THE SUPERNOVA SHOCK .6.

The supernova shock originates from the convective region and breaks o ut at about 300 km. The driving force is the recombination of nucleons into alpha-particles. The net energy per gram available for the shock is estimated. Matter accumulates in the convective region by accretio n; the density of this matter can be calculated from the density and v elocity of the matter falling in from the outside. From these argument s the energy given originally to the shock is estimated to be about 1 foe, in rough agreement with observation. It is speculated that this e nergy does not depend much on the mass of the progenitor.