Exploiting timing capabilities of the CHEOPS mission with warm-Jupiter planets

TL;DR

This study demonstrates CHEOPS's high-precision transit timing capabilities for warm-Jupiters, showing that combining multiple transits enhances timing accuracy, which is crucial for detecting potential external perturbers.

Contribution

The paper provides a detailed analysis of CHEOPS's transit timing performance and shows how combining multiple observations improves detection of transit-timing variations.

Findings

Achieved transit time precision of 13-16 seconds for bright targets

Combined multiple transits to reach about 2-minute timing precision for fainter targets

Longer observational baselines can improve TTV detection sensitivity

Abstract

We present 17 transit light curves of seven known warm-Jupiters observed with the CHaracterising ExOPlanet Satellite (CHEOPS). The light curves have been collected as part of the CHEOPS Guaranteed Time Observation (GTO) program that searches for transit-timing variation (TTV) of warm-Jupiters induced by a possible external perturber to shed light on the evolution path of such planetary systems. We describe the CHEOPS observation process, from the planning to the data analysis. In this work we focused on the timing performance of CHEOPS, the impact of the sampling of the transit phases, and the improvement we can obtain combining multiple transits together. We reached the highest precision on the transit time of about 13-16 s for the brightest target (WASP-38, G = 9.2) in our sample. From the combined analysis of multiple transits of fainter targets with G >= 11 we obtained a timing precision of about 2 min. Additional observations with CHEOPS, covering a longer temporal baseline, will further improve the precision on the transit times and will allow us to detect possible TTV signals induced by an external perturber.