Nightscapes & Deep Sky Colors

Astrophotography Brian A. Morganti

NGC 7635 Bubble Nebula

NGC 7654 (M52) Open Cluster



This a one of those rare spots in the sky where you can observe two very different objects in the same field of view.  The Bubble Nebula (NGC7635) is located near Cassiopeia and the "bubble" is visible in the lower right of the photo.  It is shaped by powerful solar winds from a Wolf-Rayet star impacting a giant molecular cloud.  This star is an energetic OB type star HD 220057, whose stellar winds have blown away gas near the star and formed a bubble of ionized glowing gas. The star HD 220057 is a hot massive giant 40 times more massive than our Sun. 

Open star cluster M52 (NGC7654) is visible in the upper left of the photo and is a cluster of hundreds of young stars that formed together around 35-50 million years ago, making it a relatively young star cluster.  M52 has a diameter of about 15-19 light-years. The brightest member of the star cluster is a magnitude 8.2 yellow G-type giant, while most of the stars are blue-white B3 main sequence stars.  The two objects are similar distances from Earth: M52 at about 5,100 light-years and the Bubble Nebula at about 7,100 light-years.


  • Date & Location:  October  1/2 & 2/3, 2013  - StarEffects Observatory, Bernville, PA

  • Weather:  Calm, Average temperature of 56F for both nights.

  • Sky Conditions:  N1: Clear - Average Transparency   N2: Clear > patchy cirrus - Average Transparency

  • SQM-L:  N1: 20:46 start - 20:58 end.  N2:  20:51 start - 20:48 end.

  • Optics:  TeleVue NP101is Refractor 540mm @ f5.4 no Field Flattener used

  • Filter:  CLS-CCD Astronomic DSLR clip in  (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:  234 min (26 x 9minute subs = 3hrs-54min total) @ ISO 800 RAW using Custom White Balance

  • Calibration Frames:  16-10min Darks, 16 Bias, 12 Field Flats w/Alnitak Flat Man - All Custom White Balance

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

  • Comments:  This is another re-do of an image I took 4 years ago which is shown below for comparison.  Overall satisfied with the results, but certainly still room for improvement. 


Earlier image attempt & capture details below from 2009



  • Date & Location:  December 12, 2009 (evening) - Bernville, PA

  • Weather:  Calm wind, 28F.

  • Sky Conditions:  Thickening Cirrus clouds with poor transparency. 

  • 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:  58 min (6 x 5 min, 7 x 4 min) @ ISO 800 RAW

  • Calibration Frames:  No dark frame subtraction (28F)

  • Processing:  Photoshop CS4, Noise Ninja, GradientXTerminator, NIK 

  • Comments:  Given the abundance of cirrus clouds and higher than normal light pollution from a local event I am surprised this image even shows a hint of the "bubble".  I'll need to try this one again when better sky conditions prevail.


Astrophotography  -  Nightscapes & Deep Sky Colors