What is a white darf star?

Answer 1

A white dwarf star is a small, dense remnant of a star that has exhausted its nuclear fuel and shed its outer layers, typically after undergoing a red giant phase. It primarily consists of carbon and oxygen, supported against gravitational collapse by electron degeneracy pressure. White dwarfs are usually about the size of Earth but contain a mass comparable to that of the Sun. Over billions of years, they gradually cool and fade, eventually becoming cold, dark remnants known as black dwarfs.