I decided to do a deep dive into just the core of the Heart Nebula itself. Mellotte 15 is the name for the bright structure in the image, but the rest of the nebula itself is pretty extensive, and features the nearby soul nebula. IMO the uncropped heart nebula looks more like a chode with huge balls, but I can kinda see where it got it's heart name.... Captured over 8 nights in November 2024 from a bortle 9 zone.
Acquisition: 29 hours 50 minutes (Camera at -15°C), unity gain
Ha - 58x600"
Oiii - 62x600"
Sii - 59x600"
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
made SHO image and extracted stars to be processed separately
StarXterminator to completely remove stars from each Ha, Oiii, and Sii image
HistogramTransformation to stretch nonlinear
Stars only image:
SpectrophotometricColorCalibration (narrowband working mode)
HSV repair
arcsinhstretch
scnr > invert > scnr > invert to remove greens and magentas
HistogramTransformation
(combined with starless pic later on)
Nonlinear:
PixelMath to combine monochrome Ha Oiii and Sii images into a color image with SHO --> RGB, respectively
HistogramTransformation to adjust red green and blue color channels separately (basically stretched R and B, and toned the G down some)
LRGBCombination using stretched Ha as luminance
DeepSNR
Shitloads of Curve Transformations to adjust lightness, hues, contrast, saturation, etc
Clone stamp to remove one weird small blue speck near the core of the nebula (might've just clipped the colors a little too much in the histogram adjustments above^)
LocalHistogramEqualization (two rounds of this. one at kernel radius 16 for small scale detail, and one at 500 for large structures)
More curves
DarkStructureEnhance script (0.15 amount)
Pixelmath to add in the stretched RGB stars only 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))
some more curves
One more round of noiseX for small scale noise reduction