What is a black dwarf?

A black dwarf is a theoretical celestial object that could result from a white dwarf star, the final stage in the life cycle of most stars. White dwarfs are very dense and hot, but eventually cool and fade away over time. The process of a white dwarf cooling down and becoming a black dwarf is estimated to take trillions of years.

Black dwarfs are considered to be the final stage of stellar evolution, where all the available energy in a star has been expended and the object has cooled to the point where it no longer emits heat or light. Due to the immense length of time it takes for a white dwarf to cool to the point of becoming a black dwarf, none are believed to exist in the universe at present.

The concept of a black dwarf is a recent one, and has only been theorized in recent decades by astronomers. It is considered to be a possible end point for most stars, although some stars may not be massive enough to form a white dwarf, and may end their lives as different types of celestial objects, such as a neutron star or a black hole.