http://arxiv.org/abs/1710.04707
We present 12 new transit observations of the exoplanet WASP-46b obtained with the 1.54-m telescope at Estaci\’on Astrof\’isica de Bosque Alegre (EABA, Argentina) and the 0.40-m Horacio Ghielmetti and 2.15-m Jorge Sahade telescopes at Complejo Astron\’omico El Leoncito (CASLEO, Argentina). We analyse them together with 37 light curves from the literature to re-determine the physical parameters and search for additional planets via transit timing variations (TTVs). We consider the 31 transits with uncertainties in their mid-transit times ($e_\mathrm{T_{0}}$) $<$ 1 minute, to perform the first homogeneous study of TTVs for the system, finding a dispersion of $\sigma= 1.66$ minutes over a 6 year baseline. Since no periodic variations are found, our interpretation for this relatively high value of $\sigma$ is that the stellar activity could be affecting the measured mid-transit times. This value of dispersion allows us to rule out the presence of additional bodies with masses larger than 2.3, 4.6, 7, and 9.3 $M_{\mathrm{\bigoplus}}$ at the first-order mean-motion resonances 2:1, 3:2, 4:3, and 5:4 with the transiting planet, respectively. Despite the 6 year baseline and a typical light curve precision of $2 \times 10^{-3}$, we find that we cannot significantly demonstrate a slow decrease of the orbital period of WASP-46b. We place a lower limit of Q${\star}$ > $7 \times 10^{3}$ on the tidal quality factor and determine that an additional 6 year baseline is required to rule out Q${\star}$ < $10^{5}$.
R. Petrucci, E. Jofre, L. Ferrero, et. al.
Mon, 16 Oct 17
11/59
Comments: Accepted MNRAS, 16 pages, 10 Figures, 8 Tables