The spectroscopic orbits of three double-lined eclipsing binaries: I. BG Ind, IM Mon, RS Sgr
We present the spectroscopic orbit solutions of three double-lineseclipsing binaries, BG Ind, IM Mon and RS Sgr. The first precise radialvelocities (RVs) of the components were determined using high resolutionechelle spectra obtained at Mt. John University Observatory in NewZealand. The RVs of the components of BG Ind and RS Sgr were measuredusing Gaussian fittings to the selected spectral lines, whereastwo-dimensional cross-correlation technique was preferred to determinethe RVs of IM Mon since it has relatively short orbital period among theother targets and so blending of the lines is more effective. For allsystems, the Keplerian orbital solution was used during the analysis andalso circular orbit was adopted because the eccentricities for alltargets were found to be negligible. The first precise orbit analysis ofthese systems gives the mass ratios of the systems as 0.894, 0.606 and0.325, respectively for BG Ind, IM Mon and RS Sgr. Comparison of themass ratio values, orbital sizes and minimum masses of the components ofthe systems indicates that all systems should have different physical,dynamical and probable evolutionary status.
|
Effect of tidal evolution in determining the ages of eclipsing-variable early main sequence close binary systems
New Claret evolutionary model-tracks, constructed for the first time forstudying close binary systems (CBS) including tidal evolution constants,are used to determine the age of 112 eclipsing-variable stars in theSvechnikov-Perevozkina catalog by the method of isochrones. There issome interest in comparing the calculated ages with previous estimatesobtained for these same close binary systems using evolutionarymodeltracks for individual stars taking their mass loss into account. Acorrelation of the ages of the principal and secondary components isnoted, which is most marked for massive close binaries with principalcomponents having masses M1 ? 3 M?. Arejuvenating effect is found to occur for the systems studied here ascalculated on the new tracks; it is most distinct for low-mass closebinaries with a total mass M1 + M2 ? 3.5M? and is predicted theoretically in terms of magneticbraking. The calculated broadband grid of isochrones, from zero-agemain-sequence (ZAMS) to the age of the galaxy, can be used forestimating the ages of close binaries from other catalogs. Ages aregiven for the 112 eclipsing-variable close binaries with detachedcomponents lying within the main sequence.
|
Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
|
Photoelectric Minima of Some Eclipsing Binary Stars
Not Available
|
Evolution of interacting binaries with a B type primary at birth
We revisited the analytical expression for the mass ratio distributionfor non-evolved binaries with a B type primary. Selection effectsgoverning the observations were taken into account in order to comparetheory with observations. Theory was optimized so as to fit best withthe observed q-distribution of SB1s and SB2s. The accuracy of thistheoretical mass ratio distribution function is severely hindered by theuncertainties on the observations. We present a library of evolutionarycomputations for binaries with a B type primary at birth. Some liberalcomputations including loss of mass and angular momentum during binaryevolution are added to an extensive grid of conservative calculations.Our computations are compared statistically to the observeddistributions of orbital periods and mass ratios of Algols. ConservativeRoche Lobe Over Flow (RLOF) reproduces the observed distribution oforbital periods but fails to explain the observed mass ratios in therange q in [0.4-1]. In order to obtain a better fit the binaries have tolose a significant amount of matter, without losing much angularmomentum.
|
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.
|
Photometry of 20 eclipsing and ellipsoidal binary systems
ERRATUM: In the published paper the phase diagrams of pi Sco and AL Sclwere ommitted. The version reproduced in JAD11, 7 is the completeversion. A total of almost 2000 V observations of 20 eclipsing andellipsoidal bright binary stars was collected between 1991 and 2001 forthe purpose of determining more recent epoch ephemerides for the lightcurves than are available in the literature. The original purpose was toprovide the Sydney University Stellar Interferometer (SUSI) with orbitalperiods and particularly the accurate times of minimum separation (lightcurve minima), so that the SUSI observations need not be used todetermine them.This paper provides the periods, the times of primary minima and thephases of secondary minima for the 20 stars at an epoch as near aspossible to the year 2000. No attempt has been made in this report todetermine other parameters such as {apsidal motion} or stellar radii.Since the program was started in 1991, data for these stars taken in theperiod from late 1989 to early 1993 has also been available from theHipparcos satellite; the light curves shown here include both sets ofobservations.
|
Photometry of 20 eclipsing and ellipsoidal binary systems
A total of almost 2000 V observations of 20 eclipsing and ellipsoidalbright binary stars was collected between 1991 and 2001 for the purposeof determining more recent epoch ephemerides for the light curves thanare available in the literature. The original purpose was to provide theSydney University Stellar Interferometer (SUSI) with orbital periods andparticularly the accurate times of minimum separation (light curveminima), so that the SUSI observations need not be used to determinethem.This paper provides the periods, the times of primary minima and thephases of secondary minima for the 20 stars at an epoch as near aspossible to the year 2000. No attempt has been made in this report todetermine other parameters such as {apsidal motion} or stellar radii.Since the program was started in 1991, data for these stars taken in theperiod from late 1989 to early 1993 has also been available from theHipparcos satellite; the light curves shown here include both sets ofobservations.
|
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.
|
SB9: The ninth catalogue of spectroscopic binary orbits
The Ninth Catalogue of Spectroscopic Binary Orbits(http://sb9.astro.ulb.ac.be) continues the series of compilations ofspectroscopic orbits carried out over the past 35 years by Batten andcollaborators. As of 2004 May 1st, the new Catalogue holds orbits for2386 systems. Some essential differences between this catalogue and itspredecessors are outlined and three straightforward applications arepresented: (1) completeness assessment: period distribution of SB1s andSB2s; (2) shortest periods across the H-R diagram; (3)period-eccentricity relation.
|
Up-to-Date Linear Elements of Eclipsing Binaries
About 1800 O-C diagrams of eclipsing binaries were analyzed and up-todate linear elements were computed. The regularly updated ephemerides(as a continuation of SAC) are available only in electronic form at theInternet address: http://www.as.ap.krakow.pl/ephem/.
|
Einige interessante Bedeckungsveraenderliche.
Not Available
|
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
|
On the origin of binaries with twin components
The existence of a statistically significant excess of dwarf binarieswith mass ratios from 0.95 to 1, as first noted by Lucy & Ricco (?),is confirmed by modern data. Excess of such binaries, called twins, isfound only for periods shorter than 40 days, and in the 2-30 days periodrange they constitute 10-20% of the total binary population. Twins musthave been formed by a special mechanism. It cannot be a mass transfer incontact pre-main-sequence binaries, fission is also unlikely. As shownby Bate (2000), accretion onto a close binary shifts mass ratio towards1, so twins may originate from binaries that became close while stillsurrounded by massive envelopes. Many twins are members ofhigher-multiplicity systems and/or clusters, which probably explains anearly formation of a close binary by stellar dynamics.
|
Determination of empirical mass-luminosity and mass-radius relations for main-sequence stars that are the components of eclipsing binary systems
Based on a new catalog of photometric, geometrical, and absoluteelements for 112 eclipsing binary systems with both components on themain sequence and with known photometric and spectroscopic orbitalelements, we redetermined the mass-luminosity and mass-radius relations:M_bol = 4.46 - 9.52 lg M (lg M > -0.4), M_bol = 6.58 - 5.00 lg M (lgM <= -0.4), lg R = 0.096 + 0.652 lg M (lg M > 0.14), lg R = 0.049+ 0.993 lg M (lg M <= 0.14). For most systems, the masses and radiiof the components are determined with an accuracy of 2-3% and 2-4%,respectively. We estimated the parameters of these relations by theleast-squares method using the procedure for correcting the estimatesthus obtained for noise in the argument.
|
Orbital circularization in detached binaries with early-type primaries
Extending our previous study, the present paper reports on thediscussion of the orbital circularization in 37 detached binaries withearly-type primaries. From comparison of the theoretical predictionswith the orbital eccentricities of our binary systems, we find thatZahn's circularization theories are substantially consistent with theobserved data for overwhelming majority of our samples. However, we alsonote that three binaries of whom both components are asynchronizedrotators possess circular orbits. How to understand the circularism ofthe three systems remains a problem not only to Zahn's theories, but toall other present circularization mechanisms.We think that studies onthe circularization of pre-main-sequence binary systems could providesome clues for the problem.
|
The calculation of critical rotational periods in three typical close binary systems based on synchronization theory.
Not Available
|
Measurement and study of rotation in close binary stars. (V) Orbital circularization.
Not Available
|
Synchronization in the early-type detached binary stars.
With a set of homogeneous and refined rotational velocities, we discussthe synchronism in the "normal" (all the particular stars, such as Ap,Am and Of, are excluded) early-type detached binaries. Being differentfrom previous statistical studies, the present paper not onlyinvestigates the rotational synchronism of each component, but alsoestimates its age from new stellar evolutionary grids, and calculatesits synchronization time scale with Zahn's dynamically tidal theory.Significantly, we find that the dynamically tidal synchronizationmechanism is substantially compatible with the observed data from thecomparison of the rotational properties of our components with thetheoretical predictions.
|
Measurement and study of rotation in close binary stars (IV) Comparison between observation and predictions of two theories.
Not Available
|
Measurement and study of rotation in close binary stars (III) Statistical analysis of synchronization.
Not Available
|
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.
|
Measurement and analysis of rotation in close binaries. II. Calculation of synchronism.
Not Available
|
Measurement and Analysis of Rotation in Close Binary Stars - Part One - Observations and Results
Not Available
|
Predicting the Secondary Minima Depths and Spectra of the Main Components for the Dm-Type Eclipsing Variable Stars
Not Available
|
Dynamical theory of viscous tides in binary systems
Explicit analytical formulae for tidal velocities in star components ofa binary system are obtained. Compressibility and viscosity of thestellar matter and the inclination of the star axis of rotation to theorbital plane are taken into account. The polytropic model of the staris used. Numerical values of radial, azimuthal and tangential componentsof the tidal velocity are obtained for main sequence stars.
|
A Study of the DM and SD Type Eclipsing Variables by Means of the Cluster Analysis Technique
Not Available
|
Not Available
Not Available
|
The nitrogen abundance in the atmospheres of single and binary stars
The nitrogen abundances for 47 single, 11 visual double, and 41 closebinary stars are obtained from high-dispersion Wlambdadeterminations of nitrogen lines using atmospheric models andtheoretical calculations of N II lines, taking LTE errors into account.The mean value of lg N(N) is found to be 8.05 for single stars, 8.50 forclose binaries, and 8.15 for visual double stars. A correlation is foundbetween the nitrogen abundance and the helium and carbon abundances. Itis suggested that considerable mixing between the central part of starsand the atmosphere occurs in binary stars.
|
The carbon abundance in the atmospheres of single and binary stars
The carbon abundance in the atmospheres of single stars and the brightercomponents of binary stars are determined on the basis ofhigh-dispersion W(lambda) data, using the LTE atmospheric model for C IIlines and the non-LTE model for C III lines. The mean value of lg N (C)for 38 single stars was found to be 8.5 + or - 0.3. For 48 binary stars,the mean value was 8.3 + or - 0.3. The lesser carbon abundance in theatmospheres of binary stars may be explained by a more intense transferof matter from hydrogen burning regions to the atmosphere in theCNO-cycle compared to normal single stars.
|
