IC 5146: The Cocoon nebula

IC 5146 The Cocoon nebula (also known as Caldwell 19, Sh2-125 and Barnard 168) is a nebula in the constellation Cygnus. 

Its distance from us varies according to the sources consulted, ranging from 2500 to 4000 light-years. This beautiful nebula is nearly 15 light-years wide.

The Cocoon Nebula has a complex structure: it is classified as both a reflection and emission nebula. The nebula glows mostly with the characteristic red light of ionized hydrogen, although the fainter outer parts of the cloud show other colours due to the ionization of other elements such as oxygen, as well as the reflection of starlight.

I previously imaged this nebula in 2007. I did it with my old Canon 20Da camera (thus in RGB). This image, which is still on my website, can be consulted in full resolution here, (and I also put a copy at the end of this post for comparison 😊...)

For this new image, in addition to using a higher resolution telescope (TOA-150), I planned to give it considerably more exposure time, in this case in LRGB and also to add hours of narrowband exposure with Ha and OIII filters.

The first image on the right is the LRGB version, which has an accumulated exposure of 26 hours (L data has been captured whit TOA-150 and RGB data with FSQ-106N).

The second image is the L-Ha R-Ha G B-OIII version, which has a total accumulated exposure of 52 hours (all narrowband data has been captured with TOA-150).

The processing of this last image has been really complex for me, and I am still not sure that I have been able to get the best out of my data.

Click on the images for full resolution versions, or go to the Gallery section for complete exposure details.

Image processing: Pixinsight.

Observatory automation and remote operation with Talon6.