Is the final stage of a star a white dwarf or a black hole?

Answer 1

A black hole may only occur at the end of the life of a very massive star. Most other stars will collapse into a dense White dwarf, which will gradually become a black dwarf star over many billions of years.

Answer 2

The black hole stage in stellar evolution is at the end of a star's life when its fuel is exhausted, and it no longer has the outward pressure from heat originating in the core caused by fusion processes, and begins to collapse under its own gravity. Normally it would reach a limit owing to the Pauli exclusion principle at the white dwarf stage (electron degeneracy pressure) and stop as a white dwarf and halt its inward collapse; however if its mass is too great it will exceed the outward pressure (Chandrasekhar limit) and continue to collapse until it hits the neutron star stage, where its inward collapse is limited by nucleon degeneracy pressure (O-V limit).. however, if its mass creates gravity which exceeds the outward pressure at this stage, it will continue to collapse (and perhaps become a quark star, limited by quark degeneracy pressure, although the precise mechanics are not fully understood) and become a black hole, with a singularity of infinite density and escape velocity which exceeds the speed of light.

The process of star collapse is herein simplified - there may be many stages where the star during its collapse will throw off mass typically in the form of a portion of its gas envelope because of instability, (supernova explosion), etc, yet still have sufficient leftover mass to have a remnant like a black hole.

Answer 3

The final stage of a star is a white dwarf. The white dwarf condenses into a diamond(carbon).