M13 is a Sawyer-Shapley Class V globular cluster that lies 25,000 light-years from Earth. Class V implies that the concentration of the cluster is low enough that stars can easily be resolved within its core. A curious feature of M13 is a Y-shaped dark lane in its southeast portion (upper left). William Parsons, the 3rd Earl Rosse first noticed this in the 1850s through his leviathan telescope. Amateurs today have dubbed it "the propeller". Exposures: L:R:G:B=230:50:50:50 minutes = 6 hours 20 minutes total exposure at f/7.2.

This image was published in the July, 2018, November, 2018, and October 2019 issues of Astronomy Magazine.