HATS-11b AND HATS-12b: Two Transiting Hot Jupiters Orbiting Subsolar Metallicity Stars Selected for the K2 Campaign 7

Abstract

We report the discovery of two transiting extrasolar planets from the HATSouth survey. HATS-11, a V = 14.1 G0- star shows a periodic 12.9 mmag dip in its light curve every 3.6192 days and a radial velocity variation consistent with a Keplerian orbit. HATS-11 has a mass of 1.000 0.060  M, a radius of 1.444 0.057  R and an effective temperature of 6060 150  K, while its companion is a 0.85 0.1  2 MJ, 1.510 0.078  RJ planet in a circular orbit. HATS-12 shows a periodic 5.1 mmag flux decrease every 3.1428 days and Keplerian RV variations around a V = 12.8 F-star. HATS-12 has a mass of 1.489 0.071  M, a radius of 2.21 0.21  R, and an effective temperature of 6408 75  K. For HATS-12b, our measurements indicate that this is a 2.38 0.11  MJ, 1.35 0.17  RJ planet in a circular orbit. Both host stars show subsolar metallicities of -0.390 0.060  dex and -0.100 0.040  dex, respectively, and are (slightly) evolved stars. In fact, HATS-11 is among the most metalpoor and, HATS-12, with a  log g of 3.923 0.065  , is among the most evolved stars hosting a hot-Jupiter planet. Importantly, HATS-11 and HATS-12 have been observed in long cadence by Kepler as part of K2 campaign 7 (EPIC216414930 and EPIC218131080 respectively).