Model-independent diagnostics of highly reddened Milky Way starclusters: age calibration(Research Note)

摘要

Diagnostic tools that will be able to characterize clusters based only on the available photometry will be needed to study large samples of the newly found objects.Methods. The brightness difference between the red clump and the main-sequence turn-off point have been used as a model-independent age calibrator for clusters with ages from a few 108 to 1010 yr in the optical. Here we apply for the first time the method in the near-infrared.