2018MNRAS.481..596J

We present the discovery and confirmation of two new transiting giant planets from the Kepler extended mission K2. K2-260 b is a hot Jupiter transiting a V = 12.7 F6V star in K2 Field 13, with a mass and radius of M_* = 1.39_–0.06^+0.05 M_☉ and R_* = 1.69 ± 0.03 R_☉. The planet has an orbital period of P = 2.627 d, and a mass and radius of M_P=1.42+0.31^_–0.32 M_ J_ and R_P=1.552+0.048^_–0.057 R_ J_. This is the first K2 hot Jupiter with a detected secondary eclipse in the Kepler bandpass, with a depth of 71 ± 15 ppm, which we use to estimate a geometric albedo of A_g ∼ 0.2. We also detected a candidate stellar companion at 0.6 arcsec from K2-260; we find that it is very likely physically associated with the system, in which case it would be an M5-6V star at a projected separation of ∼400 au. K2-261 b is a warm Saturn transiting a bright (V = 10.5) G7IV/V star in K2 Field 14. The host star is a metal rich ([Fe/H] = 0.36 ± 0.06), mildly evolved 1.10_–0.02^+0.01 M_☉ star with R_* = 1.65 ± 0.04 R_☉. Thanks to its location near the main-sequence turn-off, we can measure a relatively precise age of 8.8_–0.3^+0.4 Gyr. The planet has P = 11.633 d, M_P = 0.223 ± 0.031 M_ J_, and R_P=0.850+0.026^_–0.022 R_ J_, and its orbit is eccentric (e=0.39 ±0.15). Its brightness and relatively large transit depth make this one of the best-known warm Saturns for follow-up observations to further characterize the planetary system.