comets – duck pics

c/2025 a6

admin — Sat, 11 Oct 2025 19:09:07 +0000

Comet C/2025 A6 on the morning of 11 October 2025 in the constellation UMa, at a distance of 0.74 AU, 28 days before reaching perihelion.

C/2025 A6 was only discovered on 03.01.2025, and from around the beginning of August developed into an object of much greater brightness than originally assumed.
This image was taken on 11.10.2025, at around 3:45 UTC from 256 exposures of 3.2 seconds each at f/1.4, which were then integrated.

The length of the tail in this image is approximately 3.5°: the bright star at the top of the image is ψ UMa. The comet was not visible to the naked eye at the time the image was taken. However, it was relatively easy to spot with 7×50 binoculars.

c/2022 e3

admin — Sun, 02 Mar 2025 12:48:15 +0000

Comet C/2022 E3 is the greenish diffuse streak to the right of (a), taken on 10.02.2023 at 20:01 UTC in the constellation Taurus. It was of rather modest appearance.
(b) = Mars. Next to (c) is COSPAR 2010-043D = NORAD 37155, a Russian Briz-KM rocket upper stage that was launched from Plesetsk on 08.09.2010 and deployed 4 payloads. The altitude at the time the photo was taken was 1200 km, the distance 1320 km. This satellite was not visible to the naked eye. The streak at (d) is an even higher orbiting satellite, hence the shorter track. The scale is 1°, the exposure time was 10s at f/2.8.

Comet C/2022 E3

This content is licensed under a Creative Commons Attribution 4.0 International license.

c/2023 a3

admin — Sat, 01 Mar 2025 20:26:37 +0000

C/2023 A3 passed through its perihelion on 27.09.2024, after which its absolute brightness steadily decreased. It reached its smallest distance to Earth on 12.10.2024 and I was able to see it effortlessly as a bright object on the western horizon for the first time on the evening of 13.10.2024. However, I didn’t have a camera with me.
As the weather was very bad the following days, I was only able to take a few photos of the comet under unfavorable conditions at times where the brightness had significantly decreased.
These pictures were all taken from the 5th and 6th floor of a building on the campus of University of Heidelberg. On all days, the view was not only severely obscured by clouds, but also by haze. In fact, the comet was only visible in the finder of the camera, but not to the naked eye.

The first image shows the comet with the campus in the foreground on 16.10.2024 at 17:47 UTC and was taken with a fast 35mm objective. The comet was located in the constellation Serpens Caput at a distance of 76.6 Gm, with an altitude above the horizon of 15°.

c/2023 a3 over Heidelberg on October 16, 2024

Due to the weather, the second image was not taken until 6 days later, on 22.10.2025 at 17:38 UTC with a fast 85mm objective from a distance of 99.6 Gm. The comet was now already 26° above the horizon and had moved into the constellation Ophiuchus.

c/2023 a3 on October 22, 2024

Finally, the third photo was taken one day later, on 23.10.2024 at 18:06 UTC from a distance of 104.4 Gm, at an altitude of about 24°, again with f=85mm. At this time, the comet was on one of the orbital plane of Starlink satellites, so that they continuously passed through the image field. As soon as one was gone, the next one had arrived. This shows the extent of the pollution of the night sky by these constellations. Due to the exposure of 10s, the satellite is distorted into a long streak. In the extension of the comet’s plasma tail, at the top left of the image, you can see a concentration of stars: it is the open star cluster IC 4665, which is about 340 parsecs from Earth. Open star clusters are groups of stars that have formed together from a giant molecular cloud.

c/2023 a3 on October 23, 2024 in the company of a Starlink satellite