The stability in the most external region of the Oort Cloud: The evolution of the ejected comets

TL;DR

This study investigates the dynamical effects of the Galaxy on the outer Oort Cloud, identifying an outer boundary and analyzing the ejection process of the most external comets through simulations of test particles.

Contribution

It introduces a new outer boundary for the Oort Cloud based on the dynamical behavior of objects affected by Galactic tides, linking it to the disruption of wide binary stars.

Findings

Galactic tide perturbations influence the outer Oort Cloud similarly to wide binary star evolution.

A dynamical structure around 10^5 au contains unbound objects, indicating a transition region.

The outer boundary of the Oort Cloud is defined by the stability analysis of external objects.

Abstract

In this paper, we present a study about the dynamical effects of the Galaxy on the external region of the Oort Cloud. The aims of this paper are: i) to determine an outer limit for the Oort Cloud; and ii) to analyse the dynamical behaviour of the most external objects of the Cloud and how they are ejected from the Solar System. This is undertaken by following the temporal evolution of massless test particles in the Galactic environment of the solar neighbourhood. Here we show that the effect of the perturbations from the Galactic tide in the particles is similar to that find for the evolution of wide binary stars population. Moreover, in the Oort Cloud we found a dynamical structure around 10 5 au conformed by objects unbound of the Sun. This structure allows us to define a transition region of stability and an outer boundary for the Oort Cloud, and it is also in agreement with previous results about the disruption of wide binary stars.