O-type star

An O-type star (O) is a star within the O-class, a spectral class indicating stars with ionized helium absorption lines, a blue color, and a surface temperature above 30,000 K. The spectral energy distribution (SED) peaks in the XEUV range. Main sequence stars of this class are on the order of 50 solar masses, 10 solar radii, and 100,000 times solar luminosity. Such main sequence stars burn their hydrogen in a few million years. Characteristics of O-type main sequence stars:

There are also giant stars and white dwarfs that fall under the O-class. Examples of O-type stars are Mu Columbae (spectral type O9.5 V) and Mu Normae (a supergiant, spectral type O9.7Iab).