Pre- and postperihelion photometry of Comet Halley from several observatories

Photoelectric observations of P/Halley were carried out during several weeks between 15 Sept. 1985 and 25 June 1986. All measurements were made using the standard IAU/IHW cometary filters. Large amplitude night-to-night changes over periods of several days superimposed on the general trend of slow brightness variation were seen. Smooth and irregular variations with a range up to 0.2 mag on time scales of several hours were observed. Present photometric scans of comet Halley through the various filters are presented. Successive integrations were made every 5 arc sec, radially from the center out to a distance of 5 arcmin, essentially along the sunward-antisunward direction and in the direction perpendicular to it.