From International Astronomical Union Circular No. 7467

M. Kidger, Instituto de Astrofisica de Canarias, writes that nightly observations made since July 23 in U, B, V, R, and Z broadband filters with the 1-m Jacobus Kapteyn Telescope show what appears to be the complete disruption of the comet's nucleus: "The central condensation was highly condensed and showed the typical 'teardrop' form on July 23.9 and 24.9 UT, although its brightness decreased by a factor of about 3 between the two nights. On July 25.9 the central condensation was seen to be strongly elongated (length about 15") in p.a. 80 deg, with a very flat brightness distribution. The condensation's brightness faded further and its length increased to about 30" and 45"-50" (p.a. 80 deg) on July 26.9 and 27.9, respectively. On July 27.9, there was no evidence of any local brightness peak that would indicate the presence of subnuclei. The expansion velocity of the condensation is about 40 m/s, indicating that it is particulate material and not gas. The gas tail, which virtually disappeared between July 23.9 and 24.9, has reformed as an extension of the major axis of the central condensation."