Nova
A nova is the explosion of a star. A very important nova is a supernova.
At the end of its life, depending of its power, of its size, of its external and internal temperatures, the star will create a red giant star, a nova or a supernova
Websites of the CNRS http://cdfinfo.in2p3.fr/Culture/Supernovae/ and of the NASA http://imagine.gsfc.nasa.gov/docs/science/know_l2/supernovae.html are very well documented in this subject.
See also back hole, sun, supernova
Related web site: http://chandra.harvard.edu/xray_sources/supernovas.html