THE BAKERIAN LECTURE, 1993. - MECHANISM OF SUPERNOVAE

Supernovae of type II happen at the end of the evolution of massive stars, 10 times the mass of the Sun, M., or more. To begin with, the central core, of mass about 1.5 M., collapses; the large gravitational energy remains for a while in the core. It is then released in the form of neutrinos. A small fraction, 1 or 2%, of the neutrino energy is absorbed in the mantle of the star, i.e. the region 100 or 500 km from the centre; this drives the shock. It is essential that vigorous convection occurs in the shocked material. With reasonable assumptions, one can estimate the energy in the shock to be of the order 10(51)erg, in agreement with observation. The argument is based on observation and analytical calculations, with a minimum of help from elaborate computations.