Metallicity calibration of a DDO CN index and other low-resolution indices for G and K stars

Department of Physics and Astronomy, N283 ESC, Brigham Young University, Provo, UT 84602-4360, U.S.A.

Received: 26 March 1999
Accepted: 26 May 1999

Abstract

Metallicity calibrations of low-resolution parameters are potentially useful for (at least) two problems: the properties of moving groups, and the supermetallicity problem in K giants. In this paper, metallicity calibrations are derived for six sets of parameters. One of these parameters is the DDO CN index δCN. This parameter and three others are calibrated for use with evolved G and K stars. Two additional sets of low-resolution parameters are calibrated for use with G and K dwarfs. The calibrations are derived by comparing the input data with two catalogs of homogenized high-dispersion results from diverse authors (see Taylor 1995, 1999a). Using rms errors that are given in the catalogs, intrinsic rms errors are derived for metallicities deduced from the calibrations. The errors turn out to be comparable to those that apply for averaged high-dispersion results.