Neutrinos and Asteroseismology of Stars over the Helium Flash

TL;DR

This paper explores how neutrino emissions can be used alongside asteroseismology to study the internal processes of stars undergoing the helium flash, providing new insights into stellar evolution.

Contribution

It introduces a detailed modeling approach linking neutrino signals with asteroseismic data to analyze the helium flash in stars, enhancing understanding of stellar internal structure.

Findings

Neutrino emissions can imprint on asteroseismic parameters.

A precision of 0.3 μHz in Δν can distinguish stellar composition models.

Asteroseismology can identify stars experiencing helium subflashes.

Abstract

The helium flash, occurring in stars of 0.6-2.0 M$_\odot$ at the end of the red giant branch, is not observable via optical means due to the energy of the process being used to lift the core out of degeneracy. Neutrinos, which are linked to the ignition of reactions triggered during the flash and serve as the only cooling process in the inert core, can help characterize changes in internal structure. In this work, we create 18 stellar models across three mass and six metallicity values, chosen in the context of the stellar abundance problem, to compare the evolutionary path up to and probe the helium flash by conducting a detailed study of neutrino emission throughout this crucial phase of stellar evolution. We demonstrate how thermal neutrino emissions could have an imprint on global asteroseismic parameters and use them as an additional tool to infer the impact of compositional changes. We find that a precision of 0.3 $\mu$Hz in the determination of $\Delta \nu$ is enough to distinguish between between the two most prominent solar composition models and confirm that asteroseismic observation can be enough to classify a star as undergoing the process of helium subflashes. We also predict nuclear neutrino emission fluxes and their evolution for all relevant sources.