NASA, Neutron Stars Rip Each Other Apart to Form Black Hole

This supercomputer simulation shows one of the most violent events in the universe: a pair of neutron stars colliding, merging and forming a black hole. A neutron star is the compressed core left behind when a star born with between eight and 30 times the sun s mass explodes as a supernova. Neutron stars pack about 1. 5 times the mass of the sun equivalent to about half a million Earths into a ball just 12 miles (20 km) across.