Image of M13 from an anonymous source

Image of M13 captured from Usenet. Also in Pat Murphy's collection.

The famous globular cluster M13 in Hercules, seen in a blue-light image taken with the Lowell Observatory 1.1-meter telescope. The nonlinear intensity mapping simultaneously shows stars with a wide brightness range, from the brightest red giants down to the main sequence.

From Bill Keel's image collection at the University of Alabama.