Strip Photometry of Comet Halley

Post--perihelical observations of Comet Halley were performed on 25 nights at the 50-cm reflector of UFRGS by the technique of strip photometry. A slit of dimensions 8' x 8" scanned the comet image at a speed of 1.345" x cos (declination) /sec, in east-west direction or inversely. For photometry we used NASA interference filters C2, C3, CO+, H20+, λ4865 and λ6840. Calibration used IHW standard stars and scans of field stars. Significant signals are detected for H2O+, C2 and C3. Time evolution of coma is seen from profiles. No color effect was observed from the continuum filters.