HATS-15b and HATS-16b: Two Massive Planets Transiting Old G Dwarf Stars

Ciceri, S.; Mancini, L.; Henning, T.; Bakos, G.; Penev, K.; Brahm, R.; Zhou, G.; Hartman, J. D.; Bayliss, D.; Jordan, A.; Csubry, Z.; de Val-Borro, M.; Bhatti, W.; Rabus, M.; Espinoza, N.; Suc, V.; Schmidt, B.; Noyes, R.; Howard, A. W.; Fulton, B. J.; Isaacson, H.; Marcy, G. W.; Butler, R. P.; Arriagada, P.; Crane, J. D.; Shectman, S.; Thompson, I.; Tan, T. G.; Lazar, J.; Papp, I.; Sari, P.
2016
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
DOI
10.1088/1538-3873/128/965/074401
We report the discovery of HATS-15 b and HATS-16 b, two massive transiting extrasolar planets orbiting evolved (similar to 10 Gyr) main-sequence stars. The planet HATS-15 b, which is hosted by a G9 V star (V = 14.8 mag), is a hot Jupiter with mass of 2.17 +/- 0.15 M-J and radius of 1.105 +/- 0.040 R-J, and it completes its orbit in about 1.7 days. HATS-16 b is a very massive hot Jupiter with mass of 3.27 +/- 0.19 M-J and radius of 1.30 +/- 0.15 R-J; it orbits around its G3 V parent star (V = 13.8 mag) in similar to 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.