 Unexpectedly, they found that this cluster is composed of three generations of stars, all born within 200 million years of the formation of the cluster.Astronomers have argued that globular clusters can produce only one generation of stars, because the radiation from first generation stars would drive the residual gas not consumed in the first star generation phase out of the cluster.However, the great mass of a cluster such as NGC 2808 may suffice to gravitationally counteract the loss of gaseous matter.