HATS-23 is a Sun-like G-type star (about 1.12 solar masses, 5,780 K, 1.20 solar radii), 639 light-years from Earth. HATS-23 b is a 1.47-Jupiter-mass companion, with an orbital period of 2.2 days, at 0.034 AU from its star, and an equilibrium temperature near 1,654 K, on an eccentric orbit (e ≈ 0.11), discovered in 2017 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.