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

PETRUCCI, ROMINA; JOFRÉ, EMILIANO; FERRERO, LETICIA; CÚNEO, VIRGINIA; SAKER, LEILA; LOVOS, FLAVIA; GÓMEZ, MERCEDES; MAUAS, PABLO J. D.

San Juan

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

Instituto de Ciencias Astronómicas de la Tierra y el Espacio

We present 10 new transit observations of the exoplanet WASP-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 (e_T0 ) < 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 (χ2 = 2.16). Since no periodic variations are found, our interpretation for this result is that the e_T0 values might be underestimated and/or the stellar activity could be affecting the measured mid-transit times. We compute a dispersion of σ = 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 MEarth 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.