Mysterious bluish structures in Cassiopeia

[gorann]

Recently I noticed some faint blue structures in one of my Samyang 135 images of Sh2-183, but they were too faint for me to be sure they really existed. Moreover, I could not find any images of these possible objects. So a few days ago I took the chance of aiming my  dual-RASA8 rig at this area in Cassiopeia, catching about 7 hours. And, there they were. I imaged with my IDAS NBZ dual-band filter, so Ha and Oiii. Thus, these blue structures are likely to be Oiii emitting nebulosity although I cannot be 100 % sure they are not blue reflection nebulosity (there is that bright star nearby). They do look at least partly quite filamentous, which opens for the possibility that they are part of a supernova remnant (SNR). However, when I look in the SNR catalogue (https://www.mrao.cam.ac.uk/surveys/snrs/snrs.data.html) there is nothing registered in that spot. The closest is Tycho Brahe's SN (https://www.mrao.cam.ac.uk/surveys/snrs/snrs.G120.1+1.4.html), which is just outside the right edge of my image. But that SNR is as far as I understand it only emitting X-rays (and radio waves), and no visual light. 

Any suggestions for what it could be?

The image also shows Oiii filaments around Sh2-181, which are also seen in another of my recent images (https://www.astrobin.com/1dm109/)

Cheers, Göran

[Ags]

I suspect you will find the structures are made of blue stuff 😀

[Mal22]

6 hours ago, Ags said:

I suspect you will find the structures are made of blue stuff 😀

Yep. I’ve seen blue stuff before, and this is it. 
 

@gorann great image! 

[dweller25]

Great image 👍

[assouptro]

Don’t know what they are but I hope you’ve found something new! That would be awesome! 😊

Great image Gorann! 

[Tomatobro]

Gorann's nebula? I like the sound of that!

[gorann]

2 hours ago, assouptro said:

Don’t know what they are but I hope you’ve found something new! That would be awesome! 😊

Great image Gorann! 

 

2 hours ago, Tomatobro said:

Gorann's nebula? I like the sound of that!

Thanks Guys! Well Marcel Drechsler of course found something. It is registered in the Simbad database as GSH 122+02-77, an "Interstellar Shell". Marcel says that the shell is at the edge of a faint zone with radio emissions, but it doesn't seem to be an SNR at first glance.

http://simbad.cds.unistra.fr/simbad/sim-id?Ident=GSH+122%2B02-77&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id

So someone registered it but no one seems to have imaged it, however that works. At least I and Marcel have been unable to find any images other than mine. Great fun!!! Goran's nebula would be OK😁

[Elp]

I'd call it the Snail Nebula. With the red shell and slime trail underneath it looks like a snail turbo-ing through the universe.