Supernova

A supernova is a stellar explosion that produces an extremely bright object made of plasma that declines to invisibility over weeks or months. There are several different types of supernovae and two possible routes to their formation. A massive star may cease to generate fusion energy from fusing the nuclei of atoms in its core and collapse inward under the force of its own gravity to form a neutron star or black hole, or a white dwarf star may accumulate material from a companion star until it nears its Chandrasekhar limit and undergoes runaway nuclear fusion in its interior, completely disrupting it (note that this should not be confused with a surface thermonuclear explosion on a white dwarf called a nova). In either case, the resulting supernova explosion expels much or all of the stellar material with great force.
The explosion drives a blast wave into the surrounding space, forming a supernova remnant. One famous example of this process is the remnant of SN 1604, shown to the right.
"Nova" (pl. novae) is Latin for "new", referring to what appears to be a very bright new star shining in the celestial sphere; the prefix "super" distinguishes this from an ordinary nova, which also involves a star increasing in brightness, though to a lesser extent and through a different mechanism. However, it is misleading to consider a supernova as a new star, because it really represents the death of a star (or at least its radical transformation into something else).