Astronomy
The Moon
Dwarf Stars

Why do white dwarfs have a lower luminosity than the sun?

Answer

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Wiki User
12/09/2009

White Dwarfs are degenerate stars. They are created when the host star has exhausted it's supply of hydrogen. Its luminosity comes from the emission of stored thermal energy, it has no other means of energy as all fusion has ceased nor can it generate any energy from gravitational collapse.

A white dwarf is very hot when it is formed, but as it has no source of energy, it will gradually cool down. This means that in time it will lessen and redden with time and eventually cool to become a black dwarf.