Here's an image of the outburst coma taken from Chelmsford tonight
(2024-01-18T18:48, 19x60s, 0.56"/pix). The FoV is 1.2 arcmin square, N
up. The comet was quite low down so the seeing is poor (about 2.9 arcsec
FWHM).

The bright dust coma is around 18 arcsec diameter and there is a faint
gas coma around twice that diameter implying a gas outflow velocity
twice that of the dust. The dust coma is flattened off to the east
(left) and there is some sign of a fainter notch in the coma to the east.

The diameter of the coma implies that the outburst happened, possibly, 6
hours before Denis detected it.

It will be interesting to see how this outburst develops.

Nick.