular momentum loss from these binaries. Astrong mass-radius relation for observed contact binaries is formedbased on the parameters given by Maceroni & Van't Veer. It is shownthat the parameters of SS Com and EQ Tau given by Brancewicz &Dworak do not agree with the mass-radius relation. This may suggest thatthe two systems are not yet in contact. In order to understand thephysical properties of these binaries, complete photoelectric or CCDlight curves and radial velocity observations are needed.
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Photometric study of the short period W UMa system - FZ Orionis
Photoelectric B, V observations of the eclipsing binary system FZOrionis obtained from the Japal-Rangapur Observatory during the years1981 to 1992 are presented and studied. No period changes in the systemare detected. The light curves are analysed using the Wilson-Devinneymethod and the system parameters are derived.
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Photoelectric Minima of Selected Eclipsing Binaries and Maxima of Pulsating Stars
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The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars
The Henry Draper Extension Charts (HDEC), published in the form offinding charts, provide spectral classification for some 87000 starsmostly between 10th and 11th magnitude. This data, being highlyvaluable, as yet was practically unusable for modern computer-basedastronomy. An earlier pilot project (Roeser et al. 1991) demonstrated apossibility to convert this into a star catalogue, using measurements ofcartesian coordinates of stars on the charts and positions of theAstrographic Catalogue (AC) for subsequent identification. We presenthere a final HDEC catalogue comprising accurate positions, propermotions, magnitudes and spectral classes for 86933 stars of the HenryDraper Extension Charts.
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FZ Orionis: A short period W UMa system
Photoelectric U, B, and V observations of the eclipsing binary system FZOrionis obtained by the author during three years 1984, 1985 and 1986are presented and studied. The present photometry may settle the disputeregarding the class and the period of the system light variation bewteenthe GCVS 1969 (Beta Lyr; p = 1.597 d) and Figer (1983) and Le Brogne etal (1984) (W UMa; p approximately equals 0.4 d) in favour of the latter.A period change was detected which may be elucidated as due to thepresence of a third body and mass exchange between the components. Timesof ten minima were determined and new ephemeris have been deduced. Thepresent light and color curves were investigated and preliminaryparameters for the system could be estimated.
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The Catalogue of Multiple and Double Stars of T-Associations in machine-readable form
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Eclipsing binaries, Lacerta to Orion, in 1969-1986
Photoelectric and visual observations of 37 known and suspectedeclipsing binaries are discussed. Revised light elements are derived forHP Lyr, V839 Oph and V530 Ori. WZ Leo is probably constant. Both of thealternative periods given in the literature for UW Ori appear to beincorrect. The period of V543 Ori is confirmed to be 52.42d., and not26.21d.
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Catalogue of Eclipsing and Spectroscopic Binary Stars in the Regions of Open Clusters
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Strömgren four-colour observations of Northern Hemisphere binary systems
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Beobachtungen der Nova Persei 1974.
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Beobachtungen veranderlicher Sterne.
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132 neue Veräderliche
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