Detectivity domain for a putative WASP-43 c planet, assuming e_c = 0 (black) and e_c = 0.05 (red). The solid curves delimit the mass-period region where planets yield maximum TTV on WASP-43 b above 114 s (3-σ detection based on the present data). The dotted curves show the 1-σ threshold. Nearly horizontal solid, dashed and dotted lines shows RV detection limits for RV semi-amplitude K = 5, 10 and 15 m s^-1 respectively.