Interstellar Comet 3I/ATLAS

Comet 3I/ATLAS or C/2025 N1 (ATLAS) is the third known object from outside our solar system to be discovered passing through our celestial neighborhood. Astronomers have categorized this object as interstellar because of the hyperbolic shape of its orbital path. (It does not follow a closed orbital path about the Sun.) When the orbit of 3I/ATLAS is traced into the past, the comet clearly originates from outside our solar system.
As of 2025, three interstellar objects have been discovered traveling through the Solar System:
1I/ʻOumuamua in 2017, 2I/Borisov in 2019, and 3I/ATLAS in 2025. The prefix "1I" identifies the object as the first confirmed interstellar interloper, "2I" as the second, and so on.



This morning was the first morning with a clear sky. I used my DSLR Nikon D7500 with a zoom lens to image the comet in constellation Leo. It was not easy with the moon almost 60° illuminated.


Setting: Nikon D7500 with zoomlens.
No Guiding and no cable (as it was broken the night before).
Software: APP, ASTAP, CS4, DeNoise AI, Stellarium, SkySaferi.


Workproces: stacking 7 images with APP each ISO6400 4s. The picture was edited using APP tools light pollution and background calibration. Next, ASTAP was used to extract the green channel and Denoise AI to remove noise. This noise free image was again uploaded in ASTAP and star annotation was set. Unknown star annotation identified the position of the comet. This on the "same" location as found in Stellarium and SkySafari.