Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
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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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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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Diffuse interstellar bands in the spectra of massive young stellar objects
We have compared the B - V color excess, E(B - V), obtained for a sampleof five optically visible massive young stellar objects (YSOs) both fromdiffuse interstellar bands (DIBs) in their spectra and from theiroptical continuum slopes. Our targets are HD 200775, BD+40.4124 deg, MWC1080, MWC 297 and MWC 349A. First, E(B - V) towards each of the targetsis derived by dereddening the observed continua to match those of B-typestandard stars. A survey of DIBs in the spectra of the massive YSOs, anda control field star, then reveals that the DIBs are significantlyweaker in the former than would be expected based on the total E(B - V)values. This result is strengthened by the finding that the DIBs in thecontrol field star, HD 154445, have on average the strength expectedfrom its continuum E(B - V). A rough estimate of the foregroundreddening of intervening diffuse interstellar medium shows it to besmaller than the DIB E(B - V), implying that at least part of the DIBcarriers are formed within the parental molecular clouds in which theYSOs are embedded. The DIB E(B - V) compares favorably with the totalE(B - V) towards BD+40.4124 deg, but is almost negligible in the line ofsight towards MWC 297. Despite this general, but not unexpected,deficit, we provide evidence that the DIB at 5849 A is a good tracer oftotal extinction in these lines of sight.
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MWC 297, B1.5Ve: a zero-age main-sequence star in the Aquila Rift
Moderate-resolution optical spectra of the significantly reddened HerbigBe star MWC 297 are presented. The data are of sufficient quality thatit has been possible to obtain a spectral type for this star bycomparing heavy element absorption features with those present in earlyB field stars of known spectral type. The best fit is to B1.5V, with anuncertainty of half a sub-type. It is estimated that vsini for MWC 297is about 350 +/- 50 km s^-1, suggesting that the star's rotation axis isalmost in the plane of the sky. The reddening towards this object isreviewed and is derived afresh from spectra at wavelengths spanning theB-R optical bands. Using A_v~=8 and the absolute magnitude correspondingto B1.5V, it is argued that the distance to MWC 297 is 250 +/- 50 pcrather than ~500 pc as has recently been quoted in the literature. Atthis distance the star can be located very plausibly in the Aquila Rift. We go on to present a MERLIN 5-GHz radio map of the source which showsit to be markedly elongated in the north-south direction (to a dimensionof 125 au at 250 pc). Existing data on the optical linear polarizationof MWC 297 suggest a complicated picture that leaves open the questionof whether the radio axis might trace an ionized electron-scatteringequatorial disc. We also present and briefly discuss high-resolutionBralpha and Hei1.083-μm line profiles obtained within a week of theoptical spectra. The Hei profile is very complex, but confirms that MWC297 is an outflow source. It is noted that the Hi emission lines areundoubtedly highly variable, although the time-scales for this are notyet clear.
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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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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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Confirmation among visual multiples of an increase of AP stars with age
Open clusters with ages below certain threshold values contain no Apstars and those with greater ages contain numbers of Ap stars thatapparently increase with age. But in view of the few young clustersstudied, the data could also be interpreted in terms of randomdifferences in the frequencies of Ap stars between individual clusters,rather than an age effect. Data on 77 field visual multiple systems(that originated from many different clusters and associations) in whichthe primaries are O5-A1 stars and the secondaries occur in the absolutemagnitude range of the Ap stars were, therefore, obtained. Againspectral classification shows no Ap stars in systems with ages notgreater than 1,000,000 yr and a steady increase in Ap stars thereafter.The numerical agreement with the cluster data is good, confirming thatthe cluster data are exhibiting a real age effect.
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Meridian observations made with the Carlsberg Automatic Meridian Circle at Brorfelde (Copenhagen University Observatory) 1981-1982
The 7-inch transit circle instrument with which the present position andmagnitude catalog for 1577 stars with visual magnitudes greater than11.0 was obtained had been equipped with a photoelectric moving slitmicrometer and a minicomputer to control the entire observationalprocess. Positions are reduced relative to the FK4 system for each nightover the whole meridian rather than the usual narrow zones. Thepositions of the FK4 stars used in the least squares solution are alsogiven in the catalog.
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Optical observations of ultraviolet objects. II - Classification and photometry /l = 0 to 145 deg/
UBV photometry and MK spectral classification are presented for a sampleof stars originally selected as UV objects from satellite photometrywith the S2/68 experiment. Although most stars of the sample arespectroscopically normal, a number of hot, subluminous stars were alsofound. Radial velocities are given for some of the stars observed. It isproposed that the majority of the apparently normal early B stars athigh galactic latitudes which are not runaway stars are subluminousdisc-population analogues of horizontal branch B stars of Population II.
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H-beta photometry of northern intermediate galactic latitude early-type stars and galactic structure away from the plane
Photoelectric H-beta photometry is presented for 255 early-type stars atintermediate galactic latitudes. Absolute magnitudes and distances arederived for the more luminous stars. Those with visual magnitudes lessthan or equal to 2.5 and at distances of up to 1 kpc from the galacticplane may follow the spiral structure in the plane.
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On the origin of intermediate-latitude OB stars
An attempt is made to trace the origin of early-type stars observed atappreciable distances from the galactic plane. Because uncertainties inthe proper motions make space motions and hence dynamical lifetimesrather inaccurate, a theory of oscillations normal to the plane has beenused to compute radial velocities for 138 intermediate-latitude OBstars. These theoretical values are then compared with the observedradial velocities, and it is found that the low-velocity stars wereprobably ejected from the plane some time after formation, while thehigh-velocity stars were ejected very soon after formation. Velocitiesof ejection perpendicular to the plane are computed and show a narrowdistribution with a mean absolute value of 7 km/s together with a spreadof velocities from about 40 to over 200 km/s. The data are in reasonableagreement with a 'sling' effect and 'runaway' origin for the stars inthe sample.
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UBV photometry and MK spectral classification of northern early-type stars at intermediate galactic latitudes
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1977MNRAS.180..691H&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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Some Spectroscopic Characteristics of the OB Stars: an Investigation of the Space Distribution of Certain OB Stars and the Reference Frame of the Classification
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971ApJS...23..257W&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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Equivalent widths of interstellar calcium lines
Not Available
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The Distribution of Extra-Galactic Nebulae
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1934ApJ....79....8H&db_key=AST
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INHABITED SKY
