WISE J1147−2040

WISEA J114724.10−204021.3 is a sub-brown dwarf or rogue planet in the TW Hydrae association, a nearby group of very young stars and brown dwarfs. The object is notable because its estimate mass, times the mass of Jupiter, places it in the mass range for rogue planets. As such, it is a free-floating object, unassociated with any star system.
The object was discovered using information from NASA's Wide-field [Infrared Survey Explorer|WISE] and the 2MASS. Researchers inferred the young age for WISEA 1147 because it is a member of a group of stars that is only 10 million years old, and they estimated its mass using evolutionary models for brown dwarf cooling.