THE TRANSIT LIGHT CURVE PROJECT. XIV. CONFIRMATION OF ANOMALOUS RADII FOR THE EXOPLANETS TRES-4b, HAT-P-3b, AND WASP-12b

We present transit photometry of three exoplanets, TrES-4b, HAT-P-3b, and WASP-12b, allowing for refined estimates of the systems' parameters. TrES-4b and WASP-12b were confirmed to be "bloated" planets, with radii of 1.706 [plus-minus] 0.056R [subscript Jup] and 1.736 [plus-minus] 0.092R [subscript Jup], respectively. These planets are too large to be explained with standard models of gas giant planets. In contrast, HAT-P-3b has a radius of 0.827 [plus-minus] 0.055R [subscript Jup], smaller than a pure hydrogen-helium planet and indicative of a highly metal-enriched composition. Analyses of the transit timings revealed no significant departures from strict periodicity. For TrES-4, our relatively recent observations allow for improvement in the orbital ephemerides, which is useful for planning future observations.United States. National Aeronautics and Space Administration (Origins program award NNX09AB33G)National Science Foundation (U.S.) (Center of Excellence for Learning in Education, Science, and Technology, Research Science Institute program