HATS-61 is a Sun-like G-type star (about 1.08 solar masses, 5,542 K, 1.66 solar radii), 680 light-years from Earth. HATS-61 b is a 3.40-Jupiter-mass companion, with an orbital period of 7.8 days, at 0.079 AU from its star, and an equilibrium temperature near 1,226 K, on an eccentric orbit (e ≈ 0.09), discovered in 2018 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.