Iris nebula

Diffuse nebula


caption= Iris Nebula (NGC 7023 and LBN487) Courtesy Hunter Wilson
name = Iris Nebula
type = Reflection
epoch = J2000.0
ra = 21^h 01^m 35.60^s
dec = +68° 10′ 10.0"
dist_ly = 1,300 ly
appmag_v = 6.8
size_v = 18' x 18'
constellation = Cepheus
radius_ly = 3 ly
absmag_v =
notes =
names = NGC 7023 and LBN487, Caldwell 4

The Iris Nebula, also NGC 7023 and Caldwell 4, is a bright reflection nebula and Caldwell object in the constellation Cepheus. NGC 7023 is actually the cluster within the nebula, LBN 487, and the nebula is lit by a mag. +7 star, SAO 19158. [cite web|url=http://www.astrocruise.com/milky_way/N7023_05.htm|title=NGC 7023|last=Perkins|first=Philip|date=2005|publisher=astrocruise.com|accessdate=2008-08-06] It shines at magnitude +6.8. It is located near the Mira-type variable star T Cephei, and near the bright magnitude +3.23 variable star Beta Cephei (Alphirk). It lies 1,300 light-years away and is six light-years across. [cite web|url=http://apod.nasa.gov/apod/ap041104.html|title=APOD: 2004 November 4 - NGC 7023: The Iris Nebula|last=Nemiroff|first=Robert|coauthors=Bonnell, Jerry|date=2004 November 4|publisher=APOD (NASA)|accessdate=2008-08-06]

References

*cite book|last=Pasachoff|first=Jay M.|title=Stars and Planets|publisher=Peterson Field Guides|location=New York, NY|date=2000|pages=578 pg|chapter=Atlas of the Sky|isbn=0-395-93432-X|language=English
*cite book|last=Caldwell-Moore|first=Sir Patrick|title=Firefly: Atlas of the Universe|publisher=Firefly Books Limited|date=2003|isbn=1-55297-819-2|language=English

External links

* [http://www.seds.org/~spider/ngc/ngc.cgi?7023 NGC 7023]
* [http://simbad.u-strasbg.fr/sim-id.pl?Ident=NGC%207023 Simbad - NGC 7023]
* [http://vizier.u-strasbg.fr/viz-bin/VizieR-S?NGC%207023 VizieR - NGC 7023]
* [http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=NGC%207023 NED - NGC 7023]