Log in

View Full Version here: : NGC 1769, 1763, N11 etc Ha OIII and now with 12 hrs SII


Placidus
24-11-2016, 08:45 PM
A busy, complex, morphologically diverse region. Pretend we've not posted any teasers on this.

Full size image here. (https://photos.smugmug.com/Category/Star-Forming-Regions/i-wW5QN84/0/O/Angry%20Bee%20NGC%201769%201763%20H a%208%20OIII%208%20SII%2012hrs.jpg)

The two brightest areas, reminiscent of the eyes of an angry bee, are NGC 1769 and NGC 1763, both strong in OIII, mapped to blue.

Below them is a large cavity carved out by open cluster NGC 1760. The walls of this cavity are yellowish, strong in H-alpha (green) and SII (red).

Towards 3 o'clock, and looking very like Thor's Other Helmet, is the supernova remnant N11. Here are discrete, almost non-overlapping structures strong in H-alpha, OIII, and SII.

Immediately to the right of N11 is a very small nebula with several embedded stars, which is almost implausibly strong in SII.

Well above 1769 and 1763 is another large but otherwise quite different cavity, this time with pure blue walls, almost devoid of H-alpha or SII, but very strong in OIII.

Stretching upward toward top right (and also more faintly toward bottom left) are very many long, faint, sharp, yellowish tendrils, reminiscent of the stinging tentacles of a weightless marine creature. These tendrils are also strong in H-alpha and SII but weak in OIII.

SII 12 hrs, H-alpha 8hrs, OIII 8hrs, all in 1 hr unbinned subs. Field 36 min arc across, north up, original image 0.55 sec arc/pixel. Processing with GoodLook 64. The 12,000 or so brightest stars have been mapped to white.

Very best,
Mike and Trish

Slawomir
24-11-2016, 09:05 PM
I love it. Both the image and explanation are splendid. I will use your inspiring record of this fascinating area of the night sky as a reference for my current project of the same region.

Atmos
24-11-2016, 09:09 PM
Very nice MnT! :thumbsup: Excellent execution of the area and no Devon worms for Mike to see either :lol:

The LMC amazes me with the, as you have pointed out, non-overlapping structures. Besides the Tarantula region most of the LMC seems to be definite in emission lines with little relative mixing of elements.

glend
24-11-2016, 09:50 PM
Very nice Mike and Trish. I am jealous as i am still trying to complete the Oiii on my image of this area. Bloody clouds.

RickS
24-11-2016, 09:52 PM
Fantastic image, M&T, with some amazingly twisted and complex structures. Thor's other helmet and the small Sii rich neb look like they accidentally wandered into a bad neighbourhood.

I'm even starting to like the green :)

Cheers,
Rick.

cometcatcher
24-11-2016, 10:10 PM
Fascinating image M&T!

strongmanmike
24-11-2016, 10:11 PM
...yeeeah me too...ah sigh.. imaging fashion...:lol:

Great stuff mike and trish :thumbsup:...its one of the craaaziest looking objects out there.

Mike

Placidus
25-11-2016, 06:44 AM
Thanks again, Suavi. Your image is coming along beautifully. We await its completion eagerly.





Hi, Glen. Ta. Hope you'll get a clear shot at it soon.



Thanks muchly, Rick. Haven't read it anywhere, but we'd guess that the two really big cavities are the result of strong stellar winds from huge stars, followed by many past supernova explosions. Not good old country comfort.



Thanks Kevin!



It deserves that title Mike. Andy, looking at it from a little wider viewpoint, sees it not as a pollen-swallowing bee surmounted by three goldfish but as a (traditionally crazy) Tassie devil.

markas
25-11-2016, 10:44 AM
Great image of a wonderfully complx area.

Mark

Retrograde
25-11-2016, 10:51 AM
That's beautiful and exquisitely detailed Mike & Trish.
I really loved the in-depth explanation too :thumbsup:

Placidus
25-11-2016, 10:51 PM
Thanks Mark.



Hi, Pete. Very glad you liked it.

Wish I understood more about what we're looking at. When is it the ejectate of just one supernova in largely empty space? When is it the ejecta of multiple supernovas hitting dense pre-existing medium? When is it pre-supernova stellar winds carving out a cavity? How does one tell? Why exactly, in detail, do we see predominantly OIII here and H-alpha there? (I've got the general principles but not the case by case details). Would so much like to know.

Best,
Mike