SIMBAD references

The birthrate of stars of masses {ges}10 M_☉ is estimated from a sample of just over 400 O3-B2 dwarfs within 1.5 kpc 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 ∼176 stars/kpc3/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 ∼200,000.