A chemical analysis of seven red giants of the Galactic cluster NGC 4349

Abstract

In this study, we undertake a comprehensive investigation of seven red giant stars of NGC 4349 (#005, #009, #079, #127, #168, #174, and #203) and one non-member star (#053). Accurate abundances of 19 chemical species and ¹²C/¹³C isotopic ratio are determined using high-signal-to-noise FEROS spectra and standard spectroscopic analysis. Seven of the giant stars in our sample present a mean iron abundance of [Fe/H] = -0.16 ± 0.04, while the star NGC 4349-053 is classified as a non-member of the cluster, based on the membership analysis with the UPMASK code. Also, we estimate an age of 282 ± 32 Myr and E(B - V) = 0.40 ±0.02, after fitting an isochrone for the metallicity of NGC 4349 and with the photometric and astrometric data sets from the literature. Furthermore, we carry out for the first time a chemical composition study for star $\#079$, so far neglected in the literature. This red giant star is in a binary system and presents chemical abundances compatible with the open cluster. However, its parallax and proper-motion components suggest otherwise. Finally, we identify NGC 4349 as a young open cluster with slightly enriched s-process elements ([s/Fe] = +0.16 ± 0.05 dex). In the context of the so-called chemical clocks, NGC 4349 presents a concordance with some observed relationships for H-burning elements and α- and s-process elements.