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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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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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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The interstellar 217 NM band - A third catalogue of equivalent widths
A catalog of equivalent widths of the 217 nm interstellar absorptionband as well as other parameters characterizing the extinction curve inthe ultraviolet has been compiled for 790 O and B stars. A relativelytight correlation between the equivalent width of the 217 nm band andE(B-V) indicates that the absorber of this band is connected with thepopulation of larger interstellar grains responsible for the visualextinction. The parameter characterizing the amount of extinction in thefar UV is only weakly correlated with E(B-V), a result in accord withthe assumption that a second population of very small grains causes therapid increase of the far-UV extinction.
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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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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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The S201 far-ultraviolet imaging survey. II - A field in Cygnus
Far-ultraviolet imagery of a region in Cygnus, a 20 deg diameter fieldcentered near (1950) R. A. 21 h 31.2 m decl. +37 deg 25 arcmin, wasobtained by the S201 far-ultraviolet camera during the Apollo 16mission. In a 10 minute exposure covering the 1250-1600 A wavelengthrange (effective wavelength 1400 A), 730 star images can be detected,corresponding to a limiting ultraviolet magnitude of about m (1400) =10. Assuming nominal interstellar extinction values in this region nearthe galactic plane, this result corresponds to the detection of A0 Vstars to a distance of 300 pc and of B0 V stars to 1500 pc.Uncertainties in spectral classification and interstellar extinction forindividual objects are probably more significant than calibration ormeasurement errors. Most of the objects detected are identified withstars in the Smithsonian Astrophysical Observatory Star Catalog (1966),or the Catalog of Stellar Identifications (1979) or both, but 87 objectsremain unidentified (or are identified with late-type stars).
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A search for stars physically associated with the 16-day Cepheid X Cygni. I - Luminous stars in the field
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1983AJ.....88..650T&db_key=AST
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Ultraviolet interstellar extinction toward 1367 stars observed by ANS
Five-band UV photometry is used to investigate the character ofinterstellar extinction toward 1367 stars of spectral type B3 andearlier, with observations producing a galactic average of 5.11, 4.78,6.52, 4.10 and 1.95 at 1550, 1800, 2200, 2500, and 3300 A, respectively.Differences in the strengths of the UV extinction features of thesestars appear to be independent, since objects with either strong or weak2200 A extinction can have strong, normal or weak far-UV extinction.Further investigation reveals that some of the deviant stars areembedded in localized regions whose average extinction curves divergedramatically from the galactic mean. The anomalous extinction of theseregions attests to localized inhomogeneities in the UV characteristicsof interstellar dust. Because the evaluation of UV extinction toward aparticular star would be more accurate if based on the average curve ofthe region immediately surrounding that star rather than that of theentire Galaxy, it is recommended that the galactic average presented beused with caution to correct astronomical data of individual objects.
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The abundance of negative hydrogen in small hot interstellar clouds
The observed intensities of the diffuse interstellar absorption band at4430 A have minimum values, for given stellar distances, that areequivalent to the reddening caused by the small Ambarzumian-type cloudsstudied by Stromgren (1972). This indicates that there is no negativehydrogen present between these clouds, which are then identified withthe hot H I phase of interstellar matter. The equilibrium density of H-inside such clouds is calculated from mean densities of neutral hydrogenatoms and free electrons, derived from radio observations for the localregion outside the large Orion-arm clouds. The filling factor of thesmall clouds is taken to be the same as that preserved in the structureof the Gum Nebula from before its ionization. An electron temperature of3375 K corresponding to the local degree of ionization of thesmall-cloud hydrogen then leads to a mean density of negative hydrogenequal to 20 trillions per sq cm per kpc, in agreement with the observeddiffuse-band intensities.
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Spectroscopic observations of stars in HII regions.
Not Available
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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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The space distribution and kinematics of supergiants
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970AJ.....75..602H&db_key=AST
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The radial velocities of distant cepheids and galactic models
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1967MNRAS.136..141F&db_key=AST
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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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The kinematics of B stars, cepheids, galactic clusters and interstellar gas in the Galaxy
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1965MNRAS.130..245F&db_key=AST
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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 measures of the 4430 A diffuse interstellar band
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1963MNRAS.125..141W&db_key=AST
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Observed Variations in the Law of Interstellar Reddening.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1962ApJ...136..100W&db_key=AST
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A Catalogue of H II Regions.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1959ApJS....4..257S&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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The dependence of interstellar absorption of light on the wavelength
Not Available
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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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INHABITED SKY
