HAT-P-27 is a Sun-like G-type star (about 0.92 solar masses, 5,316 K, 0.86 solar radii), 199 light-years from Earth. HAT-P-27 b is a 0.62-Jupiter-mass companion, with an orbital period of 3.0 days, at 0.040 AU from its star, discovered in 2011 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. HAT-P-27 b skims its star closer than Mercury orbits the Sun.