Spatial profile of the brightest FeI line (λ3719 Å; black squares) and the brightest NiI line (λ3458 Å; blue diamonds) observed in comet 46P. The measured surface brightness (SB; in arbitrary units) is plotted as a function of the projected nucleocentric distance p in arcsec. The red line represents a p⁻¹ distribution of the SB convolved with a 135 FWHM Gaussian that accounts for the seeing and tracking imperfections.