This nebula is unique among such formations. Many of the nebulae visible in the night sky are emission nebulae, but Iris Nebula (NGC 7023), is a reflection nebula. This means that its colour comes from the diffuse light of its central star, which is in a stellar field in the constellation Cepheus.
Located about 1,400 light-years away, the Iris Nebula is 6 light-years in diameter. The research of such nebulae helps scientists understand more about the elements that combine to form stars.