William Herschel discovered NGC 6857 = H III-144 = h2062 on 6 Sep 1784 (sweep 258) and recorded "a patch containing some nebulosity. 240 confirmed it, irregularly long." John Herschel made 3 observations and wrote on 1 Aug 1829 (sweep 198), "a nebulous looking patch; 12" diam; in Milky Way; ill-defined; perhaps only some extremely minute stars mixed with larger which as distinct." This nebula wasn't found (one attempt) at Birr Castle.

400/500mm - 17.5" (8/7/91): very bright, moderately large, about 1' diameter, irregular outline, roughly circular but edges difficult to define, irregular surface brightness. The mag 13.5 central star is quite prominent offset north of center. Surrounded by four fours; a mag 12 star at the SW edge [40" from center], two mag 13 stars off the NE end [40" from center] and off the NW end [52" from center], a mag 14 star at the SE end. Located in a rich star field. Excellent contrast gain with OIII filter. Extremely faint nebulosity may extend to the west. This is a compact HII region within Sh 2-100, which mainly spreads out towards the west. CGCG misclassifies as a planetary nebula.

Notes by Steve Gottlieb