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 \pm 0.056 ~ { } \text { R } _ { Jup } and 1.736 \pm 0.092 ~ { } \text { R } _ { 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 \pm 0.055 ~ { } \text { R } _ { 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 .