Key points are not available for this paper at this time.
Spectra of the λ4300 CH and λ3883 CN bands have been obtained for a sample of red giants in M3 and Mi 3 for which 0/Fe abundances have been published in the literature. Measurements of the C/Fe and N/Fe abundances have been made by comparing the observed spectra with synthetic spectra calculated from model atmospheres. Giants in both clusters exhibit an anticorrelation between CN band strength and both 0/Fe and C/Fe abundances, coupled with a CN-N/Fe correlation. The total (C+ N+ 0)/Fe abundance is the same within the observational uncertainties among both CN-strong and CN-weak giants. These observations are in accord with the hypothesis that and C→N O→N processed material has been brought to the surface of the CN-strong cluster giants.
Smith et al. (1996) studied this question.