C/2025 K4 ( Siverd )

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Updated on December 22, 2025

Profile Discovery Date May 30, 2025 Magnitude 19.1 mag Discoverer Robert Siverd (Asteroid Terrestrial-Impact Last Alert System (ATLAS) search program)

Orbital Elements Epoch 2025 Nov. 21.0 TT = JDT 2461000.5 T 2025 July 28.25058 TT Pike q 2.5321646 (2000.0) P Q z +0.0230612 Peri. 326.93021 +0.00154052 +0.83198432 +/-0.0000476 Node 297.08242 -0.72756925 -0.37967717 e 0.9416051 Incl. 38.54438 -0.68603251 +0.40453348 From 29 observations 2025 May 30-Sept. 18, mean residual 0".5.

Magnitudes Graph m1 = 12.5 + 5 log d + 10.0 log r

The orbital elements are published on M.P.E.C. 2025-X127. The magnitudes graphs are made with Comet for Windows.