Left: Comet 240P and its fragment 240P-B, imaged (20x DIT=60s) on 1 December 2025, with the STK in the R-band. The direction to the Sun and that of the heliocentric velocity of the comet are shown as a yellow and blue arrows. The mean projected separation was 100760 ± 160 km between the comet and its fragment, with the fragment located southwest of 240P at a mean position angle of 235.3 ± 0.2°.

Right: Derived absolute R-band magnitude of comet 240P and its fragment during our entire observation campaign. While the absolute R-band brightness of the comet increased by only 0.34 ± 0.14 mag, the fragment brightened by 2.20 ± 0.15 mag as the distance of both objects from the Sun decreased from 2.16 to 2.13 au.