2008A&A...485..871G

We report high-precision transit photometry for the recently detected planet HD17156b. Using these new data with previously published transit photometry and radial velocity measurements, we perform a combined analysis based on a Markov Chain Monte Carlo approach. The resulting mass M_p=3.09^+0.22_–0.17M_Jup and radius R_p=1.23^+0.17_–0.20R_Jup for the planet places it at the outer edge of the density distribution of known transiting planets with ρ_p=1.66^+1.37_–0.60ρ_Jup. The obtained transit ephemeris is T_Tr=2454438.48271^+0.00077_–0.00057+Nx21.21747^+0.00070_–0.00067BJD. The derived plausible tidal circularization time scales for HD17156b are larger than the age of the host star. The measured high orbital eccentricity e=0.6719^+0.0052_–0.0063 can thus not be interpreted as the clear sign of the presence of another body in the system.