TASTE. III. A homogeneous study of transit time variations in WASP-3b

TL;DR

This study conducts a homogeneous analysis of transit timing variations in WASP-3b, using new and archival data, to assess the presence of additional planets and refine orbital parameters.

Contribution

It provides a comprehensive, homogeneous re-analysis of transit data for WASP-3b, refines its orbital parameters, and evaluates TTV signals with new observations.

Findings

No confirmed TTV signal in new data

Orbital period measurements are inconsistent with constancy

Refined ephemeris and physical parameters for WASP-3b

Abstract

The TASTE project is searching for low-mass planets with the Transit Timing Variation (TTV) technique, by gathering high-precision, short-cadence light curves for a selected sample of transiting exoplanets. It has been claimed that the "hot Jupiter" WASP-3b could be perturbed by a second planet. Presenting eleven new light curves (secured at the IAC80 and UDEM telescopes) and re-analyzing thirty-eight archival light curves in a homogeneous way, we show that new data do not confirm the previously claimed TTV signal. However, we bring evidence that measurements are not consistent with a constant orbital period, though no significant periodicity can be detected. Additional dynamical modeling and follow-up observations are planned to constrain the properties of the perturber or to put upper limits to it. We provide a refined ephemeris for WASP-3b and improved orbital/physical parameters. A contact eclipsing binary, serendipitously discovered among field stars, is reported here for the first time.