TOI-159 is a Sun-like F-type star (about 1.66 solar masses, 7,287 K, 1.62 solar radii), 348 light-years from Earth. TOI-159 b is a 3.49-Jupiter-mass companion, with an orbital period of 3.8 days, at 0.056 AU from its star, and an equilibrium temperature near 1,891 K, on an eccentric orbit (e ≈ 0.24), discovered in 2026 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.