In 1966 when George Abell compiled his catalog of planetary nebulae entry 85 in Cassiopeia was mis-classified. While it has some resemblance to a planetary nebula it is subsequently been found to be the remnants of a supernova explosion . However, unlike the Cygnus loop it’s emission is mainly in H-a with very little O-III.
I’m still collecting data for this object but this is a process of the first 12 hours of images shot through a Baader 3.5nm Ha filter.
There is an older, fainter supernova remnant in Cygnus and it lies just up from the double star Albireo. At about 30000 years old (Veil 7500 years) and further away 2500 ly (Veil 1500 ly) it is correspondingly fainter. The part I’ve imaged here has the designation Sh2-91.
I last took pictures of this object back in 2014 with my QHY9 colour camera and it wasn’t entirely prominent but by combining the old data with 4 hours shot through my new Baader 3.5nm Ha filter a more distinctive image is formed.
I’ve rejected some of the original frames that had some thin cloud and re-stacked, then registered the new Ha frames and combined using the Pixinsight NBRGBCombination script.
I finally took the plunge and ordered a Moravian G3-16200 camera. This is a monochrome camera and whilst the pixels are slightly larger than the KAF-8300 equipped QHY9 there are also a lot more of them. Setting up has been rather a long process that still isn’t completed but at least it’s attached and able to take pictures. The increased sensor size and weight has highlighted some issues with my Takahashi FSQ85-ED Baby-Q. There is some tilt in the optical train and stars are elongated in the corners. Hopefully, I’ll be able to work out solutions for these problems.
One of my purchases was a Baader 3.5nm Ha filter and this image was taken with it last night. The night’s are still very short here so only 2 hours in 20 minute sub-frames of the emission nebula IC1396 in Cepheus.
On a wet and windy bank holiday Monday I finally got back to this subject for another attempt at processing. Having dedicated about 23 hours acquiring the images and spending countless more hours processing the data I still felt that there was more in this image than I’d managed to extract.
I’ve learnt a lot about the Pixinsight tools I regularly use on other projects and added a few more to the toolbox. Overall, I’m very happy with this result.
Astronomy Now magazine were kind enough to use this image in their June 2016 edition.
This is an image from last December when I gathered 6 hours worth of 10 minute subframes over several evenings. This is a large colourful emission nebula in Cassiopeia and is part of the Perseus spiral arm of our galaxy.
With some favourable nights back in October I increased the number of 15 minute subframes I’d acquired of the Iris nebula and the final tally was around 23 hours. A few were rejected and the remainder stacked and processed in Pixinsight.
This is a wider field of view around the Iris nebula in Cepheus (vdB139) and shows the extensive dust clouds that surround the reflection nebula itself. This is another of those objects that I’m in a constant state of gathering more frames for; so far this is up to 8 hours in 15 minute subframes.
This has been my longest imaging project to date coming in at over 17 hours of RGB data in 10 and 20 minute subframes. The reason for this has been the very faint nature of the target against the light pollution here. To reduce the noise to acceptable values it’s been necessary to acquire rather more images. Contrasted with the pristine skies of Tivoli, Namibia it’s bought home the difficulties and additional work required to successfully target faint objects from UK skies.
Having pollarded a willow in the garden and removed an Alder I now have a much clearer view across the southern horizon and for objects above Sirius I don’t have to worry about obstructions. Having also replace the Observatory Netbook with a dual core Atom embedded PC board this was a convenient test target to ensure that all was working as it should be.
This is 200 minutes of exposure in 10 minute sub frames, processed in Pixinsight.
Bob Samuel had also imaged this object with Ha, SII and OIII filters using his ED80 and combined them with my colour data for this result: