Spectroscopic and Photometric Investigation of Some Potentially Chemically Peculiar $\delta$ Scuti Stars

TL;DR

This study conducted spectroscopic and photometric analyses of ten Delta Scuti stars to identify chemical peculiarities and pulsation properties, revealing only three stars with chemical peculiarity, emphasizing the importance of detailed abundance analysis.

Contribution

The paper provides updated spectroscopic analysis of chemically peculiar Delta Scuti stars, identifying true chemical peculiarities and highlighting the necessity of detailed abundance studies for accurate classification.

Findings

Only three stars show chemical peculiarity: AU Scl, FG Eri, and HZ Vel.

Remaining stars are chemically normal.

Pulsation modes and stellar parameters were derived from TESS data and evolutionary models.

Abstract

Investigating chemically peculiar pulsating stars is crucial for understanding the pulsation driving mechanism in detail. To reveal the true peculiarity properties of stars detailed spectroscopic analysis is essential. Therefore, in this study, we focused on Delta Scuti stars previously identified as chemically peculiar but needed comprehensive updated spectroscopic analysis to uncover the chemical abundance structure of them. We selected ten targets which have public high-resolution spectroscopic and photometric data. Performing spectral analyses, we determined the spectral classification, atmospheric parameters, and detailed chemical abundance distributions of the selected stars. The pulsation properties were also analyzed using TESS data and pulsation modes for the highest amplitude pulsation frequencies were derived. We estimated the masses and ages of the targets using the evolutionary tracks and isochrones. As a result of the study, we show that only three targets exhibit chemical peculiarity: AU Scl and FG Eri as metallic A (Am) stars, and HZ Vel as a $\lambda$ Bootis. However, others were found to be chemically normal stars. This study show us the importance of chemical abundance analysis in the classification of chemical peculiar stars.