B-type star

…luminosity of all O and B stars. This energy output is about equal to the total power provided by supernovae, but the latter radiate most of their energy either in nonionizing radiation or in providing kinetic energies to their expanding shells. Other potential energy sources fall far short.

…very hot blue-white O and B types (some of which are less than 1,000,000 years old), are designated as extreme Population I objects. All known Population I members occur near and in the arms of the Milky Way system and other spiral galaxies. They also have been detected in some…

The hot B-type stars, such as Epsilon Orionis, are characterized by lines of helium and of singly ionized oxygen, nitrogen, and neon. In very hot O-type stars, lines of ionized helium appear. Other prominent features include lines of doubly ionized nitrogen, oxygen, and carbon and of triply…

…of spectral types O and B. They have absolute luminosities as bright as any star in the Galaxy—on the order of one million times the luminosity of the Sun. Such stars have very short lifetimes, only lasting a few million years. With luminous stars of this type there need not…

Class B stars typically range from 10,000 K to 25,000 K and are also bluish white but show neutral helium lines. The surface temperatures of A-type stars range from 7,400 K to about 10,000 K; lines of hydrogen are prominent, and these stars are white.…