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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A search for hot post-AGB stars in the IRAS Point Source Catalog.
In this paper a first step is made to search for hot post-AGB stars inthe IRAS Point Source Catalog. In order to find objects that evolved offthe AGB a longer time ago than post-AGB objects discussed in theliterature, objects that were not detected at 12 μm by IRAS wereselected, The selection yielded 15 objects, of which 12 have spectraltype B, and would appear to be efficient in finding hot objects.However, this result does not necessarily mean that these are oldevolved objects. Some stars are associated with dense galactic cirrusand are probably normal massive supergiants, and a number of stars aregood post-AGB candidates because of their galactic latitudes and theircool, extended infrared emission. The possibility remains that theseobjects are normal supergiants heating the local interstellar medium.Finally, three remaining objects appear to be genuine post-AGB(candidate) stars, as is attested by their spectral and photometricproperties. The main conclusion derived from modelling their spectralenergy distributions is that the objects evolved off the AGB about 1000years ago, significantly longer than what is found for other post-AGBstars. Emission lines have appeared in the spectrum of one of theseobjects, SAO 243756, over the last 20 years. SAO 243756 bears closeresemblance to other objects that have been proposed to have entered thePlanetary Nebula phase recently. Several aspects of the problem ofselecting post-AGB stars in general are discussed.
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The Henry Draper Extension Charts: A catalogue of accurate positions, proper motions, magnitudes and spectral types of 86933 stars
The Henry Draper Extension Charts (HDEC), published in the form offinding charts, provide spectral classification for some 87000 starsmostly between 10th and 11th magnitude. This data, being highlyvaluable, as yet was practically unusable for modern computer-basedastronomy. An earlier pilot project (Roeser et al. 1991) demonstrated apossibility to convert this into a star catalogue, using measurements ofcartesian coordinates of stars on the charts and positions of theAstrographic Catalogue (AC) for subsequent identification. We presenthere a final HDEC catalogue comprising accurate positions, propermotions, magnitudes and spectral classes for 86933 stars of the HenryDraper Extension Charts.
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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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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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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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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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Interstellar dust and distances to planetary nebulae.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973ApJ...181..135L&db_key=AST
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UBV and Hgamma observations of early-type field stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972AJ.....77..376L&db_key=AST
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Radial velocities of 65 early-type stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1972AJ.....77..138A&db_key=AST
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Correlation Between the Regional Variations in Wavelength Dependence of Interstellar Extinction and Polarization
Abstract image available at:http://adsabs.harvard.edu/abs/1968ApJ...154..115S
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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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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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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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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 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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INHABITED SKY
