WASP-38 is a Sun-like F-type star (about 1.76 solar masses, 6,180 K, 1.52 solar radii), 136 light-years from Earth. WASP-38 b is a 3.44-Jupiter-mass companion, with an orbital period of 6.9 days, discovered in 2010 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. The planet's large radius (13.8 Earth radii) indicates a bloated atmosphere heated by intense stellar radiation.