Classification and properties of UV extinction curves
The catalog of Savage et al. (\cite{ref27}) reporting colour excesses of1415 stars from ANS photometry offers the opportunity to deeplyinvestigate the characteristics of UV extinction curves which differfrom the standard extinction of the diffuse interstellar medium. To thisaim we have selected a sample of 252 curves, which have been comparedwith the relations derived by Cardelli et al. (\cite{ref4}; CCM in thefollowing) for a variety of R_V values in the range 2.4-5 and have beenclassified as normal if they fit at least one of the CCM curves oranomalous otherwise. We find that normal curves with small R_V are justas numerous as those with large R_V. The anomalous objects are arrangedinto two groups according to the strength of the bump at 0.217 mu . Fora given value of c_2 this increases along the sequence: type Aanomalous, normals and type B anomalous, suggesting that this sequenceshould correspond to an increase of the amount of small grains along thesightline. Considerations concerning the environmental characteristicsindicate that the anomalous behaviour is not necessarily tied to theexistence of dense gas clouds along the line of sight.
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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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Anomalous Proper-Motions in the Cygnus Super Bubble Region
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993A&AS..101...37C&db_key=AST
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An Einstein Observatory SAO-based catalog of B-type stars
About 4000 X-ray images obtained with the Einstein Observatory are usedto measure the 0.16-4.0 keV emission from 1545 B-type SAO stars fallingin the about 10 percent of the sky surveyed with the IPC. Seventy-fourdetected X-ray sources with B-type stars are identified, and it isestimated that no more than 15 can be misidentified. Upper limits to theX-ray emission of the remaining stars are presented. In addition tosummarizing the X-ray measurements and giving other relevant opticaldata, the present extensive catalog discusses the reduction process andanalyzes selection effects associated with both SAO catalog completenessand IPC target selection procedures. It is concluded that X-rayemission, at the level of Lx not less than 10 exp 30 ergs/s, is quitecommon in B stars of early spectral types (B0-B3), regardless ofluminosity class, but that emission, at the same level, becomes lesscommon, or nonexistent, in later B-type stars.
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Extinction law survey based on UV ANS photometry
The paper presents an extensive survey of interstellar extinction curvesderived from the ANS photometric measurements of early type starsbelonging to our Galaxy. This survey is more extensive and deeper thanany other one, based on spectral data. The UV color excesses aredetermined with the aid of 'artificial standards', a new techniqueproposed by the authors which allows the special check of Sp/L match ofa target and the selected standard. The results indicate that extinctionlaw changes from place to place.
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MK classifications of stars in Cygnus
MK spectral classifications are given for 24 stars of types B and A inselected area No. 4 of Fehrenbach and Burnage (1981) for radial-velocityinvestigations. The spectroscopic observations were made with the Marlyspectrograph at the 120-cm telescope of the Observatoire de HauteProvence. A spectral atlas of the standard stars is given, and the maincriteria for classification are described. Many of the target stars havebroad lines and one of them (HD 192605) is especially interesting,having a large Balmer progression of radial velocity.
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A catalog of ultraviolet interstellar extinction excesses for 1415 stars
Ultraviolet interstellar extinction excesses are presented for 1415stars with spectral types B7 and earlier. The excesses with respect to Vare derived from Astronomical Netherlands Satellite (ANS) 5-channel UVphotometry at central wavelengths of approximately 1550, 1800, 2500, and3300 A. A measure of the excess extinction in the 2200-A extinction bumpis also given. The data are valuable for investigating the systematicsof peculiar interstellar extinction and for studying the character of UVinterstellar extinction in the general direction of stars for which theextinction-curve shape is unknown.
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Distribution of OB stars and absorbing matter in the region around P CYG
The results of spectrophotometric observations of 277 OB stars in a 7 x7-deg region around P Cyg, obtained in 8-sec, 45-sec, and 8-minexposures on ORWO ZU-21 plates with a 4-deg 272-A/mm-dispersionobjective prism on the 40-in. Schmidt telescope at BiurakanAstrophysical Observatory on October 14-19, 1979, are presented intables and graphs and characterized. Data reported include 400-480-nmabsolute spectrophotometric gradients, color excesses, and distances. Itis found that concentrations of OB stars with associated absorbingmatter exist toward the associations Cyg OB9 (two concentrations at 800and 1800 pc), Cyg OB3 (three concentrations at 1.4, 2.5, and 3.7 kpc),OB1 (at 1.6 kpc), Cyg OB8 (at 1.5 kpc), and over the entire observedregion at a distance of about 500 pc.
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Catalogue d'etoiles O et B.
Not Available
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Photoelectric 4430 A observations of 506 O, B and A stars.
Not Available
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Photoelectric observations of the intensity of the 4430 band in 147 O,B, and A stars in the Northern Milky Way
Not Available
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Structure de la galaxie dans la région de P Cygni
Not Available
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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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Interstellar Polarization of 405 Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1954ApJ...120..454H&db_key=AST
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A Study of the Concentration of Early-Type Stars in Cygnus.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1951ApJ...114..492R&db_key=AST
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A Finding List of O and B Stars of High Luminosity.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1951ApJ...113..141N&db_key=AST
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Stellar Spectra and Colors in a Clear Region in Cygnus.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1949ApJ...110..478N&db_key=AST
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INHABITED SKY
