Metallicities of Nearby K-Dwarfs

Abstract

The so-called ``G-dwarf problem'' emerged in the 1960's when it was noticed that the observed metal distribution of nearby stars differs from what is expected in simple models of the evolution of the Galaxy. We have determined metallicities for a sample of over 100 K dwarfs drawn from the Hipparcos catalog, using R-I colours to estimate effective temperatures and Geneva photometry to estimate [Fe/H]. We show there is a K-dwarf problem. K-dwarfs have life-times older than the Galactic disc, so these are an ideal star with which to investigate the disc's chemical evolution. Further photometric observations of K dwarfs are under way.