In astrophysics and cosmology, stellar evolution refers to the life history of stars that is driven by the interplay of internal pressure and gravity.

Essentially, throughout the life of a star a tension exists between the compressing force of the star's own gravity and the expanding pressures generated by the nuclear reactions taking place in its core. After cycles of swelling and contraction associated with the burning of progressively heavier nuclear fuels, the star eventually expends its useable nuclear fuel and resumes contraction under the force of its own gravity. There are three possible fates for such a collapsing star. The particular fate for any star is determined by the mass of the star left after blowing away its outer layers.

A star less than 1.44 times the mass of the Sun (termed the Chandrasekhar limit) collapses until the pressure compacted electron clouds exerts enough pressure to...