IC 5146, also Caldwell 19, and the Sh2-125, Cocoon Nebula, is a reflection/emission nebula and Caldwell object in the constellation Cygnus. IC 5146 is a star cluster and the nebula is Sh2-125. It is located near the naked-eye star Pi Cygni, the open cluster NGC 7209 in Lacerta, and the bright open cluster M39. The cluster is about 4,000 ly away, and the central star that lights it formed about 100,000 years ago; the nebula is about 12 arcmins across, which is equivalent to a span of 15 light years. When viewing IC 5146, dark nebula Barnard 168 (B168) is an inseparable part of the experience, forming a dark lane that surrounds the cluster and projects westward (down on this image) forming the appearance of a trail behind the Cocoon.
(text taken from Wikipedia)
Date: 08/22/2010
Size:
Image Data
Telescope: RCOS 14.5" f/8
Mount: ASA DDM85
Detector: STL-11000M
Filters: Astrodon Gen 2
Exposures: LRGB 440:140:120:120 min (20 min subframes)
