All datasets acquired with Moana from DSO (Dark Sky remote Observatory), near Fort Davis, TX, USA.
IC 5146 (also
Caldwell 19,
Sh 2-125,
Barnard 168, and the
Cocoon Nebula) is a
reflection/
emissionnebula and
Caldwell object in the constellation
Cygnus. The NGC description refers to IC 5146 as a cluster of 9.5 mag stars involved in a bright and dark nebula. The cluster is also known as Collinder 470. It shines at magnitude +10.0
[/+9.3/+7.2. Its celestial coordinates are RA 21h 53.5m , dec +47° 16′. 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 forming the appearance of a trail behind the Cocoon.
IC 5146 is a stellar nursery where star-formation is ongoing. Observations by both the
Spitzer Space Telescope and the
Chandra X-ray Observatory have collectively identified hundreds of
young stellar objects.=10.5px Young stars are seen in both the emission nebula, where gas has been ionized by massive young stars, and in the infrared-dark molecular cloud that forms the "tail". One of the most massive stars in the region is BD +46 3474, a star of class B1 that is an estimated 14±4 times the
mass of the sun.Another interesting star in the nebula is BD +46 3471, which is an example of a
HAeBe star, an intermediate mass star with strong emission lines in its spectrum.
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