Astronomers find that young star cluster is surrounded by a halo of "sibling" stars
Monday 28 January 2013
Stars tend to form in groups and over time the majority of these groups disperse to become field stars, like our sun. Understanding this process of cluster dissolution is important in unravelling how the Milky Way grew over time. It is a challenging task, however, because it is extremely difficult to identify the dispersed clusters.
A team of astronomers, including Mark Gieles from the Department of Physics, identified a candidate cluster with the name IC 2391 that is surrounded by a halo of "sibling stars". Some of these stars are at large distance from the cluster (more than a hundred light-years) and are most likely escaping from the cluster. The astronomers used a combination of distance, velocity and chemical properties of the halo stars to establish their relation to the cluster IC 2391. The results were accepted for publication in Monthly Notices of the Royal Astronomical Society and a pre-print is available here.
The animation below (credit: Mark Gieles, Department of Physics, University of Surrey) illustrates how the halo of stars forms around the cluster in 30 million year time.