Type II Supernova are the coolest. At the end of the high mass star's life, the star experiences a supernova explosion. As protons and electrons fuse to become neutrons/neutrinos, this massive star becomes a neutron star. In Type II Supernovas, "in-falling material hit the neutron star surface generating an intense "supersonic shockwave" that blows the outer parts of the star apart in a Supernova Explosion." Keep in mind all this happens in less than a second.
Super awesome. The flash from the explosions makes the rings glow.