A consistent analysis of three years of ground- and space-based photometry of TrES-2

TL;DR

This study combines four years of Kepler and ground-based photometry to analyze the orbital stability of TrES-2b, finding no significant inclination change but hinting at possible minor variability.

Contribution

It provides a comprehensive joint analysis of space and ground data to refine orbital parameters and investigate orbital inclination changes of TrES-2b.

Findings

No significant secular inclination change detected

Transit timing variations are ruled out

Possible minor inclination variability remains marginally significant

Abstract

The G0V dwarf TrES-2A, which is transited by a hot Jupiter, is one of the main short-cadence targets of the Kepler telescope and, therefore, among the photometrically best-studied planetary systems known today. Given the near-grazing geometry of the planetary orbit, TrES-2 offers an outstanding opportunity to search for changes in its orbital geometry. Our study focuses on the secular change in orbital inclination reported in previous studies. We present a joint analysis of the first four quarters of Kepler photometry together with the publicly available ground-based data obtained since the discovery of TrES-2b in 2006. We use a common approach based on the latest information regarding the visual companion of TrES-2A and stellar limb darkening to further refine the orbital parameters. We find that the Kepler observations rule out a secular inclination change of previously claimed order as well as variations of the transit timing, however, they also show slight indication for further variability in the inclination which remains marginally significant.