Transit timing variation in exoplanet WASP-3b

Abstract

Photometric follow-ups of transiting exoplanetsmay lead to discoveries of additional, lessmassive bodies in extrasolar systems. This is possible by detecting and then analysing variations in transit timing of transiting exoplanets. We present photometric observations gathered in 2009 and 2010 for exoplanetWASP-3b during the dedicated transit-timing-variation campaign. The observed transit timing cannot be explained by a constant period but by a periodic variation in the observations minus calculations diagram. Simplified models assuming the existence of a perturbing planet in the system and reproducing the observed variations of timing residuals were identified by three-body simulations.We found that the configuration with the hypothetical second planet of mass ~15M⊕, located close to the outer 2:1 mean-motion resonance, is the most likely scenario reproducing observed transit timing. We emphasize, however, that more observations are required to constrain better the parameters of the hypothetical second planet in the WASP-3 system. For final interpretation not only transit timing but also photometric observations of the transit of the predicted second planet and high-precision radial velocity data are needed. © 2010 The Authors. Journal compilation. © 2010 RAS.