There is another piece of beautiful nebulosity in the Cepheus constellation – it is Iris nebula (NGC7023 or Caldwell 4). It is typical reflection nebula lit by the 7 magnitudo star SAO 19158 placed in its center. Actually the NGC7023 symbol does not denominate the nebula itself, but the star cluster placed immediately to the west of the nebulosity region. The correct designation of the nebula is LBN487. Dust particles that shines in the Iris nebula are leftovers from when the star was formed.
The whole complex is about 1300 light years away and its radius is about 3 light years. There are also faint hints of red color surrounding the central star – this is evidence that some hydrogen emission takes place.
The photo above has been exposed during three nights – 10h total exposure of luminance and 5h total RGB channels. Processing took me more less the same amount of time – I started all over again four times from scratch. Iris nebula is quite demanding target and requires dark sky (not at my site), fast optics (I am almost there) and large aperture (not really me 🙂 )
Below cropped nebulosity center: