To distinguish between properties of the two major types of supernovae: massive star supernovae and white dwarf supernovae. all supernovae represent the explosions of stars, but current understanding suggests there are two basic types of supernovae: one that occurs when a massive star reaches the end of its life, and the other that occurs when a white dwarf star explodes because its mass has exceeded the white dwarf limit (also called the chandrasekhar limit) of 1.4 solar masses.