A device that measures the resistance of an electrical circuit to the flow of electricity. Cool, and becoming a dead, black body, it is nevertheless extremely dense. A typical white dwarf has 60 percent of the Sun's mass but is little larger than the Earth. But no white dwarf is visible to the naked eye. When the Sun becomes a white dwarf, its radius will be about 0.01 of its present radius.
White dwarfs have relatively low rotational velocities.
Faint very-compact stars at the end of their life. Also used as convenient photometric and flux standards. Some RR Lyrae stars are white giants. The time-reversal of a black hole. A white hole is a singularity from which matter emerges unpredictably, but into which matter cannot enter.