The Frequencies of Supernovae in Binaries

All explosive events of greater-than-nova magnitude (in both peak brightness and total energy emission) which single stars and components of close binary stars may experience as a result of their evolution are described, and the occurrence frequencies of these events are estimated. This paper is an extension of a previous study devoted to the theoretical estimation of Galaxy-wide formation frequencies of different types of binary stars and of products of their evolution. The theoretically predicted events display a considerable diversity and may include examples of supernovae of types not yet identified observationally. An observational counterpart of an event predicted by the theory may be the unusual explosion detected in M31 by Rich et al. (1989) and Mould et al. (1990). This explosion appears to require the liberation of nuclear energy contained in about 0.01 solar mass of hydrogen-rich matter, or about 10 exp 47 - 10 exp 48 ergs. It is argued that the entire energy range 10 exp 45 (typical supernovae) to 3 x 10 exp 50 ergs (type Ia supernovae) may be filled by events of a qualitatively similar type.