universetoday.com
Ultra Cool Star Measured
Using a combination of ground and space-based telescopes, an international team of astronomers have measured the mass of an ultra-cool star and its companion brown dwarf. The star is located 40 light-years away, and contains only 8.5% the mass of the Sun. Its companion brown dwarf is even lighter; only 6% the mass of the Sun. They orbit one another at a distance of only 2.5 times the distance of the Earth and the Sun. Measuring these low mass objects is difficult because there's no relation between their size and brightness. But in a binary system like this, astronomers can determine their mass by measuring how the objects interact with each other.
Fraser Cain