Encounters in star clusters and survival probabilities for planets

The stability of young planetary systems is strongly influenced by multiple factors, both internal and external. In this paper, we investigate the link between the environment in which young stars form and the possibility of having stable planetary systems around them. We analyze the robustness of such systems after an encounter with another star within the same stellar cluster. We employ a model for the star cluster to extract the encounter properties, such as the mass of the perturber star and its velocity. We perform numerical simulations on systems with a single planet perturbed by an external star, in order to calculate the emission probabilities of the planet. We also calculate analytically the stellar encounter rates in the cluster. We find that such probabilities are strongly dependent on the thermal velocity of the cluster. We also notice that these probabilities are generally quite small, below 3% for the systems tested by us.