CTB1 / Abell 85

Since I got into astronomy and astrophotography, CTB1 was my favorite object of them all. Its shape and structure instantly got my attention and the fact that there is not a lot of information about it fueled my curiosity even more.
After some early attempts with a DSLR and the William Optics Z61 in early 2020 it became clear that this would be one big challenge for myself and my equipment. This supernova remnant which was first categorized as a planetary nebula early on, is one of the faintest and therewith hardest objects for visual astronomy. You are looking at ~40 hours of total exposure time in HA, SII and OIII collected over several nights between 06/2020 and 02/2021. One could easily go up to 80 h and it would still improve the image, I’m sure.

Adding at least 40 hours of image processing to the bill, the final image is a mixture of starless narrowband data, blended with RGB stars, a luminance layer of all narrowband data stacked together and a lot of color tweaking to get to a remotely “natural” look. All in all, I’m very glad I’ve put in the work and I’m looking forward to some easier targets for now.

This project marks another publication in Sterne und Weltraum by SPEKTRUM Verlag.