PDA

View Full Version here: : NGC 7293 Helix Nebula in Ha only ( additional Ha data )


Startrek
13-09-2024, 12:51 PM
Here’s a revised image of NGC 7293 Helix Nebula in Ha only. Further to my last SHO image, I captured more Ha on this target as this was the only way to increase detail whilst keeping noise at bay. The original Oiii data had a very high noise floor and Sii data had virtually no signal just mainly noise.
Total Ha data comprised of 343 x 180 sec dithered subs or about 17 hrs of acquisition.
The final result in Ha under my Bortle 8 City suburban light polluted skies had significantly improved from my original SHO version posted a week or so ago. This result was far more encouraging than the original showing more fine detail in the outer regions of the object.
I’ll probably add the original Oiii and Sii data to this image at some stage but I doubt it will improve the result on this Ha image other than the ability to produce a colour version.

Link to Astrobin below for full resolution……,

https://www.astrobin.com/1i1j2n/

Attached original framed version and crop version at IIS 200kb size

Comments welcome
Thanks for looking

Martin

rmuhlack
13-09-2024, 02:29 PM
You've got some faint detail there now. well done

Dave882
14-09-2024, 10:57 AM
Yeah that’s heaps deeper Martin. I think the Ha certainly showcases those faint extents well. Well done!

xiongz
14-09-2024, 11:55 AM
Hi Marin,

This is really good. I searched Helix images on the net when I was checking on mine. Your details were just as good as best ones out there. I thought long subs would be better but yours with 3min seemed to be just fine (even at F5), and 3nm filters do work well for nebulae under B8 skies.

John

foc
14-09-2024, 07:34 PM
I love that Ha view of the Helix...those many hours of data you recorded were well worth while.

Startrek
15-09-2024, 09:06 AM
Thanks Richard
It’s hard work under B8 skies to bury the noise but quite pleased now with the additional Ha data
Martin

Startrek
15-09-2024, 09:08 AM
Thanks Dave
Yep those additional hours with Ha did the trick
Such a challenging target
Martin

Startrek
15-09-2024, 09:16 AM
Thanks John,
Most folk advise to push longer subs in the order of 5 to 10 minutes or longer but I disagree in relation to the 2600MM camera , very faint targets under B8 skies or with smaller shorter focal length scopes. Maybe for larger brighter targets but not dim targets, you’re always fighting with the noise floor.
The sweet spot for my rig using the Antlia 3nm filters is 3 min

Martin

Startrek
15-09-2024, 09:17 AM
Thanks Ross

gregbradley
15-09-2024, 05:35 PM
You captured it all which is hard to do.
Looks great.

Greg

Startrek
15-09-2024, 08:28 PM
Thanks Greg,
This last new moon period was the longest run of clear nights in memory so took advantage and gathered as much data as possible under my heavy light polluted skies in Sydney.
The final result was most pleasing

Cheers
Martin