Precise Times of Minimum Light of Neglected Eclipsing Binaries
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CCD Times of Minima of Selected Eclipsing Binaries
374 CCD minima observations of 187 eclipsing binaries are presented. Theobserved stars were chosen mainly from catalogue BRKA of observingprogramme of Variable Star Section of CAS.
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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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Times of Minimum Light of Neglected Eclipsing Binaries
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Apsidal motion in southern eccentric eclipsing binaries: V539 Ara, GG Lup, V526 Sgr and AO Vel
Several new times of minimum light have been observed photoelectricalyfor the early-type double-lined eccentric eclipsing binaries V539 Ara (P= 3.2 deg, e = 0.05), GG Lup (1.9 deg, 0.15), V526 Sgr (1.9 deg, 0.22)and AO Vel (1.6 deg, 0.07). The O{-}C diagrams are analysed using allreliable timings found in the literature and improved values for theelements of the apsidal motion are computed. We find more precise,relatively short periods of apsidal motion of about 162, 102, 155 and 54years for V539 Ara, GG Lup, V526 Sgr and AO Vel, respectively. Thecorresponding internal structure constants, log k_2, are then found tobe 2.33, 2.16, 2.36 and 2.24 under the assumption that the componentstars rotate pseudosynchronously. The relativistic effects arenegligible, being about 6 7% of the total apsidal motion rate in allsystems. Using the light-time effect solution, for V539 Ara we havefound a third component orbiting with a period of about 42 years, for AOVel we confirmed the third body with an orbital period of 33 years.
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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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149 Bedeckungssterne der BAV-Programme. Eine Analyse der Beobachtungstatigkeit seit den Angangen.
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Das Brunner Punktesystem.
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Studies of Intermediate-Mass Stellar Models Using Eclipsing Binaries
Evolutionary computations for intermediate-mass stars are analyzed usingobserved parameters for eclipsing SB2 binaries and theoreticalparameters based on evolutionary tracks. Modern observations cannot beused to distinguish between models with and without convectiveovershooting for stars in the vicinity of the main sequence.Statistically significant discrepancies between the observed andcomputed stellar parameters are associated with systematic errors inphotometric effective temperatures. After taking into account systematiceffects, the theoretical computations fit the observational datauniformly well throughout the entire mass interval studied. Empiricaland semiempirical (i.e., reduced to the ZAMS and with solar elementalabundances) formulas for the mass-luminosity, mass-effectivetemperature, and mass-radius relations are proposed.
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Age and Metallicity Estimates for Moderate-Mass Stars in Eclipsing Binaries
We estimate the ages and metallicities for the components of 43 binarysystems using a compilation of accurate observational data on eclipsingbinaries for which lines of both components are visible in theirspectra, together with two independent modern sets of stellar evolutionmodels computed for a wide range of masses and chemical abundances. Theuncertainties of the resulting values are computed, and their stabilityis demonstrated. The ages and metallicity are compared with thosederived in other studies using different methods, as well as withindependent estimates from photometric observations and observations ofclusters. These comparisons con firm the reliability of our ageestimates. The resulting metallicities depend significantly on thechoice of theoretical model. Comparison with independent estimatesfavors the estimates based on the evolutionary tracks of the Genevagroup.
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Apsidal motion in eccentric eclipsing binaries: TV Ceti and V451 Ophiuchi
Several new times of minimum light recorded with photoelectric meanshave been gathered for two bright eccentric eclipsing binaries TV Cet (P= 9fd1 , e = 0.055) and V451 Oph (P = 2fd2 , e = 0.013). Analysis of allavailable eclipse timings of TV Ceti has revealed a small motion of theline of apsides of dot ω = 0.000 30 +/- 0.000 08 degcycle-1, corresponding to an apsidal period of U = 30 000 +/-8 000 years. The contribution from the general relativity effects isdominant (dot ωrel/dot ω ~ 80 % ). In thissystem, the third body on an eccentric orbit with a period of 28.5 yearsis also predicted. The more precise values for the apsidal motionelements were computed for V451 Oph, where apsidal motion with a periodof 170 +/- 5 years was confirmed. The corresponding internal structureconstants log k2 were derived. Some of the observationsreported in this paper were obtained at the South Africa AstronomicalObservatory, Sutherland, South Africa.
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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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Photoelectric Minima of Selected Eclipsing Binaries and Maxima of Pulsating Stars
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Eclipse Monitoring of Eccentric Binary Systems
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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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The active dynamo stars: RS CVn, BY Dra, FK Com, Algol, W UMa, and T Tau
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Catalogue of astrophysical parameters of binary systems
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Eclipsing binaries with eccentric orbits
Two groups of eclipsing binaries are dealt with: the first consists ofall binaries with enough data in the General Catalog of Variable Stars(GCVS; Cholopov et al, 1987), the other of those for which accurateparameters are known. In the first group, problems with classificationin GCVS are noticed and several examples of binaries with unexpectedparameters are named. For binaries of the second group, their fractionalradii, ages, and initial radii are used to discuss the relation of theirevolutionary status and orbital eccentricity. Dependence of eccentricityon spectral type and age is observed, and no peak in the initialeccentricity distribution at e = 0 seems to be present. It is suggestedthat binary origin by fragmentation followed by disruption of initialmultiple systems can explain all observed binaries, perhaps with theexception of contact systems in the main sequence. In several cases thecircularization must be due to mass transfer in the eccentric orbit.
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The visual surface brightness method and the radii of dwarf Cepheids
In order to determine the radii of dwarf Cepheids by applying the visualsurface brightness method, the empirical relationship between F(v) and(b - y) was derived. Seventeen stars of spectral type A to F, where bothangular diameters and uvby beta photometric data are available, wereselected from the literature. A theoretical F(v), (b-y) relation wasderived by using the Kurucz model atmospheres. It was found that thetheoretical relation is strongly dependent upon metallicity and surfacegravity. To demonstrate that the visual surface brightness method is aneffective way to determine the radii of dwarf Cepheids, both theoreticaland empirical relations were applied to seven dwarf Cepheids. The mostreliable result was obtained for AD CMi where the quality of the radialvelocity data is superior.
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Reexamination of the mass-radius relation of main sequence in binary systems
The mass-radius relation of the main sequence was reexamined using 171components of 88 double-lined detached binary systems with welldetermined absolute dimensions and masses. Empirical relations for theZAMS were obtained and compared with the theoretical models. Thepositions of the other 27 semidetached binaries in the log M - log Rdiagram are also discussed.
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Times of Minimum Light for 16 Eclipses of 8 Apsidal Motion Binaries
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A Study of the DM and SD Type Eclipsing Variables by Means of the Cluster Analysis Technique
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Nonstationary Phenomena in Eclipsing Detached Main Sequence Binaries
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An Updated List of Eclipsing Binaries Showing Apsidal Motion
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Stellar masses and radii based on modern binary data
Accurate data on absolute dimensions of eclipsing binaries published inthe astronomical literature since 1980 are collected and analyzed.Simple approximation formulas relating the effective temperature withother basic physical parameters (mass, radius, bolometric magnitude) arederived. Mean and extreme values of these parameters for each spectraltype are also tabulated. The implication of improved data for theproblem of critical rotational periods and equatorial velocities ofearly-type stars is discussed.
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Angular momenta in binary systems
The correlations of angular momenta L to masses M are studied fordifferent types of spectroscopic binaries. Postulates about equivalentstates of angular momenta for different orbital parameters areintroduced. From comparisons with galaxies and single stars, it isevidenced that there is not a unique universal function L = AM exp b,when the finite structure of the relation is analyzed: each object hasits own coefficients A, b. It seems that there are an upper and a lowerlimit for all the possible functions.
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Observations and a Time of Minimum of TV Cet
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Close binary mass anomalies and metallicity
Direct (radial velocity) and indirect (spectral type, luminosity class)mass determinations for luminosity class V binaries are compared. Theexistence of statistical biases or apparently irreconcilable individualdiscrepancies, or both, in the data is examined, and their explanationby astrophysical effects such as chemical composition and agedifferences is considered. The existence of residual discrepancies,after correction for chemical composition effects and statisticalallowance for age effects, which could only be due to otherastrophysical effects, to instrumental effects, or to selection effects,is investigated. A need for at least one additional astrophysicaleffect, suspected to be fast core rotation, is found in a few binaries.It is argued that some remaining evidence for systematic observationalerrors is more likely to be the result of selection effects rather thanan instrumental effect.
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General-relativistic periastron advances in eclipsing binary systems
The possibility of observing general-relativistic apsidal motionsoutside the solar system in well-detached eclipsing binaries isreviewed, taking into account the expected influence of the variousparameters involved. A procedure to select candidate systems amongeccentric eclipsing binaries is presented altogether with a list ofsuggested targets. A simplified method to obtain the apsidal motionrates from the observation of times of minimum light is proposed.
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INHABITED SKY
