M2 (NGC 7089)
With about 150.000 contained stars M2 is one of the most compact and bright star clusters and visible with the naked eye under extremely good conditions. While Charles Messier classified it as a nebula, it was William Herschel in 1783 who could first resolve individual stars.
The next image shows the full frame in a manual edit (580mm, ASI2600MM, LRGB 1h).