Abstract

Contributed Talk - Splinter ExoPlanets

Wednesday, 17 September 2025, 16:33

Transit Timing Prospects for Kepler Systems in the PLATO Era

Morgan Mitchell, Don Pollacco
University of Warwick

PLATO, the European Space Agency's third medium-class mission under the Cosmic Vision programme, is scheduled for launch in late 2026. Using the transit method, PLATO is expected to detect thousands of exoplanets orbiting bright, nearby stars of spectral types F5-K7. While the mission is primarily designed to enable mass measurements via radial velocities (RVs), its precise photometry and long observational baselines may also permit the detection of transit timing variations (TTVs), which can provide complementary dynamical constraints in multi-planet systems. As part of its nominal observing strategy, PLATO will conduct a two-year-long observation of a Northern field, which may partially or fully overlap with the original Kepler field. This presents an opportunity to revisit known multi-planet systems with TTVs on a photometric baseline exceeding 20 years. We simulate PLATO observations of 152 Kepler systems (361 transiting planets) with previously detected TTVs, in order to evaluate PLATO's ability to recover and improve TTV signals in these systems. Our CCD-level simulations incorporate realistic stellar variability signals and on-ground PSF-fitting photometry extraction in the presence of the targets' real photometric contaminants. While the extended baseline offers the potential for improved dynamical constraints in favourable cases, we find that PLATO's smaller collecting area and larger pixel scale present significant challenges for photometric follow-up of many Kepler targets. We identify a subset of systems most likely to benefit from PLATO observations and discuss prospects for refining their orbital architectures.