The Iris Nebula is located in the constellation Cepheus. In the case of the official designation of the Iris Nebula (NGC 7023), it is confusing what the various catalogs designate.
In this area a magnitude 7 star and a nebulosity were discovered by William Herschel on 18th October, 1794. Nowadays this star is known as SAO 19158. The nebulosity was designated NGC 7023 by Dreyer. Herschel also mentioned some magnitude 9-10 stars in this 1° area. Per Collinder has named this star group around the nebulosity as Collinder 429 open cluster in 1931. Later the nebulosity was named vDB (van den Berg) 139 too by a newer examiner. The all group, the nebulosity (NGC 7023 = vDB 139) and the open cluster (Collinder 429) together creates the Caldwell 4 in Caldwell's catalog.
The Iris Nebula is located 1,300 light-years from Earth, its diameter is about 6 light-years, and it appears near the magnitude 3.2 β Cephei. The shape of the reflection nebula glowing in blue resembles the plant Iris, hence the name of the object. Like all bluish reflection nebula, it is also illuminated by a star. In this case the star is the SAO 19158 in the centre of the reflection nebula, what was created by the star itself. The young, hot star sweep the interstellar dust and gases out from its vicinity, by its intense stellar winds. As it can be seen in the picture, the dust cloud - where new stars born, - is much bigger than the area of the reflection nebula being lit by the star, actually is even bigger than the field of view of this photo. Although the density of the cloud is rather low, it is still opaque in the visible wavelengths because of its vast proportions. It blocks the light coming from stars and other kinds of objects behind it.

Circumstances of creating this picture
I collected photons for this picture for almost than 16 hours (4 nights) at dark site (Bortle 3) near Szeged in Hungary.