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arXiv · 0812.0785

Characterization of the HD 17156 planetary system

M. Barbieri·R. Alonso·S. Desidera·A. Sozzetti·A. F. Martinez Fiorenzano·J. M. Almenara·M. Cecconi·R. U. Claudi·D. Charbonneau·M. Endl·V. Granata·R. Gratton·G. Laughlin·B. Loeillet
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Abstract

AIMS : To improve the parameters of the HD 17156 system (peculiar due to the eccentric and long orbital period of its transiting planet) and constrain the presence of stellar companions. METHODS : Photometric data were acquired for 4 transits, and high precision radial velocity measurements were simultaneously acquired with SARG@TNG for one transit. The template spectra of HD 17156 was used to derive effective temperature, gravity, and metallicity. A fit of the photometric and spectroscopic data was performed to measure the stellar and planetary radii, and the spin-orbit alignment. Planet orbital elements and ephemeris were derived from the fit. Near infrared adaptive optic images was acquired with ADOPT@TNG. RESULTS: We have found that the star has a radius of R_S = 1.43+/-0.03 R_sun and the planet R_P =1.02+/-0.08 R_jup. The transit ephemeris is T_c = 2454\756.73134+/-0.00020+N*21.21663+/-0.00045 BJD. The analysis of the Rossiter-Mclaughlin effect shows that the system is spin orbit aligned with an angle lambda = 4.8 +/- 5.3 deg. The analysis of high resolution images has not revealed any stellar companion with projected separation between 150 and 1000 AU from HD 17156.

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M. Barbieri, R. Alonso, S. Desidera, A. Sozzetti, A. F. Martinez Fiorenzano, J. M. Almenara, M. Cecconi, R. U. Claudi, D. Charbonneau, M. Endl, V. Granata, R. Gratton, G. Laughlin, B. Loeillet. 2008-12-03. Characterization of the HD 17156 planetary system. https://doi.org/10.1051/0004-6361/200811466

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