C/2025 A6 Lemmon Timelapses

How did I end up here? I have no idea. If I were forced to explain, I'd guess that because of my interest in the ham radio operation I dipped into the activity of Sun, which lead me into photographing some Auroras, then because I had no Auroras or waterspouts (what, where did that come from?), I ended up looking for different targets and that's when I realized my 900mm and 70-300mm lenses can do some astrophotography.

Anyway.

C/2025 A6 was discovered by Mount Lemmon Survey in January 2025 hence the name. It has a very high eccentricity and long orbital period so we won't be seeing it for some time after this approach. Based on short- and mid-term weather forecasts I won't be seeing it, but those of you with more luck especially on the Southern Hemisphere should still have a chance.

I used my Canon EOS 2000D with either Doer 900mm and Canon Zoom Lens EF 70-300mm. After almost completely botching my full Moon eclipse photos (still unpublished at the time of writing), I realized I'm terrible at focusing dark objects with the Doer 900mm, plus the comet (or rather: its tail) is visibly big enough for the 300mm or less to capture it well hence two lenses. Of course, I botched most of 900mm photos here too.

Some pictures are stacked with Siril, some are not. The average exposure time for the set is around 18 seconds (including total exposure time for stacks), so you can expect slight better results to what you'd see with any telescope or decent binoculars.

Timelapse from 29 October 2025, 18:42–19:22 CET:

Timelapse from 21 October 2025, 19:04–19:32 CEST:

Here's a cloud from the same day:

Now, photos of various quality. Dated 15 October, 19, 20, and last three are 21 October: