Inferring mode inertias in evolved solar-like stars

TL;DR

This paper demonstrates that measuring mixed mode characteristics in evolved solar-like stars using Kepler data enables estimation of mode inertias, offering new insights into their internal structure and evolution.

Contribution

The study introduces a method to infer mode inertias from mixed mode observations, enhancing the diagnostic tools for stellar interior analysis in evolved stars.

Findings

Mode inertias can be estimated from mixed mode measurements.

The method provides new diagnostics for internal stellar structure.

Accuracy may be affected by non-adiabatic effects.

Abstract

Asteroseismology of evolved solar-like stars is experiencing a growing interest due to the wealth of observational data from space-borne instruments such as the \emph{CoRoT} and \emph{Kepler} spacecraft. In particular, the recent detection of mixed modes, which probe both the innermost and uppermost layers of stars, paves the way for inferring the internal structure of stars along their evolution through the subgiant and red giant phases. Mixed modes can also place stringent constraints on the physics of such stars and on their global properties (mass, age, etc...). Here, using two \emph{Kepler} stars (KIC 4351319 and KIC 6442183), we demonstrate that measurements of mixed mode characteristics allow us to estimate the mode inertias, providing a new and additional diagnostics on the mode trapping and subsequently on the internal structure of evolved stars. We however stress that the accuracy may be sensitive to non-adiabatic effects.