Sh2-112,115,116, LBN331 and a ‎humongous SNR

[gorann]

Here is a rather busy part of Cygnus captured in a two panel mosaic, mainly shot under a full moon with the RASA 8 and ASI2600MC equipped with the IDAS NBX dualband (Ha+Oiii) filter. I posted the first 55 minutes of the right panel last week, mainly since it contained a very rarely imaged and extremely faint gigantic Super Nova Remnant (SNR) without a name but at least with a designation:  SNR G 082.2+0.53. From my FOV I could calculate that the SNR must have an angular diameter of 1.3°, which is nearly three times that of the moon (0.5°). The right panel now contains 4.2 hours of data (50 x 5 min) and also includes LBN331 on the top. The left panel that I captured on Thursday night contains 2.3 hours of data (28 x 5 min) and includes three nebulae from the Sharpless catalogue: Sh2-112 (down in the left corner), Sh2-115 (unfortunately a bit cut off on the left edge), and Sh2-116, which is the red dot above Sh2-115. It may be a planetary nebula. So total integration time is 6.5 hours.

I had never heard of this SNR before and I had no idea that it was in there when I first aimed at the area last week. I have the feeling that it is even fainter than the Squid and I am not sure if there are any other images of it except on this site: https://www.nebulaphotos.com/lbn-ldn/nwcygnus/

So it is possible to image with the IDAS NBX filter under a full moon, but it is not ideal. Later on Thursday night, when Cygnus fell below my obsy wall, I aimed at IC405 & 410 and it was clear that the subs became more cotrasty after a few hours when the moon fell below the forest here.

Here is my post from last week:

 

Edited November 29, 2020 by gorann

[tomato]

Beautiful panorama, l like the way the three bright stars mark the edges of the SNR. 
When I saw the initials in your title post I thought you were referring to Signal to Noise Ratio, because you are getting a humongous amount of that with this combo.😊

[gorann]

Thanks Steve! He he, you are right, a lot of both kinds of SNR😉

[Tom OD]

Looks great, and a good signal after 55mins as you say.

Tom.

[gorann]

20 minutes ago, Tom OD said:

Looks great, and a good signal after 55mins as you say.

Tom.

Thanks Tom! And even better after 6.5 hours as in the image above.

[gorann]

Tamed the strong red signal that I never liked and let green and blue up a bit with curves in PS.

 

Edited December 1, 2020 by gorann

[MartinB]

Just amazing!

[gorann]

14 minutes ago, MartinB said:

Just amazing!

Thanks Martin, much appreciated!

[Miguel1983]

That's a big target ! Nicely done !

[gorann]

4 hours ago, Miguel1983 said:

That's a big target ! Nicely done !

Big it is, or quite close! Thanks a lot Miguel!

[tooth_dr]

Lovely Goran. That filter is very interesting. It’s well matched for the RASA8 and looks ideal for my epsilon. 

[gorann]

Thanks Adam!

Yes, I guess you have been looking at these spectral transmission graphs from Hutech IDAS:

[tomato]

Getting quite a bit of vignetting when mounting this filter in the RASA8 optical window, but my custom adapter is nearing completion ...

[gorann]

54 minutes ago, tomato said:

Getting quite a bit of vignetting when mounting this filter in the RASA8 optical window, but my custom adapter is nearing completion ...

Yes, it is probably too far from the sensor when you put it in the optical window. I have very little vignetting when I use the Artesky adapter which brings the filter probably 7-8 mm closer to the sensor.

[gorann]

14 hours ago, tomato said:

Getting quite a bit of vignetting when mounting this filter in the RASA8 optical window, but my custom adapter is nearing completion ...

Will your custom adapter be similar to the Artesky adapter or do you have your very own much smarter design?

[fwm891]

@gorann Great imaging Gorann. I had to make an adapter for my RASA 8 to a) get the filter closer to the sensor and b) be able to turn the filter so the correct face of the filter is pointing to the sky.

With the 533 its fine but larger sensors without the adapter would show vignetting.

[gorann]

23 minutes ago, fwm891 said:

@gorann Great imaging Gorann. I had to make an adapter for my RASA 8 to a) get the filter closer to the sensor and b) be able to turn the filter so the correct face of the filter is pointing to the sky.

With the 533 its fine but larger sensors without the adapter would show vignetting.

Thanks!

I have the similar Baader UFC slider for my ASI1600MM with the the RASA8, but no filter slider would work for the ASI2600 since the sensor distance is 17.5 mm, and not the generous 6.5 mm we have with the 1600 or 533.

Edited December 4, 2020 by gorann

[tomato]

3 hours ago, gorann said:

Will your custom adapter be similar to the Artesky adapter or do you have your very own much smarter design?

The QHY 268c has a hefty built in tilt adjuster that takes up 6 mm of back focus, and I don't have enough back focus left to achieve the required distance using the supplied QHY spacers. Given this and the requirement to mount the filter closer to the sensor @Tomatobro is machining up a adapter to bolt directly to the tilt adjuster to achieve the correct back focus and be threaded like the Artesky adapter to take the 2" filters. It will also be a less sloppy fit in the RASA screw on collar and be minus the cushion material which I think is a really bad idea given the sensitivity of an F2 system to misalignment.

Its nearly finished, I just need to provide a QHY spacer as a template for the bolt holes.

[gorann]

The Artesky holder also wobbles a bit but it does not have the cushions. I realize it will have to have a small enough diamater to get passed the threads of the threaded attachment ring from Celestron, and then a the bottom of that Celestron ring the diameter is bigger and allows the wobbling. My plan now is to put a ring made of garden wire (the one covered by a thin plastic and sold by garden stores for tying up plants) at the bottom of the Celestron ring behind the threads. That should center the adapter and hold it centrally. It works in my inner theatre at least.

[fwm891]

20 hours ago, gorann said:

The Artesky holder also wobbles a bit but it does not have the cushions. I realize it will have to have a small enough diamater to get passed the threads of the threaded attachment ring from Celestron, and then a the bottom of that Celestron ring the diameter is bigger and allows the wobbling. My plan now is to put a ring made of garden wire (the one covered by a thin plastic and sold by garden stores for tying up plants) at the bottom of the Celestron ring behind the threads. That should center the adapter and hold it centrally. It works in my inner theatre at least.

I removed the felt cushion from the RASA and replaced it with 1mm PTFE sheet (ebay). That provides a flat almost frictionless facing allowing the camera to be rotated without having to slacken anything

[gorann]

6 minutes ago, fwm891 said:

I removed the felt cushion from the RASA and replaced it with 1mm PTFE sheet (ebay). That provides a flat almost frictionless facing allowing the camera to be rotated without having to slacken anything

Good idea Francis! Rotating the camera is a bit cumbersome.

[tomato]

Good idea! I have some ptfe available but it would add a millimetre to Tomatobro’s carefully machined adapter...

 

[gorann]

17 hours ago, tomato said:

Good idea! I have some ptfe available but it would add a millimetre to Tomatobro’s carefully machined adapter...

 

Looks very professional! I also worry that an extra 1 mm will affect star shapes. So I searched a bit on the net and there are thinner teflon sheets than 1 mm and there is also thin (0.13 mm) adhesive teflon tape that I am tempted to try.

[tomato]

I have much better star shapes now I have the correct spacing. There is such a thing as PTFE thread tape which is very thin but it might ruckle up when the camera is rotated. My best option would be to machine a mm off the adapter if that's possible.

Can you get spray on PTFE, or have I just imagined that one?

Edited December 6, 2020 by tomato

[gorann]

Nice to hear! No I am not talking about the PFTE tape I use as a handy man when I fix the plumbing. There is one with adhesive on one side, like ordinary tape.

Edited December 6, 2020 by gorann