Kepler-63 is a Sun-like G-type star (about 0.98 solar masses, 5,576 K, 0.90 solar radii), 194 light-years from Earth. Kepler-63 b is a 0.38-Jupiter-mass companion, with an orbital period of 9.4 days, at 0.080 AU from its star, on an eccentric orbit (e ≈ 0.45), discovered in 2013 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.