Non-adiabatic pulsations in ESTER models

TL;DR

This paper discusses the complex challenge of mode identification in rapidly rotating stars by analyzing non-adiabatic pulsation effects using ESTER models that incorporate rotation and energy conservation.

Contribution

It introduces non-adiabatic pulsation calculations in ESTER models accounting for rapid rotation, aiding mode identification in pulsating stars.

Findings

Non-adiabatic effects influence mode excitation.

Rotation effects are fully incorporated in models.

Results assist in interpreting pulsation spectra.

Abstract

One of the greatest challenges in interpreting the pulsations of rapidly rotating stars is mode identification, i.e. correctly matching theoretical modes to observed pulsation frequencies. Indeed, the latest observations as well as current theoretical results show the complexity of pulsation spectra in such stars, and the lack of easily recognisable patterns. In the present contribution, the latest results on non-adiabatic effects in such pulsations are described, and we show how these come into play when identifying modes. These calculations fully take into account the effects of rapid rotation, including centrifugal distortion, and are based on models from the ESTER project, currently the only rapidly rotating models in which the energy conservation equation is satisfied, a prerequisite for calculating non-adiabatic effects. Non-adiabatic effects determine which modes are excited and play a key role in the near-surface pulsation-induced temperature variations which intervene in multi-colour amplitude ratios and phase differences, as well as line profile variations.