Aug. 4, 2015

Astronomers from the University of Geneva (UNIGE) and members of the NCCR PlanetS have teased out a secret planetary system hiding in the arms of Cassiopea, just 21 light years away from us. The remarkable system, named HD219134, hosts one outer giant planet and three inner super-Earths, one of which transits in front of the star. The transiting super-Earth has a density similar to the Earth’s. It is by far the closest transiting planet known today. It provides the ideal candidate for follow-up studies and a deeper understanding of planetary formation, internal composition, and atmospheres. The system is so close that astronomers already dream about taking pictures of the new “Stars”.