HATS-1 is a Sun-like G-type star (about 0.99 solar masses, 5,870 K, 1.04 solar radii), 284 light-years from Earth. HATS-1 b is a 1.85-Jupiter-mass companion, with an orbital period of 3.4 days, at 0.044 AU from its star, and an equilibrium temperature near 1,359 K, on an eccentric orbit (e ≈ 0.12), discovered in 2012 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.