Thor's Helmet - NGC2359

SkyViking (Rolf) · #1 19-01-2013, 10:19 PM

Hi All, here is another new image from the large pile of data I was fortunate enough to gather during Dec-Jan. This time just under 11 hours on Thor's Helmet. I did plan to take some more colour data but I haven't had the chance since, so I've just combined what I had

Link to large image (2.5MB)
Link to medium resolution image
There is so much going on in this area so I had to also made a slightly different and closer crop to highlight the helmet area itself: The link is here (1.3MB)

This delicate emission nebula is located in the constellation of Canis Major at a distance of about 15,000 light years. The nebula is illuminated by a central star in its last stage of life. This is a massive so called Wolf-Rayet star which is shedding its outer layers of gas at an extremely high rate due to intense radiation pressure. Wolf-Rayet stars are thought to represent a brief stage of evolution near the end of life for giant super massive stars - the last unstable phase before the star explodes as a brilliant supernova.
In the case of Thor's Helmet a large expanding bubble has formed around the bright central star. Interaction with giant molecular clouds in the area have contributed to the overall intricate shape of the nebula and large bow shock structures radiate out from the bubble in several directions. The nebula is some 30 light years in diameter and the strong blue-green colour is due to OIII emission near the star.
This entire spectacle lies embedded in a dense star field consisting of thousands of coloured jewels each casting their own contrasting light onto this dramatic interstellar scenery.

Image details:
Date: 8th, 14th, 19th December 2012 and 5th, 6th, 9th January 2013
Exposure: LRGB: 530:44:33:33m, total 10hrs 40mins @ -28C
Telescope: 10" Serrurier Truss Newtonian f/5
Camera: QSI 683wsg with Lodestar guider
Filters: Astrodon LRGB E-Series Gen 2
Taken from my observatory in Auckland, New Zealand

Personally I'm very happy with the outcome, I think this is one of my best images to date. However it is a highly photogenic nebula so maybe that's why

Comments and critique welcome as always.

Regards,
Rolf

Stevec35 (Steve) · #2 19-01-2013, 10:24 PM

I think you got that right Rolf. A high quality Thor's helmet indeed!

Cheers

Steve

RickS (Rick) · #3 19-01-2013, 10:27 PM

Great image, Rolf!

Larryp (Laurie) · #4 19-01-2013, 10:30 PM

Superb, Rolf! Love the colours

allan gould · #5 19-01-2013, 11:02 PM

Great colours and composition. A truly excellent image.

CoolhandJo (Paul) · #6 20-01-2013, 08:07 PM

I think you got the star field and the nebula balance right. Dark sky's and lots of imaging time needed to bring out more nebula though. The colours are spot on though. Great stuff!

strongmanmike (Michael) · #7 20-01-2013, 09:56 PM

Quote:

Originally Posted by SkyViking

Personally I'm very happy with the outcome, I think this is one of my best images to date. However it is a highly photogenic nebula so maybe that's why

I agree on both counts Rolf, well done

It's a very cool looking nebula that one and you have done it justice, the big image looks really great when viewed at 50% in the browser - top job.

Mike

gregbradley · #8 21-01-2013, 07:20 AM

A lovely image Rolf. I agree its one of your finest.

One improvement I think that can be made is there are red rings around many of the yellow stars. There are a couple of blue rings around some white stars.

How do you fix? Well probably do it on a one by one basis using the ellipse marquee tool. Select around each star dragging the ellipse until its covering the red ring and then use selective colour to adjust it so the red ring disappears but the yellow of the star is intact. Then do it again. You could record an action of the removing red part so all you need to do is select over the star then hit the play button. Also feather the selection 2-4 pixels.

Greg.

Ross G · #9 21-01-2013, 09:19 AM

What a beautiful photo Rolf.

I love the colours and detail.

Great composition.

Ross.

marc4darkskies (Marcus) · #10 21-01-2013, 12:57 PM

That's lovely Rolf! Nice and deep too. Well done!

A bit too noisy to show at full res but at medium it's a standout image. The stars are a little soft for me but that's a personal taste thing.

Cheers, Marcus

iceman (Mike) · #11 22-01-2013, 04:48 PM

I can see why you're pleased with that, Rolf! What a great image!

I have a soft spot for this nebula - one of the best I've seen from dark skies with a really big scope!

It's now IOTW.

JonathanGreen · #12 22-01-2013, 05:40 PM

Love the colours Rolf, a very photogenic nebula indeed!

peeb61 (Paul) · #13 22-01-2013, 07:50 PM

Nailed it Rolf, just love all that nebulousity and you have brought it out just nice!

Paul

ZeroID (Brent) · #14 23-01-2013, 08:44 AM

You're getting the last drop out of the 10" before the upgrade for sure.
Awesome image ..

SkyViking (Rolf) · #15 23-01-2013, 09:08 AM

Thank you everyone for your kind comments. It's a faint one but I was happy to see how well it came together as I kept gathering data. The colours of this nebula are surprisingly strong, they really popped pretty much straight out of the camera.

Quote:

Originally Posted by gregbradley

A lovely image Rolf. I agree its one of your finest.

One improvement I think that can be made is there are red rings around many of the yellow stars. There are a couple of blue rings around some white stars.
...

Thanks Greg, yeah my stars are usually relatively soft. I think this helps to show the colours they have, since purely white stars are quite rare. But I agree that they don't look optimal in all cases, still working on that

I'm hoping my new scope with Royce optics will also address that to a degree. Some of this likely comes down to the quality (or lack thereof) of my current mirror.

Quote:

Originally Posted by marc4darkskies

That's lovely Rolf! Nice and deep too. Well done!

A bit too noisy to show at full res but at medium it's a standout image. The stars are a little soft for me but that's a personal taste thing.

Cheers, Marcus

Thank you Marcus, as above I'm still working on my stars but hope to get there soon. I don't mind a bit of noise though, at least it shows that everything was squeezed from the data

Quote:

Originally Posted by iceman

I can see why you're pleased with that, Rolf! What a great image!

I have a soft spot for this nebula - one of the best I've seen from dark skies with a really big scope!

It's now IOTW.

Thank you very much Mike, that's awesome

Wow, that must have been a big scope indeed. I imagine it was an impressive sight, were you able to see the actual helmet shape?
I'm not sure if I can see even a trace of this nebula visually in my 10" (haven't tried though).

David Fitz-Henr · #16 23-01-2013, 12:16 PM

That's a great image Rolf - congratulations on IOTW as well!

rcheshire (Rowland) · #17 23-01-2013, 12:48 PM

Really nice Rolf...

lacad01 (Adam) · #18 23-01-2013, 01:27 PM

Great image, appropriately captured by the "viking"

gregbradley · #19 23-01-2013, 04:39 PM

Congrats on IOTW well deserved.

Greg.

icytailmark (Mark) · #20 23-01-2013, 05:41 PM

wow fantastic so many stars in the background!!!! its mind boggling