NGC 6872 in Pavo - the largest spiral in the sky, and 100 friends

[Placidus]

The big daddy elliptical in the centre is NGC 6876, centre of a cluster of galaxies in south-eastern Pavo.

We were drawn to this rich cluster of galaxies because of the tidal stretching of the edge-on spiral NGC 6872, which is in the top left corner of the thumbnail.

Notice the intense star formation in the very blue spiral arms. The arm heading downward gets fainter and broader, and then hooks around to the right in a very faint blue club-like end. In our image, this club can be seen to be resolved into several small star-forming regions.

The salmon-pink centre shows a distinct bar, with what looks like a very tiny active nucleus.

Wikipedia says that it is interacting with IC4970, a small lenticular. We can indeed see what looks like a bridge of bright blue stars between the two.

Wiki says that tip to tip, 6872 is half a million light years across, or five times the size of the Milky Way. NASA says this colossus is the largest spiral in the sky. Some folk liken it to the shape of a condor, but condors are not radially symmetrical, so we think of it as more like a badly bent paper-clip.

The thumb is a crop on the most interesting part of the busy cluster of galaxies.

Full frame here. (https://photos.smugmug.com/Category/Astrophotography-at-Placidus/i-KZR9p9z/0/362bb9f3/O/NGC%206872%20SE%20Pavo.jpg)

In the full frame, there are at least another 170 clearly visible more or less distant galaxies.

Aspen CG16M on 20 inch PlaneWave. Luminance 17 hrs, RGB 3 hrs each, all in 30 min subs.

North is on the left. Frame is approximately 30 min arc across, 0.55 sec arc/pixel.

Hope you like it too.

[astroron]

Fantastic work Mike and Trish,just spent 10 minutes touring the galaxies and also admiring the overall view.
Thanks for sharing:)
Cheers:thumbsup:

[Stevec35]

Nicely done M&T. This is a great galaxy group indeed.

Cheers

Steve

[atalas]

:jawdrop: wow wee!what a field!hey some other little galaxies around showing tidal forces at work as well....man what an excellent piece of work guys:thumbsup::thumbsup::thumbsup:

[Placidus]

Thanks very much Ron!



Thanks, Steve,

We've just spotted your version (http://members.pcug.org.au/~stevec/ngc6872_STL6303_RC_LRGB.jpg) which produced an excellent result especially in the brighter areas in a fraction of the time.




Thanks, Louie! We try to please. Glad you spotted the other tidally interacting pairs.

Mike Sidonio (http://a4.pbase.com/o9/29/633929/1/160802507.LWgIbYpQ.NGC6876galcluste r755minLRGBgradex2HLblend3CBRexp5mi nblend2con2crop.jpg) also produced a spectacular version of this cluster, as did Geoff Smith, but the link to his image doesn't want to talk to us right now.

Best,
Mike and Trish

[atalas]

It probably feels ignored since he got his FSQ :P

[gregbradley]

A wonderful image.

Greg.

[Ryderscope]

Gee whiz there is a lot going on there MnT. Galaxies galore with wonderful detail. A nice study of what goes on when galaxies interact.

[Placidus]

Found another link to Geoff's (https://photos.smugmug.com/Astrophotography/Galaxies/i-NxrgXbn/0/0dec566a/X3/ngc6876_august_2015_v2-X3.jpg) image.

You can see the very faint club thingy that I mentioned.

[Placidus]

Thanks Greg! :)



Thanks Rodney. They string each other along!

[Andy01]

impressive field and a great result, you guys are on a roll :party2: :D

[Bart]

Ooooooh yeeaah, maaate!

That is awesome! My! :eyepop:

[Placidus]

Thanks very much Andy!



Cheers, Bart, and welcome back :hi:. You've been away for a bit.

[Paul Haese]

It's a cool group of galaxies MnT. The image scale is excellent and I really like the colour. Detail as you would expect for a 20" scope. Nice work.

[strongmanmike]

Great result guys, love this galaxy cluster, the Condor galaxy is so unusual in structure but magnificent and even more so when you learn its colossal size :thumbsup: I was happy with my result from my (smaller) scope, your half metre aperture is rather useful though...have I ever mentioned that I would love your scope :question: ;)...nice colour differentiation in the fine details too by the way :thumbsup:

Mike

[topheart]

Outstanding!!
So interesting.
Wow!
Cheers,
Tim

[Placidus]

Thanks Paul. We're trying to find the magic point where the colour saturation is strong enough to see astrophysically important differences without a fight, just as one would hope to see astrophysically important brightness differences, or differences in position, without a fight, but no stronger.



Thanks hugely Mike. We're going to have to get you to come and stay over for a couple days some time soon. It's only a tiny four hour drive!



Thanks Tim!

[Atmos]

Pretty incredible shot MnT! This is what your 20” Light bucket really excelled at :thumbsup:
So many galaxies both big and small in the field to go looking at :)

[Peter Ward]

I think you've set a new benchmark for this field.

Everything is a little tighter, deeper and better resolved compared to what has gone before.

Why aspire to be average when you can be exceptional !

Wonderful stuff :thumbsup::thumbsup:

[multiweb]

:bowdown: Unreal!

[SimmoW]

Wow, that 20 inch is paying off guys! So deep, great stuff

[Placidus]

Thanks Colin! Aye, there are smaller more expensive scopes that are much better at bright detail (like moon and planets as an extreme case), and smaller scopes given enough time can do the faint stuff, but a fair light-bucket lets you do it before the season's over.




Thanks Peter, we're thrilled that you think so. We are greatly encouraged.




Thanks muchly Marc. :D



Cheers, Simmo!

[RickS]

Fantastic work, M&T :thumbsup: :thumbsup: :thumbsup:

[h0ughy]

awesome - love the faint bits and the spiral is amazing

[Placidus]

Thanks guys. Encouraging.

[theodog]

Wow, that's.... nice.:thumbsup:

[Placidus]

Thanks Jeff

[Retrograde]

Amazing - love the full frame with the little galaxies everywhere & the big ones in the centre. :thumbsup:

[Placidus]

Thanks Pete! We're becoming fond of these galaxy clusters.

[markas]

Superb Detail - these aren't very big targets....
Mark

[cometcatcher]

Love these galaxy clusters. I still look at each one and wonder what's living there. Great stuff M&T. You guys must be having a ton of fun with this scope. It's good to see stuff I'm not familiar with.

[Slawomir]

Another beautiful image Mike and Trish that invites to contemplate on the bigger picture.

I particularly like how you have captured interaction with two galaxies.

Wonderful work :thumbsup:

[Placidus]

Thanks, Mark. Bit like a swarm of bees - the individual bees are small.



Thanks muchly Kevin. Life appeared here very early, perhaps before it was really decent, volcanic vents and what. It seemed to want to happen. With 200 billion stars per galaxy and rather a lot of galaxies ...



Thanks so much, Suavi, that's generous and encouraging. We definitely want to photograph things that tell a story, not just abstract shapes.