HAT-P-13 is a Sun-like G-type star (about 1.32 solar masses, 5,653 K), 247 light-years from Earth. HAT-P-13 b is a 0.85-Jupiter-mass companion, with an orbital period of 2.9 days, discovered in 2009 via transit. HAT-P-13 c is a 14.3-Jupiter-mass companion, with an orbital period of 1.22 years, on an eccentric orbit (e ≈ 0.66), discovered in 2009 via radial velocity. 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.