whitedwarf

A white dwarf is a stellar core remnant, a type of compact star. After a star like our Sun exhausts its nuclear fuel, it sheds its outer layers and the remaining core collapses under its own gravity. This collapsed core, typically about the size of Earth but with a mass similar to the Sun, is a white dwarf. It is incredibly dense, with a teaspoon of white dwarf material weighing several tons. White dwarfs no longer generate energy through nuclear fusion; instead, they slowly cool down over billions of years, eventually becoming cold, dark objects called black dwarfs. They are composed primarily of electron-degenerate matter, meaning electrons are packed so tightly that they resist further compression. The pressure of these degenerate electrons is what supports the white dwarf against gravitational collapse. White dwarfs are common astronomical objects, and many are found in binary systems, where they can accrete matter from a companion star. This accretion can lead to powerful outbursts known as novae, or in extreme cases, a Type Ia supernova.