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

Abstract

Asteroseismology has the potential to provide new insights into the physics of stellar interiors. We have obtained Ultraviolet and Visual Echelle Spectrograph high time-resolution observations of the δ 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 14.2min. This is one of the most evolved roAp stars. No rapid pulsations have been found in the spectra of the cool Ap star - δ Scuti star HD21190. However, we detect with unprecedented clarity for a δScuti star moving peaks in the cores of spectral lines that indicate the presence of high-degree non-radial pulsations in this star.