But while the stars are old and the clusters formed in the distant past, astronomers using the NASA/ESA Hubble Space Telescope and the MPG/ESO 2.2-metre telescope at the ESO La Silla Observatory have found that some of these clusters are still young at heart. The research is presented in the 20 December 2012 issue of the journal Nature.
"Although these clusters all formed billions of years ago," says Francesco Ferraro (University of Bologna), the leader of the team that made the discovery, "we wondered whether some might be aging faster or slower than others. By studying the distribution of a type of blue star that exists in the clusters, we found that some clusters had indeed evolved much faster over their lifetimes, and we developed a way to measure the rate of aging."
