An Etymological Dictionary of Astronomy and Astrophysics

The heating of a body that contracts under its own gravity. For a large body like a planet or star, gravity tries to compress the body. This compression heats the core of the body, which results in internal energy which in turn is radiated as → thermal energy. In this way a star could be heated by its own weight.

See also: William Thomson (Lord Kelvin) and Hermann von Helmholtz proposed that the sun derived its energy from the conversion of gravitational potential energy; → mechanism.