Comet 88P/Howell (P=5.48a) will pass perihelion for another time in April 2015, but will then be observable only from the Southern hemisphere. For mid-European observers it will appear above the eastern morning horizon im mid-July, being positioned near the borders of the constellations Cetus/Aries/Pisces. This comet typically shows an asymmetric brightness evolution pre- and post-perihelion, with a rapid brightening pre- and a much slower fading post-perihelion.

To determine the evolution of this comet I could use 181 observations for the analysis. These show a brightness evolution according to the formula

yielding a maximum brightness of 9.6 mag in mid-April. This comet usually shows a rather different evolution pre- and post-perihelion. This is indicated in the diagram, but because of the very small number of pre-perihelion observations it cannot be defined properly.

Total Brightness and Coma Diameter

The visual coma diameter increased from short of 2.5' (200.000 km) at the start of the apparition to the maximum of short of 4' (290.000 km) at the end of April. Between end of May and the start of August it was constantly estimated as slightly more than 3' (about 225.000 km). Thereafter it decreased slowly, reaching 1.0' (60.000 km) at the end of October. During the apparition the comet grew ever more diffuse with the degree of condensation decreasing from DC 3-4 to DC 1.

Andreas Kammerer

FGK observations