Nascimbeni, VCunial, AMurabito, SSada, P VAparicio, APiotto, GBedin, L RMilone, AntoninoRosenberg, AMalavolta, L2015-12-130004-6361http://hdl.handle.net/1885/78375The 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.Author/s retain copyrightKeywords: Dynamical modeling; Eclipsing binaries; Exo-planets; High-precision; Jupiters; Light curves; Low-mass; Orbital periods; Planetary system; Stars: individual; Techniques: photometric; Transit time; Transit timing; Upper limits; Astronomy; Astrophysics; Star Planetary systems; Stars: individual: WASP-3; Techniques: photometric201210.1051/0004-6361/201219601s2016-02-24