Pulkovo compilation of radial velocities for 35495 stars in a common system.
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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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WX Cen (≡ WR 48c) - a possible Type Ia supernova progenitor
We confirm the orbital period of WX Cen ≡ WR 48c determined byDiaz & Steiner and refined its value to Porb= 0.4169615(+/-22) d. The light curve of this object has a peak-to-peak variationof approximately 0.32 mag. It is non-sinusoidal in the sense that it hasa V-shaped narrow minimum, similar to the ones seen in V Sge, V617 Sgrand in compact binary supersoft sources (CBSS).Most of the emission lines in the optical spectrum are due to Balmer,HeII, CIV, NV, OV and OVI. An analysis of the HeII Pickering seriesdecrement shows that the system has significant amount of hydrogen. Theemission lines of HeII 4686 Å became weaker between the 1991 and2000/2002 observations, indicating distinct levels of activity. Thespectra of WX Cen show variable absorption features in the Balmer lineswith V=-2900 km s-1 and in emission with V=+/-3500 kms-1. These highly variable features remind us of thesatellite emission lines found in the spectra of CBSS.We estimate the colour excess as E(B-V) = 0.63 on the basis of theobserved diffuse interstellar band at 5780 Å. Given thedistance-colour excess relation in the direction of WX Cen, this impliesa distance of 2.8 +/- 0.3 kpc. Interstellar absorption of the NaI Dlines show components at -4.1 km s-1, which corresponds tothe velocity of the Coalsack, and three other components at -23.9, -32.0and -39.0 km s-1. These components are also seen with similarstrengths in field stars that have distances between 1.8 and 2.7 kpc.The intrinsic colour of WX Cen is (B-V)0=-0.2 and theabsolute magnitude is MV=-0.5.Extended red wings in the strong emission lines are seen. A possibleexplanation is that the system has a spill-over stream similar to whatis seen in V617 Sgr. We predict that when observed in opposite phase,blue wings would be observed. A puzzling feature that remains to beexplained is the highly variable red wing (V~ 700 km s-1) ofthe OVI emission lines as well as of the red wings of the H and Helines.The velocity of the satellite-like feature is consistent with the ideathat the central star is a white dwarf with a mass of M~ 0.9Msolar. With the high accretion rate under consideration, thestar may become a Type Ia supernova (SN Ia) in a time-scale of 5 ×106 yr.
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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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Peering through the Dust: Evidence for a Supermassive Black Hole at the Nucleus of Centaurus A from VLT Infrared Spectroscopy
We used the near-infrared spectrometer ISAAC at the ESO Very LargeTelescope to map the velocity field of Cen A (NGC 5128) at severalposition angles and locations in the central 20" of the galaxy. The highspatial resolution (~0.5") velocity fields from both ionized andmolecular gas (Pa?, [Fe II], Br?, and H2) are notcompromised by either excitation effects or obscuration. We identifythree distinct kinematical systems: (1) a rotating ``nuclear disk'' ofionized gas, confined to the inner 2", the counterpart of the Pa?feature previously revealed by HST/NICMOS imaging; (2) a ringlike systemwith a ~6" inner radius detected only in H2 likely thecounterpart of the 100 pc scale structure detected in CO by otherauthors; (3) a normal extended component of gas rotating in the galacticpotential. The nuclear disk is in Keplerian rotation around a centralmass concentration, dark (M/L>20Msolar/LKsolar) and pointlike at the spatialresolution of the data (R<0.25"-4 pc). We interpret this massconcentration as a supermassive black hole. Its dynamical mass based onthe line velocities and disk inclination (i>15deg) isMBH=2+3.0-1.4×108Msolar. The ringlike system is probably characterized bynoncircular motions; a ``figure of 8'' pattern observed in theH2 position-velocity diagram might provide kinematicalevidence for the presence of a nuclear bar. Based on observationscollected at the European Southern Observatory, Paranal, Chile (ESOProgram 63.P-0271A).
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Five-colour photometry of OB-stars in the Southern Hemisphere
Observations of OB-stars, made in 1959 and 1960 at the Leiden SouthernStation near Hartebeespoortdam, South Africa, with the VBLUW photometerattached to the 90 cm light-collector, are given in this paper. They arecompared with photometry obtained by \cite[Graham (1968),]{gra68}\cite[Walraven & Walraven (1977),]{wal77} \cite[Lub & Pel(1977)]{lub77} and \cite[Van Genderen et al. (1984).]{gen84} Formulaefor the transformation of the present observations to those of\cite[Walraven & Walraven (1977)]{wal77} and \cite[Lub & Pel(1977)]{lub77} are given. Table 4 is only available in electronic format the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) orvia http://cdsweb.u-strasbg.fr/Abstract.html
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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 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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UBV-beta photometry of luminous early-type stars and emission-line stars in the Southern Coalsack region
A catalog is presented giving UBV-beta photometry for 144 luminous OBstars and UBV photometry for 154 emission-line stars in a 100-sq-degregion around the Southern Coalsack. Total visual absorptions anddistance moduli have been determined for all the stars and aretabulated. Comparisons with previous observations are discussed.
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A kinematic study of faint OB stars in the southern Milky Way
Radial velocities are presented for 70 faint OB stars in Vela,Centaurus, Circinus, and Norma. The measurements were performed onimage-tube spectra of dispersion 43 Å/mm obtained at Cerro TololoInter-American Observatory. The mean radial velocities of the starsbelonging to the Centaurus OB1 and Norma OB1 associations indicate thatthey follow the galactic rotation. Stars in Vela and Circinus showdeviations from pure rotation when compared to the mean rotation curveof the Galaxy at the corresponding longitudes.
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UBV photometry for southern OB stars
New UBV photometry of 1227 OB stars in the southern Milky Way ispresented. For 1113 of these stars, MK spectral types have been reportedpreviously in a comprehensive survey to B = 10.0 mag.
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A photometric and spectroscopic study of faint OB stars in the Southern Milky Way
Abstract image available at:http://adsabs.harvard.edu/abs/1982MNRAS.201..885B
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Catalog of Luminous Stars in the Southern Coalsack Zone
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1982RMxAA...5..183M&db_key=AST
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Photometric study of faint early-type stars in the southern Milky Way
UBV photoelectric observations are presented for 101 faint early-type(mainly OB) stars in four regions of the southern Milky Way: two inVela, one in Centaurus, and one in Circinus; H-beta data are also givenfor the brightest stars. Objective-prism plates showing the H-alpharegion of the spectrum are used, together with published results fromother authors, to recognize Be stars in the sample. A new young opencluster related to the H II region RCW 38 in Vela is found at 1.7 kpcfrom the sun, and the existence of at least a spur in the local armtowards galactic longitude of about 270 deg is favored; whether such afeature extends beyond that distance cannot be decided from the data.Most of the stars studied in the Centaurus region seem to belong to theCentaurus OB 1 association, at 2.4 kpc from the sun, and lie in theSagittarius-Carina arm. It is not clear if the stars observed in theCircinus region are physically related to each other, but theirdistances to the sun also place most of them in the Sagittarius-Carinaarm.
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O stars and supergiants south of declination -53 0.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1976AJ.....81..116H&db_key=AST
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Interstellar Polarization in the Southern Milky way.
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1956ApJ...124...43V&db_key=AST
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Photo-electric colours of southern early-type stars
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