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Getting plate-solving status, please wait...

The Flying Bat, the Giant Squid & the Little Friend

Technical card

Resolution: 2074x2769

Dates:Aug. 31, 2019Sept. 1, 2019Sept. 2, 2019Sept. 6, 2019Sept. 7, 2019Sept. 8, 2019Sept. 14, 2019Sept. 15, 2019Sept. 25, 2019Sept. 26, 2019Sept. 27, 2019Sept. 28, 2019

Astrodon 3nm Ha 31mm: 276x300" (gain: 200.00) -10C bin 1x1
Astrodon 3nm OIII 31mm: 236x300" (gain: 200.00) -10C bin 1x1
Astrodon 3nm SII 31mm: 196x300" (gain: 200.00) -10C bin 1x1
Astrodon E Series Gen II Blue 31mm: 72x60" -10C bin 1x1
Astrodon E Series Gen II Green 31mm: 72x60" -10C bin 1x1
Astrodon E Series Gen II Red 31mm: 72x60" -10C bin 1x1

Integration: 62.6 hours

Darks: ~40

Flats: ~40

Flat darks: ~40

Avg. Moon age: 14.52 days

Avg. Moon phase: 36.36%

Bortle Dark-Sky Scale: 7.50

Mean SQM: 18.82

Temperature: 30.79 job: 2951612

RA center: 318.069 degrees

DEC center: 59.828 degrees

Pixel scale: 3.923 arcsec/pixel

Orientation: 359.794 degrees

Field radius: 1.885 degrees

Locations: Backyard, Coppell, Texas, United States; TAS Atoka Dark Site, Atoka, Oklahoma, United States

Data source: Backyard


... The plan was to go to TAS-Atoka dark site one more time for the Ou4 ...

Looking at the weather over the new moon weekend, The trip is not going to happen. Decided to go with available data for the processing.

This target was planned at the beginning of the year as the first light target for the pre-owned Mach1. From the backyard, the effort failed miserably. Just can't scratch it off the back once it started. Here is the result of the second try.

Comparing to the first attempt, the biggest differences are:
- Use 0.73x reducer to drop the f-stop from f5.35 to f3.89
- Capture Ou4 from dark site (not doable from the backyard)

The data for this image is all from backyard except the Ou4. There were three trips from DFW to TAS-Atoka site. Collected about 20 hours of O3 data (Yeah, it was a little crazy using 3 nights at dark site to shoot 3nm narrowband data...). The O3 data is still not enough (maybe it will never be). Processing for the Ou4 is indeed challenging. A side-by-side comparison of all 4 masters is also uploaded. Ou4 signal is tangled with the its surrounding. Combining color layers in Photoshop definitely is a joy to work with. The same O3 signal from the calibrated master frame is used without extra stretching. The Ou4 looks cleaner this way and that's what I would preferred.

Sh2-129 has an unusual shape and indeed it has lots of textures. In this project, data amount for the Ha is even more than the O3. Of course, for Ha and S2 channels, backyard has much much lower cost of time and energy. 16 hours of S2 contributes a very faint touch of the gold tune along the border of the Sh2-129 (maybe it's totally unnecessary, but I can't accept the fact that there is no S2 data! LOL).

The little friend at the bottom left corner - the star in the middle should be V421 Cep, but the name of this little cloud structure could not be found anywhere. Tried Simbad and NED without luck. Anybody know? Another interesting thing is that I can't find any official words about how far away the Ou4 is. Is it actually in the Sh2-129 or much further away?

Thanks for looking! (Special thanks to Nico Carver and Jon Rista for the encouragement and technical guidance.)

Comments are welcome!
09.29.2019 from Coppell, Texas


Pre-processing of Narrowband Masters

- Calibration / Integration, Astro Pixel Processor
- Deconvolution, PixInsight (Ha and O3)
- MultiscaleMedianTransform (Denoise), PixInsight
- ScreenTransferFunction / HistogramTransformation, PixInsight.

Pre-processing of RGB Masters

- Calibration / Integration, Astro Pixel Processor
- Dynamic Background Extraction, PixInsight
- MorphologicalTransformation, PixInsight
- ScreenTransferFunction / HistogramTransformation, PixInsight.

RGB Combination

- LRGBCombination, PixInsight
- MorphologicalTransformation, PixInsight
- ScreenTransferFunction / HistogramTransformation, PixInsight.

Narrowband Combination

- Color Combination, Photoshop

Narrband & RGB Combination

- Star Layer Combination, Photoshop
- HR8119 Star Glow, Star Spike Pro, Photoshop



Min Xie


Sky plot

Sky plot


The Flying Bat, the Giant Squid & the Little Friend, 


            Min Xie