Distances to Galaxies | Cepheid Variables | How to Look for Cepheid Variables | The Period-Luminosity Relation | Find the Cepheids in M100

1. Distances to Galaxies

The techniques we have used so far in the lab to determine distance have not taken us out past the confines of our own galaxy. The trig parallax method and the cluster Main Sequence method are the two methods we have used thus far. In this lab we will determine the distance to the galaxy M100 using a third method based on the properties of a type of star known as a Cepheid variable. This technique allows us to determine distances to nearby galaxies. We will also explore the physical properties of galaxies other than our own. So just like the clusters lab, this lab will consist of two parts. In the first you will determine the distance to the galaxy, M100, as a way of illustrating how astronomers find distances to galaxies. In the second part, you will study properties of galaxies, many of which can only be determined once distances to galaxies are known.