IC 5146
| Reflection nebula | |
|---|---|
| emission nebula | |
Amateur image of IC 5146 "Cocoon Nebula"
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| Observation data: J2000 epoch | |
| Right ascension | 21h 53m 28.7s |
| Declination | +47° 16′ 01″ |
| Distance | 3300 ly (1000 pc) |
| Apparent magnitude (V) | +7.2 |
| Apparent dimensions (V) | 12′ |
| Constellation | Cygnus |
| Designations | Cocoon Nebula, Caldwell 19, Sh 2-125 |
IC 5146 (also Caldwell 19, Sh 2-125, 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.
Coordinates: 
21h 53m 32s, +47° 16′ 06″
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