Description

The Cocoon Nebula (IC 5146) lies at a distance of 3.300 light years in the constellation Cygnus.
It is a reflection and an emission nebula and is also known as Caldwell 19 and Sharpless 2-125.

Inside the nebula a star forming region is developing a new cluster of stars which is only about 1 million years old.
The large star at the centre of the nebula has blown a hole in the nebula and is supposed to be responsible for exciting the hydrogen into emitting Ha light.

The previous DSLR widefield image (see previous version) also shows the dark nebula to the right of the Cocoon nebula, which is known as Barnard 168.

Other versions

Previous/older images:

Sep 25, 2009 – Canon 350D (80mm TMB-1h15m)

Image data

Object info
Name IC5146 – The Cocoon Nebula
Type Emission/reflection nebula
Constellation Cygnus
Right ascension 21h 53m 28s
Declination +47° 16′ 01″
Distance 3.300 ly
Other designations Caldwell 19, Sh 2-125
Image info
Image date Jul. 24, 2012
Light frames 9x 4 min. RGB (each) unbinned, 16x 5 min. UHC-S unbinned (Luminance)
Total integration 3h 8m
Dark frames 10x
Flat frames 10x p. filter unbinned. Created with an A3 size Posterpoweruk flatfield panel
Bias frames 10x
Software used CCDOps, CCDSoft, Maxim DL, Photoshop CS4
Processing CCDOPS was used for focussing. Image Acquisition was done using CCDSoft.
All separate frames were calibrated, aligned and stacked in MaxIm DL5 Pro.
Photoshop CS4 was used for further processing – curves adjustment, levels adjustment, etc.
Noel Carboni’s toolset was used as well (Local Contrast Enhancement, Deep Space Noise Reduction)
(L)RGB combine was done in Photoshop.
Equipment info
Telescope Orion Optics SPX 10″ Newton
Corrector Televue 2″ Paracorr coma corrector (FL: 1.380mm f/5.43)
Mount Losmandy G-11 Gemini
Camera SBIG ST-8300M
Guide camera Atik 1HS Mono
Guide scope Celestron 60/700 Achromat
Autoguide software PHD Guiding
Filters Baader 2″ RGB + IDAS LPS-P2
Location Landgraaf, The Netherlands
Image comments

Distance from Paracorr to CCD is not optimal.
Focus is off.