A search for transit timing variations and orbital decay in WASP-46b

R. PETRUCCI , E., JOFRÉ, L.V. FERRERO, V. CÚNEO, L. SAKER, F. LOVOS, M. GOMEZ, P. MAUAS

San Juan

Congreso; 59 Reunión Anual de la Asociación Argentina de Astronomía; 2016

Asociación Argentina de Astronomía

We present 10 new transit observations of the exoplanetWASP-46b obtained with the 1.54-m telescope at Estación Astrofísica de Bosque Alegre (EABA, Argentina) and the 0.40-m Horacio Ghielmetti telescope at Complejo Astronómico El Leoncito (CASLEO, Argentina). We analyse them together with 35 light curves from literature to re-determine the physical parameters and search for additional planets via transit timing variations (TTV). We consider the 25 transits with uncertainties in their mid-transit times (eT0 ) < 1 minute, to perform the first homogeneous study of TTV for the system, finding that a linear ephemeris is not a good fit to the observations (chi^2_r = 2.16). Since no periodic variations are found, our interpretation for this result is that the eT0 values might be underestimated and/or the stellar activity could be affecting the measured mid-transit times. We compute a dispersion of = 59 seconds for the TTV over a 4 years baseline. This allows us to rule out the presence of additional bodies with masses larger than 1.4, 2.8, 4.2 and 5.6 M at the first-order mean-motion resonances 2:1, 3:2, 4:3 and 5:4 with the transiting planet, respectively. Furthermore, no long-term periodic variations are found in the parameters i and k. Finally, we estimate ˙P = 0.001±0.003 s yr^−1 implying that there is no hint of orbital decay in WASP-46b.