Searching for Planets in the Hyades. IV. Differential Abundance Analysis of Hyades Dwarfs

We present a differential abundance analysis of Hyades F-K dwarfs in search for evidence of stellar enrichment from accreted hydrogen-deficient disk material. Metallicities and relative abundance ratios of several species have been determined. We derive a cluster mean [Fe/H]=0.13+/-0.01. Two stars show abundances ~0.2 dex larger than the cluster mean. In addition, one star, which was added by a recent study as a cluster member, shows significantly lower abundances than the cluster mean. These three stars have questionable membership characteristics. The remaining stars in the survey have an rms of 0.04 dex in the differential [Fe/H] values. The Hyades cluster members have apparently not been significantly chemically enriched. The abundance ratios of Si, Ti, Na, Mg, Ca, and Zn with respect to Fe are in their solar proportions.

Some data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.