Ultra Deep M83 The Thousand Ruby Galaxy

[alpal]

Originally Posted by strongmanmike

Thanks Paul

I'm currently at an image scale of 0.84"/pix, I'm confident the seeing quality I consistently see, would suit 0.42"/pix on many nights. My current telescope actually suffers from some astigmatism, not a huge amount but enough to mean my MaximDL measurements indicating the majority of my subs are sitting at 1.4"- 1.8" across the year, are actually more like 1.2"- 1.6" were my scope aberration free. It's actually annoying me, so yes, very confident a scope like your 16" or a smaller pixel camera on my scope, would definitely excel at high resolution imaging at Eagleview, the extra sampling could handle some more decon as well.

Mike

Hi Mike,
yes - with Paul's RCOS 16" at FL = 3,414 mm and
ZWO2600MM Pro pixel size of 3.76 microns
his arc-sec per pixel ratio is: 0.23 arc seconds.
https://www.wilmslowastro.com/softwa...m#ARCSEC_PIXEL


With your telescope -
Just using the ideas of the Nyquist sampling theorem if you
ever got sub 1 arc second seeing you would need a minimum of
0.5 arc seconds per pixel to properly measure it.
So any measurement below 2 x 0.84"/pixel or 1.68 arc seconds seeing
is probably not accurate?

Paul's telescope could take full advantage of the seeing at your wonderful location.
Can anyone please correct me if I'm wrong?

cheers
Allan

[strongmanmike (Michael)]

Originally Posted by alpal

Hi Mike,
yes - with Paul's RCOS 16" at FL = 3,414 mm and
ZWO2600MM Pro pixel size of 3.76 microns
his arc-sec per pixel ratio is: 0.23 arc seconds.
https://www.wilmslowastro.com/softwa...m#ARCSEC_PIXEL

oo
With your telescope -
Just using the ideas of the Nyquist sampling theorem if you
ever got sub 1 arc second seeing you would need a minimum of
0.5 arc seconds per pixel to properly measure it.
So any measurement below 2 x 0.84"/pixel or 1.68 arc seconds seeing
is probably not accurate?

Paul's telescope could take full advantage of the seeing at your wonderful location.
Can anyone please correct me if I'm wrong?

cheers
Allan

On the subject of sampling and seeing....one funny comparison is with my last effort on the same galaxy back in 2015, from my last observing site at Wallaroo close to Canberra, with all the same imaging gear and processing software...bloody no comparison looks like crap, I knew it wasn't my best work at the time and it's much less exposure, I remember it was a one night quicky... I now realise just how crap it was

Mike

[alpal]

Originally Posted by strongmanmike

On the subject of sampling and seeing....one funny comparison is with my last effort on the same galaxy back in 2015, from my last observing site at Wallaroo close to Canberra, with all the same imaging gear and processing software...bloody no comparison looks like crap, I knew it wasn't my best work at the time and it's much less exposure, I remember it was a one night quicky... I now realise just how crap it was

Mike

Hi Mike,
You did well.
Look at what I got:
the FWHM values I were getting were 4.9 arc seconds measured with Maxim DL.
https://www.flickr.com/photos/247194...etaken-public/

cheers
Allan

[rmuhlack (Richard)]

Impressive Mike. Good to see another example of M83's extended halo and loop. With my 8inch newtonian and similar integration I was able to reveal the loop with a heavy stretch, though not with the level of detail and clarity you have in your image (which comes from mountain top seeing/transparency, more aperture, faster optics, mono sensor etc as well as your deft processing). Nicely done.

Have you seen the earlier 1997 Malin and Hadley paper (also cited by Barnes et al 2014) which also mentions M83's extended halo and loop?

[strongmanmike (Michael)]

Originally Posted by alpal

Hi Mike,
You did well.
Look at what I got:
the FWHM values I were getting were 4.9 arc seconds measured with Maxim DL.
https://www.flickr.com/photos/247194...etaken-public/

cheers
Allan

Aaah well, we all manage to create muck occasionally

Originally Posted by rmuhlack

Impressive Mike. Good to see another example of M83's extended halo and loop. With my 8inch newtonian and similar integration I was able to reveal the loop with a heavy stretch, though not with the level of detail and clarity you have in your image (which comes from mountain top seeing/transparency, more aperture, faster optics, mono sensor etc as well as your deft processing). Nicely done.

Have you seen the earlier 1997 Malin and Hadley paper (also cited by Barnes et al 2014) which also mentions M83's extended halo and loop?

Thanks glad you liked it Richard yes saw that paper and it will be linked to from a famous site tomorrow

Mike

[alpal]

Originally Posted by strongmanmike

Aaah well, we all manage to create muck occasionally

Mike

yes Mike - when the seeing is as bad as 4.9 arc seconds it's not worth proceeding -
all you get is a blurry mess but -

when you've gone to all the trouble of setting
the system up it's hard to resist taking some kind of image.
Some nights I measured as bad as 6 arc seconds FWHM.
I think the best night I ever got in Melbourne was 2.9 arc seconds
FWHM and that was only between 2 am any 5 am using an Ha filter.
Your results getting between 1.5" and 1.8" over the more than 27 hours of data collection
are very impressive and from a dark site as well.

cheers
Allan

[Andy01 (Andy)]

Congratulations on today's APOD, Mike; well done, a fab deep image with real scientific value!
https://apod.nasa.gov/apod/ap240703.html

[alpal]

Originally Posted by Andy01

Congratulations on today's APOD, Mike; well done, a fab deep image with real scientific value!
https://apod.nasa.gov/apod/ap240703.html

Wow - Mike is a mega star now - well done.
It's a beautiful picture.

Allan

[strongmanmike (Michael)]

Originally Posted by Andy01

Congratulations on today's APOD, Mike; well done, a fab deep image with real scientific value!
https://apod.nasa.gov/apod/ap240703.html

Originally Posted by alpal

Wow - Mike is a mega star now - well done.
It's a beautiful picture.

Allan

Thanks Guys, was a nice surprise this morning, I haven't submitted to APOD for some time but I really liked the result here and thought meah, I'll give it a shot

Mike

[gregbradley]

Congrats Mike.
Well deserved. It’s the best image I have seen for ages
And there have been plenty of superb images on this site.

Greg

[seeker372011 (Narayan)]

Congratulations on an APOD

[AdamJL]

Well-deserved indeed, well done, Mike!

[Kuz]

Congratulations on the APOD Mike well deserved

[strongmanmike (Michael)]

Originally Posted by gregbradley

Congrats Mike.
Well deserved. It’s the best image I have seen for ages
And there have been plenty of superb images on this site.

Greg

Originally Posted by seeker372011

Congratulations on an APOD

Originally Posted by AdamJL

Well-deserved indeed, well done, Mike!

Originally Posted by Kuz

Congratulations on the APOD Mike well deserved

Wow, thankyou so much fellas, your kind comments mean a lot

Mike

[DiscoDuck (Paul)]

Congrats Mike. Wonderful image and very well-deserved recognition.

[strongmanmike (Michael)]

Originally Posted by DiscoDuck

Congrats Mike. Wonderful image and very well-deserved recognition.

Cheers Paul

Mike

[Stephane]

Wow, how did I miss this? This image is incredible Mike - especially given you haven’t used any AI sharpening tools. Congratulations too on the well-deserved APOD!

[strongmanmike (Michael)]

Originally Posted by Stephane

Wow, how did I miss this? This image is incredible Mike - especially given you haven’t used any AI sharpening tools. Congratulations too on the well-deserved APOD!

Cheers Stephane, he he yeah I think it may even annoy some people when I mention the lack of AI use , sorry , it's just that AI "decon" gives most images a different look, it's usually obvious and just doesn't look quite real to me and people are starting to see that as kinda "normal" but I don't recon it is, so I just like to make it clear that I don't use it. Not a life changing issue just a personal muse and go ahead and use it, no one goes to jail ...buuuut if you have to, please use it sparingly or..?.. don't

Mike

[TrevorW]

Beauty mate

[strongmanmike (Michael)]

Originally Posted by TrevorW

Beauty mate

Cheers Trev

Mike