Image taken on 2016 May, with the GSO telescope and the ATIK-One CCD. It is the result of a LRB sequence of 18Lx900s + (13R+13B)x600s, for a total of 8hr 50m of exposition.
The Iris Nebula, also known as NGC 7023 and Caldwell 4, is a bright reflection nebula and Caldwell object in the constellation Cepheus. NGC 7023 is actually the star cluster within the nebula named LBN 487, and the nebula is lit by a star, named SAO 19158 which 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. (Wikipedia)