Reflection nebula | |
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Iris Nebula (NGC 7023 and LBN487) | |
Observation data: J2000.0 epoch | |
Right ascension | 21 01 35.60 |
Declination | +68° 10′ 10.0″ |
Distance | 1,300 ly |
Apparent magnitude (V) | 6.8 |
Apparent dimensions (V) | 18' x 18' |
Constellation | Cepheus |
Physical characteristics | |
Radius | 3 ly |
Designations | NGC 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. 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.
Notes
- Perkins, Philip (2005). "NGC 7023". astrocruise.com. Archived from the original on 2008-05-18. Retrieved 2008-08-06.
- Nemiroff, R.; Bonnell, J., eds. (2004-11-04). "NGC 7023: The Iris Nebula". Astronomy Picture of the Day. NASA. Retrieved 2008-08-06.
References
- 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.
External links
- "NGC 7023". SIMBAD. Centre de données astronomiques de Strasbourg.
- SEDS – NGC 7023
- VizieR – NGC 7023
- NED – NGC 7023
- Dark Atmospheres Photography – Iris Nebula NGC 7023
- See NGC 7023 in WorldWide Telescope
- Iris Nebula on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
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Caldwell |
Caldwell catalogue | |
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