# Instabilities in Multi-Planet Circumbinary Systems

## TL;DR

This paper investigates the dynamical instabilities in multi-planet circumbinary systems, showing how resonances and chaos influence their architecture and stability, with implications for planet formation and migration.

## Contribution

It reveals how planet-planet and binary resonances induce chaos, shaping system architectures and constraining migration rates in circumbinary planetary systems.

## Key findings

- Resonances can drive chaos in circumbinary systems.
- Chaos limits maximum stable eccentricities.
- Constraints on minimum migration rates of planets.

## Abstract

The majority of the discovered transiting circumbinary planets are located very near the innermost stable orbits permitted, raising questions about the origins of planets in such perturbed environments. Most favored formation scenarios invoke formation at larger distances and subsequent migration to their current locations. Disk-driven planet migration in multi-planet systems is likely to trap planets in mean motion resonances and drive planets inward into regions of larger dynamical perturbations from the binary. We demonstrate how planet-planet resonances can interact with the binary through secular forcing and mean-motion resonances, driving chaos in the system. We show how this chaos will shape the architecture of circumbinary systems, with specific applications to Kepler 47 and the Pluto-Charon system, limiting maximum possible stable eccentricities and indicating what resonances are likely to exist. We are also able to constrain the minimum migration rates of resonant circumbinary planets.