The nature of cyanogen inhomogeneities within star clusters

Abstract

Spectroscopic and photometric observations have been made of the cyanogen band strength distributions within the five globular clusters NGC 362, NGC 3201, MS, M71 and MSS. Of these, the first three, and probably M71, are found to exhibit bimodal CN distributions. In NGC 3201, MS and M71, the CN-enhanced giants, on average, have weaker CH and/or CO bands than the CN-poor giants. This suggests the presence of a C,N abundance anticorrelation between the CN-weak and CN-strong populations of giants. Show more