Cygnet and Swan SHO completed

[Placidus]

Last night, with moral support from Rodney Ryderscope, we added the final 7 hours of 2x2 binned SII to the region immediately NW of the Swan (M17).

Original image here (https://photos.smugmug.com/Category/Star-Forming-Regions/i-n5GZtKW/0/7059e843/O/Swan%20and%20Cygnet%20Ha%207%20hrs% 201x1%20OIII%20SII%207%20hrs%20each %202x2.jpg)

We were struck by the extreme difference between what we are calling the Cygnet (centre and top of image) and the Swan (bottom right): the Swan is very strong in OIII (making it extremely bright visually), but the Cygnet is relatively much stronger in SII.

Sticking our swan-necks out, one explanation for that might be that there have been past supernova explosions in the region of the cygnet that have enriched it with SII, but it is further from the hot OB stars that would make it glow brightly in OIII. Even if that is hopelessly wrong, the difference is very striking.

Green: H-alpha 7 hrs in 1hr unbinned subs; red and blue: SII and OIII 7 hrs each in 1hr 2x2 binned subs. Total exposure 21 hrs. 3nM filters. 20 inch scope. Field approx 0.5 deg. Original image 0.55 sec arc/pixel. North is on the left.

Galaxy time now!

Best,
Mike and Trish

[cometcatcher]

There is a difference between the two isn't there. Very interesting image M&T.

[strongmanmike]

It's almost looks like a Peacock now, huh? :eyepop:..very cool.

I know cropping for aesthetics ain't yer thang guys but...it might be a cool image cropped to remove the bit of the swan below..? It's almost like you have discovered a new nebula :lol:

Mike

[gregbradley]

A very interesting segment of this nebula not normally captured very deeply. Nice work.

Greg.

[tornado33]

Great stuff, the difference really is noticeable, shows the value of narrowband imaging.
Scott

[Stevec35]

Certainly a different view of this area but very effective. Nice work M&T.

Steve

[Ryderscope]

Excellent and I can still see the polar bear along with the cygnet :D

[codemonkey]

Very nice!

[Placidus]

Thanks, Kevin. We'd love to have an expert explanation for what's going on.



Thanks muchly Mike. We can certainly see that the picture would make more sense artistically if we cropped off the Swan. We also wonder about a mosaic. We're half-way.



Cheers Greg!



Thanks, Scott. We should get off our bums and work out the actual SII to H-alpha ratios for the two regions, make sure that processing and leaky filters aren't to blame. Don't think so.



Ta, Steve!



Cheers, Rodney. The polar bear is there too, but more so in just the H-alpha image.



Thanks Lee.

[Slawomir]

Certainly a different take on this fascinating dso. Striking difference between the two sections of this nebula - wondering what might have caused it?

[topheart]

I like it! ....The different field of view!
Well done!
Cheers,
Tim

[Placidus]

Thanks Suavi and Tim. We probably should have just posted this final version only, but we were having such fun as the data slowly emerged, and the three versions - Ha, Ha-OII, and Ha-OIII-SII look so different aesthetically, we hope we've gotten away with it.

[multiweb]

Exquisite resolution and image scale. Love it. :thumbsup::thumbsup::thumbsup:

[Placidus]

Thanks, Marc, that's kind.

[petershah]

I really love the way you have processed this you still have the slight green hints from the Ha line that is quite often taken out in post process...superb image :thumbsup:

[Geoff45]

Very nice Mike. The next step has to be a mosaic.
Geoff

[Placidus]

Thanks, Peter. :hi: Nice to have some company on the "can leave hints of green" front. We live on a farm in the middle of a severe drought. We would love to have some hints of green outside. Science aside, it's not an ugly colour!



Thanks Geoff. We tried making it stitch to our much earlier Swan, but the overlap was just a tiny corner and it looked grim. So either proper mosaic as you suggest, or, as Strong Mike suggests, just crop the swan off completely.

[RickS]

Great image scale and detail as always, M&T. I don't mind a little green either.