# Supernovae and black holes?

I think i am correct in saying that a supernova ($Type$ $II$) is caused by the collapse of the core of a giant star. This contraction of the core is stopped by the Pauli exclusion principle and the core becomes rigid. The outer layers now rebound of the rigid core and are thrown into space as a supernovae. But presumably this leaves behind a neutron star and not a black hole. For a black hole to form the Pauli exclusion principle would not be strong enough to stop the collapse? If so what causes the outer layers to rebound, as there is no ridged object for them to rebound off? What I am basically asking is when a black hole forms what mechanism causes the supernovae?

• Take a look at the table here on Wikipedia. It is slightly more speculative than it advertises, but you can see that most blace-hole-forming scenarios do not lead to SNe. Some may lead to GRBs, but these are powered by jets rather than spherical shocks. – user10851 May 3 '14 at 22:50