Giant stars

Definition

Giant stars are a class of stars that have significantly larger radii and luminosities than main-sequence stars of the same surface temperature. They represent a later stage in stellar evolution when the star has exhausted the hydrogen in its core.

5 Must Know Facts For Your Next Test

1. Giant stars have expanded outer envelopes, making them much larger in diameter compared to main-sequence stars.
2. They can be classified into several subtypes, including red giants, blue giants, and yellow giants, based on their temperature and color.
3. The expansion into a giant phase occurs after a star exhausts its hydrogen fuel in the core and begins burning helium or other heavier elements.
4. A well-known example of a red giant is Betelgeuse in the constellation Orion.
5. Giant stars play a crucial role in enriching the interstellar medium with heavier elements through processes like stellar winds and supernovae.

Review Questions

• What causes a star to expand into a giant phase?
• Name one example of a giant star.
• How do giant stars contribute to the enrichment of the interstellar medium?

Related terms

Main-Sequence Stars: Stars that are fusing hydrogen into helium in their cores, representing the primary stage of stellar evolution.

Supergiant Stars: Extremely large stars that are even more massive and luminous than giant stars, often ending their lives as supernovae.

Stellar Evolution: The process by which a star changes over time, from formation through various stages like main-sequence, giant phase, and ultimately death.