Supernova

Eventually the massive star's core collapses rapidly and the star explodes as a supernova. The remnant of the core may become a neutron star or, if sufficiently massive, a black hole. A supernova is not a stage in the Sun-sized star's life cycle.

Without sufficient support from fusion, gravity makes the core collapse very rapidly. This collapse leads to a vast explosion called a supernova, which throws the star's outer layers into space. The explosion is not the final remnant: a highly compressed core remains.

After further stages of fusion, its core collapses and its outer layers are expelled in a supernova. The remaining core may be a neutron star or, for a sufficiently massive star, a black hole. The Sun is not massive enough to follow this route.