Analysis of RGU Photometry in Selected Area 51

Abstract

A low-latitude anticenter field (l=189 °, b=+21 °) is investigated by using the full calibration tools of RGU photometry. The observed RGU data are reduced to the standard system and the separation of dwarfs and evolved stars is carried out by an empirical method. Stars are categorized into three metallicity classes, i.e. -0.25<[M/H]≤+0.50, $-1.00<[M/H]≤-0.25, and [M/H]≤-1.00 dex, and their absolute magnitudes are determined by the corresponding color-magnitude diagrams. The unusually large scattering in the two-color diagrams is reduced by excluding 153 extra-galactic objects, identifying them compared with the charts of Basel Astronomical Institute and University of Minnesota, and by the criterion and algorithm of Gaidos et al. [1]. The local logarithmic space density for giants, D^*(0)=6.75, lies within the local densities of Gliese and Gliese & Jahreiss. The local luminosity function in our work for the absolute magnitude interval 3<M(G)≤7 agrees with Hipparcos' luminosity function better than Gliese's luminosity function, whereas it is larger than these luminosity functions for the interval 7<M(G)≤8. This discrepancy may be due to many reasons, i.e. cumulative catalog errors, binarity etc.