Pinwheel Galaxy - Messier 101, NGC 5457 (RGB8), OortCloud

Pinwheel Galaxy - Messier 101, NGC 5457 (RGB8)

Pinwheel Galaxy - Messier 101, NGC 5457 (RGB8), OortCloud

Pinwheel Galaxy - Messier 101, NGC 5457 (RGB8)

Equipment

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Acquisition details

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Description

The Pinwheel Galaxy (Messier 101, NGC 5457) is a spiral galaxy located 27,000,000ly away in the constellation Ursa Major (Great Bear, a.k.a. Big Dipper). It is highly asymmetrical, likely due to a near collision with its companion galaxy, NGC 5474, which is heavily distorted, and visible toward the bottom of the image. At least ten other background galaxies are also visible.

Equipment:

-William Optics Zenithstar 73mm FPL-53 doublet APO refractor.

-William OpticsFlat73r focal reducer/field flattener.

-SkyWatcher EQ6R-Pro equatorial mount.

-ZWO ASI533MC-Pro color camera with ZWO luminance filter.

-William Optics Uniguide 32mm guide scope.

-ZWO ASI462MC color camera with Antlia 685nm IR-pass filter.

-ZWO ASIair Pro.

Pre-processing/Calibration performed in DeepSkyStacker:

-32 180-second lights (gain 0), calibrated with temperature matched darks, flats, and bias frames (30 each at minus 10 degrees Celsius).

-Debayered with Auto Homogeneity Directed interpolation.

-Stacked with Auto Adaptive Weighted Average algorithm.

-Export to 3-plane FITS.

Post-processing performed in Siril:

-Crop.

-Background Extraction.

-Photometric Color Calibration.

-Arcsinh Transformation.

-Histogram transformation.

-Export to TIFF.

Final image adjustments performed in GIMP:

-Fine tune black level (Levels).

-Fine tune colors (Curves).

-Modify saturation balance (Curves).

-Increase saturation (Color Saturation).

-Increase contrast (Curves)

-Export to PNG.

Shot from my light polluted back yard (Bortle 6-7) under a 48% illuminated waxing half Moon.

Comments

Histogram

Pinwheel Galaxy - Messier 101, NGC 5457 (RGB8), OortCloud