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One for Halloween...NGC6960, The 'Witches Broom'

RobH

By RobH
in Imaging - Deep Sky

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RobH

RobH

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Hello all......I haven't managed to post an image since June, so am pleased to finally get one!!

The aptly named ‘Witches Broom’ is part of the remains of a star that went supernova between 5 and 8000 years ago and can be found in the constellation of Cygnus. The bright star in the centre is 52 cygni, a naked eye star in reasonable conditions, so it’s quite easy to find this nebula, although it’s quite faint.

As so many well known objects were, it was discovered by William Herschel, on the 5th September 1784.

Imaging details.

The image is a combination of narrowband data for the nebula, and RGB for the stars. Ha alpha was used for red, OIII for blue, and a 50/50 mix of Ha and OIII for green. The Ha/OIII was also used as a luminance layer for the nebula, although only at 50% opacity.

Data was obtained over several sessions from July to September 2011 from Weymouth, Dorset.

Telescope. TMB 80/480 F6

Camera. Atik 16HR.

Ha. 31 x 600s.

OIII. 34 X 600s.

RGB ( 16 of each). Red @ 40s, Green @ 30s, Blue @ 50s.

Total imaging time. 11 hrs 22 minutes.

Full sized image can be found here.....

http://middlehillobservatory.co.uk/IMAGES/Full%20size%20pics/Witches%20broom%20Master%202011.jpg

Cheers

Rob

robh-albums-rob-hodgkinsons-images-picture14223-witches-broom-master-2011-web.jpg

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RobH

RobH

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Thanks all, I am pretty pleased with this, I especially like the OIII filamentary detail, and it's also first light for Stefski's old TMB80/480, which is an awsome scope :D.

As I have a high res image of the other main section of the veil complex, the 'Network nebula', I suppose next summers task is to shoot the rest of the region and then do a mosaic. Or maybe add some SII .....that'd be new ground for me as I've not really delved into hubble pallette territory.

Cheers

Rob

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RobH

RobH

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Thanks all :)

Olly....I used your technique of using the clone tool set to 'darken' on 51 cygni....works very well indeed. Thanks for the tip :D

@John.....yes, it is interesting that the star density above and below the nebula is so different.....I wonder if there's a lot of hidden dust behind that's obscuring things?

Cheers

Rob

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ollypenrice

ollypenrice

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Thanks all :D

@John.....yes, it is interesting that the star density above and below the nebula is so different.....I wonder if there's a lot of hidden dust behind that's obscuring things?

Cheers

Rob

If you look at wider field images of the broom that extend beyond the broomstick itself you can see that there is a distinct change in sky background colour and star count, making a continuation of the line of the handle. I've always interpreted this as a continuation of the propagating shock wave but without enough matter to produce an ionized bow shock. So yes, I think there are lots of compression waves outside the clean swept sky within the loop and I dare say the sky is more opaque outside it because of this stuff driven ahead of the broom itself. Some of these advance waves show in Rob's image.

BTW Rob, I tried an all mono presentation of Tom's and my Ha and O111 data combined. It looks pretty striking and makes more things visible than the colour, I reckon. Quick to do.

Olly

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RobH

RobH

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I'll give that a bash later today perhaps Olly......planning on spending most of the day horizontal though as I've gott a day off in a very comfy hotel, and have been doing 7 day weeks for the last month!!

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Uranium235

Uranium235

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I was wondering how you got such a dark blue with your narrowband version (50%mix of Ha/OIII for green), I think it looks great :)

Was it in PS?

Rob

Edit: Ahhh just found it, ive got it as an action as part of noels actions, it works a treat :D

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RobH

RobH

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I was wondering how you got such a dark blue with your narrowband version (50%mix of Ha/OIII for green), I think it looks great :)

Was it in PS?

Rob

Edit: Ahhh just found it, ive got it as an action as part of noels actions, it works a treat :D

Hi there.....Yes, I use PS, but not Noel's actions.....I just fiddle about until it looks right to me, and I specifically wanted the detail of NB but the colour that you get with RGB....glad you like it :o

Cheers

Rob

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