The impact of flybys on the evolution of solar system analogs, the debris disk systems.

Abstract

Debris disks represent the last phase of the evolution of protoplanetary disks. As a by-product of the planet formation process, debris disks might host planetesimal belts, dust, and gas.  One of the possible events responsible for the formation and/or evolution of debris disk systems  are flybys. To constrain the influence of encounters in the formation and evolution of debris disks, Bertini et al. (2023) reconstructed the flybys experienced by a statically significant sample of debris disks in the last 5 Myr and predicted for the next 2 Myr. In this talk I will present the sample of 254 debris disks with ages between 2 Myr and 8 Gyr. The Gaia eDR3 position, proper motions and radial velocities have been used to reconstruct the relative linear motions between each debris disk and all possible perturbed in volume of the sky around it. We found that 90% of the analyzed systems have at least a close flyby, implying that the very high incidence of encounters (in particular, close encounters) experienced by the systems in the last 5 Myr. I will also discuss the debris disk systems with known planets, companions and/or flyby(s). It is important to highlight that also our solar system itself experienced at least a close encounter. This implies the fundamental impact of flybys in the evolution of debris disks. The confirmation of the statistical significance of flybys in debris disk systems can also be responsible for stirring of debris material.