The Helix Nebula

User avatar
Graeme
Cosmic Lounger
Posts: 1189
Joined: 11 Feb 2010, 12:23
Location: Medway, Kent, UK

The Helix Nebula

Post by Graeme »

The Helix Nebula. A planetary nebula in Aquarius. A cloud of glowing ionised gas floating away from the hot remains of a dying star. The Helix Nebula has sometimes been referred to as the "Eye of God" and the "Eye of Sauron".

I can't claim the credit for capturing this one. It was imaged in filtered narrow band hydrogen α oxygen iii and nitrogen ii light and offered up for processing by my old mate Rob from Brisbane. This is my attempt at processing his data:

Capture.JPG
You do not have the required permissions to view the files attached to this post.
Last edited by Graeme on 12 Nov 2020, 20:26, edited 1 time in total.
_______________________________________

http://www.averywayobservatory.co.uk/

User avatar
HansV
Administrator
Posts: 78235
Joined: 16 Jan 2010, 00:14
Status: Microsoft MVP
Location: Wageningen, The Netherlands

Re: The Helix Nebula

Post by HansV »

Nice!
Best wishes,
Hans

User avatar
Rudi
gamma jay
Posts: 25455
Joined: 17 Mar 2010, 17:33
Location: Cape Town

Re: The Helix Nebula

Post by Rudi »

Ionised gas. As long as it does not start floating towards earth. :grin:
Regards,
Rudi

If your absence does not affect them, your presence didn't matter.

User avatar
HansV
Administrator
Posts: 78235
Joined: 16 Jan 2010, 00:14
Status: Microsoft MVP
Location: Wageningen, The Netherlands

Re: The Helix Nebula

Post by HansV »

The Helix Nebula is about 650 lightyears from the Earth. So gas with the extremely high velocity of 10% of the speed of light would take 6500 years to reach us...
Best wishes,
Hans

User avatar
stuck
Panoramic Lounger
Posts: 8125
Joined: 25 Jan 2010, 09:09
Location: retirement

Re: The Helix Nebula

Post by stuck »

The image is great :thumbup: keep them coming!

For those of you struggling with the science bit:
Graeme wrote:
12 Nov 2020, 20:25
...imaged in filtered narrow band hydrogen α oxygen iii and nitrogen ii light...
try reading this:
https://www.atik-cameras.com/news/begin ... d-imaging/

Ken

User avatar
Graeme
Cosmic Lounger
Posts: 1189
Joined: 11 Feb 2010, 12:23
Location: Medway, Kent, UK

Re: The Helix Nebula

Post by Graeme »

The process also filters out a lot of light pollution so the final image is a lot less noisy.

The three files are layered in processing and allocated to the red, green and blue channels. Could be hydrogen α red, oxygen iii green and nitrogen ii blue but there are no rules really!

The Hubble Space Telescope creates those stunning images using the Hubble palette and allocates SII – Red, Ha – Green and OIII – Blue.

A lot of people here probably understand the physics better than I do but I find putting it into practice and producing the final image hugely entertaining!

Here's another explanatory link: https://astrobackyard.com/narrowband-imaging/

Regards

Graeme
_______________________________________

http://www.averywayobservatory.co.uk/

User avatar
Graeme
Cosmic Lounger
Posts: 1189
Joined: 11 Feb 2010, 12:23
Location: Medway, Kent, UK

Re: The Helix Nebula

Post by Graeme »

Here's a link to The Sky Searchers astronomy forum where I posted the image above.

If you fancy having a try at processing the image, feel free to download the data and give it a go.

https://theskysearchers.com/viewtopic.php?f=107&t=14445

You will need Photoshop or Gimp or something similar.

Regards

Graeme
_______________________________________

http://www.averywayobservatory.co.uk/

User avatar
BobH
UraniumLounger
Posts: 9214
Joined: 13 Feb 2010, 01:27
Location: Deep in the Heart of Texas

Re: The Helix Nebula

Post by BobH »

Beautifully done, Graeme! Kudos and keep 'em coming!
Bob's yer Uncle
(1/2)(1+√5)
Intel Core i5, 3570K, 3.40 GHz, 16 GB RAM, ECS Z77 H2-A3 Mobo, Windows 10 >HPE 64-bit, MS Office 2016

User avatar
stuck
Panoramic Lounger
Posts: 8125
Joined: 25 Jan 2010, 09:09
Location: retirement

Re: The Helix Nebula

Post by stuck »

Graeme wrote:
13 Nov 2020, 13:26
...understand the physics...
It's been a while since I had to get my brain round hydrogen orbitals, electron decay and photons.

Ken

User avatar
Graeme
Cosmic Lounger
Posts: 1189
Joined: 11 Feb 2010, 12:23
Location: Medway, Kent, UK

Re: The Helix Nebula

Post by Graeme »

BobH wrote:
13 Nov 2020, 19:05
Beautifully done, Graeme! Kudos and keep 'em coming!

Thanks Bob, will do!

stuck wrote:
13 Nov 2020, 19:26
Graeme wrote:
13 Nov 2020, 13:26
...understand the physics...
It's been a while since I had to get my brain round hydrogen orbitals, electron decay and photons.

Ken

It's just capturing photons at different frequencies, turning them back into electrons, counting them and giving the number a colour! :smile:

Regards

Graeme
_______________________________________

http://www.averywayobservatory.co.uk/

User avatar
stuck
Panoramic Lounger
Posts: 8125
Joined: 25 Jan 2010, 09:09
Location: retirement

Re: The Helix Nebula

Post by stuck »

Graeme wrote:
13 Nov 2020, 13:41
...
If you fancy having a try at processing the image, feel free to download the data and give it a go...
I realise this is more than just a tad overcooked but it was fun to learn how to combine the three mono images.
NGC7293_4web.jpg
Graeme wrote:
13 Nov 2020, 19:54
...
It's just capturing photons at different frequencies...
Yes, I realise how it works. I was more musing on how long it's been since I'd had to think about electron decay and emitted photons. If you ask my kids, I did my degree when dinosaurs roamed the planet :laugh:

Ken
PS sometimes my boys are a bit more forgiving and just ask me what it was like when I was a boy and I went out hunting mammoths with their Grandad.
You do not have the required permissions to view the files attached to this post.

User avatar
HansV
Administrator
Posts: 78235
Joined: 16 Jan 2010, 00:14
Status: Microsoft MVP
Location: Wageningen, The Netherlands

Re: The Helix Nebula

Post by HansV »

Oh wow, is that from the same source image(s)? Not bad for a dinosaur!
Best wishes,
Hans

User avatar
stuck
Panoramic Lounger
Posts: 8125
Joined: 25 Jan 2010, 09:09
Location: retirement

Re: The Helix Nebula

Post by stuck »

HansV wrote:
14 Nov 2020, 15:59
Oh wow, is that from the same source image(s)?...
Yes, the link Graeme gives to theskysearchers gives you a link to a Dropbox folder that holds three TIFF files, one for each of the narrowband frequencies. I opened them up in my (dinosaur) version of PS and then pasted each one into a different channel of a new/empty image. I did it that way because, as yet, I've not figured out how to do that in my copy of Affinity Photo (which is bang up to date). I then saved this combined image as a TIFF, and then reopened it in Affinity Photo. In there it was then a case of messing with the levels, curves, contrast etc. on each channel.

Ken

User avatar
HansV
Administrator
Posts: 78235
Joined: 16 Jan 2010, 00:14
Status: Microsoft MVP
Location: Wageningen, The Netherlands

Re: The Helix Nebula

Post by HansV »

It worked very well!
Best wishes,
Hans

User avatar
Graeme
Cosmic Lounger
Posts: 1189
Joined: 11 Feb 2010, 12:23
Location: Medway, Kent, UK

Re: The Helix Nebula

Post by Graeme »

That's brilliant Ken! For a first go I would say you're a natural! I usually stretch the separate files and cut the black level then merge the channels. Seems to work well merging first too.

Have you mapped the Oiii to green in the centre there?

Regards

Graeme
_______________________________________

http://www.averywayobservatory.co.uk/

User avatar
stuck
Panoramic Lounger
Posts: 8125
Joined: 25 Jan 2010, 09:09
Location: retirement

Re: The Helix Nebula

Post by stuck »

Graeme wrote:
14 Nov 2020, 17:26
...Have you mapped the Oiii to green in the centre there? ...
Umm, Can't remember :laugh: I thought opened each file, in turn, as they were listed in Explorer, which would have given me:
Ha --> red
Nii --> green
Oiii --> blue
but I was messing around so much anything is possible.

\Ken

User avatar
stuck
Panoramic Lounger
Posts: 8125
Joined: 25 Jan 2010, 09:09
Location: retirement

Re: The Helix Nebula

Post by stuck »

It seems what I thought I did was not what I did. This version is definitely:
Ha -->Red
Nii -->Green
Oiii -->Blue
and tweaked so I can deliver that immortal line, "Here's looking at you kid"

Ken
You do not have the required permissions to view the files attached to this post.

User avatar
HansV
Administrator
Posts: 78235
Joined: 16 Jan 2010, 00:14
Status: Microsoft MVP
Location: Wageningen, The Netherlands

Re: The Helix Nebula

Post by HansV »

One Ring To Bind Them All...
Best wishes,
Hans

User avatar
stuck
Panoramic Lounger
Posts: 8125
Joined: 25 Jan 2010, 09:09
Location: retirement

Re: The Helix Nebula

Post by stuck »

Yeah, that too :laugh:

User avatar
Graeme
Cosmic Lounger
Posts: 1189
Joined: 11 Feb 2010, 12:23
Location: Medway, Kent, UK

Re: The Helix Nebula

Post by Graeme »

Just out of interest this is what the three files look like in grey scale:

https://theskysearchers.com/viewtopic.p ... ii#p101239

Regards

Graeme
_______________________________________

http://www.averywayobservatory.co.uk/