Log in

View Full Version here: : The Low-Flying Crab


Dave882
20-02-2024, 10:31 PM
This is the 3rd year in a row I've tried to nail this space-critter (aka M1). And with almost constant cloud for the last 4 months I count myself fortunate to finally be able to get a few hours worthy of processing.

Taken with (and only remotely possible due to) the L-Ultimate 3nm dual-band pass filter, I was pleased to be able to reveal some of the fascinating structure within this SNR. The original supernova was actually recorded by Chinese astronomers in 1054! It's mind-boggling to think how this SNR has evolved during the last 1000yrs - and imagine what a time-lapse video would reveal over the next 1000!

I can only get line-of-sight for an hour or 2 on its way down and so all the data is taken under 30degrees elevation. I'd love to have a bit more time but I think it's just too far gone for this season so will leave it here for now.

A total of 3hrs with the L-Ultimate (120sec subs) and 30min with RGB (30sec subs). Ha & Oiii channel extraction in APP, and then processed in PI. The atmospheric dispersion was really really pronounced but cleaned up reasonably well using BlurEx - without which I'd only be able to present a starless version. I recombined in both HOO and Foraxx pallet utility, both with RGB stars. Final tidy-up in LightRoom.

Higher res version here:
Foraxx (https://storage.googleapis.com/dso-browser.com/astrophotography/picture-34066fea3e83a9568874779d1d741a76-original.jpg)
HOO (https://storage.googleapis.com/dso-browser.com/astrophotography/picture-ad031450d976f3ddd88e9042170f0a2b-original.jpg)

C14 non edge @f7 with the Starizona reducer LF
EQ8 pro
Asi2600mc pro gain 100
Asi220mm / celestron OAG
ZWO EAF
ASIAIR pro / APP / PI / LR
Bin2 during capture.

Comments and suggestions welcome!
Thanks for looking.

Startrek
21-02-2024, 07:43 AM
Dave,
Another great image of a difficult target with minimal data
My preference is the HOO as the Starfield looks more natural
I’ve seen photos of the Crab from folk who have captured 20 and 30 hours of data , so yours is excellent for only 3 hours plus punching through all that low level atmospheric dispersion
Well done again !!

Martin

Dave882
21-02-2024, 08:23 PM
Thanks Martin I appreciate your comments! Yes it’s such a challenge shooting low and toward the city smog from my location. You can tell by the noise level I’m a bit short of data but yes still happy with the result. :)

strongmanmike
24-02-2024, 08:40 AM
Don't see many Crabs on IIS, a hard object to shoot well from down our way, so well done on this commendable attempt Dave :thumbsup:

Mike

Stephane
24-02-2024, 10:04 AM
That’s beautiful Dave. As Mike said, a rare treat on IIS. Well done!

RobF
24-02-2024, 11:26 AM
Wouldn't it have been wonderful to see it go off all those years ago! :)
Amazing work - most people doing NB usually doing much wider FOV fluffy nebs - but that's come out beautifully. Thanks for sharing.

Dave882
25-02-2024, 08:47 PM
Thanks guys much appreciate the comments! It’s certainly low…but not unobtainable so reckon even with a mid-sized newt/sct it’s worth a go!