This is a region referred to as the “Small Sagittarius Cloud”. It appears that the entire field of stars was mis-labeled as a star cluster (M24) by Messier. While there is a small, open cluster named NGC6603, in the center it is too dim for his telescope to have recorded it. The region also includes some dark dust clouds, and lies about 10.000 lys away.

PlaneWave 12.5″ Astrograph with an ST11000 camera, Astrodon filters, and ASA gearless DDM-85 mount. F/5 (29/8min L, 5/8min each 2×2 RGB).