I already photographed it in 2022 (and reprocess it last year), but I wasn't happy with the quality of stacks and of the final image. So, I did it again, a brand new capture.
I started the capture on 27th April and I finished it on 5th May. Setup: Omegon 203/800, ASI1600MM Pro. Total exposure- 12 hours. Frames: 33x5m R, 20x5m G, 20x5m B, 71x5m L. I took more frames for red filter not only because the camera is less sensitive on this band, but also I wasn't sure if I have clear skies for additional
The final image is better than the previous one ( viewtopic.php?p=203773&hilit=M100#p203773 ). Better details, better colors and more defined halo around the galaxy.
--When I checked the frames taken on 5th May (using ASIFitsView, then Blink), I noticed that a "star" moves between the others. In 5 hours it moved about 1 arcmin. I would say to myself that it must be an asteroid. I was really lucky that I saw it, only because it was next to M100. A colleague from the local forum identified it using this tool: https://ssd.jpl.nasa.gov/tools/sb_ident.html#/
The name of asteroid is 2582 Harimaya-Bashi. It has a diameter of 28.87Km (three times larger than the one who killed the dinosaurs). More about this asteroid: https://in-the-sky.org/data/object.php? ... &year=2024
I made an animated gif with 6 cropped frames ( one hour between them). I don't know if it plays on this site.
Clear skies!
Member of the RASC
