A white dwarf is one common kind of stellar “corpse.” Stars of intermediate and low mass tend to end their lives as white dwarfs. As the energy produced by nuclear fusion dwindles and ends in the cores of these stars, they collapse under their own weight until the atoms in the stars’ plasma bump up against one another. Any further collapse of the star is halted by the atoms’ electrons interacting with one another, a condition called electron degeneracy. The collapse concentrates the remaining heat of the dying star into a tiny space, causing the white dwarf to glow white-hot. A white dwarf the mass of the Sun will only be as large as our planet Earth, a shrinkage of about one hundred times in diameter and a million times in volume. One teaspoon of white dwarf star material weighs several tons.