Supernova
Supernova ->> FORMATION OF A SUPERNOVA The mass of a star determines whether it will end its life in a supernova explosion. During the courses of their lifetimes, all stars convert hydrogen to helium in thermonuclear fusion reactions in their cores. Thermonuclear fusion reactions occur when the intense heat and gravitational force in a star’s nucleus force hydrogen atoms together. The atoms merge, or fuse together, creating helium atoms and releasing large amounts of energy in the form of electromagnetic radiation and heat. Massive stars have faster rates of fusion than smaller stars, so large stars may use up their fuel faster. After most of the hydrogen is used up, a star goes into a carbon-building phase, in which nuclear fusion turns the helium into carbon. After the helium is exhausted, most stars gradually cool until they no longer emit radiation. When a star eight or ten times more massive than the Sun exhausts its helium, however, the nuclear burning cycle is far from com