Speculative illustration of a ringed brown dwarf. On the upper left is a loose cluster of young blue stars. This brown dwarf is 13 to 65 times more massive than the planet Jupiter while its diameter is only slightly greater than Jupiter's due to its greater density. The brown dwarf emits a dim magenta glow, a result of lithium and/or deuterium fusion. Stars courtesy NASA/Goddard Space Flight Center Scientific Visualization Studio.