Globular clusters

Definition

Globular clusters are tightly bound groups of stars, typically containing hundreds of thousands to millions of members. They orbit the galactic core and are among the oldest objects in the universe.

5 Must Know Facts For Your Next Test

1. Globular clusters contain some of the oldest known stars, often over 10 billion years old.
2. They are found in the halo of galaxies and can provide insights into the early stages of galaxy formation.
3. These clusters lack significant amounts of gas and dust, indicating little to no new star formation occurs within them.
4. The density of stars in a globular cluster is much higher than that in open clusters or within galaxies themselves.
5. Studying globular clusters helps astronomers estimate the age of the universe by comparing their stellar populations to theoretical models.

Review Questions

• What distinguishes globular clusters from open clusters?
• Why are globular clusters important for understanding the age of the universe?
• Where within a galaxy are globular clusters typically located?

Related terms

Open Cluster: A loosely bound group of stars that generally contains younger stars and fewer members compared to globular clusters.

Stellar Population:

Groups of stars categorized by their ages, compositions, and locations within galaxies.

Galactic Halo:

A spherical region surrounding a galaxy that contains older stars, including many globular clusters.