TESS Observations of Kepler systems with Transit Timing Variations

Transit timing over a long photometric baseline offers the promise of characterizing low mass exoplanets in multi-transiting systems with interacting planets. The Kepler mission provided a four year photometric baseline which enabled several multi-planet systems to have planetary masses measured from transit timing variations (TTV).

We identify targets in the Kepler field that may be further constrained by TTV, with additional photometry from the Transiting Exoplanet Survey Satellite (TESS).

Despite the reduced signal-to-noise ratio of TESS transits compared to Kepler, we recover 48 transits at 13 multi-transiting systems in Sectors 14, 15, 26, 40 and 41 using pixel level decorrelation to model the noise and transits. We report updated ephemerides and mass constraints where possible at these systems.

In most cases, transit timing uncertainties from TESS light curves exceed the projected uncertainties in transit timing variations following the Kepler mission, and the TESS photometry does not add significant constraints to planetary masses. However, we find strong evidence of a non-transiting perturber at Kepler-396 (KOI-2672) that was missed from the Kepler data alone. We explore two plausible configurations of this system with a third planet that could explain the measured transit times.