Transcript: Star formation is very complex. Thus when astronomers talk about the theory of star formation they’re talking about a theory that is not yet highly refined where many details remain to be worked out. Star formation occurs in dense regions from which light cannot emerge. There are four basic stages. In the first, cores form within a molecular cloud. A giant molecular cloud could potentially form hundreds or thousands of stars. In the second stage the cores collapse to form protostars and surrounding disks. In the third stage fusion begins, initially hydrogen fusing to form deuterium, and a wind blows out from the star along the rotation axes. In the fourth stage the wind fans out to form a wind in all directions, and the young star becomes visible, still surrounded by its nebular disk.