It was formerly thought that the dust was left over from the formation of the cluster, but at the age of approximately 100 million years generally accepted for the cluster, almost all the dust originally present would have been dispersed by radiation pressure. Instead, it seems that the cluster is simply passing through a particularly dusty region of the interstellar medium.
It was formerly thought that the dust was left over from the formation of the cluster but at the age of approximately 100 million years generally accepted for the cluster almost all the dust originally present would have been dispersed by radiation pressure Instead it seems that the cluster is simply passing through a particularly dusty region of the interstellar medium