Black dwarf

Definition

A black dwarf is a theoretical stellar remnant that results when a white dwarf has cooled sufficiently that it no longer emits significant heat or light. It represents the final evolutionary stage of low-mass stars.

5 Must Know Facts For Your Next Test

1. Black dwarfs are predicted to form from white dwarfs over a timescale longer than the current age of the universe.
2. A black dwarf will have a mass similar to that of the original white dwarf, typically around 0.6 to 1.4 solar masses.
3. They do not emit light and are therefore invisible to direct observation with current technology.
4. The formation process involves the gradual cooling and crystallization of a white dwarf over billions of years.
5. No black dwarfs currently exist because not enough time has passed since the universe's formation for any white dwarf to cool into one.

Review Questions

Related terms

White Dwarf:

A small, dense stellar remnant left after a low-mass star has exhausted its nuclear fuel and shed its outer layers.

Red Giant:

A late evolutionary stage in which a low- or intermediate-mass star expands significantly and cools after exhausting hydrogen in its core.

Planetary Nebula:

An expanding shell of ionized gas ejected from red giant stars late in their life cycle, preceding the formation of a white dwarf.