Photometry and Spectroscopy for Luminous Stars

III/76) surveys (Cat. J/ApJS/115/271); MK classifications for the northern stars were similarly compiled and made electronically available to interested parties, though were not formally published. Work on the radial velocity and four-color compilations has since been discontinued, but interested readers may still obtain those (for the LS-South stars) from the author.

Most of the LS objects are OB stars, but there are as well a number of A, F, and G supergiants and a few white dwarfs and Wolf Rayet stars. These surveys reached a limiting photographic magnitude of ~13.5, and were based on objective-prism surveys of dispersion 580{AA}/mm at H{gamma} More details can be found in the files "obnotes.htm" (HTML format). Abstract of the paper: The birthrate of stars of masses >=10M_{sun}_ is estimated from a sample of just over 400 O3-B2 dwarfs within 1.5kpc of the Sun and the result extrapolated to estimate the Galactic supernova rate contributed by such stars.

The solar-neighborhood Galactic-plane massive star birthrate is estimated at ~176stars/kpc^3^/Myr. On the basis of a model in which the Galactic stellar density distribution comprises a "disk+central hole" like that of the dust infrared emission (as proposed by Drimmel and Spergel), the Galactic supernova rate is estimated at probably not less than ~1 nor more than ~2 per century and the number of O3-B2 dwarfs within the solar circle at ~200000.