NGC 6744 and Galactic Cirrus dust

strongmanmike (Michael) · #1 03-10-2008, 12:47 AM

Well took a few days but I finally got around to (round 1) of my processing of the data I collected at Wiruna last weekend.

First image is a nice widish field around the beautifull spiral NGC 6744 in Pavo.

I wanted to go much deeper over the two days but I lost a number of subs (and precious time investigating

) due to mechanically routed guide issues (later rectified), and friggin satellites! - they were doing it on purpose I am sure

Plus the seeing was atrocious most of the time and poor the rest pluuuuus it was very windy with strong scary gusts, so the faint stuff has basically been smeared...

Never the less... I was very happy to reveal that lovely Galactic Cirrus dust again and while not as extensive, due to much less exposure time and the above conditions, like in my deep Cen A image it is all over the field, like smoke

Perhaps a bit blue for some of you (I seem to lean toward a blue feel) and as I do, I went easy on the noise reduction again

.

anyway here it is:

Full Frame 70% size (5meg)
http://www.pbase.com/strongmanmike20...69309/original

Crop of main galaxy (2.3meg)
http://www.pbase.com/strongmanmike20...69154/original

Enahanced Luminance to show extent of Galactic Cirrus dust (1meg):
http://www.pbase.com/strongmanmike20...69838/original

aaaand for those who wish to, here is the whole shabbang 13.5meg full frame full res image, to swim around in counting all the background galaxies

:
http://www.pbase.com/strongmanmike20...70854/original

Cheers

Mike

multiweb (Marc) · #2 03-10-2008, 01:07 AM

That's a great picture Mike. The high-res is amazing. And you said you had problems with the wind?

There's no hints of even a slight breeze in your frame

h0ughy (David) · #3 03-10-2008, 01:08 AM

help me I am drowning in your dust.... so i see you have more data Mike - fantastic!

strongmanmike (Michael) · #4 03-10-2008, 01:15 AM

Quote:

Originally Posted by multiweb

That's a great picture Mike. The high-res is amazing. And you said you had problems with the wind?

There's no hints of even a slight breeze in your frame

Hi Marc

Yeh the long thin shape of the Starfire coupled with the sturdiness of the NJP and my pedestal pier make it reasonably viable to continue even through the sort of rediculous conditions we had over the weekend. The image is softer than it would have been of course

...oh well, beggers can't be chosers, t'was that or pack it in and have nothing to show for the weekend...besides, I'm not sure I or anyone else could stand another repro of Centaurus A

Glad you liked the image

Mike

Matty P (Matt) · #5 03-10-2008, 01:22 AM

Wow!!! Absolutely amazing!

Like always a very impressive image Mike. The Hi-Res version is quite something. There is so much to see.

There is no hint of terrible conditions in this image.

Very well done.

strongmanmike (Michael) · #6 03-10-2008, 01:29 AM

Quote:

Originally Posted by Matty P

Wow!!! Absolutely amazing!

Like always a very impressive image Mike. The Hi-Res version is quite something. There is so much to see.

There is no hint of terrible conditions in this image.

Very well done.

Thanks so much Matt glad you liked it so much, comments like that make the shock of watching, my telescope being buffeted by Sydney to Hobart force winds and my focus stars jumping all over the place swelling in and out, from a dot to a fuzz ball in seconds, all worth carrying on for, cheers

Mike

Dennis · #7 03-10-2008, 06:48 AM

Hi Mike

What a stunning portrait of this beautiful galaxy. The wide field setting is absolutely gorgeous. Everything looks spot on – you’ve done a terrific job despite the conditions and problems you’ve alluded to.

Thanks for the pre-breakfast intergalactic romp!

Cheers

Dennis

Phil · #8 03-10-2008, 07:34 AM

Stunning shot well done.
Phil

h0ughy (David) · #9 03-10-2008, 07:45 AM

after the 5th look at this it is amazing how many faint fuzzies are in the background

Alchemy (Clive) · #10 03-10-2008, 07:56 AM

what can i say, it looks good, but i will wait for the repro...s to see if its your best

good to see you have had the opportunity to get out and do some more.

now that you are in a bright location homewise, are you considering doing some narrowband work?

marc4darkskies (Marcus) · #11 03-10-2008, 08:15 AM

Very nice Mike - top shot as always!

Nice to scan around for the fuzzies.

Buuut, for my taste at least, it's an teensy bit blue and the colour noise up close is a weensy bit too much as well. It's hard to judge on my crappy work LCD monitor though (only 6 bit I think) - it acts like an astro image defect exaggerator

.

How long were your subs? I'll bet you had to do some serious stretching to reveal the cirrus?

Cheers,
Marcus

Garyh · #12 03-10-2008, 08:41 AM

Beautiful Mike! Love the closeup!
cheers Gary

sjastro · #13 03-10-2008, 11:12 AM

Nice image Mike.

NGC 6744 is one of the most difficult objects to image.

Regards

Steven

Tamtarn · #14 03-10-2008, 11:31 AM

Superb Mike. Such a beautiful field in the full res. Considering you had less than perfect conditions it's an amazing result.

strongmanmike (Michael) · #15 03-10-2008, 09:16 PM

Quote:

Originally Posted by Dennis

Hi Mike

What a stunning portrait of this beautiful galaxy. The wide field setting is absolutely gorgeous. Everything looks spot on – you’ve done a terrific job despite the conditions and problems you’ve alluded to.

Thanks for the pre-breakfast intergalactic romp!

Cheers

Dennis

Glad it was such a cullinary entre big D, nothing like a pan galactic cirrus blaster for breaky

Quote:

Originally Posted by Phil

Stunning shot well done.
Phil

Cheers Phil

Quote:

Originally Posted by h0ughy

after the 5th look at this it is amazing how many faint fuzzies are in the background

I love what a largish field at good image scale can do under true dark skies, shame about the poor seeing and wind though as there would have been even more to look for

Quote:

what can i say, it looks good, but i will wait for the repro...s to see if its your best

Oh I am sure this will be the case, I am not happy with it already

Quote:

good to see you have had the opportunity to get out and do some more.

now that you are in a bright location homewise, are you considering doing some narrowband work?

Ahhhhh... image, my Kingdom to image

You got it Clive! Some narrowband filters are on the way soon

but strangely I probably wont use'em where I am since my sky access is very limited regardless of the light pollution

Quote:

Very nice Mike - top shot as always!

Nice to scan around for the fuzzies.

I agree Markus this FOV under dark skies and viewed at full res is pretty cool

Quote:

Buuut, for my taste at least, it's an teensy bit blue and the colour noise up close is a weensy bit too much as well. It's hard to judge on my crappy work LCD monitor though (only 6 bit I think) - it acts like an astro image defect exaggerator

.

Ah yes I know...it's probably hard to make sense of in this age of super smooth imaging but as I have said before I think my previous experience with grainy film has desensitised me to fine scale image noise...

?

Quote:

How long were your subs? I'll bet you had to do some serious stretching to reveal the cirrus?

I almost always use 10min subs, which at F7.5 and under dark skies seems to be ok and is a nice comprimise between risking dissapointment through subs being ruined by tracking error, satellite trails, wind gusts, equipment slipping etc etc and getting more signal each sub..when you are 100% portable and mizerly about your time it is really important to be mindful of these things I guess..?

Yes I did some stretching and with rather limited and softer data this time compared to Cen A, it was deffinitelly harder to extract the faint stuff and fine details without blowing out the noise too much..I tried but like you say... it "is" only my first attempt afterall huh?

Quote:

Originally Posted by Garyh

Beautiful Mike! Love the closeup!
cheers Gary

Thanks Gary, I wonder what other versions I will come up with..?

Quote:

Originally Posted by sjastro

Nice image Mike.

NGC 6744 is one of the most difficult objects to image.

Regards

Steven

Thanks very much Steve!

I agree 100%, NGC 6744 is indeed hard to nail. It does help to have good data though, 2 and a bit hrs Lum is not really enough here (had a bit more but many subs were lost to the prevailing conditions, a couple of rare equipment problems and satellites), my deep Cen A image with 20hrs of data was much easier to work with.

Quote:

Originally Posted by Tamtarn

Superb Mike. Such a beautiful field in the full res. Considering you had less than perfect conditions it's an amazing result.

Thanks Barb?..Dave? ok, both of ya, I was very surprised to get this much too, I can only imagine what good still steady skies would have revealed

I think the dark skies helped atleast though.

Mike

winensky · #16 03-10-2008, 11:18 PM

Many wonderful comments all richly deserved for such a fine image.

jase (Jason) · #17 04-10-2008, 05:31 AM

Excellent Mike, simply excellent. The spiral arms show impressive definition on this tough target. Star colours look pretty good too. M and K spec type could perhaps been a little move developed but this is minor. Did you also factor atmosp. extinction on this one? Well done.

strongmanmike (Michael) · #18 04-10-2008, 07:57 AM

Quote:

Originally Posted by jase

Excellent Mike, simply excellent. The spiral arms show impressive definition on this tough target. Star colours look pretty good too. M and K spec type could perhaps been a little move developed but this is minor. Did you also factor atmosp. extinction on this one? Well done.

Thanks Jase, I know there would have been a couple of other niggly things you would have noticed but perhaps in my inevitable repro I will address these? Aren't M class stars red? There are plenty of redish stars in there..? I purposely stayed with the slight blue cast in the image as it made the stars and galaxy shine a little more and the Cirrus stands out a little better..?..I also used no noise reduction again, pushing the data to the limit I guess, maybe I'll try it differently in the repro?...Ooooh I'm getting excited about the repro already...

BTW wandering around during the wee hours while my rig imaged away through the wind made me think of you a few times mate, I thought to myself hmmm? Jase has a point regarding remote imaging....

But the whole travelling to a dark sky, setting up, camping etc, and I took my teenage son with me too who had great fun catching Yabbies in the Wiruna dam, all makes for a great time I guess? Bit like a fishing trip

Mike

Jeffkop (Jeff) · #19 04-10-2008, 08:45 AM

Another outstanding image Mike ... wish I knew more about all this to provide some useful comment. How do you know so much of the detail about all the images you take ... the detail is nearly as rewarding as the image ... Fantastic

strongmanmike (Michael) · #20 04-10-2008, 11:01 AM

Quote:

Originally Posted by winensky

Many wonderful comments all richly deserved for such a fine image.

Thanks Matt I'm glad everyone enjoyed it, standing out in the wind, in poor seeing with satellites wizzing through so many sub frames and a temporarily slipping focus assemply sure put doubt in my mind, my perfect experience over 3 days at Wiruna for my Deep cen A shot was probably a fluke.?

Quote:

Originally Posted by Jeffkop

Another outstanding image Mike ... wish I knew more about all this to provide some useful comment. How do you know so much of the detail about all the images you take ... the detail is nearly as rewarding as the image ... Fantastic

Thanks Jeff

What details are you refering to?

Mike