Influence of the Centaurs and TNOs on the main belt and its families

TL;DR

This study examines how Centaurs and Trans-Neptunian Objects influence the dynamical evolution of the main asteroid belt through chaotic scattering and close encounters, affecting some old asteroid families and the orbits of certain asteroids.

Contribution

It provides new insights into the role of Centaurs and TNOs in shaping the main belt's orbital structure and the potential origins of some asteroids.

Findings

Centaurs and TNOs can modify main belt asteroid orbits during close encounters.

They are unlikely to disperse young asteroid families significantly.

Some outer belt asteroids may originate from Centaurs or TNOs with short lifetimes.

Abstract

Centaurs are objects whose orbits are found between those of the giant planets. They are supposed to originate mainly from the TransNeptunian objects, and they are among the sources of NearEarth Objects.TransNeptunian Objects (TNOs) cross Neptune's orbit and produce the Centaurs. We investigate their interactions with main belt asteroids to determine if chaotic scattering caused by close encounters and impacts by these bodies may have played a role in the dynamical evolution of the main belt. We find that Centaurs and TNOs that reach the inner Solar System can modify the orbits of main belt asteroids, though only if their mass is of the order of 1 billion less the mass of the sun for single encounters or, one order less in the case of multiple close encounters. Centaurs and TNOs are unlikely to have significantly dispersed young asteroid families in the main belt, but they can have perturbed some old asteroid families. Current main belt asteroids that originated as Centaurs or Trans-Neptunian Objects may lie in the outer belt with short lifetime less than 4 My, most likely between 2.8 au and 3.2 au at larger eccentricities than typical of main belt asteroids.