HATS-15 b and HATS-16 b: Two massive planets transiting old G dwarf stars
Ciceri et al
We report the discovery of HATS-15 b and HATS-16 b, two massive transiting extrasolar planets orbiting evolved (∼10 Gyr) main-sequence stars. The planet HATS-15 b, which is hosted by a G9V star (V=14.8 mag), is a hot Jupiter with mass of 2.17±0.15MJ and radius of 1.105±0.0.040RJ, and completes its orbit in nearly 1.7 days. HATS-16 b is a very massive hot Jupiter with mass of 3.27±0.19MJ and radius of 1.30±0.15RJ; it orbits around its G3 V parent star (V=13.8 mag) in ∼2.7 days. HATS-16 is slightly active and shows a periodic photometric modulation, implying a rotational period of 12 days which is unexpectedly short given its isochronal age. This fast rotation might be the result of the tidal interaction between the star and its planet.