The early-type semidetached binary system V716 Centaurus
New high-resolution spectra of V716 Cen revealed for the first timelines of the secondary component and its radial velocities. Thesimultaneous solution of the new radial velocity curves and theHipparcos light curve yield the reliable absolute dimensions of thissemidetached system. The masses for the primary and secondary areM1 = 5.68 +/- 0.07Msolar and M2 = 2.39+/- 0.05Msolar, respectively, and the radii are R1= 4.08 +/- 0.07Rsolar and R2 = 3.36 +/-0.02Rsolar. We derive also effective temperatures ofTeff1 = 15500 +/- 50 K and Teff2 = 9000 +/- 80 K,and equatorial rotational velocities of vrot sini = 137 +/- 2km s-1 and vrot sini = 116 +/- 7 kms-1. These rotational velocities imply that the componentsrotate synchronously. The distance to the system is d = 339 +/- 8 pc, ingood agreement with the less accurate Hipparcos distance (337 +/- 72pc). The primary is underluminous and the secondary overluminouscompared to normal main-sequence stars of the same mass. This impliesthat the secondary component of the semidetached system is in slow masstransferring stage after mass ratio reversal, although the Hα-lineprofiles do not show clear evidence for this.
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Atmospheric paramaters for the eclipsing binary IZ Persei
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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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Beobachtungsergebnisse Bundesdeutsche Arbeitsgemeinschaft fur Veranderliche Sterne e.V.
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Astrometric orbits of SB^9 stars
Hipparcos Intermediate Astrometric Data (IAD) have been used to deriveastrometric orbital elements for spectroscopic binaries from the newlyreleased Ninth Catalogue of Spectroscopic Binary Orbits(SB^9). This endeavour is justified by the fact that (i) theastrometric orbital motion is often difficult to detect without theprior knowledge of the spectroscopic orbital elements, and (ii) suchknowledge was not available at the time of the construction of theHipparcos Catalogue for the spectroscopic binaries which were recentlyadded to the SB^9 catalogue. Among the 1374 binaries fromSB^9 which have an HIP entry (excluding binaries with visualcompanions, or DMSA/C in the Double and Multiple Stars Annex), 282 havedetectable orbital astrometric motion (at the 5% significance level).Among those, only 70 have astrometric orbital elements that are reliablydetermined (according to specific statistical tests), and for the firsttime for 20 systems. This represents a 8.5% increase of the number ofastrometric systems with known orbital elements (The Double and MultipleSystems Annex contains 235 of those DMSA/O systems). The detection ofthe astrometric orbital motion when the Hipparcos IAD are supplementedby the spectroscopic orbital elements is close to 100% for binaries withonly one visible component, provided that the period is in the 50-1000 drange and the parallax is >5 mas. This result is an interestingtestbed to guide the choice of algorithms and statistical tests to beused in the search for astrometric binaries during the forthcoming ESAGaia mission. Finally, orbital inclinations provided by the presentanalysis have been used to derive several astrophysical quantities. Forinstance, 29 among the 70 systems with reliable astrometric orbitalelements involve main sequence stars for which the companion mass couldbe derived. Some interesting conclusions may be drawn from this new setof stellar masses, like the enigmatic nature of the companion to theHyades F dwarf HIP 20935. This system has a mass ratio of 0.98 but thecompanion remains elusive.
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Some Photoelectric Minima of Eclipsing Binary Stars
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Beobachtungssergebnisse Bundesdeutsche Arbeitsgemeinschaft fuer Veraenderliche Sterne e.V.
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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.
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On Rotation of an Isolated Globule
During CO observations of new Southern objects with the 15-m SEST mmtelescope (Cerro La Silla, Chile) we have found that the globuleconnected with the object CLN127-128 rotates with an angular velocity4.3 · 10-14 s-1, which corresponds to the velocity of extremelyfast rotating globules. The object CLN127-128 is a chain of three stars;two of them are connected with bright nebulae, and the third is asuspected Herbig Ae/Be star. All three stars are bright in near IR,which is specific for the existence of circumstellar shells (or disks)around them. The specific angular momentum of the globule confirms thatit is in virial equilibrium. Besides the finding of a rotating globule,CO observations suggest the presence of a blue-shifted outflow fromCLN127-128 with a velocity of -1.1 km/s (in the system connected withthe globule).
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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/.
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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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Beobachtungsergebnisse Bundesdeutsche Arbeitsgemeinschaft fur Veraenderliche Sterne e.V.
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Beobachtungsergebnisse Bundesdeutsche Arbeitsgemeinschaft fur Veraenderliche Sterne e.V.
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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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CCD Times of Minima of Eclipsing Binary Systems
We present several CCD minima observations of 22 eclipsing binaries.
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Photoelectric Minima of Selected Eclipsing Binaries and Maxima of Pulsating Stars
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Variations of the orbital periods in semi-detached binary stars with radiative outer layers
A detailed analysis of the period changes of sixteen semi-detachedbinaries which contain only stars with radiative outer layers(ET-systems) has been performed and their respective O-C diagrams arebrought and discussed. It was found that the course of the periodvariations is monotonic and in some systems the period is even constant.This detailed analysis of extensive sets of timings covering severaldecades brings a strong support to an earlier finding of te[Hall(1989)]{hal89} and develops it further. We show that all systems withthe orbital periods shorter than nine days display constant period orits increase, with the exception of an uncertain case of V 337 Aql. Thecourse of the period variations in TT Aur appears more complex but thecyclic term can be plausibly explained by the third body. A search forgeneral relations between the parameters of the systems and the periodchanges was undertaken. The mass ratio q appears to play a role in theperiod variations. Clear changes in systems with orbital periods shorterthan 9 days were detected only for q>0.4 while constant periods arecommon in systems with q<0.4 in this period range. The sense of thesecular changes in most systems is in accordance with the dominantconservative mass transfer in evolved binary and corresponds to the slowphase. The role of the evolutionary scenarios (case A versus B) and theinfluence of changes of the rotational angular momenta of the componentsare discussed.
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Neglected binaries of special interest
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The calculation of critical rotational periods in three typical close binary systems based on synchronization theory.
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Separating the spectra of binary stars I. A simple method: Secondary reconstruction
We present a practical method for the analysis of spectroscopicbinaries, reconstructing the lines of the two components of the system.We show that the problem of the separation of binary spectra can besolved in an easy way, under most common conditions. One pair ofobservations may be sufficient, if taken at different orbital phases ofthe system, preferably at opposite quadratures. The separation procedureis discussed analytically, and a technique is described, which allows torestore the secondary lines in few steps. An algorithm is also provided,which derives the radial velocity of the secondary star, by directlyanalysing a difference line-profile obtained from the two input spectra.The efficiency of the method is tested, by reconstructing artificialline-profiles and simulated binary spectra as well. Then the procedureis applied to the eclipsing binary IZ Per, revealing for the first timeits faint secondary spectrum. Based on observations performed at theObservatoire de Haute Provence (OHP), and made available through theTrieste-Aurelie-Archive (TAA).
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Measurement and study of rotation in close binary stars (III) Statistical analysis of synchronization.
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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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A photometric analysis of the algol binary HD 21155
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Measurement and analysis of rotation in close binaries. II. Calculation of synchronism.
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Measurement and Analysis of Rotation in Close Binary Stars - Part One - Observations and Results
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New rotational velocities for eclipsing binaries, and a comparison of spectroscopic and photometric rotations
Rotational velocities are determined spectroscopically for 38 eclipsingbinaries, including many long-period, nominally semidetached, systems.We note that spectroscopic rotations may differ from rotations derivedfrom light-curve modeling using the Wilson-Devinney program. In'direct-impact' mass-transferring systems, or in most systems withperiods smaller than about 7 days, observations suggest that the tworotations are usually about the same. In cases where the stream missesthe gainer and an accretion disk forms, however, photometric rotationestimates often exceed spectroscopic determinations. The possiblephysical significance of this situation is briefly discussed. Doubt iscast on the likelihood that the rotation of the hot component of U Sgehas changed detectably in the last 30 years.
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Eclipsing binaries, Pegasus to Sagittarius, in 1972-1987
Photoelectric and visual observations of 34 known and suspectedeclipsing binaries are discussed. Revised light elements are derived forDM Per and Beta Per. EL Sge is confirmed to vary with a period ofapproximately 0.333d. Large deviations from the published elements arereported for BG Peg, AB Per, LS Per, SU Psc, SZ Psc and TU Sge. Thecatalogue period of BQ Peg is probably incorrect.
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Observations of CNO Processing in Massive Interacting Binary Systems
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