A dynamical survey of the trans-Neptunian region I.: Mean-motion resonances with Neptune

TL;DR

This study conducts a comprehensive dynamical survey of the trans-Neptunian region, analyzing 4121 objects to identify mean-motion resonances with Neptune and their role in orbital stability over 100 million years.

Contribution

It introduces the FAIR method for semi-automatic identification of high-order and inclination-type MMRs, expanding the understanding of TNO dynamics.

Findings

MMRs play a stabilizing role in the trans-Neptunian region.

Real TNOs are located in regular, resonance-protected regions.

The study identifies both temporary and long-term resonance captures.

Abstract

In this paper, we present a large-scale dynamical survey of the trans-Neptunian region, with particular attention to mean-motion resonances (MMRs). We study a set of 4121 trans-Neptunian objects (TNOs), a sample far larger than in previous works. We perform direct long-term numerical integrations that enable us to examine the overall dynamics of the individual TNOs as well as to identify all MMRs. For the latter purpose, we apply the own-developed FAIR method that allows the semi-automatic identification of even very high-order MMRs. Apart from searching for the more frequent eccentricity-type resonances that previous studies concentrated on, we set our method to allow the identification of inclination-type MMRs, too. Furthermore, we distinguish between TNOs that are locked in the given MMR throughout the whole integration time span ($10^8$\,years) and those that are only temporarily captured in resonances. For a more detailed dynamical analysis of the trans-Neptunian space, we also construct dynamical maps using test particles. Observing the fine structure of the $ 34-80 $~AU region underlines the stabilizing role of the MMRs, with the regular regions coinciding with the position of the real TNOs.