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.; Jordán, A.; Csubry, Z.; de Val-Borro, M.; Bhatti, W.; Rabus, M.; Espinoza, N.; Suc, V.; Schmidt, Brian; 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.; Lázár, J.; Papp, I.; Sari, P.

HATS-15b and HATS-16b: two massive planets transiting old G dwarf stars

Date

2016-07

Authors

Ciceri, S.

Mancini, L.

Henning, T.

Bakos, G.

Penev, K.

Brahm, R.

Zhou, G.

Hartman, J. D.

Bayliss, D.

Jordán, A.

Publisher

IOP Publishing

Abstract

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 G9 V star (V = 14.8 mag), is a hot Jupiter with mass of 2.17 ± 0.15 MJ and radius of 1.105 ± 0.040 RJ, 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 MJ and radius of 1.30 ± 0.15 RJ; 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.