IC 5146

IC 5146 (also Caldwell 19, Sh 2-125, and the Cocoon Nebula) is a reflection^[1]/emission^[2] nebula and Caldwell object in the constellation Cygnus. IC 5146 refers specifically to the star cluster and Sh2-125 to the nebula.^[3] It shines at magnitude +10.0^[4]/+9.3^[2]/+7.2.^[5] Its celestial coordinates are RA 21^h 53.5^m, 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.^[1][4] The cluster is about 4,000 ly away, and the central star that lights it formed about 100,000 years ago;^[6] the nebula is about 12 arcmins across, which is equivalent to a span of 15 light years.^[5] 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.

References

External links

• SEDS – IC 5146
• Simbad – IC 5146
• NED – IC 5146
• IC5146
• Sharpless Catalog 125
• IC 5146 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images

Coordinates: 21^h 53^m 32^s, +47° 16′ 06″