Emission band and continuum photometry of Comet West (1975n) - I. Heliocentric dependence of the flux in the emission bands and the continuum

Spectrum scans of the coma of Comet West (1975n) covering the range $$\lambda \lambda \,3700-5700$$ Å were made on eight nights when the heliocentric distance of the comet varied from 0.588 to 0.853 AU. These have been used to derive the absolute flux in the CN (0, 0), C₃ (4050), C₂ (1, 0) and C₂ (0, 0) bands as well as in the continuum. Enhancements in the band emissions were noticed on three nights in CN (0, 0), C₃ (4050) and C₂ (1, 0). The column densities of neutral sodium atoms are derived from scans around 5900 A on four nights. The column densities of CO⁺ ions corresponding to four prominent band sequences are evaluated from two scans of the tail.