The Iris Nebula, (NGC 7023, Caldwell 4)

5.1.15

The Iris Nebula, also NGC 7023 and Caldwell 4, is a bright reflection nebula and Caldwell object in the constellation Cepheus, (The Caldwell Catalogue is an astronomical catalog of 109 star clusters, nebulae, and galaxies for observation by amateur astronomers. The list was compiled by Patrick Moore as a complement to the Messier Catalogue). NGC 7023 is actually the cluster within the nebula, LBN 487, and the nebula is lit by amagnitude +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.

This is a crowd image, made by combining 156 Creative Commons images. Integration time is based on an average of 50 random samples.

Author: Morten Balling