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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.
| 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.
| 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.
| The distribution of early-type stars and dust around L = 114 deg
Photoelectric H-beta photometry is presented for about 125 early-typestars in a 12-sq deg area centered at l = 114 deg, b = 1.5 deg. Moststars were previously measured in UBV. The study of the color excessesof the stars shows that a dust cloud covers part of the area. This cloudis situated about 1.5 kpc from the sun. Except for that cloud the onlycolor excess found in the area originates within 1 kpc from the sun. Thefrequency maximum of OB stars is found between a distance of 2 and 4kpc, which is the intersection with the Perseus arm.
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Dades d'Observació i Astrometria
| Constel·lació: | Cassiopeia |
| Ascensió Recta: | 23h47m13.21s |
| Declinació: | +60°18'52.8" |
| Magnitud Aparent: | 8.512 |
| Distancia: | 444.444 parsecs |
| Moviment propi RA: | -3.1 |
| Moviment propi Dec: | -2.6 |
| B-T magnitude: | 8.916 |
| V-T magnitude: | 8.546 |
Catàlegs i designacions:
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