Study of red giant stars in Galactic open clusters

Galactic open clusters are still the only example of single stellar populations: gravitationally bound stars that presents different masses but the same age and chemical composition. Despite multiple stellar populations are found in globular clusters, its existence in open clusters is still widely discussed in the literature. In globular clusters, one of the most common abundance variations found is the anticorrelation between CN and CH, which is the best studied since the molecular bands are easy to be measured using low resolution spectra. However, the sample of open clusters analysed is still small when comparable to that of globular clusters. Therefore, the UFRGS Open Cluster Survey (UOCS) aims to map over 150 red giant stars in 25 Galactic open clusters to seach for CN and CH abundance variations. We present partial results regarding the survey characterization, data reduction, kinematic analysis, and determination of a sample of observed stars’ effective temperature and surface gravity.