Population II

Definition

Population II stars are older, metal-poor stars found in the halo and bulge of the Milky Way Galaxy. They formed early in the galaxy's history and have low concentrations of elements heavier than helium.

5 Must Know Facts For Your Next Test

1. Population II stars are typically found in the halo and globular clusters of the Milky Way.
2. These stars have low metallicity, meaning they contain fewer elements heavier than helium.
3. Population II stars are generally older than Population I stars.
4. They provide important clues about the early stages of galactic evolution.
5. Their lower metallicity is due to forming when the universe had not yet produced many heavy elements.

Review Questions

• Where in the Milky Way Galaxy are Population II stars primarily located?
• What distinguishes Population II stars from Population I stars in terms of their composition?
• Why are Population II stars significant for understanding galactic evolution?

Related terms

Population I Stars:

These are younger, metal-rich stars found primarily in the disk of the Milky Way.

Metallicity:

The proportion of a star's mass that is not hydrogen or helium; often used to trace stellar generations.

Globular Cluster: A spherical collection of old stars, which often contains a high concentration of Population II stars.