THE SURFACE DISTRIBUTION OF CARBON STARS IN THE GALAXY

The results on the deep low dispersion (1250 A/mm at H fl , 30 ffi ! l ! 165 ffi , 195 ffi ! l ! 210 ffi , jbj ! 5 ffi ; 7000 A/mm at A band, 50 ffi ! l ! 115 ffi , b=0 ffi , b=\\Sigma3.5 ffi ) spectral surveys of the MILKY WAY are presented. More than 2250 carbon stars were identified among them 1440 new ones. The C/M5 + ratio increases from 0.02 to 0.3 when longitude varies from 30 ffi to 210 ffi . On the basis of A GENERAL CATALOG OF GALACTIC COOL CARBON STARS the surface distribution of carbon stars has been studied. I. INTRODUCTION Theoretical models for AGB stars indicate that the Carbon Star (CS) phase may last up to 10 6 years which is strongly limited by rapid mass loss rates up to 10 \\Gamma4 M fi yr \\Gamma1 (Kleinmann 1989). This lifetime is consistent with the analysis of Claussen et al. (1987), who used the space distribution of high luminosity CS and their main sequence progenitors to argue that the lifetime of CS lies between 10 5 and 10 ...