The Cocoon Nebula

Caldwell 19, also known as the Cocoon Nebula, is a small star-forming region of nebulosity in the constellation of Lacerta (near Cygnus) about 4,000 light years away. It is a young star forming region. The dark tail coming off of the nebula is Barnard 168, a dark nebula.

November 29, 2023

I’ve learned a new processing method that better captures the details in the dark dusty areas of the image, and better handles the stars. So I went ahead and reprocessed the same data from my prior post, and this is the result. I think it looks wonderful, though I’m sure I could always use a bit more integration time! The dusty tail you see is known as Barnard 168. The Barnard catalogue is full of all of these dark dusty areas, and ‘m excited to capture more of them now that I’ve learned a better method to process my data!

Technical Details

Imaging Telescope: William Optics RedCat 51 II

Imaging Camera: ZWO ASI533MC Pro

Mount: Sky-Watcher EQ6-R Pro

Filter: SVBony UV/IR Cut 2”

Accessories: ZWO ASIAIR Plus, ZWO EAF, ZWO Filter Drawer (Gen 2)

Software: Siril, Photoshop, NoiseXterminator, Starnet

Guiding Telescope: William Optics UniGuide 32

Guiding Camera: ZWO ASI174MM

Imaging Dates: Nov. 21, 2023

Frames (gain 101.0) f/4.9 -10c: 89×180″(4h27m)

Integration Time: 4h27m

Darks/Flats/Dark Flats: 30/30/26

Bortle Dark-Sky Scale: 4.00

November 22, 2023

My first image of Caldwell 19, a star forming region known as the Cocoon Nebula. The image also includes Barnard 168, a region of dark nebulosity that looks like a long tail extending up from the nebula. Anything under 8-10 hours is generally considered a short amount of integration time for a nebula, and a very short time for dark nebula. That said, at 4 hours and 27 minutes, I’m generally happy with how this image turned out so far. I will certainly be adding more integration time to this one in the future, but I think I will need to purchase a filter to enhance the contrast of the nebulosity against the blanket of stars. Most regions of nebulosity are in the galactic plane, which as you can imagine, has seemingly infinite stars. (They say the milky was has about 100 billion stars!)