Movatterモバイル変換

• Damasso, M.
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• Esposito, M.
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• Nascimbeni, V.
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• Desidera, S.
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• Bonomo, A. S.
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• Bieryla, A.
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• Malavolta, L.
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• Biazzo, K.
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• Sozzetti, A.
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• Covino, E.
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• Latham, D. W.
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• Gandolfi, D.
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• Rainer, M.
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• Petrovich, C.
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• Collins, K. A.
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• Boccato, C.
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• Claudi, R. U.
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• Cosentino, R.
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• Gratton, R.
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• Lanza, A. F.
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• Maggio, A.
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• Micela, G.
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• Molinari, E.
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• Pagano, I.
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• Piotto, G.
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• Poretti, E.
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• Smareglia, R.
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• Di Fabrizio, L.
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• Giacobbe, P.
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• Gomez-Jimenez, M.
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• Murabito, S.
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• Molinaro, M.
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• Affer, L.
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• Barbieri, M.
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• Bedin, L. R.
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• Benatti, S.
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• Borsa, F.
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• Maldonado, J.
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• Mancini, L.
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• Scandariato, G.
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• Southworth, J.
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• Zanmar Sanchez, R.

Abstract

Aims: For more than 1.5 years we spectroscopically monitored the star KELT-6 (BD+31 2447), which is known to host the transiting hot-Saturn KELT-6 b, because a previously observed long-term trend in radial velocity time series suggested that there is an outer companion.
Methods: We collected a total of 93 new spectra with the HARPS-N and TRES spectrographs. A spectroscopic transit of KELT-6 b was observed with HARPS-N, and simultaneous photometry was obtained with the IAC-80 telescope.
Results: We proved the existence of an outer planet with a mininum mass M_psin i = 3.71 ± 0.21 M_Jup and a moderately eccentric orbit (e = 0.21_-0.036^+0.039) of period P ~ 3.5 years. We improved the orbital solution of KELT-6 b and obtained the first measurement of the Rossiter-McLaughlin effect, showing that the planet has a likely circular, prograde, and slightly misaligned orbit with a projected spin-orbit angle of λ = -36 ± 11 degrees. We improved the KELT-6 b transit ephemeris from photometry and provide new measurements of the stellar parameters. KELT-6 appears as an interesting case for studying the formation and evolution of multi-planet systems.

Based on observations made with (i) the HARPS-N spectrograph on the Italian Telescopio Nazionale Galileo (TNG), operated on the island of La Palma by the INAF - Fundacion Galileo Galilei (Spanish Observatory of Roque de los Muchachos of the IAC); (ii) the Tillinghast Reflector Echelle Spectrograph (TRES) on the 1.5-m Tillinghast telescope, located at the Smithsonian Astrophysical Observatory's Fred L. Whipple Observatory on Mt. Hopkins in Arizona; (iii) the IAC-80 telescope at the Teide Observatory (Instituto de Astrofísica de Canarias, IAC).Figure 4 and Tables 2 and 3 are available in electronic form athttp://www.aanda.org

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