This image was secured during the installation of the 0.9-m telescope at the BYU West Mountain Observatory. Data for this image is from August 27, 2009. This was the first night that a CCD had been mounted on the telescope so that imaging was possible. This 'First Light' image shows the globular cluster known as M15 in the constellation of Pegasus. The distance to this cluster is more than 33,000 light years and yet individual stars are easily resolved all through the cluster. Globular cluster stars have an extremely low abundance of heavy elements as compared to stars found in the solar neighborhood and represent the oldest population of stars known in the Galaxy. It is interesting to note the many cool red giant stars that are visible in the cluster as well as a large number of evolved horizontal branch stars that are blue in color. Many of the horizontal branch stars are known to be RR Lyrae variable stars that are useful as distance indicators since it is possible to determine their luminosity and compare that value to their apparent magnitude as measured from the observed images. The color image processing for this picture is the work of Dr. Rob Gendler. Dr. Gendler is well known for producing amazingly detailed astronomical images that are often featured on the Astronomy Picture of the Day.
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