Stellar association

Loose star cluster

A stellar association is a very loose star cluster, looser than both open clusters and globular clusters. Stellar associations will normally contain from 10 to 100 or more visible stars. An association is primarily identified by commonalities in its member stars' movement vectors, ages, and chemical compositions. These shared features indicate that the members share a common origin. Nevertheless, they have become gravitationally unbound, unlike star clusters, and the member stars will drift apart over millions of years, becoming a moving group as they scatter throughout their neighborhood within the galaxy.

This keyword could refer to multiple things. Here are some suggestions: