HAT-P-63 is a Sun-like G-type star (about 0.93 solar masses, 5,400 K, 0.97 solar radii), 403 light-years from Earth. HAT-P-63 b is a 0.61-Jupiter-mass companion, with an orbital period of 3.4 days, at 0.043 AU from its star, and an equilibrium temperature near 1,237 K, on an eccentric orbit (e ≈ 0.07), discovered in 2021 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.