Prospecting for chemical tags among open clusters

TL;DR

This study reveals that heavy element abundances vary among open clusters with solar metallicity, enabling chemical tagging of stars and reconstruction of dissolved clusters from field star populations.

Contribution

It demonstrates the potential of heavy element abundance variations for chemical tagging and cluster reconstruction, a novel approach in stellar population studies.

Findings

Heavy elements La, Ce, Nd, Sm vary among open clusters.

Variations scale with s-process contributions at solar metallicity.

Spread in heavy elements also observed in field stars.

Abstract

Determinations of the chemical composition of red giants in a large sample of open clusters show that the abundances of the heavy elements La, Ce, Nd and Sm but not so obviously Y and Eu vary from one cluster to another across a sample all having about the solar metallicity. For La, Ce, Nd and Sm the amplitudes of the variations at solar metallicity scale approximately with the main s-process contribution to solar system material. Consideration of published abundances of field stars suggest that such a spread in heavy element abundances is present for the thin and thick disk stars of different metallicity. This new result provides an opportunity to chemically tag stars by their heavy elements and to reconstruct dissolved open clusters from the field star population.