The Galactic Supernova Rate

The combined evidence from external galaxies and from the historical SNe in our Galaxy gives a best estimate of the Galactic SN frequency of one event every 40 +/- 10 yr. About 85% of these SNe come from massive progenitors and are expected to cause neutrino bursts. The result is in agreement with additional evidence from the number of progenitor stars, radio SN remnants, the Galactic iron abundance, the Galactic gamma-ray flux, the absence of a neutrino detection so far, and the birthrate of pulsars. It is also consistent with the observation that the very largest late-type spirals produce approximately 10 SNe per century. The combined SN rate of the Magellanic Clouds is 0.6, that of M31 plus M33 1.8 SNe per century.