A search for pulsational line profile variations in the delta Scuti star HD21190 and the Ap Sr star HD218994

TL;DR

This study investigates pulsational line profile variations in two peculiar stars, discovering HD218994 as a new rapidly oscillating Ap star and identifying non-radial pulsations in HD21190, enhancing understanding of stellar pulsations.

Contribution

The paper reports the first detection of pulsational line profile variations in HD21190 and confirms HD218994 as a new roAp star, expanding the catalog of pulsating Ap stars.

Findings

HD218994 is a new roAp star with a 5.1-minute pulsation period.

No rapid pulsations detected in HD21190, but non-radial pulsations are present.

HD218994 is the 36th known star of its type.

Abstract

We present the results of our recent search for pulsational line profile variations in high time resolution UVES spectra of the most evolved Ap star known, the delta Scuti star HD21190, and of the Ap Sr star HD218994. We found that HD218994 is an roAp star with a pulsation period of 5.1 min, which makes it the 36th star known to be a roAp star. No rapid pulsations have been found in the spectra of the delta Scuti star HD21190. However, we detect moving peaks in the cores of spectral lines, which indicate the presence of non-radial pulsations in this star.