O-type stars or hot, blue-white stars, are really amazing. They have temperatures that go higher than 30,000 K (kelvin) . Stars like this are very rare, but since they are extremely bright, they can be seen at great distances. Did you know, that 4 of the 90 brightest stars that can be seen from earth are O-type stars. Because they are so huge in mass, their lives are quite short, and usually end in a violent supernova explosion resulting in black holes, or neutron stars. They emit intense ultraviolet light, and so appear to us as bluish-white.
Rigel is a blue star whose home is in the constellation of Orion approximately 860 light-years away from us. It is also the brightest. It is calculated to be anywhere from 61,500 to 363,000 times as luminous as the Sun, and 18 to 24 times as massive. Its radius is over 70 times that of the sun, and its surface temperature is 12,100 K. Rigel's mass-loss due to its steller wind is estimated to be 10 million times more than that of the Sun.