K2-287 b: An Eccentric Warm Saturn Transiting a G-dwarf

Jordan, Andres; Brahm, Rafael; Espinoza, Nestor; Cortes, Cristian; Diaz, Maths; Drass, Holger; Henning, Thomas; Jenkins, James S.; Jones, Matias, I; Rabus, Markus; Rojas, Felipe; Sarkis, Paula; Vuckovic, Maja; Zapata, Abner; Soto, Maritza G.; Bakos, Gaspar A.; Bayliss, Daniel; Bhatti, Waqas; Csubry, Zoltan; Lachaume, Regis; Moraga, Victor; Pantoja, Blake; Osip, David; Shporer, Avi; Suc, Vincent; Vasquez, Sergio
2019
ASTRONOMICAL JOURNAL
DOI
10.3847/1538-3881/aafa79
We report the discovery of K2-287b, a Saturn mass planet orbiting a G-dwarf with a period of P approximate to 15 days. First uncovered as a candidate using K2 campaign 15 data, follow-up photometry and spectroscopy were used to determine a mass M-p = 0.317 +/- 0.026 M-J, radius R-p = 0.833 +/- 0.013 R-J, period P = 14.893291 +/- 0.000025 days, and eccentricity e = 0.476 +/- 0.026. The host star is a metal-rich V = 11.410 +/- 0.129 mag G-dwarf for which we estimate a mass M-* = 1.056(-0.021)(+0.022) M-circle dot, radius R-* = 1.070 +/- 0.010 R-circle dot, metallicity [Fe/H] = 0.20 +/- 0.05, and T-eff = 5673 +/- 75 K. This warm eccentric planet with a time-averaged equilibrium temperature of T-eq approximate to 800 K adds to the small sample of giant planets orbiting nearby stars whose structure is not expected to be affected by stellar irradiation. Follow-up studies on the K2-287 system could help constrain theories of planet migration in close-in orbits.