Novae from isolated white dwarfs as a source of helium for second generation stars in globular clusters

TL;DR

This paper investigates how classical and recurrent novae from isolated white dwarfs could significantly enrich the helium content of second-generation stars in globular clusters, offering a potential explanation for observed multiple stellar populations.

Contribution

It introduces the idea that novae from isolated white dwarfs are a major source of helium enrichment in globular clusters, a novel perspective in understanding their stellar populations.

Findings

Helium abundances in clusters can be substantially increased by novae.

Novae may be a dominant source of intracluster medium enrichment.

Proposes a new test for helium enhancement as the cause of multiple main sequences.

Abstract

We explore the possible contribution of classical and recurrent novae from isolated white dwarfs accreting from the intracluster medium to the abundances of "second generation" globular cluster stellar populations. We show that under reasonable assumptions the helium abundances of clusters can be enhanced substantially by these novae and argue that novae should be considered as an important, and perhaps even dominant channel in the evolution of the intracluster medium. We also discuss a possible test for whether helium enhancement really is the cause of the multiple main sequences in globular clusters that is independent of the positions of stars in the color-magnitude diagram.