Star Clusters Project

Do you ever wonder about stars? When you look up at the night sky or at images of stars do you think that they all look the same? Do you think we can understand more about stars if we study groups of them?

What do you know about how stars form? What about what gets left behind once they've formed? How long do you think stars live for and what factors affect this? What can we measure just by looking at pictures of stars and how is this done? How can stars be classified according to these properties that we can measure? Can we learn about large populations of stars just by looking at smaller groups?

Star clusters provide fantastic (in fact, out of this world) laboratories for us to study populations of stars. It allows us to understand the way that stars evolve and what can influence this evolution. The main way that astronomers do this is by using a colour magnitude diagram (or CMD).

The image on this page is of an open cluster of stars called Messier 25 (M25). To get data from the image astronomers use something called photometry. This is a way to measure the brightness of each star in the cluster. There are different pieces of software that are used to do this. An example of free, easy-to-use Windows software for photometry is Makali'i. The name comes from the Hawaiian word for the Pleiades, which is another open cluster.

Why not try this out for yourself? This project supports you to:

• use photometry to measure the brightness of stars in star clusters
• create a colour-magnitude diagram using your data
• identify the evolutionary stage of the stars you are studying

Read an overview of this activity and some instructions

Or start some background research.