PH1 is a Sun-like F-type star (about 1.53 solar masses, 6,407 K, 1.73 solar radii), 1,033 light-years from Earth. PH1 (Kepler-64 b) is a circumbinary planet in a quadruple star system, found by citizen scientists in the Planet Hunters project. PH1 b is a 0.53-Jupiter-mass companion, with an orbital period of 138 days, at 0.652 AU from its star, and an equilibrium temperature near 481 K, on an eccentric orbit (e ≈ 0.07), discovered in 2012 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. PH1 b circles its star within the inner habitable zone.