New Estimates of the Solar-Neighborhood Massive Star Birthrate and the Galactic Supernova Rate
The birthrate of stars of masses >=10 Msolar is estimatedfrom a sample of just over 400 O3-B2 dwarfs within 1.5 kpc of the Sunand the result extrapolated to estimate the Galactic supernova ratecontributed by such stars. The solar-neighborhood Galactic-plane massivestar birthrate is estimated at ~176 stars kpc-3Myr-1. On the basis of a model in which the Galactic stellardensity distribution comprises a ``disk+central hole'' like that of thedust infrared emission (as proposed by Drimmel and Spergel), theGalactic supernova rate is estimated at probably not less than ~1 normore than ~2 per century and the number of O3-B2 dwarfs within the solarcircle at ~200,000.
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A Possible Detection of a Second Light-Time Orbit for the Massive, Early-Type Eclipsing Binary Star AH Cephei
All published and newly observed times of minimum light of the massive,early-type eclipsing binary star AH Cep were analyzed. After subtractingthe light-time effect due to the well-known third body from theresiduals of the observed times of minimum light, it was found that thesecond-order O-C residuals varied in a cyclical way. It was assumed thatthe secondary oscillations were produced by a light-time effect due to afourth body so all the times of minimum light were reanalyzed with adifferential least-squares scheme in order to obtain the light-timeorbits due to both the third and fourth bodies. The periods,eccentricities, and semiamplitudes of the light-time orbits for thethird and fourth bodies were derived as P3=67.6 andP4=9.6 yr, e3=0.52 and e4=0.64, andK3=0.0608 and K4=0.0040 days, respectively. Theradial velocities of AH Cep published so far do not conflict with thehypothesis of the multiplicity of the system, but their accuracies arenot high enough to support the interpretation. Other properties of thedistant bodies are discussed for assorted possible inclinations of theirorbits.
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Catalog of Galactic OB Stars
An all-sky catalog of Galactic OB stars has been created by extendingthe Case-Hamburg Galactic plane luminous-stars surveys to include 5500additional objects drawn from the literature. This work brings the totalnumber of known or reasonably suspected OB stars to over 16,000.Companion databases of UBVβ photometry and MK classifications forthese objects include nearly 30,000 and 20,000 entries, respectively.
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Mesures de vitesses radiales. VIII. Accompagnement AU sol DU programme d'observation DU satellite HIPPARCOS
We publish 1879 radial velocities of stars distributed in 105 fields of4^{\circ} \times 4^{\circ}. We continue the PPO series \cite[(Fehrenbachet al. 1987;]{Feh87} \cite[Duflot et al. 1990, 1992 and 1995),]{Du90}using the Fehrenbach objective prism method. Table 1 only available inelectronic form at CDS via to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
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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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Empirical temperature calibrations for early-type stars
Three temperature calibrations of suitable photometric quantities havebeen derived for O and B stars. A sample of 120 stars with reliableT(eff.) determinations has been used for establishing each calibration.The different calibrations have been critically discussed and compared.Temperature determinations for 1009 program stars have been obtainedwith an accuracy of the order of 10 percent.
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A photometric and spectroscopic study of the early-type binary AH Cephei
The authors present new Strömgren photometry and medium-dispersionspectroscopy of the early-type close binary AH Cephei. The masses andradii of the two components are found to be 18.1±0.9 and15.9±0.8 solar masses and 6.7±0.2 and 6.2±0.2 solarradii respectively. Two possible values of the effective temperature ofthe primary component lead to two sets of possible luminosities for thecomponents. Comparison with currently available evolutionary tracks forsingle stars suggests that this system could evolve into contact duringits main-sequence lifetime.
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The variation of interstellar extinction in the ultraviolet
One hundred and fifty-four reddened stars that are apparently normal inthe visible were selected from the S2/68 Ultraviolet Sky Survey. Theultraviolet data for 92 of these cannot be explained in terms of a fixedinterstellar extinction law. Between 1400 and 2740 A, the extinctioncurve for each star can be well represented by two parts; astraight-line scattering component and a Lorentzian 2200 A absorptionfeature. Independent variations are found in both parts and these cannotbe explained by photometric or spectral classification errors. Bothparts vary smoothly, implying that there is no fixed extinction law, andone star in three is found to depart from the mean law by more than 1mag at either 1500 or 2200 A. The two variations allow not only all 154stars to be explained but also anomalous stars reported by otherauthors. These are not special but merely situated towards the limits ofthe variations. A variation in the relative proportions of graphite andsilicate grains goes some way towards explaining the observations. Theprofile of the 2200 A feature is determined, the symmetrical shape isconfirmed, and the profile fits a Lorentzian very closely.
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Catalog of O-B stars observed with Tokyo Meridian Circle
A catalog of the O-B stars, selected from 'Blaauw-Parenago' list andRubin's catalog, has been compiled on the FK4 system by the observationsmade with Gautier 8-inch Meridian Circle at the Tokyo AstronomicalObservatory during the period, 1971 to 1979. It contains 1059 stars andwas compiled for the future establishment of high precision propermotions of O-B stars.
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Increasing periods of AH CEP and V 382 CYG
New light elements are derived for the early-type eclipsing variables AHCep and V 382 Cyg. For both binaries, the available data may beexplained by a prolongation of the periods. The prolongation isestimated as Delta-P/P = 3.5d x 10 to the -9th and 1.0d x 10 to the -9thper cycle for AH Cep and V 382 Cyg, respectively. In the case of AH Cepthe minima were deeper in recent years than before.
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Intrinsic Polarization in XZ Cephei
Not Available
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Periods and period variations of some eclipsing variables.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975A&AS...20..199G&db_key=AST
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UBV photometry of 180 early-type stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974PASP...86..795G&db_key=AST
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Spectral Classifications of 239 Early-Type Stars
Not Available
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Troisième catalogue de l'Observatoire de Besançon comprenant 764 étoiles réduites à 1950, 0 sans mouvement propre et 326 étoiles FK3 pour l'époque moyenne d'observation
Not Available
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Photoelectric distances of 461 Northern OB-stars and galactic structure from Hγ- luminosities Author: Beer, A.
Abstract image available at:http://adsabs.harvard.edu/abs/1964MNRAS.128..261B
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Proper motions of 650 bright B-type stars.
Not Available
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INHABITED SKY
