Metallicities for 13 nearby open clusters from high-resolution spectroscopy of dwarf and giant stars. Stellar metallicity, stellar mass, and giant planets

TL;DR

This study accurately measures stellar metallicities in 13 open clusters using high-resolution spectroscopy, highlighting the importance of line selection and exploring the relationship between metallicity, stellar mass, and giant planet formation.

Contribution

It provides a detailed analysis of stellar parameters and metallicities in open clusters, emphasizing the impact of line-list choice on abundance determinations and discussing implications for planet formation.

Findings

Average metallicities are close to solar.

Line-list choice affects metallicity measurements.

Metallicity and stellar mass influence giant planet occurrence.

Abstract

We present a study of accurate stellar parameters and iron abundances for 39 giants and 16 dwarfs in the 13 open clusters IC2714, IC4651, IC4756, NGC2360, NGC2423, NGC2447 (M93), NGC2539, NGC2682 (M67), NGC3114, NGC3680, NGC4349, NGC5822, NGC6633. The analysis was done using a set of high-resolution and high-S/N spectra obtained with the UVES spectrograph (VLT). These clusters are currently being searched for planets using precise radial velocities. For all the clusters, the derived average metallicities are close to solar. Interestingly, the values derived seem to depend on the line-list used. This dependence and its implications for the study of chemical abundances in giants stars are discussed. We show that a careful choice of the lines may be crucial for the derivation of metallicities for giant stars on the same metallicity scale as those derived for dwarfs. Finally, we discuss the implications of the derived abundances for the metallicity- and mass-giant planet correlation. We conclude that a good knowledge of the two parameters is necessary to correctly disentangle their influence on the formation of giant planets.