So technically 32 Cygni is just the bright star in the pic, and the rest of it is just hydrogen gas floating around in space. The constellation Cygnus has a ton of this hydrogen-alpha gas floating around, and I kinda just pointed at a semi-random spot in the constellation to get a pic. Although this was taken with an Ha filter, the stars are true color RGB, and I mapped the Ha channel to red so it closely resembles the actual color of hydrogen-alpha. Also for those curious here is a starless version that better shows the faint nebulosity/structures. Also pls ignore the crunchiness around 32 Cyg itself, it’s an artifact of my camera’s microlensing + the star removal program I use. Captured over like a dozen nights in December 2024 from a bortle 9 zone.

Places where I host my other images:

Flickr | Instagram

---

Equipment:

• TPO 6" F/4 Imaging Newtonian

• Orion Sirius EQ-G

• ZWO ASI1600MM-Pro

• Skywatcher Quattro Coma Corrector

• ZWO EFW 8x1.25"/31mm

• Astronomik LRGB+CLS Filters- 31mm

• Astrodon 31mm Ha 5nm, Oiii 3nm, Sii 5nm

• Agena 50mm Deluxe Straight-Through Guide Scope

• ZWO ASI-290mc for guiding

• Moonlite Autofocuser

Acquisition: 29 hours 18 minutes (Camera at -15°C), unity gain

• Ha - 161x600"

• R - 51x60"

• G - 59x60"

• B - 48x60"

• Darks- 30

• Flats- 30 per filter

Capture Software:

• Captured using N.I.N.A. and PHD2 for guiding and dithering.

PixInsight Preprocessing:

• BatchPreProcessing

• StarAlignment

• Blink

• ImageIntegration per channel

• DrizzleIntegration (2x, Var β=1.5)

• Dynamic Crop

• DynamicBackgroundExtraction

  duplicated each image and removed stars via StarXterminator. Ran DBE with a shitload of points to generate background model. model subtracted from original pic using the following PixelMath (math courtesy of /u/jimmythechicken1)

  $T * med(model) / model

Narrowband Linear:

• Blur and NoiseXTerminator

• StarXterminator to completely remove stars from each the image

• HistogramTransformation to stretch nonlinear (calling this the Ha image now)

Broadband/RGB linear:

• ChannelCombination to make color image from R G and B stacks

• StarX (correct only)

• SpectrophotometricColorCalibration

(duplicated image at this point, to be used for stars only processing later)

• StarX to completely remove stars (at this point it’s just background, with a little bit of signal in the R channel)

• Blended unstretched Ha image into the red (and a little bit of the blue channel) with this pixelmath:

  R = $T+B*(Ha- med(Ha))

  G = $T

  B = $T+B*0.2*(Ha- med(Ha))

  honestly can’t remember what I used for the B constant, but the default is 2 in my pixelmath ¯\_(ツ)_/¯

• HistogramTransformation to stretch nonlinear (calling this the Starless image now)

Stars only processing:

• HSV repair to fix blown out star cores

• StarXterminator to generate an image containing only the stars (without any background)

• ArcsinhStretch + Histogramtransformation to stretch nonlinear (Calling this the Stars image now)

Nonlinear:

• LRGBCombination to add the stretched Ha image to the stretched Starless image as a luminance layer

• NoiseXterminator

• Background neutralization

• Several curve transformations to adjust lightness, contrast, saturation, color balance, etc

• LocalHistogramEqualization

• Another round of noiseX

• Pixelmath to add in the stretched RGB Stars image from earlier

  This basically re-linearizes the two images, adds them together, and then stretches them back to before. More info on it here)

  mtf(.005,

  mtf(.995,Stars)+

  mtf(.995,Starless))

• few more curve adjustments

• FastRotation 180 degrees (pic was originally upside down)

• DynamicCrop again (just a little bit)

• Resample to 60%

• Annotation

Hey cool pic! Thanks for sharing it and the detailed writeup! Can I use it as a wallpaper on my tablet please?