The approximate size of brown dwarf TWA 5B (center) compared to Jupiter (right) and the Sun (left). Although brown dwarfs are similar in size to Jupiter, they are much more dense and produce their own light whereas Jupiter shines with reflected light from the Sun. TWA 5B is estimated to be between 15 and 40 times the mass of Jupiter, making it one of the least massive brown dwarfs known. (Credit: NASA/CXC/M.Weiss)
