Photoelectric photometry of comets in the system of standard IHW filters and the special case of comet P/Halley

Magnitudes of comets P/Giacobini‐Zinner (1984e), P/Halley (1982i), P/Hartley‐Good (1985 1), and Thiele (1985 m) in the bandpasses of the standard IHW comet filters are presented. For comet P/Halley production rates for CN, C 3 , C 2 , and solids were derived. For the gaseous components these show a strong dependence on heliocentric distance. The dependence is less steep for the solids which may be due to relatively pronounced backscattering properties in case of comet P/Halley. During one night (1985 Dec. 22/23) intensity profiles along three sections through the coma of comet P/Halley were measured. Compared with theoretical profiles they show a global anisotropy of the coma and possibly local structure.