WILD DUCK CHASE ENDS

Astronomers have solved the riddle of how stars in a single cluster can be different colours – suggesting different ages – when they would be expected to have been formed together. A Korean and Belgian team studied the Wild Duck Cluster, M11, made up of around 2,900 stars, with the University of Arizona’s MMT telescope. By examining the stars’ spectra – using data from splitting star light – they found the range of colours is down to different rates of rotation, not age.