NGC 6857 (PK 70+1.2*, in Sh2-100 <LBN 161>) Bright Nebula in Cygnus

Located at: RA 20 hours 01 minutes 49 seconds, Dec +33 degrees 31 minutes 32 seconds

Size: 38" in (3.0') Magnitude: 11.4 photographic in (--) Class: HII in Emission - Sharpless 3 2 3)

North is up

West to the right

Telescope:

 14.5" f5 Newtonian reflector

Camera:

 ST-8XME, self-guided, binned 1x1, temp -10c, camera control MaxIm DL 4.56

Image:

Lumicon Red filter, 500 minutes (50 x 10 minute subs), 08/25/26/27/2015; seeing 2.2-3.8 FWHM per CCDStack

Processing:

CCDStack 2.90.5589.16047, Photoshop CS5.1

Location:

 Rolling Roof Observatory, Thousand Oaks, CA 91360 (+34d 13m 29s -118h 52m 20s)

Notes:*

* NGC 6857 was misclassified as a Planetary Nebula, but is just the brightest part of Sh2-100. See CDS data.

Although NGC 6857 is recorded OK, Sh2-100 could have used more time (and and Ha filter). One of several objects imaged this August in Cygnus, while the nearly full moon made imaging in the south impractical.

From the NGC / IC Project:

Contemporary Visual Observation(s) for NGC 6857
NGC 6857 = PK 70+1.2 = LBN 161 = Sh 2-100
20 01 47.6 +33 31 38
Size 1.0x1.0

17.5": 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 E.  This is a compact 
HII region within Sh 2-100 and it is misclassified as a planetary in CGPN.

- by Steve Gottlieb