Uncertainties in Cluster Ages

Cluster ages are determined by comparing the stars in the cluster to computer models of the cluster. Although there is rough agreement about the ages of stars in open clusters determined by various methods, there is some uncertainty because computer models assume details about the interior of stars that are matters of some conjecture. One example is the amount of convection (turbulent mixing) that takes place in the interior of relatively young stars; changing the assumptions can alter the estimated age of the cluster.