K2-260 b: A hot Jupiter transiting an F star, and K2-261 b: A warm Saturn around a bright G star

M. C. Johnson, F. Dai, A. B. Justesen, D. Gandolfi, A. P. Hatzes, G. Nowak, M. Endl, W. D. Cochran, D. Hidalgo, N. Watanabe, H. Parviainen, T. Hirano, S. Villanueva, J. Prieto-Arranz, N. Narita, E. Palle, E. W. Guenther, O. Barragán, T. Trifonov, P. NiraulaP. J. MacQueen, J. Cabrera, Sz Csizmadia, Ph Eigmüller, S. Grziwa, J. Korth, M. Pätzold, A. M.S. Smith, S. Albrecht, R. Alonso, H. Deeg, A. Erikson, M. Esposito, M. Fridlund, A. Fukui, N. Kusakabe, M. Kuzuhara, J. Livingston, P. Montañes Rodriguez, D. Nespral, C. M. Persson, T. Purismo, S. Raimundo, H. Rauer, I. Ribas, M. Tamura, V. Van Eylen, J. N. Winn

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

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 MP = 1.42-0.32 +0.31 MJ and RP = 1.552-0.057 +0.048 RJ. 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 Ag ~ 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, MP = 0.223 ± 0.031 MJ, and RP = 0.850-0.022 +0.026 RJ, 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.

Original languageEnglish (US)
Pages (from-to)596-612
Number of pages17
JournalMonthly Notices of the Royal Astronomical Society
Volume481
Issue number1
DOIs
StatePublished - Nov 21 2018

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Keywords

  • K2-261 b
  • Planets and satellites: detection
  • Planets and satellites: individual: K2-260 b

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    Johnson, M. C., Dai, F., Justesen, A. B., Gandolfi, D., Hatzes, A. P., Nowak, G., Endl, M., Cochran, W. D., Hidalgo, D., Watanabe, N., Parviainen, H., Hirano, T., Villanueva, S., Prieto-Arranz, J., Narita, N., Palle, E., Guenther, E. W., Barragán, O., Trifonov, T., ... Winn, J. N. (2018). K2-260 b: A hot Jupiter transiting an F star, and K2-261 b: A warm Saturn around a bright G star. Monthly Notices of the Royal Astronomical Society, 481(1), 596-612. https://doi.org/10.1093/mnras/sty2238