M83: Southern Pinwheel Galaxy on Queensland Astrofest 2025

[Pilgrim (Igor)]

Southern Pinwheel Galaxy through the dew and fog of Queensland Astrofest'2025, 24.05.2024

A total of 2 hours and 14 minutes of exposure just as much as the dew and the creeping fog allowed on the second night of Queensland Astrofest 2025. However, the sky was absolutely stunning, both in terms of darkness and the stability of the seeing. Of course, it's not an outstanding result, but it's more than I expected and a great memory of meeting astronomy enthusiasts at the Duckadang camp.

SW Quattro 300P + 0.95 Sharpstar coma corrector, F/3.8. on EQ6R Pro mount. Asi2600MM camera, ZWO LRGB filters set.

Frames:
LRGB composition of 46×2 min L and 7 x 2 min for each R, G, B. Total integration is just 2h 14m

Bortle 3 sky.

Full version with Click 2 Zoom: https://www.astrobin.com/4cmmd2/0/

[gregbradley]

Very nicely done.
Greg

[Pierre_C]

Very nicely balanced, Igor.

[alpal]

Great picture Igor,
and there are so many faint background galaxies to see as well.
That's amazing for just over only 2 hours of integration.

cheers
Allan

[Startrek (Martin)]

Excellent image of M83 with only limited data , and beautifully processed too
Well done !!
There’s just no substitute for dark skies as I image from both B8 ( 18.50 mag/arc sec 2 ) and B3 ( 21.60 mag/arcsec2 )

What’s more impressive is that your humble 20kg rated EQ6-R pro mount is carrying that big steel Newt with ease by the looks of your image. Payload must be pushing close to 30kg. I have an EQ6-R in Sydney , they are just workhorses these mounts.
Mine only carries an 8” f5 Carbon newt so payload only around 13kg.

As a matter of interest what were your guiding numbers that evening ?

Cheers
Martin

[Pilgrim (Igor)]

Thanks a lot Alan, Greg, Pier and Martin!

Originally Posted by alpal

Great picture Igor,
That's amazing for just over only 2 hours of integration.

Dark skies truly work wonders. In the Brisbane (B7-8), achieving something similar would have taken around 40 hours, and even then, it’s uncertain whether I would have managed to overcome the gradients enough to reveal faint surroundings.

[Pilgrim (Igor)]

Originally Posted by Startrek

Excellent image of M83 with only limited data , There’s just no substitute for dark skies as I image from both B8 ( 18.50 mag/arc sec 2 ) and B3 ( 21.60 mag/arcsec2 )

Yeah, that night I measured 21.5 M/arcsec2 in Camp Duckadang with my DIY sq-meter.

Originally Posted by Startrek

What’s more impressive is that your humble 20kg rated EQ6-R pro mount is carrying that big steel Newt with ease by the looks of your image. Payload must be pushing close to 30kg. I have an EQ6-R in Sydney , they are just workhorses these mounts.
Mine only carries an 8” f5 Carbon newt so payload only around 13kg.

As a matter of interest what were your guiding numbers that evening ?

Cheers
Martin

Just weighed the telescope and the "imaging head" (camera, filter wheel, coma corrector and off-axis guider assembled).
The tube is 19.6 kg, and the imaging head is 1.65 kg, making a total of 21.25 kg—just barely exceeding the recommended load capacity (ooops. not actually, as I weighed it without the tube rings which are pretty heavy).
Anyway, balancing all of this requires 30 kg of counterweights, so the load is truly extreme for this mount.

But here, the main factor isn't the weight, it’s the tube's wind resistance.
As long as everything is properly balanced and there are no sudden gusts of wind, the guiding performance is good, with an RMS of around 0.4-0.5" on both axes. Just like that night, and the FWHM was about 2" on best frames.

I hope I won’t be torturing the EQ6R with this tube for too long. I’m currently building a large mount that will handle this telescope without counterweights, along with me sitting on top of it! I’ll be starting a thread about it soon.

[TrevorW]

Nice image, thanks for posting

[h0ughy (David)]

Wow what a cracker of a shot

[strongmanmike (Michael)]

Always good to produce something at a star party, it's very fulfilling and, along with the beers, wine, the Hough and other good company , makes it all worthwhile and this is a very nice image of M83.

Mike

[xiongz (Zonghou Xiong)]

This is definitely the sharpest image I have ever seen for this scope by far, congratulations. I had been wondering if primary mirror on SW Quattro 12 was capable of producing best results under Australian skies, as mine had been plaqued with various issues. It turned out that some plays in the focuser itself were main causes. It's amazing that a lightweight mount EQ6r not only could carry this scope but also helped produce such a wonderful result that rivals best home observatories when seeing conditions were right.

John