Fr.: Gl 229B
The prototype of → T dwarfs discovered by Nakajima et al. (1995, Nature 378, 463). This → brown dwarf lies 21.8 → light-years away and orbits a primary star of type M1 V every about 40 years. It has a temperature of less than 1,200 K, and a mass approximately 20-50 times that of Jupiter. Its luminosity is about 2 x 10 -6 that of the Sun.
Gl, referring to the → Gliese catalogue.