Iris Nebula

Coordinates: Sky map 21h 01m 36s, +68° 09′ 48″
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(Redirected from NGC 7023)
Iris Nebula
Reflection nebula
Iris Nebula (NGC 7023 and LBN487)
Observation data: J2000.0 epoch
Right ascension21h 01m 35.60s
Declination+68° 10 10.0″
Distance1,300 ly
Apparent magnitude (V)6.8
Apparent dimensions (V)18' x 18'
Physical characteristics
Radius3 ly
DesignationsNGC 7023 and LBN487, Caldwell 4, Cr 429
See also: Lists of nebulae

The Iris Nebula (also known as NGC 7023 and Caldwell 4) is a bright reflection nebula in the constellation Cepheus. The designation NGC 7023 refers to the open cluster within the larger reflection nebula designated LBN 487.

The nebula, which shines at magnitude +6.8, is illuminated by a magnitude +7.4 star designated HD 200775.[1] It is located near the Mira-type variable star T Cephei, and near the bright magnitude +3.23 variable star Beta Cephei (Alfirk). It lies 1,300 light-years away and is six light-years across.[2]


Map showing location of NGC 7023
  1. ^ Perkins, Philip (2005). "NGC 7023". Archived from the original on 2008-05-18. Retrieved 2008-08-06.
  2. ^ Nemiroff, R.; Bonnell, J., eds. (2004-11-04). "NGC 7023: The Iris Nebula". Astronomy Picture of the Day. NASA. Retrieved 2008-08-06.


  • Pasachoff, Jay M. (2000). "Atlas of the Sky". Stars and Planets. New York, New York: Peterson Field Guides. pp. 578 pg. ISBN 978-0-395-93432-6.
  • Caldwell-Moore, Sir Patrick (2003). Firefly Atlas of the Universe. Firefly Books Limited. ISBN 978-1-55297-819-1.

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