Abstract
ABSTRACT. It is now well established the importance of carbon stars as indicators of the intermediate age stellar population (Blanco, Hoag and McCarthy 1978). Among the results derived from surveys carried out in the Galaxy, the Magellanic Clouds, and in spheroidal dwarf galaxies of the Local Group it has been found that the number ratio between the carbon stars and M stars of spectral type MS, or later, (C/M5+) is significantly correlated with the metal content of these star systems. In this paper a determination of the C/M5+ ratio in the galactic disc along a line galactic center-Sun-anticenter is presented. Previous space density analysis for M and C stars derived from near-infrared objective-prism surveys carried out in the direction of the galactic center and anticenter have been used. The C/M5+ ratio varies from 0.1 toward the galactic center to 0.3 toward the anticenter. This tendency is opposite to the running of the metal abundance on the galactic disc, from the center outward. The mean value of the C/M5+ ratio for the Galaxy (0.2), the Large Magellanic Cloud (2), the Small. Magellanic Cloud (33) and the spheroidal dwarf galaxies (50-100) are significantly correlated with the metal index of these star systems. Kay woJL : GALAXY-STF#CTUR - STARS-LATE TYPE - STARS-CARBON
