Messier 13 star cluster

I'm generally not too interested in imaging star clusters, but gave M13 a try during an almost full moon. M13 is 145 light years in diameter, and about 25,000 light years from Earth. It may contain up to half a million stars. If you click on the photo to enlarge it you will be able to see the variation in star colors, especially the so called 'blue-stragglers' which mystify astronomers. These are very bright, relatively new short lived stars that don't match the characteristics of the other stars in the cluster.  This image is a total of 45 minutes exposure with my Hyperion Astrograph with the exposure run controlled by CCDAutopilot 4. The image was taken the night of   May 24, 2010 under clear skies and good seeing conditions except for the bright moon.

All images © Mel Martin 2021     Contact Me