The Great Puffy Space Pelican (Aaron Freimark)

The Great Puffy Space Pelican

Link to TIFF/FITS: https://www.dropbox.com/s/0z93rr7ly68npj2/Pelican-RGB-Stars-crop.xisf?raw=1

It's the Great Puffy Space Pelican.

The Pelican Nebula is one of the largest, brightest nebulae of the summer (here in the Northern Hemisphere).

And it's finally summer! Which means I can put away my broadband red, green and blue filters, and instead take out my narrowband filters. Narrowband filters allow only one very, VERY specific color to pass. So I need long exposures to gather light — 5 minutes each here — but I filter out all the background light pollution that usually brightens the skies.

Which specific color? Nebula are filled with excited hydrogen gas. My filters allow me to capture the PRECISE wavelength a hydrogen electron emits when excited. That energy, in the form of red light of a specific frequency, travels unchanged 10,000 years until it reaches my telescope. So we see here the physics of both the great and miniscule.

1. WeightedBatchProcessing, weighted by count of Stars + Registration

2. Local Normalization

3. Drizzle Integration

4. Dynamic Crop

5. EZ Decon on Ha

6. EZ Denoise on each filter

7. ArcsinhStretch a little

8. In Photoshop, paint a simple mask to cover the largest stars

9. StarNet++ to remove stars to a separate document (one for each channel) — except for the largest stars which would otherwise be wrecked by StarNet

10. ArcsinhStretch the (mostly) starless images a tiny bit more

11. HDRMultiscaleTransform on Ha

Stars:

1. PixelMath to create HOO stars

2. Histogram Transformation to made stars desired size

3. Photometric Color Calibration (why not?)

RGB:

1. PixelMath to create RGB: R: Ha / G: 0.1*Ha + 0.9*OIII / B: OIII

2. LRGBCombination to re-apply Ha as the L channel

3. CurvesTransformation to bring out more color

4. UnsharpMask

5. A touch of Topaz Denoise AI

6. PixelMath to add stars again: K: 1 - (1-RGB * 1-starsRGB)

7. Crop and rotate

Mid-Hudson Astronomical Association (MHAA)
Northeast Imagers
INDI Users

	Distinct awarded users	Total awarded images
Image of the day
Top picks
Top pick nominations

	Image of the day	Top pick	Top pick nominations	Total submitted
Deep sky
Solar system
Extremely wide field
Star trails
Northern lights
Noctilucent clouds
Landscape

	Image of the day	Top pick	Top pick nominations	Total submitted
Backyard
Traveller
Own remote observatory
Amateur hosting facility
Public amaeteur data
Professional, scientific grade data
Mix of multiple sources
Other
Unknown

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Status	Advanced success
Started	...
Astrometry.net job	4613938
PixInsight job	2874G93O6KGNO59Z2UAMDRRU49FIO5EW
PixInsight queue size	n/a
PixInsight stage	n/a

RA (center)	20h51m13s.99
RA (top/left)	20h56m37s.61
RA (top/right)	20h48m46s.40
RA (bottom/right)	20h45m58s.98
RA (bottom/left)	20h53m35s.87

Dec (center)	+43°59′54″.9
Dec (top/left)	+44°44′30″.4
Dec (top/right)	+45°08′03″.3
Dec (bottom/right)	+43°14′35″.10
Dec (bottom/left)	+42°51′54″.0

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