Pulkovo compilation of radial velocities for 35495 stars in a common system.
Not Available
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New Estimates of the Solar-Neighborhood Massive Star Birthrate and the Galactic Supernova Rate
The birthrate of stars of masses >=10 Msolar is estimatedfrom a sample of just over 400 O3-B2 dwarfs within 1.5 kpc of the Sunand the result extrapolated to estimate the Galactic supernova ratecontributed by such stars. The solar-neighborhood Galactic-plane massivestar birthrate is estimated at ~176 stars kpc-3Myr-1. On the basis of a model in which the Galactic stellardensity distribution comprises a ``disk+central hole'' like that of thedust infrared emission (as proposed by Drimmel and Spergel), theGalactic supernova rate is estimated at probably not less than ~1 normore than ~2 per century and the number of O3-B2 dwarfs within the solarcircle at ~200,000.
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Catalog of Galactic OB Stars
An all-sky catalog of Galactic OB stars has been created by extendingthe Case-Hamburg Galactic plane luminous-stars surveys to include 5500additional objects drawn from the literature. This work brings the totalnumber of known or reasonably suspected OB stars to over 16,000.Companion databases of UBVβ photometry and MK classifications forthese objects include nearly 30,000 and 20,000 entries, respectively.
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Absolute proper motions of open clusters. I. Observational data
Mean proper motions and parallaxes of 205 open clusters were determinedfrom their member stars found in the Hipparcos Catalogue. 360 clusterswere searched for possible members, excluding nearby clusters withdistances D < 200 pc. Members were selected using ground basedinformation (photometry, radial velocity, proper motion, distance fromthe cluster centre) and information provided by Hipparcos (propermotion, parallax). Altogether 630 certain and 100 possible members werefound. A comparison of the Hipparcos parallaxes with photometricdistances of open clusters shows good agreement. The Hipparcos dataconfirm or reject the membership of several Cepheids in the studiedclusters. Tables 1 and 2 are only available in electronic form at theCDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/Abstract.html
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Multicolor Polarization Study of ARA OB1
We present the results of a multicolor polarimetric study of stars inthe association Ara OB1. Several objects belonging to the clusters NGC6204, 6193, and 6167 and the local field were observed as part of aglobal study of the region. The polarimetry shows that the orientationof the polarimetric vectors of each star is very similar within eachcluster. The average values are 35.5d+/-15.1d and 52.2d+/-16 deg for NGC6204 and 6193, respectively. An average value of 106.5d+/-9.9d is foundfor NGC 6167, but the angle distribution is asymmetric, and a secondcomponent can be fitted to the angle histogram (P.A.~120.8d+/-11.6d),showing a behavior not observed in NGC 6204 and 6193. So, we suggestthat some of the observed stars perhaps belong to another starsgrouping, located behind NGC 6167 and between a dust layer with adifferent orientation of the grains. The large difference in thepolarization angle between NGC 6167 and the other two clusters couldalso be explained because NGC 6167 is supposed to be at the center of agas-expanding structure and it is possible that this cluster was theorigin of the star formation process in the Ara OB1 association,triggered by stellar winds or supernova explosions.
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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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Red and infrared colours of B stars and the reddening law in the Galaxy
The red and infrared intrinsic colours of B stars are derived fromphotometric observations through the UBV(RI)_CJHK and Hβ filters of257 early-type stars. Those stars for which the UBV and Hβmeasurements match the published spectral class, and which show no othersigns of peculiarity, are used to determine the intrinsic photometriccolours of B stars in the red and infrared. From these intrinsic coloursthe interstellar reddening relationships for the red and infraredcolours are evaluated, and the results are compared with previousestimates of these quantities. The values of R, E(B-V) and the distanceare then determined for the individual stars. R is confirmed to be closeto 3.1 in most cases, but was found to be much larger in somedirections. The relationship between R and the location of a star in theGalaxy is investigated. Usually the abnormally reddened stars seemed tobe associated with known regions of star formation. The paper alsoidentifies seven likely variable stars and a number of stars withpossible dust shells.
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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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Deep Hα survey of the Milky Way. III. The l=338deg area.
The Galactic plane has been observed between l=337deg and l=342deg inthe frame of an Hα Survey of the Southern Milky Way. This area isknown to be rich in radio sources but poor in Hα emission. Theanalysis of high resolution profiles of the Hα emission observedin this direction nevertheless enabled to distinguish 6 differentvelocity components: 2 faint layers of diffuse ionized hydrogen at 0 and-12km/s (V_LSR_), 2 brighter layers at -28 and -39km/s includingindividual HII regions, a faint patch at -50km/s and two isolated brightHII regions at -61km/s. Combining these Hα observations withstellar and radio data we conclude about the most probable distances forthe different components.
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A spectroscopic database for Stephenson-Sanduleak Southern Luminous Stars
A database of published spectral classifications for objects in theStepenson-Sanduleak Luminous Stars in the Southern Milky Way catalog hasbeen compiled from the literature. A total of 6182 classifications for2562 stars from 139 sources are incorporated.
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The interstellar medium in the ARA OB1 field
We report here the results of a detailed study of two surveys of H I, atlambda = 21 cm, in the field of the stellar association Ara OB1.Subtracting the background with a procedure developed here, we were ableto identify two H I shell-like features, at roughly the same positionbut at different velocities, whose parameters were determined. On thebasis of their kinematical distances, two concentrations of OB stars(one at 1400 pc, belonging to Ara OB1, and another at 2500 pc) might bethe progenitors of these shells. The nearest H I shell may havetriggered a process of star formation.
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Stromgren and H beta photometry of OB associations and open clusters. I - ARA OB1
Stromgren and H beta photometry of 38 stars in the field of Ara OB1 ispresented. The excesses, the absolute magnitudes and the temperatures ofthe stars have been obtained. The masses and the ages are alsoestimated, based on the models of Maeder and Meynet. Two differentgroups have been distinguished by their space locations at V0 - MV =10.23 and 12.01 mag (assuming a normal extinction law). The more distantgroup is younger and more massive. The magnitude and the excess of theWR star MR62 point to its probable membership of this group. There aregood reasons to suspect a value of the total-to-selective absorptionratio that is greater than the normal 3.2, which leads to a significantreduction of the true distance moduli.
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The calibration of the Stromgren photometric system for A, F and early G supergiants. I - The observational data
An empirical calibration of the Stromgren uvby-beta photometric systemfor the A, F, and early G supergiants is being derived. This paperexplains the observational program and the photometric reductiontechniques used and presents a catalog of new Stromgren photometry forover 600 A, F, and G supergiants.
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The distribution of OB stars and dust in a Milky Way field at (l,b) = (335 deg, 0 deg)
New photoelectric UBV photometry for 103 stars and MK spectroscopy for110 stars in a 21 sq-deg field at (l,b) = (335 deg, 0 deg) are studied,in addition to previous data for stars in this field. Most of the 112 OBstars considered may be separated into three groups associated with thespiral structure of the inner galaxy: one at 1.34 + or - 0.05 kpc, oneat 2.41 + or - 0.08 kpc, and one at 3.69 + or - 0.23 kpc. The remaining21 stars lie along the line-of-sight, with some possibly being asdistant as 9 kpc. The dust is found to be distributed in two distinctclouds, one in the local arm at 190 + or - 30 pc and the other in aninterarm cloud of variable extinction at 690 + or - 70 pc.
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Five-colour photometry of early-type stars in the direction of galactic X-ray sources
The results of five-color (Walraven system) photometry of 551 O- andB-type stars located in 17 fields of a few square degrees aroundgalactic X-ray sources are presented. From a comparison ofreddening-free combinations of color indices with theoretical values,calculated for model atmospheres of Kurucz (1979), effective temperatureand surface gravity for these stars are derived. In addition theirabsolute magnitude are determined by combining these parameters with theresults of evolutionary calculations of massive stars. These effectivetemperatures are in good agreement with the temperature scale ofBohm-Vitense (1981) for stars of luminosity classes II to V. For thesupergiants the effective temperatures are about 40 percent higher. Forstars of luminosity classes III to V the absolute magnitudes agree wellwith the results of independent luminosity calibrations of spectraltypes, but for brighter stars they deviate systematically. Thephotometric data are also used to study the interstellar reddening inthe direction of the X-ray sources.
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On the intrinsic UVBY colours of early-type supergiants
The present photoelectric uvby observations of 43 late O-type to earlyA-type supergiants are combined with published results to extend theZhang (1983) determination of the intrinsic color lines in the(b-y)/c(1) diagram. Zhang's conclusion that the H-beta index is wellcorrelated with luminosity class is reaffirmed by the results obtained,although the degree of separation found here is less clear. It is notfound, however, that beta has a significant minimum between the B1 andB3 spectral types.
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Geneva intrinsic colours of the supergiants of spectral types A and F
The aim of this research note is to expose a photometric method todetermine the intrinsic values of the Geneva color index (B2-V1) for thesupergiants of spectral types A and F. The different stages which led tothis objective are presented, and the method is tested with a few starsbelonging to clusters for which color excesses were found in theliterature. A list of stars classified as supergiants which behavephotometrically as dwarfs is indicated.
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Interstellar NaI absorption towards the stellar association ARA OB1
Observations have been made of the interstellar D-line absorption of NaI towards a loose grouping of OB stars (containing the association AraOB1 and probably the H-alpha emission regions RCW 107 and 108) centeredat 1 = 337.5 deg and b = - 0.5 deg. The individual absorption spectracontain several velocity components which show well-defined groupings at- 37, -18 and 0 km/s. The corresponding median optical depths are 2, 7and 6. The evidence indicates that both the -37 and -18 km/s Na I cloudsare located in the Carina-Sagittarius spiral arm. Several H II regionsare located at similar longitudes, but most are close to zero latitudeand are more distant than the arm. The association contains the galacticcluster NGC 61993. The results suggest that the turbulence seenoptically towards this cluster has been caused by the interactionbetween two cloud groups moving towards each other at velocities of 10to 15 km/s.
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New UBVRI photometry for 900 supergiants
A description is presented of the results obtained in connection with asystematic program of supergiant photometry on the Johnson UBVRI system.During the eight years after the start of the program, almost 1000 starshave been observed, about 400 three or more times each. The originalselection of stars used the spectral type catalog of Jaschek et al.(1964) to choose supergiants. Since observations were possible from bothChile and Canada, no declination limits were imposed, and no particularselection criteria were imposed other than to eliminate carbon stars.These are so red as to require enormous extrapolations of thetransformation equations.
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UBV-/H-beta/ photometry of luminous stars between L equals 335 deg and L equals 6 deg
Results are reported for photoelectric UBV and H-beta photometry of 316luminous OB stars and early-type supergiants in the region between 335and 6 deg galactic longitude. UBV magnitudes for the 316 stars and betaindexes for 37 of them are presented. Absolute magnitudes, distances,and color excesses are determined for the 161 stars with measured betaindexes or known MK spectral types. The results are discussed in termsof the spiral structure of the Galaxy. From the data obtained forprogram stars assumed to be cluster members, distances are derived forthe open clusters NGC 6167 (1.7 kpc), NGC 6193 (1.3 kpc), Hogg 22 (2.0kpc), NGC 6231 (1.9 kpc), and Tr 27 (1.6 kpc).
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Infrared photometry of southern early-type stars
The paper presents infrared photometry tied to the JHKL (1.2-3.5microns) broadband photometric system for 229 southern early-type stars.To determine data for stars of low reddening intrinsic visual-IR colorindices were used; the E(V-K)/E(B-V) diagram was applied to evaluate theratio of total selective extinction. A mean value of R = 3.12 plus orminus 0.05 was found for stars close to the galactic plane, but a highervalue of R (about 4.0) applies to the Orion and Sco-Oph regions.Infrared two-color diagrams were used to investigate the occurrence ofinfrared excess emission in different classes of shell star; no excesseswere found for supergiants or Of stars. It is concluded that theanomalous position HD 164740 in the two-color diagrams is produced bystrong infrared excess and not by a peculiar extinction law.
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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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The correlation of the interstellar extinction law with the wavelength of maximum polarization
Results are reported for IR photometry of 56 southern stars for whichvalues of the wavelength of maximum polarization (lambdamax)are available. Lambdamax is plotted against EV-K/Esub B-V for each star, and previously published IR data are combinedwith these results, bringing the total number of stars for analysis to98. The plots are evaluated separately for a group of 73 stars withapparently normal spectra and a group of 25 stars with spectralpeculiarities associated with circumstellar shells. It is deduced thatthe ratio (R) of total to selective extinction and lambdamaxare related by the formula R = 5.6 times lambdamax (inmicrons). It is concluded that lambdamax is generally a morereliable grain-size parameter than R and that the most reliable methodof determining the visual absorption for individual stars is currentlythe relation AV = 5.6 (lambdamax) E sub B-V.
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Finding list and spectral classifications for southern luminous stars.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976AJ.....81..225M&db_key=AST
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Southern open star clusters VI. UBV-Hbeta photometry of 18 clusters from Centaurus to Sagittarius.
Abstract image available at:http://adsabs.harvard.edu/abs/1975A&AS...20..155M
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Wavelength dependence of interstellar polarization and ratio of total to selective extinction
A multichannel polarimeter-photometer which uses dichroic filters toseparate the (UBVR) spectral regions is described. The instrument wasused with a 24-inch rotatable tube telescope for polarimetricobservation of nearby stars. Polarization data for 364 nearby stars aretabulated, together with the wavelength dependence of linear andinterstellar polarization.
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UBV Photometry of 500 Southern Stars [erratum: 1973MNSSA..32...48C]
Not Available
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Observations of stars in HII regions : spectral classification and UBVphotometry.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1971AJ.....76..260C&db_key=AST
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Régions H II de l'hémisphère austral
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1970A&AS....3....1G&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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INHABITED SKY
