LUMINOUS BLUE VARIABLE

'Luminous blue variables', also known as 'S Doradus variables', are extraordinarily rare, very bright and massive hypergiant variable stars. They exhibit long, slow changes in brightness, punctuated by occasional outbursts. They can shine millions of times brighter than the Earth's Sun and with masses up to 150 times that of the Sun, they are thought to approach the theoretical upper limit for stellar mass. With masses this large, they burn out very quickly, in only a few million years. If they were any larger they would blow themselves apart; indeed Eta Carinae appears to be doing exactly that and will explode in a hypernova within the next million years.
Current theory [1] holds that LBVs are a stage in the evolution of very massive stars required for them to shed excess mass. They may evolve to Wolf-Rayet Stars before going supernova.
Examples of luminous blue variables include:

★ Eta Carinae

★ Pistol Star

★ LBV 1806-20

★ P Cygni

★ S Doradus

★ HD 269850=R127

★ HD 269006=R71

★ AG Carinae

★ Wray 17-96

★ AF Andromedae

★ AE Andromedae

★ HD 5980