Kepler-428 is an orange K-type dwarf (about 0.87 solar masses, 5,150 K, 0.80 solar radii), 686 light-years from Earth. Kepler-428 b is a 1.27-Jupiter-mass companion, with an orbital period of 3.5 days, at 0.043 AU from its star, and an equilibrium temperature near 1,070 K, on an eccentric orbit (e ≈ 0.22), discovered in 2014 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.