HAT-P-8 is a Sun-like F-type star (about 1.27 solar masses, 6,200 K, 1.57 solar radii), 212 light-years from Earth. HAT-P-8 b is a 1.28-Jupiter-mass companion, with an orbital period of 3.1 days, 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. The planet's large radius (15.7 Earth radii) indicates a bloated atmosphere heated by intense stellar radiation.