WASP-16 is a Sun-like G-type star (about 1.78 solar masses, 5,700 K, 1.14 solar radii), 194 light-years from Earth. WASP-16 b is a 1.24-Jupiter-mass companion, with an orbital period of 3.1 days, discovered in 2009 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. The planet's large radius (13.7 Earth radii) indicates a bloated atmosphere heated by intense stellar radiation.