UBVRI CCD photometry of the OB associations Bochum 1 and Bochum 6.
We report the first deep $UBVRI$ CCD photometry of 2460 stars in thefield of two poorly studied OB associations Bochum 1 and Bochum 6. Weselected 15 and 14 probable members in Bochum 1 and Bochum 6respectively using photometric criteria and proper motion data of Tycho2. Our analysis indicates variable reddening having mean value of$E(B-V)=$ 0.47$\pm$0.10 and 0.71$\pm$0.13 mag for Bochum 1 and Bochum 6respectively. Using the zero-age main-sequence fitting method, we derivea distance of 2.8$\pm$0.4 and 2.5$\pm$0.4 Kpc for Bochum 1 and Bochum 6respectively. We obtain an age of 10$\pm$5 Myrs for both theassociations from isochrone fitting. In both associations high and lowmass stars have probably formed together. Within the observationaluncertainties, mass spectrum of the both associations appears to besimilar to the Salpeter's one.
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Distances and Metallicities of High- and Intermediate-Velocity Clouds
A table is presented that summarizes published absorption linemeasurements for the high- and intermediate-velocity clouds (HVCs andIVCs). New values are derived for N(H I) in the direction of observedprobes, in order to arrive at reliable abundances and abundance limits(the H I data are described in Paper II). Distances to stellar probesare revisited and calculated consistently, in order to derive distancebrackets or limits for many of the clouds, taking care to properlyinterpret nondetections. The main conclusions are the following. (1)Absolute abundances have been measured using lines of S II, N I, and OI, with the following resulting values: ~0.1 solar for one HVC (complexC), ~0.3 solar for the Magellanic Stream, ~0.5 solar for a southern IVC,and ~solar for two northern IVCs (the IV Arch and LLIV Arch). Finally,approximate values in the range 0.5-2 solar are found for three moreIVCs. (2) Depletion patterns in IVCs are like those in warm disk or halogas. (3) Most distance limits are based on strong UV lines of C II, SiII, and Mg II, a few on Ca II. Distance limits for major HVCs aregreater than 5 kpc, while distance brackets for several IVCs are in therange 0.5-2 kpc. (4) Mass limits for major IVCs are0.5-8×105 Msolar, but for major HVCs theyare more than 106 Msolar. (5) The Ca II/H I ratiovaries by up to a factor 2-5 within a single cloud, somewhat morebetween clouds. (6) The Na I/H I ratio varies by a factor of more than10 within a cloud, and even more between clouds. Thus, Ca II can beuseful for determining both lower and upper distance limits, but Na Ionly yields upper limits.
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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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A Radial Velocity Database for Stephenson-Sanduleak Southern Luminous Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1997AJ....113..823R&db_key=AST
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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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The Diffuse Ionized Interstellar Medium: Structures Resulting from Ionization by O Stars
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993ApJ...417..579M&db_key=AST
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Distance to the anti-center shell
High-resolution, high-sensitivity echelle spectra have been obtainedtowards early-type stars located within the boundaries of theAnti-Center Shell (ACS), an anomalous velocity H I structure in theanticenter region of the Galaxy. The observations indicate that theshell is certainly more distant than 500 pc, and quite possibly moredistant than 2500 pc. No anomalous velocity C II absorption featureswere detected. These results support the hypothesis that the ACS is theresult of collision of high-velocity clouds with the Galactic H I disk.
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The rotation and structure of the galaxy beyond the solar circle. I - Photometry and spectroscopy of 276 stars in 45 H II regions and other young stellar groups toward the galactic anticentre
Abstract image available at:http://adsabs.harvard.edu/abs/1979A&AS...38..197M
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Southern open star clusters. IV. UBV Hbet photometry of 26 clusters from MON to Vel.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1975A&AS...20...85M&db_key=AST
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A catalogue of galactic O stars. The ionization of the low density interstellar medium by runaway stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1974RMxAA...1..211C&db_key=AST
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Studies of Faint B-Type Stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1950ApJ...111..495P&db_key=AST
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