Luhman 16 is a binary system of two brown dwarfs, located in the southern constellation Vela at a distance of 6.51 light-years from the Sun. These are the closest-known brown dwarfs and the closest system found since the measurement of the proper motion of Barnard's Star in 1916, and the third-closest-known system to the Sun. The primary is of spectral type L7.5 and the secondary of type T0.5±1. The masses of Luhman 16 A and B are 35.4 and 29.4 Jupiter masses, respectively, and their ages are estimated to be 400–800 million years. Luhman 16 A and B orbit each other at a distance of about 3.5 astronomical units with an orbital period of approximately 26.6 years.