HAT-P-33 is a Sun-like F-type star (about 1.82 solar masses, 6,446 K, 1.79 solar radii), 396 light-years from Earth. HAT-P-33 b is a 0.92-Jupiter-mass companion, with an orbital period of 3.5 days, discovered in 2011 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 (20.7 Earth radii) indicates a bloated atmosphere heated by intense stellar radiation.