Click image for higher resolution
 
Object name: NGC6888 - Crescent nebula   Optics:   TEC 180 FL with original flattener
  Objekt type: Emission nebula   Focal lenght:   1260 mm
  Constellation: Cygnus   Camera:   FLI ML 16803-65
  Location / Date: Remseck / August 2012   Exposure:   27 x 1200 sec Ha / 25 x 1200 sec OIII / 31 x 1200 sec SII / 1 x 300 sec RGB
  Distance: approx. 5000 ly   Filters:   Astrodon 3 nm narrowband and L-RGB filters
  Apparent dimensions: approx. 18' x 12'   Mount:   10micron GM2000 HPS
  Real dimensions: -   Autoguiding:   Off-Axis Guider - SX Lodestar
  Brightness: approx. 7.4 mag   Software:   MaxIm DL / Registar / Photoshop CS5 / PixInsight
  Position (R.A. / DEC): 20h 12' 7" / +38° 21.3'   Image processing:   Tone mapping according to real colors
 
 


E
xplanation

The stellar wind from the Wolf-Rayet star WR 136 formes NGC6888.
Total exposure time was about 30 h.