Nightscapes & Deep Sky Colors

Astrophotography Brian A. Morganti

NGC 7023 - Iris Nebula


50% full resolution view of central area below


The Iris Nebula in the constellation of Cepheus floats like a delicate blue-violet flower 1,200 light years away and is illuminated by a massive young  7.4 magnitude star at its core.   It is a complex mixture of emission, reflection, and dark nebula; listed as van den Berg 139 and LBN 487 and star cluster NGC7023.  Brilliant blue starlight reflecting from a cloud of dust provides most of the Iris Nebula's shimmering facade, tempered by faint red luminescence of dust grains energized by intense ultraviolet radiation.  Additional dust that is more distant from the central star reflects light only dimly, creating an opaque veil hiding more distant background stars. 

The branches of the central nebula might contain complex carbon molecules known as PHAs (= Polycyclic Aromatic Hydrocarbons), suggested by infrared observations. However, the dominant color of the central reflection nebula is blue,  as would be expected from dust particles reflecting the starlight. Other, dark parts of the cold molecular cloud reveal great and obscuring structures.


  • Date & Location:  August  15 & September 3/4, 2013  - StarEffects Observatory, Bernville, PA

  • Weather:  Calm, Average Aug 15th: 51F - Average Sep3/4: 59F, both nights high dewpoints

  • Sky Conditions:  Clear with above average transparency on both nights. 

  • SQM-L:  N1 - 20:42 start - 20:62 end.  N2 - 20:44 start - 20:66 end.

  • Optics:  TeleVue NP101is Refractor w/TeleVue Field Flattener = 540mm @ f5.4

  • Filter:  IDAS-LPS 48mm (Light Pollution Suppression)

  • Mount:  AP900GTO

  • Guiding:  Orion SSAG @ 5 second exposures w/TeleVue TV60is

  • Camera:  Canon T1i (500D) Hap Griffin Modified - Baader UV/IR

  • Exposure:  290 min (29 x 10 minute subs - 4hrs-50min total) @ ISO 800 RAW using Custom White Balance

  • Calibration Frames:  12-10min Darks, 12 Bias, 12 Field Flats w/Alnitak Flat Man - All Custom White Balance

  • Processing:  Images Plus 4.50b, PS CS6, NIK filters

  • Comments:  It has been three years since I first attempted to photograph this beautiful nebula and I wanted to see what I could do by dramatically increasing the length of the subs and overall exposure time.  This combined with better processing techniques yielded far more nebulosity throughout the wide field frame and in the "Iris" itself.  Overall pleased with the results and may be the best I can achieve using a DSLR camera at my present location.   


Comparison below from previous imaging session in 2010



  • Date & Location:  August 7 & 10, 2010  - Bernville, PA

  • Weather:  Calm, 58F & 65F.

  • Sky Conditions:  Clear with average transparency 7th, below average on the 10th.

  • Optics:  TeleVue NP101is Refractor with 0.8x TeleVue Reducer = 432mm @ f4.3

  • Filter:  Astronomic  EOS clip-in CLS-CCD (Light Pollution Suppression)

  • Mount:  Losmandy G-11 equatorial with Gemini V4

  • Guiding:  Orion Solitaire w/TeleVue TV60is

  • Camera:  Canon T1i (500D) Hap Griffin Modified - Baader UV/IR

  • Exposure:  30 min (3 x 5min, 1 x 7min, 1 x 8) @ ISO 800 RAW

  • Calibration Frames:  In Camera Dark Noise Reduction

  • Processing:  Images Plus 3.82b, Photoshop CS4, NIK

  • Comments:  The above image is a bit dim and small for a 4" scope but image processing was able to bring out some of the faint surrounding dark nebulosity.  Many more images are necessary to bring out the faint details. 


Astrophotography  -  Nightscapes & Deep Sky Colors