Asteroseismology of chemically peculiar stars

TL;DR

This paper reviews how pulsations in chemically peculiar stars, especially magnetic Ap stars, provide insights into stellar interiors, magnetic fields, and atmospheric structures through asteroseismic observations and analysis.

Contribution

It summarizes recent advances in asteroseismology of chemically peculiar stars, highlighting the use of high-resolution spectroscopy and space photometry to study pulsations and magnetic effects.

Findings

Constrained fundamental stellar parameters using roAp frequency spectra.

Probed stellar interior properties through pulsation analysis.

Mapped horizontal structures of magnetically-distorted p-modes.

Abstract

Pulsational variability is observed in several types of main sequence stars with anomalous chemical abundances. In this contribution I summarize the relationship between pulsations and chemical peculiarities, giving special emphasis to rapid oscillations in magnetic Ap stars. These magneto-acoustic pulsators provide unique opportunities to study the interaction of pulsations, chemical inhomogeneities, and strong magnetic fields. Time-series monitoring of rapidly oscillating Ap stars using high-resolution spectrometers at large telescopes and ultra-precise space photometry has led to a number of important breakthroughs in our understanding of these interesting objects. Interpretation of the roAp frequency spectra has allowed constraining fundamental stellar parameters and probing poorly known properties of the stellar interiors. At the same time, investigation of the pulsational wave propagation in chemically stratified atmospheres of roAp stars has been used as a novel asteroseismic tool to study pulsations as a function of atmospheric height and to map in detail the horizontal structure of the magnetically-distorted p-modes.