Until mid-July 8 section members sent 47 observations of comet 46P/Wirtanen. The following analysis includes additional about 100 international observations. Regarding the brightness development, the analysis shows that this comet displays a high activity parameter n and a different evolution before and after the perihelion. The maximum brightness of 9.3m was reached around perihelion. The resulting formulae are:
pre-perihelion: m = 7.3m + 5×log D + 35×log r post-perihelion: m = 8.3m + 5×log D + 6.5× log r
Total Brightness and Coma Diameter
The diameter of the weakly condensed coma increased steadily from 2' (130,000 km) to a maximum of 2.5' (190,000 km). The maximum degree of condensation (DC 3-4) was observed 10 days prior to perihelion.
Andreas Kammerer
