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Placidus
05-08-2018, 05:26 PM
We've grown increasingly fascinated by the relatively faint nebulosity NW of M17.

It is shown superbly in the top 40% of a recent wide field 32 hr SHO image by Suavi (https://www.astrobin.com/full/355006/C/).

Here we had a more narrow field view of said patch, and it turns out that the Swan has had a Cygnet, only just emerged from its shell and still all wet and scrawny.

Mum's chest is the very bright patch at the bottom right corner, but she is mostly out of field.

Original image here. (https://photos.smugmug.com/Category/Star-Forming-Regions/i-XN99ZvT/0/0d7dc4f4/O/Cygnet%20Ha%207%20hrs.jpg)

[Edit: the link now points to a slightly less deconvolved and sharpened version than when first posted]

Perhaps one of the cygnet's ancestors was an archaeopteryx, leathery wings held out Cormorant style, still confined by the shape of the egg perhaps. You can see the cygnet's head and long thin neck, and perhaps even some dark legs all dangling down-oh.

The cygnet turns out to be almost as large on the sky as mum. Either it is closer to us, or it was a painful egg-laying.

Aspen CG16M on 20" PlaneWave. 3nM H-alpha. 7 hrs in 1 hr subs.

North is on the right. Field approx 35 min arc. Original image 0.55 sec arc/pixel.

We're in a good mood here at Placidus, because despite the drought, we've got just enough feed to look after 26 yearling heifers for our neighbour for a few weeks, so it's looking all rural out the window, and more rain tonight.

Very best,
Mike and Trish

Slawomir
05-08-2018, 05:47 PM
Fantastic detail MnT!

I must admit I compared your data with my recent image of the Swan and it is clear beyond any doubt that in spite of a shorter integration your image reveals much much more and in significantly higher quality. Top shelf image :thumbsup:

As for the cows - these peaceful grass grazing machines can certainly add to the charm and tranquillity of a countryside.

gregbradley
05-08-2018, 06:08 PM
A fabulously detailed shot bringing up new territory there.

Greg.

kosborn
05-08-2018, 06:24 PM
Lovely image! And here was I patting myself on the back because I'm now doing 10 minute subs.


Kevin

Stevec35
05-08-2018, 06:36 PM
Unusual composition but it looks great and the usual entertaining writeup too

Steve

willik
05-08-2018, 07:02 PM
That looks great and the detail:eyepop:
Martin

RickS
05-08-2018, 07:58 PM
Very cool alternate to the usual M17, M&T :thumbsup: It did look slightly wormy, so perhaps a little too much decon? I'm sure Mikey will let us know if it sets off his decon alarm :lol:

cometcatcher
05-08-2018, 08:55 PM
Beautiful filamentary nebula. Great stuff M&T.

Placidus
05-08-2018, 09:06 PM
Thanks, Suavi. You probably wrote this while we were busy editing our post to include a link to your image, which was the actual inspiration.

We hope to add some OIII and SII before the season is over.

Andy01
05-08-2018, 10:06 PM
WOW!:eyepop:
I've always liked that bit of M17, somehow the dark dust lane almost disappears in every colour rendition - so seeing it here, proud & bold supported by the plumes of Ha above is wonderful. :thumbsup:

AstroBogan
06-08-2018, 09:09 AM
Stunning as always :eyepop:

Placidus
06-08-2018, 02:25 PM
Thanks muchly, Andy. In that dust there is a row of animal faces all in profile, all facing toward about 4 o'clock: a lion, three kangaroos (or perhaps ferrets?), and a panther smoking a very fat cigar.



Thanks Jacob!

Perhaps the original is very slightly too sharpened. Here is a version (https://photos.smugmug.com/Category/Star-Forming-Regions/i-XN99ZvT/0/0d7dc4f4/O/Cygnet%20Ha%207%20hrs.jpg) with only 2/3 the number of decon rounds, and only half the wavelet sharpening. The bright stuff at bottom right (mummy swan) looks better, but the rest of it is barely changed.

atalas
06-08-2018, 03:19 PM
Excellent M&T:thumbsup::thumbsup::thumbsup:the creative juices are flowing.

Lognic04
06-08-2018, 06:13 PM
WOW!!! :eyepop:
I have to ask, how do you not blow out the stars with 1 hour subs?!!

Placidus
06-08-2018, 06:52 PM
Thanks muchly, Louie. There's plenty to get the imagination going in there.



Thanks, Logan.

Part of the trick is the 3nM H-alpha filter only lets through about 1% of the visible light.

Another is that the quantum wells on the 16803 chip are pretty deep. They can register 100,000 photo-electrons.

About 30 of the 8000 or so detectable stars in the image have indeed reached 65535 A/D counts in the exact centre, but each pixel has an anti-blooming gate that stops the full well affecting neighboring pixels. The outer reaches of these 30 or so stars that are burned out in the exact centre are still fine.

The long subs work well. We do enough subs to be able to statistically reject cosmic rays and satellite trails. In the dome, there is no problem with wind buffet up to about 40 KPH. We don't image if my hat won't stay on. We got the polar alignment spot on about 6 years ago and with our 2.5 tonne pier 1.8 metres into solid rock, we haven't had to touch it, so there's no problem with field rotation. As regards to tracking and guiding glitches, the FWHM is no worse after 1 hour than it is after 60 seconds.

We have very dark skies (except near the horizon), and for 3nM H-alpha, such long subs are justified. It is also just plain convenient to only have 6 or 8 subs to analyze.

Very best,
Mike

Atmos
06-08-2018, 08:36 PM
The signet is flapping and playing in the hydrogen gas "lakes".

Gorgeous image MnT, the depth and contrast is top shelf :)

strongmanmike
06-08-2018, 08:46 PM
This is really great guys, bold and contrasty. Love the new presentation of this perennial favourite too, it really is a new nebula when oriented like that and really does look like a young swan flapping it's wings as it is standing up :thumbsup: Really looking forward to seeing it in full narrowband now and with M17 cut off the bottom there, should look good in its own right.

Mike

Placidus
07-08-2018, 07:09 AM
Thanks Colin! We can hear the Tchaikovsky playing in the mist.



Cheers, Mike! Your actual swan has the pose perfectly. Will definitely do lots of OIII and SII. Might need 2x2 binning for those. :)

Best,
MnT

Slawomir
07-08-2018, 06:32 PM
Glad that you liked my attempt at this bright yet challenging to adequately present magnificent dso. I'm am really looking forward to seeing your image that includes OIII and SII.

Ryderscope
07-08-2018, 11:16 PM
Definitely a lovely presentation inspired by a familiar object. We see many shapes in addition to those identified. A nice journey.

Placidus
08-08-2018, 05:10 PM
Thanks so much! The OIII version is on its way - not so very much OIII though. We hope to get some SII as soon as the weather permits.



You'll have to come to Placidus and tell us about the additional shapes.

Best,
Trish