WASP-123 is a Sun-like G-type star (about 1.17 solar masses, 5,740 K), 198 light-years from Earth. WASP-123 b is a planet with 15.1 Earth radii, and an equilibrium temperature near 1,500 K, discovered in 2016 via transit. The planet was found when it crossed the face of its star, producing periodic dips in brightness that reveal its size and orbital period to space-based photometry. The planet's large radius (15.1 Earth radii) indicates a bloated atmosphere heated by intense stellar radiation. With an equilibrium temperature around 1,500 K, the dayside atmosphere is hot enough to vaporise many common minerals.