M83 Southern Pinwheel Galaxy Ha LRGB ( Bortle 8 Skies )

[Startrek]

I’ve been working on this project since January and finally gathered enough data to fashion some sort of image above all the heavy noise gradient . Every time the new moon comes around cloudy nights appear and then disappear when the moon’s up.


Bortle 8 City Suburban location
New Moon period
Seeing conditions average to good

Telescope 8” f5 Klaus Helmerich Carbon Fibre ( Self Built ) focal length 1050mm.
Mount Skywatcher EQ6-R Pro
Imaging camera ZWO2600MM cooled to -10C , Gain 0 for LRGB and Gain 100 HCG for Ha
TS Optics GPU coma corrector with Beamtech 15mm spacing ring
Antlia LRGB and Ha 3nm filters
PHD2 Multistar guiding ( 0.40 to 0.50 arc sec total )
Orion 60mm guide scope with helical focuser
ZWO EFW 7 x 2”
ZWO EAF focuser
Tracking and Goto EQMOD and Stellarium
Aquisition and Capture , APT

Luminance 336 x 30sec dithered subs
Red 160 x 30sec dithered subs
Green 138 x 30sec dithered subs
Blue 149 x 30 sec dithered subs
Ha 61 x 2 min dithered subs

Full Calibration Suite
Darks from Library
Flats for LRGB and Ha
Flat Darks for LRGB and Ha
Total integration 8.5 hours

Subs reviewed in ASTAP

Data analysed, calibrated , stacked and aligned in ASTAP

Post processed in Startools version 1.8 via Compose module using Luminance / Color : L + Synthetic L from RGB , RGB.

SV Deconvolution PSF module was used with default settings only.

NB: This image is presented as documentary astrophotography and does not use any AI enhanced or AI assisted technology during post processing.

Link to Astrobin for full resolution….,
https://www.astrobin.com/full/4vy31b/0/

Thanks for Looking

Comments most welcome

Martin

[decay]

Hi Martin,

kudos for your dedication to do broadband imaging under Bortle 8 skies. I wouldn't have thought that such results are possible. The HII and the starbust regions look very nice, as well as the dust lanes do. Well done! This galaxy has a very unique look - and there are a lot of different looking renditions out there. The core or the inner region often shows 'more yellow', comprising a greater extend. But on the other hand your colour balance looks fine, so this seems to be the 'right' result with regard to the data you captured.

This a a very interesting object. I read about having more than one core, as a result of a collision with another small galaxy. And the starburst areas are a result of this event, too. And they say there is a small black hole in its centre which together with a star in its orbit builds a tiny quasar.

Best regards, Dietmar.

[Startrek]

Hi Dietmar,
Yes broadband imaging from a big City is not easy but can be done, although my 8hrs of data is barely enough. We just don’t get consistent clear skies to be able to gather data each New Moon.However I am pleased to fashion some sort of image out of the noise.
At 1050mm my scope has its optical limitations with atmospheric seeing the governing factor.
You are correct this Galaxy has 2 cores but I’m unable to achieve depth of resolution to resolve it.
I tried to expose more of the dust lanes and arms using Superstructure (Brightness) but in doing so also exposed more finer noise grain.I try to keep Denoise to a level not higher than 5 pixels otherwise the noise “smear” is too obvious.
Some folk who have consistent clear skies during New Moon generally gather 1000’s of 20 sec and 30 sec subs and produce remarkable broadband galaxy images under the heaviest of light pollution. I’m not so lucky
Thanks again for your kind comments
On to my next project ……

Martin