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We have examined the CN 4216 \AA~ band strengths of red giants in 17 old open clusters using moderate resolution spectroscopy taken at KPNO and CTIO 4-meter telescopes. Variations in the CN 4216 \AA~ band strengths of red giants have been observed in a number of globular clusters. It is not clear whether this dispersion is due to a variation in the primordial abundances of carbon and nitrogen or to mixing processes in the convective envelope during a star's ascent up the red giant branch. Since old open clusters are of intermediate age and metallicity between young disk stars and globular clusters, by studying the CN band strengths of old open cluster red giants, we hope to add new insight to the question of CN variation. While a few CN 4216 \AA~ anomalous stars have been found in our sample, most open clusters we observed exhibit little variation in CN band strength. The lack of CN variation suggests that either the evolution for old open cluster red giants is significantly different from globular cluster red giants, probably because of their higher metallicity, or that the initial abundances of carbon and nitrogen were more homogeneous for old open clusters than for globular clusters.
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