The Iris Nebula (also known as NGC 7023 and Caldwell 4) is a bright reflection nebula in the constellation Cepheus.
The nebula, which shines at magnitude +6.8, is illuminated by a magnitude +7.4 star designated HD 200775. The nebula’s dominant color, blue, is the result of dust grains reflecting star light.
More technical details on my astrobin profile: NGC 7023 – AstroBin
Last Update: August 15, 2025
