 Once the protostar enters into its main sequence phase , it is classified as a star . Even though most planetary disks can form planets , observations show that intense stellar radiation should have destroyed any proplyds that formed near the Trapezium group , if the group is as old as the low mass stars in the cluster . Since proplyds are found very close to the Trapezium group , it can be argued that those stars are much younger than the rest of the cluster members . 
