SCYON Abstract

Received on September 28 2005

Chemical Homogeneity in the Hyades

Authors	G.M. De Silva (¹), C. Sneden (²), D.B. Paulson (²), M. Asplund (¹), J. Bland-Hawthorn (³), M.S. Bessell (¹), K.C. Freeman (¹)
Affiliation	(¹) Mount Stromlo Observatory, Australian National University, Weston ACT 2611, Australia; (²) Dept of Astronomy, University of Texas, Austin, TX 78712; (³) Anglo-Australian Observatory, Eastwood NSW 2122, Australia.
Accepted by	Astronomical Journal
Contact	gayandhi@mso.anu.edu.au
URL
Links	Hyades

Abstract

We present an abundance analysis of the heavy elements Zr, Ba, La, Ce, and Nd for Hyades cluster F-K dwarfs based on high resolution, high S/N ratio spectra from Keck/HIRES. The derived abundances show the stellar members to be highly uniform, although some elements show a small residual trend with temperature. The rms scatter for each element for the cluster members is as follows; Zr = 0.055 dex, Ba = 0.049 dex, Ce = 0.025 dex, La = 0.025 dex, Nd = 0.032 dex. This is consistent with the measurement errors, and implies that there is little or no intrinsic scatter among the Hyades members. Several stars thought to be non-members of the cluster based on their kinematics are found to deviate from the cluster mean abundances by about 2 sigma. Establishing chemical homogeneity in open clusters is the primary requirement for the viability of chemically tagging Galactic disk stars to common formation sites, in order to unravel the dissipative history of early disk formation.