In this X-ray image of the open star cluster called the Pleiades, the brightest objects have the hottest coronas. The seven green squares are around the seven brightest stars, the Seven Sisters.
Amazing But True!
- The Pleiades open cluster contains hundreds of stars.
- The star cluster formed around 100 million years ago.
- Many stars in the open cluster are much more luminous than our sun.
- Six stars of the Pleiades are visible even in cities where there is a lot of light pollution.
With the links below, learn more about open star clusters. Then answer the following questions.
- Australian Museum, Open Star Clusters (video): http://www.youtube.com/watch?v=A7T7PzyqOV8
- NASA, Astronomy Picture of the Day, M45: The Pleiades Star Cluster (webpage with photo): http://apod.nasa.gov/apod/ap130918.html
- What is the same about the stars in an open cluster?
- What is different about the stars in an open cluster?
- Why are open star clusters important for learning about the life cycle of stars?
- What does the number of stars a person can see in the Pleiades depend on?
- What color are the stars in the cluster? Besides stars what can be seen in the photo?