The Iris Nebula


Ron Brecher

Guelph, Ontario, Canada

SBIG STL-11000M camera, Baader R, G and B filters, 10″ f/6.8 ASA astrograph, Paramount MX. Guided with SBIG’s external guide camera and 80 mm f/6.25 Lumicon achromatic refractor. Acquisition, guiding and mount control with TheSkyX. Focusing with FocusMax. Automation with CCDCommander. All preprocessing and post-processing in PixInsight. Shot from my SkyShed in Guelph, Ontario. Little to no moonlight, good to excellent transparency, and good to very good seeing throughout acquisition.

20 x 15m unbinned with each of R, G and B filters (total = 15 hr). Complete processing details are at

This is the Iris Nebula, NGC7023. It is a reflection nebula, the blue coming from light reflected off soot/dust behind the bright star. There is lots of soot and dust visible throughout the image. This nebula is in our own Milky Way galaxy, and is relatively close at about 1,300 light years from Earth. The star at the centre of the nebula is easy in binoculars, but the nebula itself is very challenging to see visually. I imaged this object in 2013, but covered a relatively small field compared to this version, which does a better job at showing how dusty this region of space is.