TASTE

III. A homogeneous study of transit time variations in WASP-3b^{⋆,⋆⋆,⋆⋆⋆}

¹ Dipartimento di Fisica e AstronomiaUniversità degli Studi di Padova, Vicolo dell’Osservatorio 3, 35122 Padova, Italy
e-mail: valerio.nascimbeni@unipd.it
² INAF – Osservatorio Astronomico di Padova, vicolo dell’Osservatorio 5, 35122 Padova, Italy
³ Departamento de Astrofísica, Universidad de La Laguna (ULL), 38206 La Laguna, Tenerife, Canary Islands, Spain
⁴ Universidad de Monterrey, Departamento de Física y Matemáticas, Av. I. Morones Prieto 4500 Pte., San Pedro Garza García, Nuevo León, 66238, México
⁵ Instituto de Astrofísica de Canarias, Vía Láctea s/n, E38200 La Laguna, Tenerife, Canary Islands, Spain
⁶ Astronomical Observatory of the Autonomous Region of the Aosta Valley, Loc. Lignan 39, 11020 Nus (AO), Italy

Received: 15 May 2012
Accepted: 8 October 2012

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.