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We specify the range to which perturbations penetrate a planetesimal system. Such perturbations can originate from massive planets or from encounters with other stars. The latter can have an origin in the star cluster in which the planetary system was born, or from random encounters once the planetary system has escaped its parental cluster. The probability of a random encounter, either in a star cluster or in the Galactic field depends on the local stellar density, the velocity dispersion and the time spend in that environment. By adopting order of magnitude estimates we argue that the majority of planetary systems born in open clusters will have a {em Parking zone}, in which planetesimals are affected by encounters in their parental star cluster but remain unperturbed after the star has left the cluster. Objects found in this range of semi-major axis and eccentricity preserve the memory of the encounter that last affected their orbits, and they can therefore be used to reconstruct this encounter. Planetary systems born in a denser environment, such as in a globular cluster are unlikely to have a Parking zone. We further argue that some planetary systems may have a {em Frozen zone}, in which orbits are not affected either by the more inner massive planets or by external influences. Objects discovered in this zone will have preserved information about their formation in their orbital parameters.
Star and planet formation are inextricably linked. In the earliest phases of the collapse of a protostar a disc forms around the young star and such discs are observed for the first several million years of a stars life. It is within these circumstel
In this era of spatially resolved observations of planet forming disks with ALMA and large ground-based telescopes such as the VLT, Keck and Subaru, we still lack statistically relevant information on the quantity and composition of the material that
As part of a national scientific network Pathways to Habitability the formation of planets and the delivery of water onto these planets is a key question as water is essential for the development of life. In the first part of the paper we summarize t
Planet formation is generally described in terms of a system containing the host star and a protoplanetary disc, of which the internal properties (e.g. mass and metallicity) determine the properties of the resulting planetary system. However, (proto)
Planets form and obtain their compositions in disks of gas and dust around young stars. The chemical compositions of these planet-forming disks regulate all aspects of planetary compositions from bulk elemental inventories to access to water and reac