Speaker
Description
Young planetary systems are subjected to different dynamical effects that can influence their orbital structure over time. In systems with more than one planet, other planets can internally influence each other, e.g. via planet-planet scattering. In addition, external perturbing effects also need to be taken into account, as stars do not form by themselves but together with other stars in young star-forming regions. This birth environment can externally affect young multi-planet systems, e.g. via fly-by encounters. Previous work has shown that the absence/presence and location of an outer Giant planet around a close-in planet system does not change how these inner planets react to a single fly-by encounter with another star. We further explore this by comparing the effects of external fly-by perturbation on four close-in Sub-Neptune planets to those caused by a situation where only the distant Giant is perturbed by the same kind of encounter. In this talk, I will show the results of several hundred N-body simulations for each of the two perturbation cases. These indicate that the close-in planet systems have a ”preferred” end state after 500 Myr, which is reached regardless of how it was perturbed. In addition, the mass of the Giant appears to not impact the reaction of the inner planet system to the fly-bys in our tested set-ups, i.e. either a single 1 or 5 M_jup Giant placed at 2.5, 5, 10 or 20 au.
