Habitability in the Omega Centauri Cluster

TL;DR

This study investigates how the dense stellar environment of Omega Centauri affects the potential habitability of planets, focusing on the distribution of habitable zones and the impact of stellar encounters on planetary stability.

Contribution

It provides the first detailed analysis of habitable zones in a globular cluster core, linking stellar parameters, cluster dynamics, and planetary habitability.

Findings

Habitable zones are generally within 0.5 AU of host stars.

High stellar encounter rates threaten planetary orbit stability.

Habitable zone boundaries are influenced by cluster density and dynamics.

Abstract

The search for exoplanets has encompassed a broad range of stellar environments, from single stars in the solar neighborhood to multiple stars and various open clusters. The stellar environment has a profound effect on planet formation and stability evolution and is thus a key component of exoplanetary studies. Dense stellar environments, such as those found in globular clusters, provide particularly strong constraints on sustainability of habitable planetary conditions. Here, we use Hubble Space Telescope observations of the core of the Omega Centauri cluster to derive fundamental parameters for the core stars. These parameters are used to calculate the extent of the Habitable Zone of the observed stars. We describe the distribution of Habitable Zones in the cluster and compare them with the stellar density and expected stellar encounter rate and cluster dynamics. We thus determine the effect of the stellar environment within the Omega Centauri core on the habitability of planets that reside within the cluster. Our results show that the distribution of Habitable Zone outer boundaries generally lie within 0.5 AU of the host stars, but that this small cross-sectional area is counter-balanced by a relatively high rate of stellar close encounters that would disrupt planetary orbits within the Habitable Zone of typical Omega Centauri stars.