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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Catalogue of H-alpha emission stars in the Northern Milky Way
The ``Catalogue of Stars in the Northern Milky Way Having H-alpha inEmission" appears in Abhandlungen aus der Hamburger Sternwarte, Band XIin the year 1997. It contains 4174 stars, range {32degr <= l() II< 214degr , -10degr < b() II < +10degr } having the Hαline in emission. HBH stars and stars of further 99 lists taken from theliterature till the end of 1994 were included in the catalogue. We givethe cross-identification of stars from all lists used. The catalogue isalso available in the Centre de Données, Strasbourg ftp130.79.128.5 or http://cdsweb.u-strasbg.fr and at the HamburgObservatory via internet.
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Discovery of the variable phase-locked polarization in LZ Cephei
The early-type non-eclipsing binary LZ Cep has been observed with theUBVRI polarimeter during 25 nights in 1996-1997. A variable phase-lockedlinear polarization has been found. The principal Fourier components ofthe observed variations are the second harmonics of the orbital period.The most probable explanation of this variability is reflection of theradiation from each component of the binary off the facing hemisphere ofits companion. We have constructed a simple numerical model of thereflection process which is capable of reproducing the amplitude andphase dependence of the polarized light-curve.
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HD 187399 - A massive interacting binary system with an eccentric orbit and intense mass transfer: polarimetric observations.
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UBV beta Database for Case-Hamburg Northern and Southern Luminous Stars
A database of photoelectric UBV beta photometry for stars listed in theCase-Hamburg northern and southern Milky Way luminous stars surveys hasbeen compiled from the original research literature. Consisting of over16,000 observations of some 7300 stars from over 500 sources, thisdatabase constitutes the most complete compilation of such photometryavailable for intrinsically luminous stars around the Galactic plane.Over 5000 stars listed in the Case-Hamburg surveys still lackfundamental photometric data.
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Astrophysics in 1996
The loudest astronomical headlines of the year came from both very near(planets orbiting stars in the solar neighborhood) and very far(galaxies and parts of galaxies at redshifts of 1 to 3 and more). Weexplore these and other happenings in our Solar System (Galileo atJupiter, Comet Hyakutake), Milky Way (the bursting pulsar, spottedstars), Local Group (masers, MACHOs, and more), and Universe(gravitational lensing, an assortment of extrema). (SECTION: InvitedReview Paper)
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Catalogue of stars in the northern Milky Way having H-alpha in emission
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UBV photometry of Be stars at Hvar: 1972--1990
A summary of results of the systematic UBV photoelectric monitoring ofbright northern Be stars carried out at the Hvar Observatory between1972 and 1990 is presented. Altogether, 76 Be stars of all luminosityclasses were observed and 13,848 UBV measurements secured.Simultaneously, 9,648 UBV measurements of 48 check stars (most of themof early spectral types) were obtained. A careful transformation of allobservations into the standard Johnson system allowed detection andmonitoring of even very mild long-term light and colour variations ofthese objects. Almost all early-type Be stars in the sample turned outto be variable. For several stars phase-locked light variations relatedto their binary nature were established. Sudden brightenings, on a timescale of a few days, were detected for o Cas and QR Vul. Tables 2 and 3are only available in electronic form at CDS via ftp tocdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html
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Eclipse Monitoring of Eccentric Binary Systems
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Physical conditions in the compact double star HD 187399
We present the results of a study of the spectra of the compact doublesystem HD 187399. We have measured and identified lines in the spectrumof the main star and computed their equivalent widths, the centralresidual intensities, and the electron densities in the atmosphere ofthe main star and the common envelope of the system. We have constructedthe curve of radial velocities of the main star and determined theexpansion velocity of the common envelope of the system: vr =90 km/sec.We have measured the velocity of the interstellar calcium: vr =-3.5km/sec. We have established the agreement of the radial velocity curvesfor the main star obtained in the present paper and in that of Merrill[1]. The comparison enabled us to make the following conjecture: therehas been no noticeable loss of mass in the system HD 187399 over thepast 35 years, and possibly all that has occurred is a flow of matterfrom one component toward the other. We note the strong similarity withthe Lyrae system.
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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 formation of Be stars through close binary evolution
The possibility that Be stars are the remnants of case B mass transferin intermediate-mass close binaries is investigated. It is shown thatonly progenitors with mass ratios greater than a certain minimum valueq-min are capable of producing a Be star after the mass transfer. Thevalue of q-min lies between 0.3 and 0.5, depending on the evolutionparameters as well as on the observationally determined lower mass limitof Be/X-ray binaries. In more than 80 percent of the predicted systems,the evolved companion is an He star, particularly among the late-type Bstars; these systems may be detectable as XUV sources.
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IUE observations of mass-loss spectral features in B5-B9 supergiants
A survey of IUE spectra is presented for supergiants of spectral classB5-B9 illustrating the behavior of line profiles associated withmass-loss effects. The main purpose of this survey is to better identifythe spectral mass-loss features which occur in such stars in order topresent a clearer observational picture of the nature and the timescaleof their variability. Time varying 'narrow' or 'discrete absorptioncomponents' (DAC) are detected across the full spectral class range butfor the Ia supergiants only. Significant variations in the wind C IV andSi IV profiles are observed corresponding to different mass-lossepisodes. The line strengths and the edge velocities of the windprofiles in the higher ionization ions and their time variability tendto decrease towards later spectral type. However, details of systematictrends with effective temperature are obscured somewhat by the scale ofvariability which is observed for a given star.
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An Updated List of Eclipsing Binaries Showing Apsidal Motion
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Photoelectric Observations of Four Stars in the W Serpentis Progression
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Observations of W Serpentis Stars
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Periodic Light Variations of HD187399
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Spectroscopic investigation of HD 187399
The paper presents the results of an investigation of the spectra of HD187399 obtained during 1982-1983 with the 6-m telescope of the SpecialAstrophysical Observatory. Fifty lines were measured and identified, anda spectrophotometric analysis carried out. The lines of hydrogen,helium, and calcium were found to structurally complex. Hydrogen-linedisplacements were used to determine the expansion velocity of the shellwhich turned out to be = 105 km/sec. An absorption band 80 A in widthwas found in the region of K Ca II; it increases steadily in the phases0.3-0.4 and disappears at the phase 0.5.
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The evolution of a single and a binary helium star of 2.5 solar masses up to neon ignition
The behavior with time of the radius, the core mass, and otherparameters of a 2.5 solar mass single helium star during its advancedevolution is calculated, and the evolution is compared with that of a2.5 solar mass helium star in a binary system which during its advancedevolution appears to transfer mass to its companion. It is investigatedwhether or not the cores of 2.5 solar mass helium stars collapse andform neutron stars. The results confirm evolution towards core collapseand confirm the model of the formation of Be/X-ray binaries by evolutionwith mass transfer in intermediate-mass binaries.
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Non-Canonical Insights into the Evolution of Stars. 1. an Alternative Model of Massive X-Ray Binaries
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The period distribution of unevolved close binary systems
Period distributions have been examined for various spectral types ofabout 600 (eclipsing and spectroscopic) close binaries, which are likelyto be substantially unevolved. The comparison with the previouscorresponding analyses of extensive (but heterogeneous) binary samplesallows a clarification of the extent of the evolutionary andobservational selection effects. Remarkably, this analysis reveals agreat deficiency of short period binaries (with periods corresponding tocase A mass transfer) in the whole spectral range. For the late spectraltypes, this result may be connected with postformation angular momentumloss caused by stellar wind magnetic braking; at least for the late Band A spectral range, a ready interpretation of this finding is thatclose binaries of corresponding periods and spectral types are rarelyformed.
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Complicated Structure of Lambda 3933 CAII Line in the Spectrum of HD187399 / V1507-CYGNI
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New UBVRI photometry for 900 supergiants
A description is presented of the results obtained in connection with asystematic program of supergiant photometry on the Johnson UBVRI system.During the eight years after the start of the program, almost 1000 starshave been observed, about 400 three or more times each. The originalselection of stars used the spectral type catalog of Jaschek et al.(1964) to choose supergiants. Since observations were possible from bothChile and Canada, no declination limits were imposed, and no particularselection criteria were imposed other than to eliminate carbon stars.These are so red as to require enormous extrapolations of thetransformation equations.
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Variable Stars in the Northern Luminous Stars Catalogues
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A search for weak galactic binary X-ray sources
Observations undertaken to investigate the relation of mass transferrates to X-ray luminosities in accreting binary X-ray sources in theGalaxy are discussed. Einstein Observatory Imaging Proportional Counterobservations were made of 23 binary systems selected as possiblycontaining a compact object. Only three of the original 17 targetobjects were detected as sources, plus two more among the six also foundto be within Einstein IPC fields. None of the sources detected, however,shows evidence for the presence of a compact component. It is concludedthat there are few, if any, binaries in which a compact star is in a lowX-ray state, and that the known hard X-ray binaries constitute theentire galactic population of such objects.
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On the Statistical Nature of BE and AE Binaries
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1981PASJ...33..399K&db_key=AST
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List of Estimated Angular Separations of Spectroscopic Binaries
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1981A&AS...44...47H&db_key=AST
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A search for X-ray binary stars in their quiescent phase
Fourteen early-type stars representative of systems which may beharboring a neutron star companion and are thus potential progenitors ofmassive X-ray binaries have been examined for X-ray emission with theHEAO A-1 experiment. Limits on the 0.5-20 keV luminosity for theseobjects lie in the range 10 to the 31-33 erg/sec. In several cases, thehypothesis of a collapsed companion, in combination with the X-raylimit, places a serious constraint on the mass-loss rate of the primarystar. In one instance, an X-ray source was discovered coincident with acandidate star, although the luminosity of 5 x 10 to the 31 isconsistent with that expected from a single star of the same spectraltype. The prospects for directly observing the quiescent phase of abinary X-ray source with the Einstein Observatory are discussed in thecontext of these results.
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