WASP-19 is a Sun-like G-type star (about 0.96 solar masses, 5,616 K, 1.01 solar radii), 268 light-years from Earth. WASP-19 b is an ultra-short-period hot Jupiter whose orbit is decaying under tidal drag from the star. WASP-19 b is a 1.15-Jupiter-mass companion, with an orbital period of 18.9 hours, at 0.017 AU from its star, and an equilibrium temperature near 2,113 K, discovered in 2009 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.