After Ophelia - The Other Cygnus Loop

[Knight of Clear Skies]

Managed a bit of a session on Monday night after the worst of Ophelia blew through. Certainly wasn't ideal conditions with intermittent cloud scampering through but I'm glad I made the effort. I concentrated on testing out my Samyang 135mm with 1600MM Cool and ZWO 7nm 31mm Ha filter, so see if it could cope with imaging at f2. First up I had a quick go at a target of opportunity, NGC7822.

But made a bit of a mess of it, missing off the small bright nebula to the right and failing to hit the focus. The above was 17 minutes of cloud-marred data.

After refocusing conditions still weren't great, so I switched over to a bright target as I wasn't expecting to get much imaging time.

The 135mm lens shows a surprising amount of detail with the small pixel camera, for example the pillar in the head of the Pelican is clearly visible. The above is 22 minutes in 1 minute subs. Unfortunately the ZWO filter can't cope with Deneb and I'm going to have to look at an alternative.

At that point conditions improved quite a bit and looking on Sat24 it seemed that I might get a good 2 or 3 hour window. Rather optimistically, I decided to try for a rarely imaged target, the supernova remnant 065.2+05.7, which spans about 4 degrees of Cygnus. The brightest filament is Sh2-91, near to Alberio.

It took a very heavy stretch to bring it out but Sh2-91 is at top left, with some hints of structure below and to the right.

Stretching even more and a hook structure starts to stand out, I think the sections below and to the right are Sh2-94 and Sh2-96.

Applying a blur filter and reducing the size makes it stand out a bit more.

Found it an interesting exercise anyway but I could probably have made better use of my imaging time - in the end the cloud rolled in to stay after about 50 minutes. Reading up on it since then it seems the SNR stands out from the background much better in OIII, there are some much better images of it here by Stephane Zoll.

[MikeODay]

Great post with some very interesting images; I particularly like the last few ‘negative’ images. 

I also quite enjoyed reading the details about your night of imaging.

Thanks for sharing.