Kozai-Lidov cycles towards the limit of circumbinary planets

TL;DR

This study investigates whether misaligned circumbinary planets can induce Kozai-Lidov cycles in inner stellar binaries, revealing that such cycles are rare except for massive, near-polar orbit planets, impacting theories of planetary system dynamics.

Contribution

The paper provides an analytic analysis of Kozai-Lidov effects in circumbinary systems, highlighting departures from traditional symmetry and identifying conditions under which cycles occur.

Findings

Kozai-Lidov cycles are rare in circumbinary systems.

Massive, near-polar orbit planets can induce Kozai-Lidov cycles.

Most circumbinary planets do not produce Kozai-Lidov oscillations.

Abstract

In this paper we answer a simple question: can a misaligned circumbinary planet induce Kozai-Lidov cycles on an inner stellar binary? We use known analytic equations to analyse the behaviour of the Kozai-Lidov effect as the outer mass is made small. We demonstrate a significant departure from the traditional symmetry, critical angles and amplitude of the effect. Aside from massive planets on near-polar orbits, circumbinary planetary systems are devoid of Kozai-Lidov cycles. This has positive implications for the existence of highly misaligned circumbinary planets: an observationally unexplored and theoretically important parameter space.