William Herschel discovered NGC 6239 = H III-727 on 12 Apr 1788 (sweep 831) and recorded "cF, S, E in the parallel [E-W]." His position was reduced exactly 1° too far south of UGC 10577 and copied by JH in the GC. Stephan found the galaxy again on 27 Jun 1876 and reported it as new in his list VII-10. Dreyer included Stephan's position in the GC Supplement as 5832. The two GC designations were combined in the NGC.

400/500mm - 17.5" moderately bright, moderately large, oval NW-SE, bright core.

600/800mm - 24" (7/2/16): at 375x; fairly bright, moderately large, elongated 5:3 WNW-ESE, 1.0'x0.6'. The north edge has a sharper light cut-off apparently due to a dust lane and is slightly concave near the center. A small, slightly brighter core is offset from center, just south of the dust lane. The south edge gently bulges out, so overall the galaxy has a weak "banana" shape. A small knot (blue HII region on the SDSS) is just distinguishable at the WNW end of the galaxy.

Notes by Steve Gottlieb