supernova - (n.)

An explosion of a massive star (with mass greater than 8 to 10 times the mass of the Sun) which ejects, at speeds about a tenth the speed of light, most of the original mass into space. The shell of material left behind may form a white dwarf, neutron star, or black hole, a region where gravity is so strong that no radiation or matter can escape. There is a short billionfold increase in luminosity.