A supernova is a powerful stellar explosion that has a galactic-level luminosity. It occurs during the last evolutionary stages of a massive star (> 8 solar masses). The original star either collapses to a neutron star or black hole, or is completely destroyed. It's triggered by a sudden gravitational collapse of a massive star's core which causes a runaway nuclear fusion.
Supernovae can expel huge amounts of material at high speeds, creating shock waves, elements from oxygen to rubidium, cosmic rays, and gravitational waves. 99% of a supernova’s energy is carried away by neutrinos, not light or heat.
| Nova | Energy release |
|---|---|
| Nova | 1037 W |
| Kilonova | 1038 W |
| Supernova | 1044 W |
| Hypernova | 1045 W |