The periodic comet 45P/Honda-Mrkos-Pajdusakova was found in the evening sky only days after its perihelion passage (Mar. 29, 2001). The Japanese K. Kadota estimated the brightness to be 10.5m and the coma diameter to be 0.8' on a CCD-exposure taken on April 4 (IAUC 7608). Thus this comet seems to be 1m fainter compared to the previous appearance in 1995/96. Until the beginning of June only 2 group member observations were received. In addition, the number of published international observations is small, therefore only 21 could be used for the first analysis. The brightness evolution can be described surprisingly well by the formula
m = 11.1m + 5×log D + 11.5×log r
indicating a brightness of 9.0m at the start of this apparition in mid-April. The coma diameter decreased from 2.5' (130.000 km) to 1.0' (60.000 km). The coma was - typical for this comet - well condensed at first (DC 5), getting ever more diffuse during the following weeks, reaching DC 3 in mid-May. This comet is no longer visible from central-European latitudes.
Total Brightness and Coma diameter
Andreas Kammerer
