Teaching astronomy for Sheridan College gave me the opportunity to prepare a laboratory activity that determines key characteristics of the open star cluster NGC 957 in the constellation Perseus.  I wrote a detailed instruction manual for my students which you can view here: Star Cluster Photometry Instructions.  You can also view plots of the color indexes, magnitudes, and temperatures at this site: Star Cluster Photometry Plots

The H-R diagram I created for the star cluster NGC 957 shows possible interpretations for the evolutionary stages of stars in the cluster.  (Click on the article title to view the image and read the full text.)