Professional astronomers and volunteers from the Planet Hunters citizens science program have discovered a low-mass, low-density exoplanet circling a Sun-like star known as PH3. The artist’s concept depicts a super-Earth-size planet. Image credit: NASA Ames / JPL-Caltech. PH3, also known as Kepler-289, KOI-1353 or KIC 7303287, is a young star located about 2,300 light-years from the Sun. Two planets in the system – Kepler-289b (PH3b) and...
