More brown dwarf news came out of the last press conference: the masses of some of the lowest mass brown dwarfs have been found using the powerful Keck telescope in Hawaii. They did this by precisely measuring the orbits of binary brown dwarfs, and from the well-known equations of how bodies orbit one another the masses were found.
Amazingly, one binary system (2MASS 1534-2952AB) appears to be comprised of two brown dwarfs each of which have only 3% the mass of the Sun! This makes them the lowest mass and coldest objects (outside of extrasolar planets orbiting other stars) for which a mass has been found. Another binary (HD 130948BC) was measured as well, and each star has a mass of 5.5% the mass of the Sun -- and as you can see in the image above, this pair orbits a third star which is more like the Sun, which ...
