|If you look up into the night sky and see a "fuzzy" patch of light it might well be a star cluster. One of the best examples of a cluster is the Pleiades, or Seven Sisters. Formed from giant gas clouds that are compressed by gravitational forces these groups of stars tend to be uniform in in composition and age while varying in size. Clusters allow us to study the evolution of stars all nearly the same age. There are two types, open clusters and globular clusters. The Pleiades has a few hundred stars loosely joined as an open cluster.|
In the previous two labs you have studied how to find distances to stars and how astronomers learn about properties of stars. Along the way you learned a little bit about stellar evolution. In this lab you will apply the knowledge you gained in the previous labs toward the study of star clusters. This lab is broken up into two parts. In the first part you will learn how to find distances to star clusters. In the second part you will learn more about stellar evolution by determining ages of star clusters. In the process you will find additional evidence that stars do indeed evolve.