An object too small to be an ordinary star because it cannot produce enough energy by fusion in its core to compensate for the radiative energy it loses from its surface. A brown dwarf has a mass less [..]

An object too small to be an ordinary star because it cannot produce enough energy by fusion in its core to compensate for the radiative energy it loses from its surface. A brown dwarf has a mass less [..]

A kind of 'failed' star: a small and opaque object whose mass is not sufficient to start, in its core, the nuclear reaction to transform hydrogen into helium. A brown dwarf cannot therefore produce enough energy to shine as a star. A brown dwarf's mass is not more than 0.08 solar masses.

A low-luminosty object with a mass that is intermediate between that of a star and a giant planet. With a mass of about 1-8% of the Sun, a brown dwarf is too small to ignite the thermonuclear fusion that defines a star. A theoretical entity until 1995, hundreds of these cool objects have been discovered in recent years.

(n.) An object substantially (~13 x) larger than Jupiter but with a mass no more than 40 percent that of the Sun. These objects are not big enough for gravitational collapse to heat them to the point [..]

is a cold and dark star too small to initiate nuclear reactions that generate heat and light.

An object too small to be an ordinary star because it cannot produce enough energy by fusion in its core to compensate for the radiative energy it loses from its surface. A brown dwarf has a mass less than 0.08 times that of the Sun.

Star whose mass is too low for hydrogen fusion to take place.