TOI-3980 is a Sun-like G-type star (about 1.24 solar masses, 5,840 K, 1.63 solar radii), 487 light-years from Earth. TOI-3980 b is a 0.59-Jupiter-mass companion, with an orbital period of 3.6 days, at 0.049 AU from its star, and an equilibrium temperature near 1,621 K, on an eccentric orbit (e ≈ 0.16), discovered in 2025 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.