A Galactic O Star Catalog
We have produced a catalog of 378 Galactic O stars with accuratespectral classifications that is complete for V<8 but includes manyfainter stars. The catalog provides cross-identifications with othersources; coordinates (obtained in most cases from Tycho-2 data);astrometric distances for 24 of the nearest stars; optical (Tycho-2,Johnson, and Strömgren) and NIR photometry; group membership,runaway character, and multiplicity information; and a Web-based versionwith links to on-line services.
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Stars with ISM Polarization Observed with HPOL. II
Polarization data are given for stars whose polarizations are mostlyinterstellar which were observed with the University of Wisconsinspectropolarimeter (HPOL) during 1995-2003. Several cases are found forwhich K in the Serkowski Law for ISM polarization is higher than allowedby published formulas.
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A study of RV in Galactic O stars from the 2MASS catalogue
We present new measurements of the interstellar reddening parameterRV=AV/E(B-V) towards 185 O stars, using J, H,Ks photometry from the 2MASS project. The results arecombined with data from the literature of 95 stars where RVhas been derived with the same technique, 22 of which in common with ourpresent sample from the 2MASS project catalogue. The averageRV from these 258 O stars is of 3.19 +/- 0.50. All objectswhose RV departs from this value by more than 2 sigma havebeen recognized. Ten objects have RV higher than this valueand two lower. It is found that anomalous RV can scarcely beassociated with anomalies in the general interstellar medium, e.g. withdifferent behaviour in different spiral arms. They are clearly linked tolocal cloud effect. In the Cygnus region RV values follow thebehaviour of the general interstellar medium, while in the Carina arm,in spite of the relatively larger distance, local cloud effects prevail.An explanation for this is suggested. The relatively few stars of oursample whose Hipparcos parallaxes are reliable, are found to havedistances systematically smaller than the distances derived by thespectroscopic parallaxes. We argue that this effect is consistent withthe recently claimed discovery of grey extinction towards OB stars.This publication makes use of data products from the Two Micron All SkySurvey (2MASS), which is a joint project of the University ofMassachusetts and the Infrared Processing and Analysis Center/CaliforniaInstitute of Technology, funded by the National Aeronautics and SpaceAdministration and the National Science Foundation.Tables 1 and 2 are only available in electronic form at the CDS viaanonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/410/905
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Spectroscopy of Galaxies in the Bootes Void
We investigate the physical properties of a sample of 26 galaxies in theBootes void and classify these galaxies based on the emission lines intheir spectra. Fourteen galaxies are classified as H II galaxies withproperties similar to field H II galaxies. Two of these galaxies,1432+5302 and 1507+4554, are extreme starburst galaxies. Approximatelyhalf of the galaxies with measurable Hα+[N II] emission haveelevated rates of star formation. Analysis of the galaxy continuasuggests that approximately one-third of the void galaxies have largepopulations of blue stars. Stellar absorption features from metals inmore than half the galaxies in the sample indicate the presence oflate-type stars. Emission lines are detected from the H I galaxy1517+3949 for the first time. Two systems, 1510+4727 and 1517+3956, areidentified as closely interacting galaxy pairs, bringing the totalnumber of known galaxy pairs in the void to four. The galaxy 1458+4944is a LINER, making at least five AGNs in the void. Classifications ofeight galaxies in the sample remain unknown. The galaxies in the Bootesvoid are similar to field emission-line galaxies with respect to stellarpopulations, emission-line properties, fraction of AGN and fraction ofgalaxy pairs. This result is inconsistent with some models of galaxyformation in low-density environments.
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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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An Atlas of Balmer Lines - H-Delta and H-Gamma
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993A&AS..101..599C&db_key=AST
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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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A new library of stellar optical spectra
Attention is given to a new digital optical stellar library consistingof spectra covering 3510-8930 R at 11-A resolution for 72 differentstellar types. These types extend over the spectral classes O-M andluminosity classes I-V. Most spectra are of solar metallicity stars butsome metal-rich and metal-poor spectra are included. This new library isquantitatively compared to two previously published libraries. It offersseveral advantages over them: it is photometrically well-calibratedindividually and consistently from star to star. Good temperature andluminosity coverage has been achieved. The incorporation of stars withwell-determined temperature, metallicity, and surface gravity parametersincreases the accuracy of the spectral type assigned to each compositelibrary star.
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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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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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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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Interstellar extinction curve - The profile of very broad structure
The interstellar extinction curve between 3500 and 10,500 A isdetermined from a series of two-color plots based on existing spectralscans. Very Broad Structure (VBS) covers the wavelength range from 5000to 8000 A and consists of three components centered at 5300, 5900 and6800 A. The VBS is shown to originate in the same agent as that ofcontinuous extinction.
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Photometry of stars in the uvgr system
Photoelectric photometry is presented for over 400 stars using the uvgrsystem of Thuan and Gunn. Stars were selected to cover a wide range ofspectral type, luminosity class, and metallicity. A mean main sequenceis derived along with reddening curves and approximate transformationsto the UBVR system. The calibration of the standard-star sequence issignificantly improved.
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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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A library of stellar spectra
Spectra for 161 stars having spectral classes O-M and luminosity classesV, III, and I have been incorporated into a library available onmagnetic tape. The spectra extend from 3510 to 7427 A at a resolution ofabout 4.5 A. The typical photometric uncertainty of each resolutionelement in the spectra is on the order of 1 percent while broad-bandvariations are smaller than 3 percent. Potential uses for the libraryinclude population synthesis of galaxies and clusters, tests of stellaratmosphere models, spectral classification, and the generation of colorindices having arbitrary wavelength and bandpass.
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The initial mass function for massive stars
A machine readable catalog of over 750 galactic O stars with publishedphotometry, spectral types, and luminosity classes has been compiled.The catalog is probably complete to a distance of about 2.5 kpc. Fromthis volume-limited data, the initial mass function (IMF) for stars moremassive than 20 solar masses has been derived. This IMF differs fromthat of Miller and Scalo (1979) and of Lequeux (1979), in havingproportionately more O type stars and not as steep a fall-off in numberof stars with increasing mass. Dividing the sample into stars inside andoutside the solar circle, a substantial difference in the IMF of themost massive stars is found. There are proportionally more toward thegalactic center. This gradient in the IMF may be related to the observedspace density of Wolf-Rayet stars, which are descendants of O typestars.
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The law of interstellar absorption in the wave-number interval 0.95/micron to 3.03/microns
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1982A&A...115..347A&db_key=AST
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A catalogue of stellar spectrophotometric data
A list of 378 sets of stellar energy distributions for 356 stars basedon photoelectric spectrophotometry is presented. Data from eight sourceshave been transformed to the Hayes-Latham calibration of Alpha Lyrae.The procedure follows that of Breger (1976) and the present list extendsprevious data, especially for stars of earliest and intermediatespectral types.
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Studies of luminous stars in nearby galaxies. I. Supergiants and O stars in the Milky Way.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978ApJS...38..309H&db_key=AST
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Observations in linearly polarized light of the intensity of the diffuse lam 6180 absorption band in 56 southern O, B and A stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1978A&A....70..195G&db_key=AST
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The influence of interstellar absorption on measured strengths of the Balmer discontinuity
The definition of the Balmer-discontinuity strength from observationalspectrophotometric data is discussed in relation to detailed results onthe wavenumber dependence of the interstellar absorption. The break inthe interstellar absorption curve at a wavenumber of about 2.33permicrons is found to introduce systematic errors in many currentlydefined strengths of the Balmer discontinuity. The errors should beproportional to the amount of the color excess caused by interstellarabsorption. Using the interstellar absorption curves established byDivan (1954) and by Nandy (1964) theoretical relations are derivedbetween the amount of interstellar absorption and the correspondinginfluence on the Balmer-discontinuity strength. These linear relationsare confirmed through tests on larger sets of observational data. At thesame time the derived relations are useful as correction formulas.
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Photoelectric measures of variable stars observed at MT. Kobau (1970-73).
Not Available
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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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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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The space distribution of the O stars in the solar neighborhood.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973AJ.....78.1067W&db_key=AST
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A new general O type stars catalogue
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973A&AS...12..277G&db_key=AST
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Observations in linearly polarized light of the intensity of the diffuse lambda 6180 absorption band in 49 O, B, and A stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1973A&A....27..261G&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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An attempt to define luminosity criteria in O stars via narrow-band photoelectric photometry
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970AJ.....75..337L&db_key=AST
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Photoelectric 4430 A observations of 506 O, B and A stars.
Not Available
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INHABITED SKY
