Pre- and post-perihelion spectrographic and photometric observations of Comet Wilson (1986 l)

The behavior of Comet Wilson before and after its passage through perihelion, which occurred on April 21, 1987, was studied on the basis of spectrographic and photometric observations. Results pertaining to spectra in the UV, blue, and red regions, and to photometry through narrow-band filters are presented. It is suggested that the fading of Comet Wilson might reflect some general trend in the comet's evolution, or that it could be the result of a geometrical effect associated with the rotation of the comet's nucleus and the presence of discrete active areas on its surface.