Migration of bodies in the Proxima Centauri and Trappist 1 planetary systems

TL;DR

This study investigates the migration and collision probabilities of planetesimals in the Proxima Centauri and TRAPPIST-1 systems, revealing potential material transfer and long-term orbital dynamics within these exoplanetary systems.

Contribution

It provides new insights into the long-term behavior of planetesimals and their potential to deliver volatiles to inner planets in these systems.

Findings

Planetesimals can remain in elliptical resonant orbits for hundreds of millions of years.

Collision probability of planetesimals with inner planets is very low (~0.0002-0.001).

Outer layers of neighboring TRAPPIST-1 planets may contain similar material.

Abstract

The motion of planetesimals was studied in the Proxima Centauri and TRAPPIST 1 exoplanetary systems. The size of the feeding zone of planet Proxima Centauri c is discussed. It was noted that after hundreds of Myrs, some planetesimals could still move in elliptical resonant orbits inside the feeding zone of this planet that had been mainly cleared from planetesimals. The probability of a collision of a planetesimal initially located in the feeding zone of planet c with inner planet b was obtained to be about 0.0002 and 0.001 at initial eccentricity of orbits of planetesimals equal to 0.02 or 0.15, respectively. A lot of icy material and volatiles could be delivered from the icy zone near the orbit of planet c to inner planets b and d. The inclinations of orbits of 80% of the planetesimals that moved between 500 or 1200 AU from the star did not exceed 10o. It was obtained that several planets in the TRAPPIST-1 system accumulated planetesimals initially located at the same distance. Outer layers of neighbouring TRAPPIST-1 planets can include similar material.