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NGC7023 / The Iris Nebula

Classification: Reflection nebula NGC7023, Caldwell 4
Constellation: Cepheus (Cep)
Object Location: Ra 21h 01m 49s Dec +68° 14’04° (current)
Size & Distance: 18 x 18 Apx 1,300 light-years.

Date & Location: 08-02-2008 Palomar Mountain, CA
Exposure: LRGB, L= 20 @ 3min, RGB=15ea. @ 4min. All (bin 1x1)
Optics: Takahashi Epsilon-180 f2.8 504mm.
Mount: Astro-Physics 900 GTO / ATS 10x36 pier
Camera: SBIG-ST10XME @-10c
Filters: Astrodon G1 RGB
Software: MaxImDL 4.56, Photoshop CS

Notes: Sky conditions: Good seeing, Calm wind, Temp 66°
Image Field of view is 68 x 101 arcmin.
This image was an Astronomy Magazine Picture Of The Day, Sept 2009

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 magnitude +7 star, SAO 19158. 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.