This comet was reported to have fragmented on or about November 4 (ATEL
17482, 17487, 17488). Recent astrometry shows a significant residual (6
arcsec on Nov 13) in the position of the main component when compared to
the orbit solution using astrometry up to November 4. This may be
biasing of the centroid, but this screenshot shows the measurement I
made on the morning of November 13 and the main component looks very
well defined so I don't think that is the case. The radius of the
aperture is 4.5 arcsec. This observation was made using the Alnitak
telescope in Spain (I79) and Denis Buczynski got similar results on the
morning of the 14th.

If anyone has any recent (post November 11) astrometry of this comet
please forward it to me and the MPC. Astrometry of the main fragment
(C/2025 K1-B) would also be very useful. It is now well separated from
the main component.

Thanks,

Nick.