WASP-63 is a Sun-like G-type star (about 1.28 solar masses, 5,550 K, 1.86 solar radii), 291 light-years from Earth. WASP-63 b is a 0.37-Jupiter-mass companion, with an orbital period of 4.4 days, discovered in 2012 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 (15.8 Earth radii) indicates a bloated atmosphere heated by intense stellar radiation.