The rate of cooling of the pulsating white dwarf star G117$-$B15A: a new asteroseismological inference of the axion mass

TL;DR

This paper uses asteroseismology of the white dwarf G117-B15A to infer a potential axion mass, suggesting extra cooling possibly due to axion emission, which impacts dark matter research.

Contribution

It provides a new asteroseismological constraint on the axion mass based on pulsation data of G117-B15A, linking stellar cooling to particle physics.

Findings

Indicates extra cooling in G117-B15A consistent with axion emission.

Estimates axion mass as approximately 17.4 meV with uncertainties.

Supports the hypothesis of axions contributing to stellar cooling processes.

Abstract

We employ a state-of-the-art asteroseismological model of G117-B15A, the archetype of the H-rich atmosphere (DA) white dwarf pulsators (also known as DAV or ZZ Ceti variables), and use the most recently measured value of the rate of period change for the dominant mode of this pulsating star to derive a new constraint on the mass of axion, the still conjectural non-barionic particle considered as candidate for dark matter of the Universe. Assuming that G117-B15A is truly represented by our asteroseismological model, and in particular, that the period of the dominant mode is associated to a pulsation g-mode trapped in the H envelope, we find strong indications of the existence of extra cooling in this star, compatible with emission of axions of mass m_a \cos^2 \beta = 17.4^{+2.3}_{-2.7} meV.