THE BAKERIAN LECTURE, 1993. - MECHANISM OF SUPERNOVAE

Supernovae of type II happen at the end of the evolution of massive st ars, 10 times the mass of the Sun, M., or more. To begin with, the cen tral core, of mass about 1.5 M., collapses; the large gravitational en ergy 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 abs orbed in the mantle of the star, i.e. the region 100 or 500 km from th e centre; this drives the shock. It is essential that vigorous convect ion occurs in the shocked material. With reasonable assumptions, one c an estimate the energy in the shock to be of the order 10(51)erg, in a greement with observation. The argument is based on observation and an alytical calculations, with a minimum of help from elaborate computati ons.