Open cluster

Definition

Open clusters are groups of stars that formed from the same molecular cloud and are loosely bound by mutual gravitational attraction. They typically contain a few hundred to a few thousand stars and are found primarily in the galactic plane.

5 Must Know Facts For Your Next Test

1. Open clusters often contain young stars, with ages ranging from a few million to several billion years.
2. They are crucial for studying stellar evolution because their star members have similar ages and compositions.
3. The Pleiades is one of the most famous examples of an open cluster.
4. Open clusters tend to disperse over time due to interactions with other stars and molecular clouds.
5. They are important tracers of spiral arm structure in galaxies since they form within these regions.

Review Questions

• What is an open cluster and where are they primarily found?
• Why are open clusters important for studying stellar evolution?
• What happens to open clusters over time, and why?

Related terms

Globular Cluster: A densely packed collection of ancient stars, typically found in the halo of galaxies.

Molecular Cloud: A cold, dense region of space where new stars form.

Galactic Plane: The plane in which the majority of a disk-shaped galaxy's mass lies.