Cocoon Nebula (IC 5146)

Nearly 15 light-years in size and located in Cygnus, some 4,000 ly away from us, this beautiful object is another stellar nursery, IC 5146 or Sh 2-125, the Cocoon Nebula. The ‘cocoon’ we see is an open cluster embedded within a red reflection nebula of hydrogen gas that is lit by a huge hot star in the center that was formed a couple of hundred thousand years ago. It is actually a double star, named Couteau 2320, after Paul Couteau who create the catalogue and observed a total of 744 double stars — some of which he discovered himself — and published a book about it.

On its right side, you can see very long filaments of cold dark dust (dark nebula) seemingly extending from the Cocoon (denoted as Barnard 168). When observed in infrared, it appears that this trails are themselves star-formation regions.


Data and processing: Goran Petrov
License: Creative Commons BY NC (free for non-commercial use, with attribution).
Click on the image to view full size (3379 × 2253).

Location: Petralica, Rankovce, Macedonia
Date: 2018-09-12
Total integration time: 7 hours

Camera 1: ATIK One 9.0, cooled to -20C
Telescope 1: Takahashi FSQ 106 ED refractor
L: 48 frames x 6 min
Ha: 14 frames x 6 min

Camera 2: ZWO ASI 1600 MC COOL, cooled to -25C
Telescope 2: William Optics 98 FLT refractor
R, G and B: total 70 frames x 3 min
Ha: 13 frames x 6 min

Processed in PixInsight.