SH2-308 The Dolphin Nebula

[gregbradley]

This was taken over 2 years. Its really a dark site target as its very faint and only really shows up in O111. So a 3nm O111 filter would have been handy here.
This is 14 hours and 29 minutes of O111, Ha, LRGB. Even so there is some residual noise. A bit of tilt hadn't been corrected at this stage so there is a little bit if you look for it.

FLI Proline 16803, AP Honders Riccardi 305mm F3.8.

I was amazed by the photos I had seen of this object. There aren't many images of it I guess because it is so faint. I wanted to image this object for quite a while now. It was also extremely hard to process. I had several goes at it and would hit a dead end and I would leave it to come back to later. Today I managed to get an image I liked.

Taken from my home observatory.


https://pbase.com/image/170938973/large

Repro version:

https://pbase.com/gregbradley/image/170941951/large regular size

https://pbase.com/gregbradley/image/170941951/original large size

Greg.

[VPAstro]

Well done Greg, great image!

[ChrisV]

That's very nice indeed. The waves of OIII around the cosmic bubble look great

[Placidus]

That's superb Greg. Your field is wider than ours. We have to do a bit of a mosaic to do just the dolphin. You've managed to show some ridiculously faint tendrils in the general background material outside the WR nebula itself.

[graham.hobart]

Amazing greg-really well defined :thumbsup:

[gregbradley]

Thanks very much. It was a very challenging image.



Yes its a very interesting bubble. That yellowish bright star is a powerful star.



Thanks M&T. I'll have to look your image up again. It is quite a wide object.



Thanks Graham. I am glad the hard work paid off, it wasn't looking too promising for a while.

Greg.

[JA]

Greg: The Dolphin Lives:thumbsup::thumbsup::thumbsup:
very well defined

Best
JA

[gregbradley]

Hehehe, cheers JA.

Greg.

[strongmanmike]

It's one of the most fascinating objects in the entire sky I recon..? It looks a little pushed but you have gone pretty deep here Greg. Great that you have so much data sitting around, you have been having lots of fun combining data lately, huh? :painting: sooo jealous (in a good way) of you two observatories with such great equipment :)

Mike

[gregbradley]

Thanks Mike. Its slightly pushed. I did wonder about that myself but decided it was overall a more impactful image but sometimes thats a hard call.It was surprisingly bright in the 330 minute O111. 12 inch F3.8 is pretty fast eh?
Yes the 2 observatories are fun but your setup is not so different 106/5 and 305/3.6. Apart from the CDK17 we are very similar.
Greg.

[strongmanmike]

Yeah, I know, I don't want to sound ungrateful, I am very fortunate to have what I have (even if I do have to push my dome all night :rolleyes: :lol:)...still, I don't have those pristine dark skies of Bigga! :eyepop: :stargaze:...I want M&T's CDK20 on the fork mount, on top of its own damn hill...behind my bloody house! that's what I really want!! :sadeyes: :lol:

Mike

[Andy01]

Sorry Greg, I agree it looks great at first, but when you dive into the high res the the stars look chunky. :question:
The data is fantastically deep but because you've stretched the heck out of it it looks unnatural.
I encourage you to have another go - but tone map so you remove the stars first, Starnet++ is perfect for this - then stretch it as you have & the pop the stars back in. :D

Here is a great video tutorial by JP Metsavainio on how it's done.
https://www.youtube.com/watch?v=EQlGsM-S8vM

[gregbradley]

Mike[/QUOTE]



Yes I hear ya. This image though was taken from Kurrajong.
I just used the EZ Processing Suite EZ Denoise that Lewis posted about.
Wow, an easy to use Pixinsight tool - good trend. It worked surprisingly well - I likeh whad I see!
and reduced some of that pushed look which also amplifies existing noise.
Same links.

Greg.

[jahnpahwa]

So unreal!! What a cool object, and you've got some great colour there too.


Thanks for posting, its just a great one to admire :thumbsup:

[gregbradley]

Thanks Jahnpahwa. I am glad you liked it.

Greg.

[multiweb]

Pretty deep shot. :eyepop: Colors are great. :thumbsup: Gotta agree with the stars off axis. You might have got some registration issues.

[Retrograde]

Amazing depth on this Greg.
Don't think I've ever seen the faint wisps surrounding it captured so well.

[gregbradley]

Thanks,trying to get to the bottom of the stars.



Thanks Pete. I was happy about that.

Greg.

[RobF]

Wow, that reeks of time and effort and it all really paid off. Congrats Greg. :thumbsup:

[gregbradley]

Thanks Rob. Yes it did take a while both acquiring the data and processing it.

Greg.

[gregbradley]

Sorry Andy I missed your post. I started watching the video. Quite good.
I did a repro and will post the alternate version which is fairly different really.

Greg.

[gregbradley]

Here is another version where the stars are preserved and a slighty different weighting on the Ha component:

https://pbase.com/gregbradley/image/170941951/large regular size

https://pbase.com/gregbradley/image/170941951/original large size

Greg.

[Atmos]

Very deep image Greg! The new version definitely has better looking stars than the original :thumbsup:

[Benjamin]

Having just done a reprocess myself on this one, I tried a similar technique to what Andy suggested. I kept the stars in but used a star less mask to bring the Dolphin/Gourd from the background which left the stars alone. I didn’t get much time on it from the burbs but got a lot out of the data this way. Not sure that helps as I had a quite different FoV. Love love the wider field you here though and the depth of the OIII :-)

[gregbradley]

Thanks Colin. I'l have to review my processing workflow and add in more star removal techniques.



Cheers Ben. Yes that is what I did in the repro.

Greg.

[Benjamin]

My apologies, I think I get the reprocess now. The glow around the Dolphin is perhaps more of the [OIII]? Too used to my limited FoV!

[gregbradley]

The pinky area is from the Ha and the blue is the O111.

Greg.

[Benjamin]

Very interesting. I had much more limited Ha and [OIII] so must have clipped it from the background. 👍🏻

[John K]

Great work Greg, the different images in the Cosmos never cease to amaze! Nicely captured.

John K.

[gregbradley]

I did try to contain these in the background as its easy to have an all lue background with this object. I checked other images of it on Astrobin and mine is more widefield than almost all of them but the ones that do show some of the background show it similarly.



Yes I know what you mean. There is always something to image that is interesting.

Greg.

[TrevorW]

Excellent a joy to view :)

[gregbradley]

Thanks very much Trevor. I am glad you liked it.

Greg.

[astronobob]

10/10 Greg,, awesome !

[TrevorW]

Actually Greg your image compares very favorably to an APOD see


https://apod.nasa.gov/apod/ap200302.html


although I believe the finer nebulousness at the edge s of your image is more realistic than a definitive cut off point

[gregbradley]

Thanks Bob. I'll probably add to it next year when its around again.



Thanks Trevor. There definitely is some background O111 and Ha, mostly O111.

Greg.

[pkinchington]

Wonderful!

[gregbradley]

Thanks Peter!

Greg.

[codemonkey]

Great work, Greg. Love the colours, deep too!

[gregbradley]

Cheers Lee. I'll revisit it next year when it comes around again.

Greg.

[marc4darkskies]

I've looked at this several times since you posted it Greg and I have to say it's a pleasure seeing something different and something that's difficult to image. So on that score alone, well done! :thumbsup: I actually prefer your original processing. It's quite compelling and I particularly like the structure visible in the fainter extents. :thumbsup:

I'll be honest though and say that the reprocessed version seems to have obliterated the structure in those fainter extents. Colours notwithstanding, the reprocessed version would benefit greatly if you could restore that structural detail.

Cheers, Marcus

[Paul Haese]

I think I preferred the original image Greg. The palette looked better to me. It's a target I really need to have a go at. Do you have the RA and Dec for it?

[Bart]

Lovely stuff, Greg. Very blue.

[gregbradley]

That's fine Marcus I feel the same way myself. I think I will reprocess this from the ground up and see if I can get a better version of the first. It has been a bear to process.



I agree Paul. I will yet again repro this one. I did do a similar version to the first the other night but the star blend was off. I'll get there!



Cheers Bart.

[Ryderscope]

I find myself coming back to this Greg as I feel that the original image has a lot going for it. It has certainly generated a lot of discussion to be sure. Whilst I agree that the stars have been pushed the detail in the nebula and the structures revealed are amazing. You have inspired me to add this one to my hit list.

[gregbradley]

Thanks Pete. Yes the first was the better image overall for detail and extent of the nebula.

I haven't given up reprocessing this one yet. I may be able to get the best of both worlds on this one still.

Greg.

[tornado33]

Very impressive indeed. Images like these rival multi metre diameter professional observatory scope not that long ago.
The tilt you mention must only be those slightly larger stars at extreme bottom right? Barely noticeable. With my Baader MPCC coma corrector ( old mk1) any tilt results in elongated or comatic stars not just larger stars. Larger format cameras sure are unforgiving but nice to have :)
Scott

[gregbradley]

Thanks for the compliments Scott.
That tilt was corrected at some point.
As I recall its only some of the exposures that have it.
I have tilt pretty much under control in my scopes.

Greg

[topheart]

Wow!
A spectacular rendition of a very difficult target!
Well done Greg!
Cheers,
Tim

[gregbradley]

Thanks Tim. A tough one to process for sure. I have spent a large amount of time and many variations on this one. More data when it comes around again in about 4 months?

Greg.

[topheart]

Yeah, it is a wet season target for me, so I've never had clear enough skies to attempt it :sadeyes: