Messier 83 – A Beautiful "Grand Spiral" Galaxy (Alex Woronow)

Messier 83 – A Beautiful "Grand Spiral" Galaxy

Messier 83 – A Beautiful "Grand Spiral" Galaxy

OTA: CDK24
Camera: Moravian 61000Pro
Observatory: Heaven's Mirror
Date of Capture: Mar 24
Date of Processing: Apr 24

Exposures Used:
R: 7 x 600 sec
G: 9 x "
B: 10 x "
L: 17 x "
H: 7 x 900 sec
Total Exposure time: 8.9 hours
Image Width: 29' 30"

Processing Tools:
1.   Commercial: PixInsight, Topaz, Radiant Photo
2.   Pixinsight Addons: NoiseXTerminator, BlurXTerminator, StarXTerminator
3.   My Scripts: NB_Assistant, AC_Restar, Subframe Weighting Tool (Excel w/ J. Hunt), ColorTweaker

Target Description:
M 83 is a "grand design," a weakly barred galaxy seen almost face-on. In this image, the galaxy is rotating clockwise. Looking at the innermost spiral arm, at about 5:00, that part of the arm and the entire arm clearly shows a blue leading edge. That blue indicates star formation. Apparently, "density wave theory" predicts the leading edge will be most active for star formation (Wikipedia). BTW, that leading-edge = max star formation also holds for the rest of the spiral arms.

Processing Description:
This image had a considerable red-to-green gradient across the image. Aahaa said I! A great chance to learn to use PI's new gradient-correction tool! 30 minutes later, and not coming close to a decent result, back I went to Dynamic Background Modeling! The gradient-correction process is too complex…, with too many adjustments and little guidance. Adjusting slider A affects slider B's, C's, and D's effects. There has got to be a better method. WAIT! I know! AI! (GradXpert is a good start, but it needs to better recognize background versus target object.)

Target Statistics:
Distance: 14.7M ly
Apparent Magnitude: 7.6
Absolute Magnitude: -20.7
Average Surface Magnitude: 22.9
Apparent DSO Span: 0.31deg (118k ly)
Pixel Span at Target: 2.6E16 km
FWHM (on raw luminance sub): 1.3"

Alex Woronow

Final
Original
B

B

Title: Annotated

Uploaded: ...

	Distinct awarded users	Total awarded images
Image of the day
Top picks
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	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
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Unknown

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Status	Advanced success
Started	...
Astrometry.net job	9594146
PixInsight job	Y404VAOO6UQNVGZ9NRIDIKV1TSN5G0FD
PixInsight queue size	n/a
PixInsight stage	TASK_LOG

RA (center)	13h37m00s.188
RA (top/left)	13h35m52s.650
RA (top/right)	13h38m08s.292
RA (bottom/right)	13h38m08s.700
RA (bottom/left)	13h35m52s.294

Dec (center)	-29°52′04″.36
Dec (top/left)	-30°01′42″.20
Dec (top/right)	-30°01′42″.45
Dec (bottom/right)	-29°42′21″.24
Dec (bottom/left)	-29°42′21″.50

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