Summary:
- Star clusters are small groups of stars, smaller than a galaxy.
- There are two main types, open clusters and globular clusters.
- Both types are held together by gravity.
- Open clusters are groups of up to a few thousand stars.
- Globular clusters contain hundreds of thousands of stars.
- The heart of the globular cluster M13 is 145 light years in diameter.
- The cluster contains red and blue giant stars.
- What stage of life is the blue supergiant in?
- What will happen to it next?
- Use the resource below to answer the questions that follow.