CTA1 and NGC40 - a very very weak SNR and a bright PN in Cepheus

[gorann]

This was the first image in over a month and the moon was virtually full, so I was a bit over-optimistic when I aimed at these targets with the dual RASA rig and NBZ filter. The planetary nebula (NGC40) is very bright and is seen centrally in the image and for a long time it was the only noticeable thing I could see in the data during processing, and it is a bit small for the wide FOV so I was quite unhappy, especially since I had spent 22.7 hours of integration on it, and stacking 681 subs (2 min amd 331 Mb each) had taken the best part of a day for two computers. However, after making a starless version (Star Xterminator) and doing some insane stretches the supernova remnant (CTA1 aka SNR G119.5 + 9.80 / +10.00 and +10.20) started to appear in the Oiii signal. It is extremely weak, and in no way comparable in strength to something like the Veil nebulae. But it looks promising and I clearly need to make a more serious attempt to capture this on a moonless night.

NGC 40 is 4500 years old and 3500 light years away and CTA 1 is 10 000 years old and 4500 light years away, so 1000 ly apart and they just happened to be in the same direction.

So, caught on the night 18-19 Dec with two RASA 8 with ASI2600MC and IDAS NBZ filters. 681 x 2 min = 22.7 hours (gain 100, offset  30, -15°C). On a Mesu 200 mount.

Cheers, Göran

EDIT: I also throw in a close up of the PN since there is some structure to be seen in it.

 

Edited December 22, 2021 by gorann

[turbotim]

Wow! very intersting good work !

[gorann]

10 hours ago, turbotim said:

Wow! very intersting good work !

Thanks a lot Turbotim!

CS, Göran