Cocoon Nebula (IC 5146)
Size: about 12'
Distance: 4,000 light years
RA: 21h 53m 24s
Dec: 47 degrees 16' 00"
The Cocoon Nebula floats like an
island within a sea of dark clouds. It is a star forming region
that contains three of the major types of nebulosities: emission,
reflection, and absorption.
These three types of gas clouds are responsible for the red, blue, and
black regions shown above. The large central star within the
Cocoon has blown a hole in the nebula and is likely responsible for
exciting the surrounding hydrogen to emit in Ha light. Please click
here for more information about this object.
Date: September 5, 2004
Sky 90 at f4.5 with field flattener/focal reducer, on the G11 Losmandy
Autoguider: SBIG STV with
Ha filter (13 nm bandpass); Type II R, G, B filter set.
20 x 5' for Ha; 6 x 5' for B; 4 x 5' for R and G, all unbinned.
Total exposure 170 minutes.
Conditions: Temperature 52 degrees F; above average
transparency; above average seeing; calm; moonlight during Ha imaging.
Post-processing: No darks,
flats, or bias frames used. Alignment done in ImagesPlus.
combined using RC Sigma Reject Plug-in for MaximDL. DDP
was performed in ImagesPlus
levels and curves adjustments in Photoshop CS (16 bit format).
note: Graphics on this website
may not be reproduced without author permission.
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