Chemical Composition of the RS CVn-type Star 29 Draconis

TL;DR

This study analyzes the chemical composition of the active RS CVn star 29 Draconis using high-resolution spectra, revealing elemental abundances and suggesting early onset of mixing processes in such stars.

Contribution

It provides detailed chemical abundances for 22 elements in 29 Draconis and insights into stellar mixing processes in chromospherically active stars.

Findings

Determined elemental abundances including key elements like C, N, O.

Found a low 12C/13C ratio indicating early mixing.

Suggests mixing processes occur earlier than current stellar evolution models predict.

Abstract

Photospheric parameters and chemical composition are determined for the single-lined chromospherically active RS CVn-type star 29 Draconis (HD 160538). From the high resolution spectra obtained on the Nordic Optical Telescope, abundances of 22 chemical elements, including the key elements such as 12C, 13C, N and O, were investigated. The differential line analysis with the MARCS model atmospheres gives Teff=4720 K, log g=2.5, Fe/H]=-0.20, [C/Fe]=-0.14, [N/Fe]=0.08, [O/Fe]=-0.04, C/N=2.40, 12C/13C=16. The low value of the 12C/13C ratio gives a hint that extra mixing processes in low-mass chromospherically active stars may start earlier than the theory of stellar evolution predicts.