What term describes the explosive death of a massive star?

The term that describes the explosive death of a massive star is a supernova. A supernova occurs when a star exhausts its nuclear fuel and can no longer support itself against gravitational collapse. The core of the star collapses, and the outer layers are expelled at tremendous velocity, creating a brilliant explosion that outshines entire galaxies for a short period.

This event is significant not only for its dramatic nature but also for its role in the universe: supernovae are responsible for creating and dispersing heavy elements throughout space, which can contribute to the formation of new stars and planets. The immense energy released during a supernova can lead to different end states for the star, including the formation of a neutron star or a black hole, depending on its original mass.

In contrast, a black hole is an end state that may form after the supernova explosion, as is a neutron star, which is a dense remnant left behind if the core's mass is within a certain range. A red giant is a phase in a star's life cycle before it potentially becomes a supernova and does not describe the explosive death itself. Therefore, supernova is the term that accurately represents the violent and energetic end of a massive star's life cycle.