# Characterization of the HD 17156 Planetary System

 Title: Characterization of the HD 17156 Planetary System Author: Barbieri, M.; Alonso, R.; Desidera, S.; Sozzetti, A.; Martinez Fiorenzano, A.F.; Almenara, J.M.; Cecconi, M.; Claudi, R.U.; Endl, M.; Granata, V.; Gratton, R.; Laughlin, G.; Loeillet, B.; Charbonneau, David Note: Order does not necessarily reflect citation order of authors. Citation: Barbieri, M, R. Alonso, S. Desidera, A. Sozzetti, A.F. Martinez Fiorenzano, J. M. Almenara, et al. 2009. Characterization of the HD 17156 planetary system. Astronomy and Astrophysics 503(2): 601-612. Full Text & Related Files: Charbonneau_HD17156System.pdf (684.1Kb; PDF) Abstract: Aims. We present data to improve the known parameters of the HD 17156 system (peculiar due to the eccentricity 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 the SARG spectrograph at 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 were acquired with the AdOpt module of TNG. Results. We found that the star has a radius of RS = 1.44$\pm$0.03 $R_\odot$ and the planet RP = 1.02$\pm$0.08 RJ. The transit ephemeris is Tc = 2 454 756.73134 $\pm$ 0.00020 + N $\cdot$ 21.21663 $\pm$ 0.00045 BJD. Analysis of the Rossiter-Mclaughlin effect shows that the system is spin orbit aligned with an angle $\beta$ = 4.8°$\pm$5.3°. The analysis of high resolution images did not reveal any stellar companion with a projected separation between of 150 and 1 000 AU from HD 17156. Published Version: doi:10.1051/0004-6361/200811466 Other Sources: http://arxiv.org/abs/0812.0785 Terms of Use: This article is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#OAP Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:4339935 Downloads of this work: