Chemical Abundances of the S star GZ Peg

TL;DR

This study analyzes the chemical composition of the S-type star GZ Peg using molecular-free spectral regions, revealing its stellar parameters and s-process element enhancement to better understand AGB star chemistry.

Contribution

It introduces a method to determine chemical abundances in cool stars by analyzing molecular-free spectral regions, providing new data on GZ Peg's composition.

Findings

Metallicity of -0.77 dex was determined.

Chemical abundances of 8 elements were reported.

Enhanced s-process elements typical of S-type stars were found.

Abstract

The chemical compositions of stars from the Asymptotic Giant Branch are still poorly known due to the low temperatures of their atmospheres and therefore the presence of many molecular transitions hampering the analysis of atomic lines. One way to overcome this difficulty is by the study of lines in regions free from molecular contamination. We have chosen some of those regions to study the chemical abundance of the S-type star GZ Peg. Stellar parameters are derived from spectroscopic analysis and a metallicity of -0.77 dex is found. Chemical abundances of 8 elements are reported and an enhancement of s-process elements is inferred, typical to that of an S-type star.