I missed the most prominent comet C/2021 A1 (Leonard) in 2021 due to permanent, constant, ever-lasting bad weather. In the last 3 months, I was able to see the star only through the holes in the clouds (except one night during our winter vacation in Laax). At least I have time to process the old data I took a long time ago. In 2020 I took pictures of two comets and here is one of them. It’s called C/2017 T2 (PANSTARRS) and on the 25th of May 2020 was possible to spot it, roaming in the constellation Ursa Major.

I was postponing the processing very long time because the comets are the most difficult object to process. There is a fixed background of the stars and deep space objects and the comet is slightly moving across the field. This means that the pictures must be registered twice and merged together afterward. Since I have plenty of time now, I was able to experiment, and here is the final image:

TelescopeNewton 254/1000 mm
Aperture254 mm
Focal length1060 mm
MountGemini G53f
AutoguidingZWO 174MM, TS 60/240 mm
CameraZWO 071 Pro @-10°C
CorrectorExplore Scientific HR coma corrector
Exposure34x180s, Gain 94, bin 1x1,