Hubble images offer better benchmark for stellar evolution

Hubble images have helped to detect minute movements in relatively new stars previously expected to have settled down by now.

The discovery, reported in June 2 in Astrophysical Journal Letters, may cause astronomers to rethink how clusters form and evolve. The new measurements will help astronomers to develop benchmarks of cluster evolution and better estimate the masses of other star clusters. Many such measurements are based on the stars having reached a more settled state known as virial equilibrium. If the stars haven’t reached this state, the mass of the cluster will be overestimated.