Caldwell 4 - Iris Nebula
 
Date:
 
September 10-14, 2015
 
Location:
 
Landers, California USA
 
Telescope:
 
Explore Scientific ED127 Apo
 
Camera:
 
SBIG STF-8300M
 
Mount:
 
Astro-Physics Mach1GTO
 
Acquisition:
 
Maxim DL Pro 6
 
Filters:
 
Baader LRGB
 
Total Integration:
 
12.42 hours
 
Subexposures:
 
L: 37 x 600s (1x1)
R: 25 x 300s (2x2)
G: 25 x 300s (2x2)
B: 25 x 300s (2x2)
 
Calibration:
 
Darks: 30ea
Bias: 30ea
Flats: 30ea
 
The Iris Nebula, also known as Caldwell 4 and NGC 7023, is a bright reflection nebula in the constellation Cepheus. NGC 7023 is actually the star 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.