Nightscapes & Deep Sky Colors

Astrophotography Brian A. Morganti

Barnard-150 (Seahorse Nebula)

 Dark Nebula



Barnard 150 (B150) dark nebula is a type of interstellar cloud that is so dense that it obscures the light from the background emission or reflection nebula or that it blocks out background stars. The extinction of the light is caused by interstellar dust grains located in the coldest, densest parts of larger molecular clouds.  The form of such dark clouds is very irregular as they have no clearly defined outer boundaries and sometimes take on convoluted serpentine shapes. The largest dark nebulae are visible to the naked eye, appearing as dark patches against the brighter background of the Milky Way. In the inner regions of dark nebulae important events take place, such as the formation of stars and masers.

B150 is also known as the Seahorse Nebula.  With a bit of imagination the dark nebula shown in the image above roughly outlines the shape of a seahorse with its head pointing downward as it floats in a sea of stars roughly 2 degrees wide in the northern sky.


  • Date & Location:  September 11 & 12, 2012 - Bernville, PA

  • Weather:  Calm Winds, Temperature range 53F to 48F (11th) & 58F to 50F (12th).

  • Sky Conditions:  11th & 12th -Clear with average transparency.

  • SQM-L: 11th = 20.39 start - 20.53 finish, 12th = 20:31 start - 20:55 finish

  • Optics:  TeleVue NP101is APO Refractor with 0.8x Focal Reducer (432mm @ f4.3)

  • Filter:  Hutech IDAS-LPS (Light Pollution Suppression)

  • Mount:  AstroPhysics AP900GTO

  • Guiding:  Orion SSAG @5 seconds exposures

  • Camera:  Canon T1i (500d) Hap Griffin modified - Baader UV/IR

  • Exposure:  43 x 10 minute subs @ ISO800 - 430 minutes total exposure (7 hours 10 min)

  • Calibration Frames:  Master Dark & Bias 50F

  • Processing:  Images Plus 4.50b, PS CS6, GradientXTerminator, NIK filter tools 

  • Comments: Dark Nebula are becoming one of my favorite images to photograph, but they do require a large number of sub-exposures and tedious processing in order to to show any fine details such as tendrils.  Although over 7 hours of exposures were used to create the above image, there were at least another 2 hours that were not used due to poor guiding or software rejection. 


Astrophotography  -  Nightscapes & Deep Sky Colors