WASP-10 is an orange K-type dwarf (about 0.75 solar masses, 4,675 K, 0.70 solar radii), 141 light-years from Earth. WASP-10 b is a 3.15-Jupiter-mass companion, with an orbital period of 3.1 days, at 0.038 AU from its star, and an equilibrium temperature near 1,370 K, discovered in 2008 via transit. The inner world is a hot Jupiter — a gas giant hugging its star at a fraction of Mercury's distance — a class that forced astronomers to rethink how giant planets form and migrate inward.