The Southern Crab Nebula

[strongmanmike]

Known as Hen 2-104 or The Southern Crab (hopefully the reason for its name is pretty obvious and much more fitting than for its northern cousin in Taurus?) this Symbiotic Star system is a relatively recently identified object in Centaurus, with its true nature only revealed as recently as 1989 in comparatively primitive B&W images (https://www.eso.org/public/news/eso8901/) taken with the 2.2m telescope at La Silla at ESO. More recently in 1999 the Hubble Space Telecope released a very famous and highly detailed image of it which put it well and truly on my all time favourite HST images list.

This target was suggested to me by my mate Sakib Rasool (a man with a veritable mine field of cool object suggestions, especially planetary nebulae, in his archives!) and given my existing fascination with the object, I decided to have a crack. I could find no amateur images of it on line.

Of course, until recently I never expected to be able to do such a tiny faint object justice, given the faintest furthest most extensions of the nebula measure just 80" X 40" so it would make it another genuine challenge for my equipment and site conditions.... buuuut aaas usual and looking to do more than the Ol' Eta Carina Nebula these days :rolleyes: :lol: my goal was to never less try and reveal as much of the outer hourglass structure and fine fiery filamentary details as possible and hopefully :prey: unearth the tiny inner 10" hourglass structure from the bright glow of the central star and that looked so cool in the Hubble image! :)

As seems to be a relatively regular occurrence, my Wallaroo skies were pretty cooperative in my endeavour and delivered some nice seeing over 3 full and rather cool, clear nights in April, with one really excellent steady night. So with the longer nights and my now rather robot like efficient manual operation :P, I managed to take the longest ever exposure I have done with the AG12 astrograph, at nearly 22hrs :2thumbs:

I am very happy with the result from an F3.8 1120mm FL 12" scope on this tiny but intriguing and never imaged object :thumbsup:

The Southern Crab (http://www.pbase.com/strongmanmike2002/image/165378421/original) 150% close in crop

Hubble comparison (http://www.pbase.com/strongmanmike2002/image/165378489/original) I got the tiny inner hourglass rings!! yaaay :cool:

Full 38' X 30' Frame (http://www.pbase.com/strongmanmike2002/image/165378484/original) just to show how small this damn thing is! :eyepop:

The nature of this Symbiotic system is well documented in this excellent paper (https://arxiv.org/pdf/0803.0448.pdf) :thumbsup:

A more outreach friendly description of the object is available HERE (http://annesastronomynews.com/photo-gallery-ii/nebulae-clouds/the-southern-crab-nebula-he2-104/)

Enjoy

EDIT: Ok, just discovered that the CHART 32 team did a lovely one HERE (http://www.chart32.de/index.php/component/k2/item/152)...but with a 1m class pro level scope at a pro observatory site, with sub arc sec seeing, they are not reeeally amateurs like the rest of us amateurs :lol:


Mike :thumbsup:

[cometcatcher]

:eyepop: Strewth Mike, that's some impressive shootin' ! Glad you could tear yourself away from Eta Carina for long enough. :rofl:

You must get great satisfaction pushing the boundaries and getting results like that. Congratulations. :thumbsup:

[Joshua Bunn]

Wow Mike! Love your work. It's soo inspiring to see these rarely imaged objects and i recon you've got a cracker right there. Such an interesting object too... looks like there was a massive explosion right there :eyepop:

[markas]

Wow, Mike. Extraordinary!!!!

Mark

[Placidus]

:bowdown:

Beautiful, technically spectacular, inspiring, and informative.

Read the long article, and kinda got the idea. Went off to read about why Mira variables pulsate. Again, kinda got the idea, but ended up confused on the details.

:party2:

Wonderful.

[lazjen]

Impressive. And I can see why it's never imaged too - it requires ticking quite a few boxes to achieve. Nice. :)

[Atmos]

Exceptional job Mike!!
Will have to have a look at the paper when I'm not at work on my phone :P

[billdan]

Congratulations Mike imaging a very rare object and also for the 22 hours exposure time. I notice you used every filter on the object, did SII reveal anything useful?

I read the white paper but the outreach version was easier on my brain.

Any chance of telling us the RA and DEC coordinates for future ref, I may have a go one day when I get my 14 inch scope up and running.

Cheers
Bill

[traveller]

Congrats Mike, what an effort and the result is just spectacular.
Just imagine what an AO can do to enhance the details... ;)
Bo

[dylan_odonnell]

Wow.. what an interesting target, and you've done it very well. Good work!

[Stevec35]

Nice one Mike. I somehow had the feeling that you had done this before. Must have dreamed it.

Cheers

Steve

[topheart]

Hi Mike,
That is an awesome result for such a small creature!!
What a great documentation of the object - this is one I have never seen before.

Thanks,
Tim

[mountainjoo]

Wow Mike, this is seriously impressive. Great presentation of an unusual and striking object.

[Derek Klepp]

That's a superb effort Mike.

[RickS]

Very cool, Mike! :thumbsup: :thumbsup:

I'm also chasing one of Sakib's targets using the scope at SRO but this one is just really faint, not incredibly tiny :)

[Octane]

Extreme imaging. Great result for your efforts.

H

[strongmanmike]

Thanks so much guys, really glad you got a little bit of a kick out of it, we all (including me) ooh and aah at and dream of great shots of the more well known objects but sometimes hammering an obscure target is not only rewarding but can turn up or reveal some interesting things :thumbsup:



:lol: Haaaalleluiiiiah brother and sister, I feeeeel the joy :party: The thing is, there are just sooo many of these intriguing blighters across the sky and available during all seasons too...love picking on a few here and there :)



It is a challenge to do these sort of targets but I have developed faith in my site conditions now and while I do often doubt it when I first look at the raw data sometimes :scared:, I am learning to trust that my processing abilities, amassed over nearly 4 decades of doing this, can make something of what can initially look rather flimsy :)





Here ya go: 14h 11' 52.06" -51deg 26' 24"



Cheers Bo

Not sure an SX AO would make a lot of difference I have heard mixed reports on its effectiveness plus, see a typical guide graph I get below :D



Cheers Dylan



Perhaps you are recalling R Aquarii (http://www.pbase.com/strongmanmike2002/image/164509166/original)or THIS (http://www.pbase.com/strongmanmike2002/image/160572742/original) one :shrug:



Glad you liked it Tmbo :thumbsup:





Thanks Jerome and Derek :thumbsup:



Sakib is a great guy, although he often attempts to temp me to hammer one of his suspected PN halo's, he also suggests many cool off the beaten track targets too :)

[strongmanmike]

Cheers H, I think so too :)

Mike

[Atmos]

Thatguide graph is worth drooling over Mike :thumbsup:

[strongmanmike]

Yeah, nothing like seeing a guide star that is doing little more than quivering around the centroid... :P

Mike

[Andy01]

Mag 14.5 and tiny? Man oh man that's a challenge :screwy:
You sure you're names' not "Masochist Mike"?
Very impressive result, well done! :thumbsup:
Makes you wonder what it would look like if we were located much closer, like the Helix for example?
Top stuff Mike :cool3:

[Tony_]

Superb image Mike!
It's incredible how much detail there is in such a small object with a relatively low FL - certainly a credit to your ability.

Tony.

[gregbradley]

Great work there Mike. Not for the faint hearted.

Greg.

[strongmanmike]

Masochist indeed but it's fun to image on the edge :D I agree, this might look rather awesome if it were over 10X closer :eyepop:



Cheers Tony, the AG12 can deliver when it wants too :P...and the seeing lets it :rolleyes:



Cheers Greg :thumbsup:

[SimmoW]

Treś exotique mon amie!!

French for 'you bloodybewdy!

[strongmanmike]

Ah ha, grazie molto amigo!! Italian for 'thanks a lot mate' :thumbsup:

[marc4darkskies]

22 hours integration on something that small huh? Impressive, extreme and interesting for sure, but I don't think I'll add it to my target list - even at 3.1m FL.

[alpal]

Hi Mike,
that's an impressive result on such a small dim target.
As I've said before - small targets are worth stacking using 3 x Drizzle in DSS.
Did you try that this time to extract that tiny bit of extra detail?

cheers
Allan

[strongmanmike]

Meah...you just jealous :P....I went to specsavers :lol:

Mike

[strongmanmike]

Cheers Al :thumbsup:..nah no drizzle (sorry :sadeyes:), ain't got that capability in the software I use :shrug: ...no AO and not even PEC :eyepop: :sad:

Mike

[alpal]

Hi Mike,
DSS - Deep Sky Stacker - which does 3 x Drizzle - is free!

Is it even possible to use AO with your Newt?
There is not much back focus on Newts but I suppose some people have done it?

I still haven't implemented my idea to close the camera shutter
whenever the guide graph goes out by more than say +/- 0.5 divisions
& then open it again when back in spec.
Then - a problem with a mount - a guide error wouldn't matter.
I am hoping that QHY will make it possible with software -
that would be nice.
I think all camera software should enable that -
it's so simple yet not one camera manufacturer does it.

So yes - there is always room for tiny improvements but
your results are amazing.

cheers
Allan

[strongmanmike]

Hmmm? maay bee...

Well, I only have 78mm back focus available, probably not...?

My system hardly ever goes over 0.5 pix anyway :shrug: only on poor seeing nights and then I just take the RGB :)


I agree and cheers mate :thumbsup:

[codemonkey]

Looks more like a spider to me! I like the full-frame, gives you some perspective and indicates how small the target it is. A solid effort, Mike, and I don't think you'll be topped on this one for some time, at least by amateurs.

[alpal]

Hi Mike,
you have all the data - Drizzle would be worth a go but then again
you have a small pixel size on your camera so you're not under-sampled.

78mm is not a lot of back focus but AO may still be possible.

0.5 pixels?
My system will run quite happily at 0.5 pixels on the guide graph for 5 minutes or more
but then it will have an occasional little spike that goes above 1 pixel.
I find that annoying as I know my data is being corrupted when that happens.
How nice would it be to close the shutter during such events?


cheers
Allan

[Paul Haese]

Wow that is a small target. Nice image of it at 150%, guide graph is impressive for such a large scope on an NJP (which is a great mount but a bit overloaded). You've obviously got that system well tuned and hence the sharp detail on these tiny targets.

[strongmanmike]

Thanks Lee, yes definitely a spider in there too :thumbsup:



Once the camera has sensed the short spike in the guide star then it has already happened and been recorded so how will closing the shutter help? If you get times where the guide star moves out for a say 10 or 20sec though, then I can see closing the shutter a useful function then..? But this just doesn't happen for me, ever, my guide star plot is only affected by seeing so it is a tight ball of dots when the seeing good and less tight ball of dots when the seeing is poor :)



Well, the NJP will really be put to the test soon, when I mount another 10kg of FSQ, Proline16803, MMOAG and Lodestar on the side :D...but given it handled THIS (http://www.pbase.com/strongmanmike2002/image/134719005/original) perfectly well, I am quietly confident it will soldier on this time too. I would be worried if I was doing multiple slews a night like with a automated system or SN search program but I only do one slew to my target and then it is sidereal tracking from there, all night.

That's the theory anyway

Mike

[Geoff45]

That's really impressive Mike. There is so much more satisfaction in getting a really difficult target to show up well rather than another brilliant shot of the ol' EC.
Geoff

[strongmanmike]

Well thank ya Geoffrey, there comes a time where one must challenge one self aaaand shoot for some of the other several hundred thousand objects worth shooting out there :P

Mike

[Slawomir]

Spectacular result Mike, excellent processing and a splendid image. Seems that a visit to Specsavers served you well... :P

[strongmanmike]

Cheers Suavi..and maaate the naked eye sky looked really bluudy Amazing on the last night of capture for this...it was like an awakening! Definiely should have gone to Specsavers sooner!

Mike

[Shiraz]

blimey, that's really impressive Mike. always a good idea to compare with Hubble to show that the features are real - really neat that you got the inner central structure.

[strongmanmike]

Cheers Ray, it kinda looks a little oh yeah :shrug:....until you see it side by side with the Hubble shot :)

Mike

[Placidus]

Inspired by your image, we had a crack at it - just 3 hours due to ongoing equipment issues, but enough to get the outer X, and show we had no chance on that inner detail. Yours is truly razor sharp.

[strongmanmike]

Interesting guys :question:...thing is, it is so small that seeing is very important I guess :shrug: So, with a good night, good image scale and an AO unit perhaps?.. and being able to collect heaps of data and only use the very best (a luxury I don't enjoy) would be the best approach on this little tagger.

Mike

[Star Catcher]

A fascinating object Mike and well done for bringing it into view for us.
Ted

[astronobob]

Extraordinary Imaging 'as always' Mike :eyepop:
Very inspiring for the many in/at this league level - chalk one up :thumbsup:

Personally, Also always appreciate the post presentations you do,,, the extra time, the attitude, humbleness on the comparisons, insights & Info etc,. :thumbsup:

Very Credible stuff :cool2:

[strongmanmike]

Cheers Ted, no 150 min exposures here...just 15 min ones :P



Glad to hear Bob, yep, I love this stuff, so I'm glad the feeling is mutual :cheers:

Mike

[Flugel88]

Very interesting and very small target your fast scope really does pull in the detail.

[strongmanmike]

Cheers Mike, yeah the AG12 is pretty useful, can't wait to pair it side by side with the impending FSQ106EDX4 (to be mated with an FLI 16803) that is due any time now :D it'll be like my own Hale 200" + Palomar 48" Schmidt combo :P

Mike