Discovery of pulsational line profile variations in the delta Scuti star HD21190 and in the Ap Sr star HD218994

TL;DR

This study used high-resolution UVES observations to identify pulsational line profile variations in two stars, discovering a new rapidly oscillating Ap star and revealing high-degree non-radial pulsations in a delta Scuti star.

Contribution

First detection of pulsational line profile variations in HD21190 and discovery of a new roAp star HD218994 with detailed pulsation characteristics.

Findings

HD218994 is a new roAp star with a 14.2 min pulsation period.

HD21190 shows high-degree non-radial pulsations through spectral line analysis.

No rapid pulsations detected in HD21190's spectra.

Abstract

Asteroseismology has the potential to provide new insights into the physics of stellar interiors. We have obtained UVES high time resolution observations of the delta Scuti star HD21190 and of the Ap Sr star HD218994 to search for pulsational line profile variations. We report the discovery of a new roAp star, HD218994, with a pulsation period of 14.2 min. This is one of the most evolved roAp stars. No rapid pulsations have been found in the spectra of the cool Ap star - delta Scuti star HD21190. However, we detect with unprecedented clarity for a delta Sct star moving peaks in the cores of spectral lines that indicate the presence of high degree non-radial pulsations in this star.