Internal structure of a white dwarf star, illustration. A white dwarf is the fate that awaits all low-mass stars such as the Sun. They are essentially the remains of the original star's core, compressed to very high densities about a million times that of the original star. They do not generate heat, but remain balanced against gravitational collapse by this high density, which generates a so-called degeneracy pressure. White dwarfs are composed of plasma, a fluid of electrons and neutrons. As they cool, they solidify from the centre outwards, forming a growing core of crystalline material called a body-centric lattice, a cubic-crystal system.