John Herschel discovered NGC 6603 = h2004 on 15 Jul 1830 and recorded "a glorious concentrated part of Milky Way, almost amounting to a globular cluster. Star 14 and 15m. The next night he logged "fine cluster of stars 15m; R; 6'; the stars are all of a size. The cl seems connected with the Milky Way. JH gave M24 as a synonym and this was mistakenly repeated in his General Catalog (GC) and Dreyer's NGC, but Herschel's description and position applies to the small, rich cluster within M24 (the Small Sagittarius Star Cloud). In the NGC, Dreyer noted "h2004 = M24. h's two observations hardly consist with this description [!, Cl, vRi, vmC, R, st 15 (M Way)], and their deviation of nearly +3m from Messier's place makes it very doubtful whether he really saw this object."

IC 4715 refers to M24 (the entire star cloud). Barnard described the star cloud in detail (AN 4239) based on photos he took in 1905 and Dreyer assumed it was new. But his position for the center is ~10 min of RA too large, so the connection with M24 was not made until more recently. See Harold Corwin's identification notes.

300/350mm - 13.1" (8/17/85): excellent resolution into 30-50 faint stars including a string oriented NW-SE running through the center. The outline forms an arrowhead shape pointing to the east. Situated in the northeast corner of M24 in a glorious region of the Small Sagittarius Star Cloud! Located 4' N of mag 8 SAO 161294. The dark nebula B93 lies ~30' NW.

400/500mm - 17.5" (7/4/86): between 50 and 70 stars are resolved, extremely dense.

Notes by Steve Gottlieb