A Cosmic Soap Bubble (Updated with more data and reprocessed)

[Andy01]

Sharpless Sh 2-308 in O2HaRGB

8hrs O3 Astrodon 5nm 900 sec subs
3hrs O3 Astrodon 5nm 900 sec subs Binx2
2.5 hrs Ha Astrodon 5nm 900 sec subs
5x2min each RGB subs for the stars

Taken from my light polluted suburban Melbourne backyard over Four nights.

Damn but this things dim - like as in "Disaster Area" dim - (A spaceship painted black with a black interior with little black lights that light up black to let you know they're on) dim - to paraphrase Douglas Adams.

I've probably bitten off far more that my f5.6 gear can chew attempting this - but I'm kinda committed now. It's finally showing more detail and less noise but I suspect this object is ideally suited for the big boys to have a proper +40hr rendition. If memory serves, Marco did a beautiful rendition last year.

Neverless, here is my attempt with the data gathered thus far - comments welcome but given the circumstances and gear used, please be kind :)

(Updated)
High Res here ...
http://www.astrobin.com/156099/B/

[RickS]

Not bad so far, Andy. I was hoping to do a long run on it too but the weather is just too poor to leave the gear out at this time of year.

[gregbradley]

That's very nice. I think you should use 2x2 binning on this one. Its about getting the signal and there isn't a lot of detail in the object.

It looks like a giant porpoise.

Greg.

[Andy01]

Rick - I reckon if you can make the time you'll do this target justice!



Thanks Greg, that 's a good tip - I'll try that. Thanks :thumbsup:

[multiweb]

That's very good. Nice details. :thumbsup:

[Placidus]

Excellent. Very nice detail.

Microscopic patch at the top of the bubble is burned out. Easy to fix if you felt heroic.

(In principle this truly wonderful beast would just exactly precisely NOT fit in my scope. I'd have to do a 4x4 mosaic.)

Well done.
Mike

[Andy01]

Cheers Marc :)



Thanks Mike - and yes you're right about the burnout patch. :shrug:

Maybe, just maybe I'll spend one more night on this beast at binx2 O3 only. Not sure about the law of diminishing returns as far as amount of data gathered vs. noise goes with this, maybe one of the experts can comment?

cheers

Andy

[RickS]

It fits perfectly in my FOV. If only I had a permanent observatory so I could image between the summer storms and clouds...



Just considering shot noise, SNR improves with the square root of the total exposure time. If you have 4 hours and add another 4 then the SNR improves by approx 1.4 times. You doubled the time so the improvement is sqrt(2). If you added 12 hours to your 4 hours then the improvement would be 2 times. Just add 396 hours and your SNR will be 10 times better :lol:

Unfortunately, with narrowband you're almost certainly not shot noise limited so the improvement will be less than I suggest above.

Cheers,
Rick.

[strongmanmike]

:scared: (slits wrist).....:lol:

Lovely work so far Andy :thumbsup:..really is a beautiful and intriguing object this one, well done, not a biggy but maybe try and get the blue down in the background a bit? :)

Mike

[Andy01]

Rick, I've done 8hrs O3 so far - if I added another 6 (and binned x2 as Greg suggested above - is that the same as 12 bin x1?) would that lead to a significant improvement in SNR?

[Andy01]

Thanks Mike - will do in the next version - assuming my sanity remains and I succeed in gathering some of those 396 hrs Rick recommended! :eyepop:

Cheers

Andy

[Ross G]

A great capture of a beautiful looking object.

I love the composition and colour.

Ross.

[Bassnut]

Thats nuts, love it!, dark, forbodeing ,rich. Ballsy effort, 10 points for different. Somehow looks monster and sinister.

[Andy01]

Hi Ross, thanks for taking the time to comment - I appreciate your positive feedback too, cheers!



Cheers Fred, year there's definitely something spooky there - reminds me of "Tin Man" from the Star Trek TNG episode. Thanks for your feedback, reckon you should consider taking a 40+ hr crack at it next mate :)

[Stevec35]

Nicely done Andy. A bit of blue noise in the background but nothing to detract from what is a fine image.

Cheers

Steve

[Andy01]

Thanks Steve, appreciate the feedback :)

[Andy01]

Ok, so I added another 3 hs O3 binx2 data last night and reprocessed it today. Gone is the blue background too :)

Here's the latest (hopefull last but never say never) version in high res...
http://www.astrobin.com/156099/B/

14 hrs and 4 nights later... :screwy:

Anyway, comments, improvements and feedback welcome - cheers

Andy

[LewisM]

One of my favourite targets - love it! I tried imaging one of the Sharpless "bubbles" myself once - even with a stack of 15 x 7 minute subs, it was BARELY discernible at full stretch!

You have rendered this one NICELY.

If you would ever like to post the FIT stacks, I would love to have a go - need to get back in the saddle and something to do during this damned cyclone!

[Andy01]

Thanks Lewis, really appreciate your comments - yeah it's bloody feint! Maybe Mag 12? I really need at least f3.5 or wider to do it justice. I can just imagine the conversation with the wife now, "Honey, can I have...." lol :)

Bugger about the cyclone - I was raised in Gladstone so I feel for those folks up there, we used to have them all the time when i was a kid, scary too.

Incidentally, I met a guy at LMDSS last sat night with a nice Vixen refractor that he purchased from yourself - he's very happy with it too :)

Cheers

Andy

[LewisM]

Yes, Phil loves it, and so he should - every bit as good as a Tak fluorite! a WONDERFUL scope - I even asked to buy it back the other day :) I ended up getting my old Tak FC-100 instead, now updated somewhat (thanks Col!)

Anyway, if you care to share FITS, let me know - I'd love to have a go. I am tired of doing my own stuff again, and again, and again...

River almost over the road here... better pick the wife up in the 4WD ;)

[Placidus]

One of the most beautiful images I've ever seen.

[Bassnut]

Excellent!, even better.

[LightningNZ]

I thought first attempt was stunning, the new image is sensational!

Greg's right, this should be the Porpoise Nebula, though maybe the Soap Bubble works better for short exposures? Either way, the detail you've picked up is amazing. I can only wonder at the forces that shaped the swirls in the nebulosity.

[Paul Haese]

Yes I like the last version myself. Great detail and off the beaten track a little.

[strongmanmike]

Looks good Andy, really looks like it is floating in space too :thumbsup:

Well done

Mike

[gregbradley]

Nice improvement there. The background seems more neutral now and better contrast with the object.

Greg.

[sjastro]

Very nice image Andy.

I'm currently in the process of imaging this one.

Steven

[Andy01]

Thanks very much Mike - that's high praise indeed coming from you sir :)



Thanks Fred, c'mon now it's your turn to do this one ;)



Wow, thankyou LightningNZ - maybe all these hours on this have been worthwhile after all - cheers mate :)



Cheers PAul, thanks for thanking the time to comment, I appreciate your feedback :thumbsup:



Thanks heaps Mike, appreciate the feedback too - cheers :)



Thanks Greg, I spent ages processing this beast, I think it was your suggestion to go Binx2 on the O3 so thanks for that tip too - seems to have helped a lot. :thumbsup:



Thanks Steve, looking forward to seeing your result! One tip - when you think you have enough data, do yourself a favour and go get even more - this sucker is Dim with a capital "D". :eyepop:

[Leonardo70]

Wonderful ..

All the best,
Leo

[Andy01]

Thanks Leo :)

[Andy01]

Sh 2-308 Reprocessed 3/3/15 :screwy: Crazy I know :)

High Res here - http://www.astrobin.com/156099/D/

I sacrificed some detail for smoothness and redid this from scratch (again).
Hopefully it will now print well :)

Still tempted to reshoot the stars with even shorter exposures as these ones are a bit oversaturated with my F5.6 rig and the KAF 8300 CCD at 2 mins.

Cheers

Andy