The light curve of periodic comet Halley 1910 II

Photometric parameters for periodic comet Halley 1910 II have been derived from 144 total visual magnitude estimates. The pre-perihelion data are best represented by an absolute magnitude of 5.47 and a power-law exponent of 4.44; post-perihelion results show that the absolute magnitude brightened to 4.94, and the exponent decreased to 3.07. Only small fluctuations in brightness about the power-law solutions are noted. Based on these results, a forecast of the visual brightness of periodic comet Halley's 1985-1987 apparition is presented.