TOI-1259 A is an orange K-type dwarf (about 0.75 solar masses, 4,775 K, 0.71 solar radii), 118 light-years from Earth. TOI-1259 A b is a 0.44-Jupiter-mass companion, with an orbital period of 3.5 days, at 0.041 AU from its star, discovered in 2021 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. TOI-1259 A b skims its star closer than Mercury orbits the Sun.