HAT-P-64 is a Sun-like F-type star (about 1.30 solar masses, 6,457 K, 1.74 solar radii), 652 light-years from Earth. HAT-P-64 b is a 0.58-Jupiter-mass companion, with an orbital period of 4.0 days, at 0.054 AU from its star, and an equilibrium temperature near 1,766 K, on an eccentric orbit (e ≈ 0.10), 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.