We report high-cadence time-series photometry of the recently-discovered transiting exoplanet system HD 17156 , spanning the time of transit on UT 2007 October 1 , from three separate observatories . We present a joint analysis of our photometry , previously published radial velocity measurements , and times of transit center for 3 additional events . Adopting the spectroscopically-determined values and uncertainties for the stellar mass and radius , we estimate a planet radius of R _ { p } = 1.01 \pm 0.09 R _ { Jup } and an inclination of i = 86.5 ^ { +1.1 } _ { -0.7 } degrees . We find a time of transit center of T _ { c } = 2454374.8338 \pm 0.0020 HJD and an orbital period of P = 21.21691 \pm 0.00071 days , and note that the 4 transits reported to date show no sign of timing variations that would indicate the presence of a third body in the system . Our results do not preclude the existence of a secondary eclipse , but imply there is only a 9.2 % chance for this to be present , and an even lower probability ( 6.9 % ) that the secondary eclipse would be a non-grazing event . Due to its eccentric orbit and long period , HD 17156b is a fascinating object for the study of the dynamics of exoplanet atmospheres . To aid such future studies , we present theoretical light curves for the variable infrared emission from the visible hemisphere of the planet throughout its orbit .