# Mechanics of Supernovae

Where does the energy from a supernova come from?

My understanding is that the iron core collapses into a large ball of neutrons - is that effectively a star-sized nuclear explosion? What is the reaction product called?

Why does the effect go supercritical, instead of finding some equilibrium rate of burn? I've read discussion that the reaction energy does not appear to be enough to explain the energy seen in a supernova? How big is the gap?

The collapse occurs because electron degeneracy pressure is circumvented by neutronisation (inverse beta decay), which removes electrons from the gas. At that point, the collapse occurs on a freefall time of $<1$ second. There is no "burn-rate" as such; just a collapse and then a "core bounce" as the equation of state hardens because of neutron degeneracy pressure and the strong nuclear force between closely packed neutrons.