WASP-23 is an orange K-type dwarf (about 0.78 solar masses, 5,150 K, 0.77 solar radii), 207 light-years from Earth. WASP-23 b is a 0.88-Jupiter-mass companion, with an orbital period of 2.9 days, at 0.038 AU from its star, on an eccentric orbit (e ≈ 0.06), 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.