Transcript: Supernovae are key players in the cycle of star birth and death. Supernovae recycle elements into the medium between stars and so provide vital ingredients for planet building and for life itself. Supernovae can also trigger the collapse of a gas cloud and so generate the birth of a new generation of stars. What’s left behind after the explosion? It’s possible that nothing is left behind in some cases, that the entire star is disrupted in the detonation. However, it is also possible to form collapsed objects that are among the most bizarre beasts in astronomy.