How Stars Look Young When They're Not: The Secret of Aging Well (1 of 2) (image) Penn State Share Print E-Mail Caption The aging of star clusters is linked more with their lifestyle than with how old they actually are, according to a new NASA/ESA Hubble Space Telescope study coauthored by Penn State astronomer Steinn Sigurdsson and other scientists, and led by Francesco Ferraro of the University of Bologna in Italy. The research reveals, for the first time, that each star cluster has its own internal clock, some of which are ticking slower than others. This image gallery shows 12 globular clusters ranked in order of increasing dynamical age as measured from the observed distribution of their blue-straggler stars. Credit F. Ferraro (UniBO) Usage Restrictions The image credit must be published along with the image. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.