Before a new class, W, was invented for Wolf-Rayet stars, those would have been stars of this class, having broad emission lines in their spectra. For a general star of this class, hydrogen lines are 
Before a new class, W, was invented for Wolf-Rayet stars, those would have been stars of this class, having broad emission lines in their spectra. For a general star of this class, hydrogen lines are relatively weak, while ionized helium and highly ionized metals are the most prominent lines due to the extreme heat. Naos, in the Puppis constellation, is a star of this type, emitting most of its radiation in the ultra-violet. A main-sequence star of this class would have a violet color, a temperature of around 40,000 Kelvins, and 500,000 times the Sun's luminosity. For 10 points, what is this spectral class, which contains the hottest and brightest stars?
Before a new class, W, was invented for Wolf-Rayet stars, those would have been stars of this class, having broad emission lines in their spectra.
{O}