Astronomers regard everything we can observe as potential tools for us to use to learn even more about the Universe. Both star clusters and variable stars are useful to confirm our theoretical models for the evolution of stars. We can do this in the case of star clusters, because we can assume the cluster stars were all born at the same time. Variable stars help confirm our models for the physics of stars, but are most useful as distance indicators that we can use to expand our knowledge of the size scale of the Universe.
First, please take the Web-based Lesson 7 quiz.
During this week, you should complete work on the lab exercise you began during Lesson 5.
You have finished the reading for Lesson 7. Double-check the list of requirements on the Lesson 7 Overview page to make sure you have completed all of the activities listed there before beginning the next lesson.