Abundance analysis of seven delta Scuti Stars

TL;DR

This study analyzes high-resolution spectra of seven delta Scuti stars to determine their chemical abundances, finding their patterns are similar to normal A- and F-type stars, with one possibly being a pulsating Am star.

Contribution

First comprehensive abundance analysis of a statistically relevant sample of delta Scuti stars comparing field and cluster stars.

Findings

No significant difference in abundance patterns between field and cluster delta Scuti stars.

Delta Scuti stars generally have abundance patterns similar to normal early A- and late F-type stars.

Identification of one star as a likely pulsating Am star.

Abstract

The current knowledge of the abundance pattern in delta Scuti stars is based on the analysis of just a few field stars. We aim to determine the general chemical properties of the atmospheres of delta Scuti stars based on a statistically relevant sample of stars and will investigate whether the abundance pattern is close to solar, an assumption generally made for pulsation models. We have analysed high-resolution, high signal-to-noise ratio spectra of seven field delta Scuti stars. We derived the fundamental parameters and the photospheric abundances and compared them to a similar sample of cluster delta Scuti stars. With the use of a t-test we demonstrated that there is no difference between the two samples, which allows us to merge them, resulting in a sample of fifteen delta Scuti stars. We did not find any substantial difference between the abundance pattern of our sample of delta Scuti stars and a sample of normal early A- and late F-type stars. One field star in our sample, HD 124953, is most likely a pulsating Am star.