High resolution elemental abundance analysis of the Hyades Supercluster

TL;DR

This study analyzes the elemental abundances of stars in the Hyades Supercluster using high-resolution spectra, revealing a heterogeneous composition and identifying a subset with Hyades cluster characteristics, contributing to understanding its origin.

Contribution

It provides the first detailed elemental abundance analysis of proposed supercluster stars, combining chemical and kinematic data to assess their membership and origin.

Findings

Four stars share Hyades cluster abundances and kinematics.

Most stars exhibit diverse chemical compositions, indicating a complex origin.

The supercluster may be a dispersed star-forming remnant or a dynamical stellar stream.

Abstract

The existence of a kinematically defined moving group of stars centred at U = -40, V = -17 km/s referred to as the Hyades Supercluster, has been suggested as the debris of an originally large star forming event, with its core being the present day Hyades open cluster. Using high-resolution UVES spectra, we present elemental abundances for a range of alpha, Fe-peak and neutron-capture elements for 26 proposed supercluster stars. Our results show that the sample stars display a heterogeneous abundance distribution, with a clump around [Fe/H] = +0.15. We also calculate stellar radial velocities and U,V,W space velocities. Enforcing a strict chemical and kinematical membership criteria, we find 4 supercluster stars share the Hyades open cluster abundances and kinematics, while many of the remaining stars fit the disc field kinematics and abundance range. We discuss our findings in the context of the Hyades supercluster being a dispersed star-forming remnant, a stellar stream of purely dynamical origin or a result of several processes.