gravitational collapse
Gravitational collapse is the process by which material is drawn together as a result of its mutual gravitational attraction. Each particle of the in-falling mass is accelerated toward the center of collapse and so gains kinetic energy which is generally manifested as pressure. Once this pressure has reached a certain level, it halts any further collapse; the stabilized object can then dispose of excess energy by radiating it into space.
Gravitational collapse is the essential precursor to the formation of stars from interstellar clouds and is also the dominant process in the closing stages of stellar evolution when white dwarfs, neutron stars, and black holes form.