Luminous Blue Variable Nebula

LBV's are very massive stars going through a brief period of extreme instability as they run out of nuclear fuel in their cores. They undergo huge outburst where they brighten dramatically and blast off several times the sun's mass from their surfaces, which their ultraviolet radiation then lights up from within. They are among the most luminous stars in the Universe with luminosities frequently exceeding 1,000,000x that of the Sun's; HST image of AG Carinae used as a reference image.