NGC/IC Project Restoration Effort

(This is a very very beta version)

NGC6857

 

Basic Information


Location and Magnitude


Right Ascension: 20:1:48.0
Declination: +33:31:30
Constellation: CYG
Visual Magnitude:

Historic Information


Discoverer: Herschel W.
Year of discovery: 1784
Discovery aperture: 18.7

Observational


Summary description: F, am Milky Way st
Sub-type: EN

Steve's Notes

===== NGC 6857 18" (7/14/07): at 174x and OIII filter appears as a small but high surface brightness nearly circular knot, just 1' in diameter and sharply defined in a very rich star field. Without a filter a mag 13 (illuminating?) star is visible at the center and two stars are at opposite edges (SW and NE). At 280x the outline surface brightness is slightly irregular. Located just inside a beautiful partial ring or loop of stars that includes a couple of double stars. While viewing this object I noticed a fairly large, 3' low surface brightness hazy region about 10' W in the field. This glow matches the location of Sh 2-99 (11' W of NGC 6857). There was no structure to this HII region and the surface brightness was uniform. 18" (9/25/06): easily swept up at 115x as a small, high surface brightness nebula, roughly 1' in diameter, situated in a rich star field. Excellent contrast gain with an OIII filter and appears quite bright with this combination. At 300x, the nebula appears as a 1'-1.5' bright glow that spreads out mostly to the south of an embedded (possibly illuminating) mag 13.5-14 star in an irregular shape. This HII region is located along one side of a near equilateral triangle of mag 12-13 stars with a mag 12 star just 40" SW. A close, faint equal pair of mag 13.5 stars follows by 4'. 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.