HATS-27 is a Sun-like F-type star (about 1.42 solar masses, 6,438 K, 1.74 solar radii), 817 light-years from Earth. HATS-27 b is a 0.53-Jupiter-mass companion, with an orbital period of 4.6 days, at 0.061 AU from its star, and an equilibrium temperature near 1,659 K, on an eccentric orbit (e ≈ 0.58), discovered in 2016 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.