The cyanogen distribution of the giants in 47 Tucanae.

Analysis of cyanogen measures of 142 stars on the red-giant branch of 47 Tucanae shows that the cyanogen distribution is preferentially bimodal, with the distribution becoming more cyanogen-rich toward the center. Most of the several observational constraints now available for 47 Tuc are suggestive of a primordial origin of its abundance anomalies, rather than of mixing.