2021 Michael A. Siniscalchi


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Odds n Ends

        Emission Nebula in Cygnus
      RA:20h 32m 34s  Dec: +47 21' 00"

Click on image for larger size.
Location & Date
Backyard, Abbott Observatory- Long Island, NY,  August, 2020
TMB130SS F/7 APO, Moonlite focuser, Losmandy G11 Gemini
Image scale 1.54 arcsec/pixel
Baader  Ha,OIII, R,G,B filters
CCD temp -15C
Ha-10x23m OIII-3x10m  Red-6x5m  Green-6x5m Blue-6x5m Bin 1x1
Planning & Acquisition
Image planning - Sequence Generator Pro
Image acquisition - Sequence Generator Pro w/PinPoint & PHD2 (guiding)
CCDStack - calibration, debloom, align, normalize, combine, deconvolution
Adobe Photoshop - Ha OIII RGB Image composition, Noise reduction, JPEG conversion
Sh2-116 is the designation of the small round patch of emission nebula within this vast Hydrogen and dust complex located in Cygnus. It is also known as Abell 71 and PK85+4.1.with the latter being designated as a planetary nebula prior to 1991. Further analysis now lists it as a hydrogen emission nebula even though Oxygen can be detected using a narrow band OIII filter.

This image is a composite of Ha and OIII combined and added to an RGB star field. Research into this objects lists it now as an emission nebula (vs. a planetary nebula) but imaging using narrow band filters clearly shows an oxygen component to it.
The below images show a strong Hydrogen alpha (Ha) structure and a 30 minute oxygen (OIII) structure.

Sh2-116 Ha (Hydrogen alpha)  230 minutes exposure
Sh2-116 OIII (Oxygen) 30 minutes exposure
Sh2-116 Red Green Blue starfield (30 minutes total per channel)