ETYM Latin, fem. sing. of novus new.
A star that ejects some of its material in the form of a cloud and become more luminous in the process.
Star suddenly increasing in brightness for short time.
Faint star that suddenly erupts in brightness by 10,000 times or more. Novae are believed to occur in close binary star systems, where gas from one star flows to a companion white dwarf. The gas ignites and is thrown off in an explosion at speeds of 1,500 kps/930 mps or more. Unlike a supernova, the star is not completely disrupted by the outburst. After a few weeks or months it subsides to its previous state; it may erupt many more times.
The name comes from the Latin “new”, although novae are not new stars at all.