Basic calibrations of the photographic RGU system IV. Metal-poor subgiant and giant stars

Abstract

We present a large grid of theoretical color-absolute magnitude and two-color diagrams in the RGU photometric system. The grid comprises wide ranges of stellar ages and physical parameters, and was computed using the YALE isochrones (Demarque et al. 1996) combined with the most recent version of the Basel Stellar Library (hereafter BaSeL) of color-calibrated theoretical model-atmosphere flux distributions (Lejeune et al. 2000).