Transit time variations for 12 exoplanets

We confirm the planetary nature of four Kepler Objects of Interest within multicandidate systems. We forward-model each of the planetary systems identified to determine which systems are likely to yield mass constraints that may be significantly improved upon with follow-up transit observations.

We find projected TTVs diverge by more than 90 minutes after 6000 days in 27 systems, including 22 planets with orbital periods exceeding 25 days. Such targets would benefit the most from additional transit-timing data. TTV follow-up could push exoplanet characterization to lower masses, at greater orbital periods and at cooler equilibrium temperatures than is currently possible from the Kepler data set alone.