Abstract Natural satellites are common around planets in our Solar System, suggesting that exosatellites are likely prevalent around extrasolar planets as well. Detecting these satellites, however, remains challenging due to observational limitations and the subtle photometric signals they produce. Transit Timing Variations (TTV) and Transit Duration Variations (TDV) offer indirect methods to detect exosatelllite by measuring the gravitational influence of a satellite on its host planet. In this paper, we perform thousands of N-body numerical simulations of star–planet–satellite and star–planet–planet systems to characterize how to distinct signatures produced by satellite to those induced by a second planet. Our numerical results showed that TTV and TDV induced by satellite have identical oscillation periods and comparable amplitudes, whereas perturbations from additional planet generally produce signals with different TTV and TDV periods. In most planet-planet cases, the TDV period is larger than the TTV period, and the TTV amplitudes are overwhelmingly larger than the TDV amplitudes. Additionally, we investigate the influence of the physical and orbital parameters of both the planet and the satellite on the TTV and TDV signals. Our results are consistent with the equations present in the literature, which describe the dependence of the TTV and TDV amplitudes on system parameters. We further show that the TTV and TDV periods induced by a satellite are related to short-period perturbations in the oscillation of the planet’s longitude of pericenter, as well as with variations in the semi-major axis and eccentricity of the planet–satellite barycenter.
Pinheiro et al. (Thu,) studied this question.