Two-colour photometry for 9473 components of close Hipparcos double and multiple stars
Using observations obtained with the Tycho instrument of the ESAHipparcos satellite, a two-colour photometry is produced for componentsof more than 7 000 Hipparcos double and multiple stars with angularseparations 0.1 to 2.5 arcsec. We publish 9473 components of 5173systems with separations above 0.3 arcsec. The majority of them did nothave Tycho photometry in the Hipparcos catalogue. The magnitudes arederived in the Tycho B_T and V_T passbands, similar to the Johnsonpassbands. Photometrically resolved components of the binaries withstatistically significant trigonometric parallaxes can be put on an HRdiagram, the majority of them for the first time. Based on observationsmade with the ESA Hipparcos satellite.
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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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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 study of the spectrum of HD 108, an unusual Of star
Spectra of the peculiar O star HD 108 obtained at a scale of 30 A/mm inthe years 1986-1991 have been studied for line displacements and lineprofiles. The wavelength regions covered are 4180-5050 A, 5100-5980 A,and 6180-7070 A. The spectra were recorded with a Reticon, and most havea signal-to-noise ratio per pixel in the continuum greater than 200. Itis argued that the spectral type is best described as O7fpe III. Thespectrum at the time of observation was similar to te description givenby Plaskett (1924), but the radial velocity has changed. In 1922 and1923 the absorption lines and the emission lines showed a displacementof -62 km/s. In the ensuing years the radial velocity shown by theabsorption lines, mostly He II, N III, and O III, has changed to about-84 km/s in 1991. The emission-line velocity remained near -62 km/suntil about 1991, when this radial velocity became (apparently) about-66 km/s. There is some reason to suspect that the last few spectraobtained in 1991 suffer from a small random negative shift. The meaningof the radial velocity results is discussed, and it is argued that by1973 the photosphere may have begun to undergo an outward surge. Thechange of motion shown by the emission lines is less than that shown bythe photospheric absorption lines. It is argued that the emission lines,both the strong sharp emission lines due to H and He I and the weakerlines due to C II, C III, N II, O II, and Si III, are formed in a polarjet which is moving almost perpendicular to the line of sight. The starHD 108 appears to be related to the luminous blues variables (LBVs) andto the B(e) stars. No forbidden emission lines, as from a nebula, weredetected in the visible spectral range. Strong distinctive P Cygni typedisplaced absorption components for the H and He I lines are not seen.Rather, one sees a sharp emission line superposed on a photospehricabsorption line. The absence of a strong P Cygni type absorptioncomponent indicates that the optical depth along the line of sight tothe jet is small in the H and He I lines. The profiles of the H and He Iemission components are somewhat asymmetric. This suggests that weak PCygni type absorption takes place in the plasma forming the emissionlines.
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Hypergiant 6 CAS and association CAS OB5.
Not Available
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A spectral survey of early-type stars in the region of Cassiopeia using an objective prism
Not Available
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Observations of interstellar diffuse absorption band at 4430 A
Observations of the interstellar diffuse absorption band at 4430 A for800 O and B stars in Neckel's (1967) catalog are being carried out, and482 spectra obtained up to September 1983 have been reduced. It isconfirmed that the strength of the interstellar diffuse absorption bandat 4430 A does not simply relate to the abundance of interstellar grainson the line of sight. The relation between the color excess E(B-V) andthe equivalent width of the band to the direction of l = 130-140 deg andb = -5 to +5 deg shows that some parameter(s) other than E(B-V) is (are)needed to understand the cause of this band.
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A Comparison of the Luminosities of Perseus-Arm Stars in the Hγ and MK Systems
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972ApJ...171..285C&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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Optical and Radio Evidence of Large-Scale Peculiar Motions in the Cassiopeiaperseus Arm
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1968ApJ...152.1019R&db_key=AST
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Catalogue d'etoiles O et B.
Not Available
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Comparison of radial velocities of the OB-stars and Cepheids in the Perseus arm
Not Available
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Interstellar Absorption Lines in Distant Stars. I. Northern Milky way.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1957ApJ...125...42M&db_key=AST
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Line Broadening in the Spectra of o- and Early B-Type Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1956ApJ...124..173S&db_key=AST
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Studies in Galactic STRUCTURE.II.LUMINOSITY Classification for 1270 Blue Giant Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1955ApJS....2...41M&db_key=AST
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Studies in Galactic Structure. I. a Preliminary Determination of the Space Distribution of the Blue Giants.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1953ApJ...118..318M&db_key=AST
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Polarization of Stellar Radiation. III. The Polarization of 841 Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1951ApJ...114..241H&db_key=AST
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Intensities of the Interstellar Band at λ 4430.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1951ApJ...113..100D&db_key=AST
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INHABITED SKY
