2021 Michael A. Siniscalchi


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Dark Nebula in Cygnus
RA: 21h 17m 41s  Dec: +43 17m 38s, Distance: ~2837 ly, Size: 31x16 arcmin

Click on image for larger size.
Location & Date
Backyard, Abbott Observatory- Long Island, NY, September 2020
TMB130SS F/7 APO, Moonlite focuser, Losmandy G11 Gemini
Image scale 1.54 arcsec/pixel
Baader 5nm Ha  & G,B filters
CCD temp -15C
Ha-6x10m, Green-9x5m, Blue-9x5m Bin 1x1 per each 4 panel mosaic
Planning & Acquisition
Mosaic planning - Sequence Generator Pro
Image acquisition - Sequence Generator Pro w/PinPoint & PHD2 (guiding)
CCDStack - calibration, de-bloom
Astro Pixel Processor -  Normalize, Alignment, Combine, mosaic stitching 
Adobe Photoshop - Color blending, Noise reduction, JPEG conversion
This is a 4 panel mosaic using Ha (Red)+G+B

I wasn't able to find any write-ups on LDN 944 specifically so I will post an excerpt from Wikipedia about dark nebulas.

   A dark nebula or absorption nebula is a type of interstellar cloud that is so dense that it obscures the visible wavelengths of light from objects behind it, such as background stars and emission or reflection nebulae. The extinction of the light is caused by interstellar dust grains located in the coldest, densest parts of larger molecular clouds. Clusters and large complexes of dark nebulae are associated with Giant Molecular Clouds. Isolated small dark nebulae are called Bok globules. Like other interstellar dust or material, things it obscures are only visible using radio waves in radio astronomy or infrared in infrared astronomy. Dark clouds appear so because of sub-micrometre-sized dust particles, coated with frozen carbon monoxide and nitrogen, which effectively block the passage of light at visible wavelengths.
LDN 944 Ha uncropped 4 panel mosaic