An iconic reflection nebula , NGC7023 or Iris nebula is part of a very large molecular cloud system in the constellation Cepheus. The bright core is illuminated by the HD 200775 star and evokes the image of the flower.
NASA describes in this way the core typical color: “The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the reflection nebula glow with a faint reddish photoluminesence as some dust grains effectively convert the star’s invisible ultraviolet radiation to visible red light.“
This image is the result of about 25 hours of integration in LRGB (15hrs L and 5.6hrs R/G/B each)
High resolution here
