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Stars

Try this!

Just like an astronomer, you can learn how to look at a star in the sky and tell something about its temperature. Arrange the following stars in order from hottest to coolest.

hottest coolest

a b c a b c a b c
Though individual stars are difficult to see in another galaxy, one can sometimes see a group of stars. Often stars within a group are the same color which gives a clue to the average temperature of the group.

From the color of these groups of stars, which end of the galaxy is hotter?

A B neither

Try this outside. On a clear night, look up at the sky. Make sure there are no bright lights and wait twenty minutes so that you eyes can adjust to see faint things. Then count the number of red and blue stars.
1. Which stars are hotter than the others?
2. Which group of stars (red or blue) are more abundant?

Adapted from the Star Light, Star Bright activity on the Amazing Space (http://amazing-space.stsci.edu) web site.

This activity was developed by Jacqueline Slay, Largo High School, Largo, MD

Imagine the Universe is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Nicholas White (Director), within the Laboratory for High Energy Astrophysics at NASA's Goddard Space Flight Center.

The Imagine Team
Project Leader: Dr. Jim Lochner
All material on this site has been created and updated between 1997-2004.

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