Cocoon mist

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Data from IC 5146 (Cocoon Nebula)
Nebula with embedded star cluster
IC5146.jpg
Image from IC 5146. To the right of the nebula, the elongated Barnard 168 dark cloud can be seen.
Constellation swan
Position
equinox : J2000.0
Right ascension 21 h 53 m , 5
declination + 47 ° 16 ′
Appearance
Apparent brightness  (visual) +7.2 mag
Angular expansion approx. 10 '
fog
Fog type Emission / reflection / absorption
Ionizing source of the emitting part embedded star cluster Collinder 470 and above all the 10-mag star BD + 46 ° 3474 (type B0 V) in its center
Star clusters
classification III 2 pn (Trumpler)
Number of stars about 100
Physical data
Affiliation Milky Way
distance (3100 ± 300) ly / (950 ± 80) pc
diameter approx. 10 ly
history
discovery Edward Barnard , October 11, 1893; regardless of this: Max Wolf , July 28, 1894
Catalog names
fog IC  5146, Sh2-125, LBN 424, Ced 198, min 2-70
Star clusters Cr  470, OCl 213, Lund 1001, C 2151 + 470

IC 5146 , also known as the Cocoon Nebula , is an astronomical nebula with an embedded open star cluster in the constellation Swan . The star cluster is called Collinder 470 .

The nebula has an apparent extension of around 10 arc minutes and is about 3,000 light years from Earth; its physical extent is about 10 light years.

The nebula is a star formation region with ionized atomic hydrogen and has both emitting , reflecting and absorbing components.
When viewed from Earth, IC 5146 is located at the eastern end of the elongated dark cloud Barnard 168 and, together with it, is part of an extended molecular cloud . A little to the west is the reflection nebula of vdB 147, which probably also belongs to the complex.

The active star formation taking place inside the cloud leads to the formation of a young open star cluster called Collinder 470, an apparent magnitude of 7.2 mag and an estimated age of a few hundred thousand years. This star cluster and especially the brightest star in its center, BD + 46 ° 3474 (type B0 V, 10 mag), are responsible for the ionization of the nebula and thus for its glow. They create a "cave" in the dust and gas of the molecular cloud and thus open up a view into its interior.

The nebula was discovered photographically by Edward Barnard on a photo taken on October 11, 1893, and later independently by Max Wolf (July 28, 1894).

See also

Web links

Individual evidence

  1. ^ GH Herbig, SE Dahm: "The Young Cluster IC 5146" ; in: The Astronomical Journal, Vol. 123, Issue 1, p. 304 (English)
  2. ↑ a b Wolfgang Steinicke: "IC 5146" (PDF; 203 kB)
  3. ^ Harvey et al .: The Spitzer Survey of Interstellar Clouds in the Gould Belt. - I. IC 5146 Observed With IRAC and MIPS ; in: The Astronomical Journal, Vol, 680, Issue 1, p. 495, bibcode : 2008ApJ ... 680..495H (English)