Why exomoons must be rare?

TL;DR

This paper argues that exomoons are likely rare because the high orbital eccentricities of exoplanets, caused by planetary migration and resonance crossing, destabilize and lead to the loss of satellites.

Contribution

It provides a simple model linking exoplanet eccentricity growth to exomoon loss, explaining the scarcity of observed exomoons.

Findings

Exoplanets often have high eccentricities due to migration.

High eccentricity destabilizes and can cause exomoon loss.

Exomoons are likely rare because of orbital instability.

Abstract

The problem of the search for the satellites of the exoplanets (exomoons) is discussed recently. There are very many satellites in our Solar System. But in contrary of our Solar system, exoplanets have significant eccentricity. In process of planetary migration, exoplanets can cross some resonances with following growth of their orbital eccentricity. The stability of exomoons decreases, and many of satellites were lost. Here we give a simple example of loss satellite when eccentricity increased. Finally, we can conclude that exomoons must be rare due to observed large eccentricities of exoplanets.