This is another image from the archives of telescope live – the spiral galaxy M83. I noticed while processing that this dataset was deep enough to include a fainter outer halo that I couldn’t find, so I wanted to show as much of this new halo as I could. It was tricky to balance the brightness of the core with the brightness of the outer halo, but using some pixelmath tricks in conjunction with HDR and GHS I think I was able to do a pretty good process. Given that this dataset was so good, I did a lot of sharpening to it, so the core and dust lanes are extremely clear! This is about 15 hours of data from Chile.
Big, bright, and beautiful, spiral galaxy M83 lies a mere twelve million light-years away, near the southeastern tip of the very long constellation Hydra. Prominent spiral arms traced by dark dust lanes and blue star clusters lend this galaxy its popular name, The Southern Pinwheel. But reddish star forming regions that dot the sweeping arms highlighted in this sparkling color composite also suggest another nickname, The Thousand-Ruby Galaxy. About 40,000 light-years across, M83 is a member of a group of galaxies that includes active galaxy Centaurus A. In fact, the core of M83 itself is bright at x-ray energies, showing a high concentration of neutron stars and black holes left from an intense burst of star formation. This sharp composite color image also features spiky foreground Milky Way stars and distant background galaxies.
Image:
Full-quality PNG here: https://live.staticflickr.com/65535/52730117569_bf3e15bb86_o.png
Annotated Image:
Full-quality image here: https://theastroenthusiast.com/wp-content/uploads/2023/03/M83_annotated_annotaed.jpg
Details:
Telescope: Planewave CDK24
Camera: FLI PL 9000
Filters: Astrodon LRGB 2GEN
Location: El Sauce Observatory
Date of Observations: 2/8/2021, 2/11/2021, 2/14/2021, 3/23/2021, 5/1/2021, 6/1/2021, 7/1/2021, 7/10/2021, 8/2/2021, 3/27/2022, 3/28/2022,
L: 15 x 600s (2h 30min)
R: 12 x 600s, 26 x 300s (4h 10min)
G: 14 x 600s, 26 x 300s (4h 20min)
B: 13 x 600s, 26 x 300s (4h 20min)
Processing: Pixinsight
Credits: Data: Telescope Live; Processing: William OstlingProcessing:
Pre-processing and Stacking
- Images were cosmetic corrected for hot pixels
- The subframes were weighted, registered, normalized, integrated, and drizzled in WBPP
Preparation of all frames:
- Stacking artifacts were cropped
- RGB Channels were combined to create an RGB image
- RGB image was plate solved
- Starless DBE was applied to L, RGB as follows:
- Starnet 2 was applied to a clone of the target image, creating an image with stars and an image without stars
- DBE was applied on the starless image to create a background model
- The background model was subtracted from the stars image
- the RGB image was photometrically color calibrated and clipped H values were fixed with the repaired HSV separation script
Deconvolution of the luminance
- a PSF was created using the dynamic PSF process
- Linear starnet was applied to create a starless image and a star mask
- the linear image was duplicated, stretched, clipped, and convoluted to create a mask
- The starless image was deconvoluted using the RVC algorithm
- the stars were added back in
- A low contrast mask was created and applied to the luminance image
- Noise Xterminator was applied with strength 73 and detail 0
- DeepSNR noise reduction was applied to RGB
Stretching
- The Luminance image was stretched using HT and GHS
- The RGB image was stretched using ArcsinH and GHS
Non-linear adjustments
- Saturation adjustments on RGB
- LRGB combination
- Exponential Transformation
- Star reduction
- HDR MST
- Saturation Adjustment
- Fix noisy stars
- LHE
- Background fix
- Sharpening using MMT and unsharp mask
- LHE
- Saturation Adjustment