The Formation and Evolution of Multiple Star Systems

TL;DR

This paper explores how multiple star systems form and evolve, focusing on the dynamics of hierarchical configurations, eccentricity changes, and the effects of tidal forces, contributing to understanding star cluster evolution.

Contribution

It introduces a modeling approach for eccentricity evolution in hierarchical systems considering tidal and apsidal effects, highlighting outcomes like orbital period shrinkage.

Findings

Eccentricity changes can lead to significant orbital shrinkage.

Hierarchical configurations are often stable but can evolve over time.

Modeling shows the impact of tidal dissipation on binary orbits.

Abstract

Multiple systems play an important role in the evolution of star clusters. First we discuss several formation mechanisms which depend on the presence of binaries, either primordial or of dynamical origin. Hierarchical configurations are often stable over long times and yet may experience evolution of the internal orbital parameters. We describe an attempt to model the eccentricity change induced by the outer component using an averaging method, together with the effects due to tidal dissipation and apsidal motion acting on the inner binary. This treatment is adopted for systems with high induced eccentricity which gives rise to some interesting outcomes of significant period shrinkage.