Within about 0.1 second, the core collapses.
After about 0.5 second, the collapsing envelope interacts with the outward shock. Neutrinos are emitted.
Within 2 hours, the envelope of the star is explosively ejected. When the photons reach the surface of the star, it brightens by a factor of 100 million.
Over a period of months, the expanding remnant emits X-rays, visible light and radio waves in a decreasing fashion.
