The phenomenon of a star exploding is called a supernova. This dramatic event occurs at the end of a star's life cycle when it exhausts its nuclear fuel, leading to a catastrophic core collapse followed by an explosive ejection of the outer layers. Supernovae are significant astronomical events that can outshine entire galaxies for a short period, and they play a crucial role in enriching the interstellar medium with heavy elements synthesized during the star's life and explosion. They often create neutron stars or black holes depending on the mass of the progenitor star.