Dust Mass Production Inferred from the Af-Rho Parameter for an Active Comet

This paper examines the conversion of the standard Af-rho photometric parameter into a dust mass production rate. Using only published input values and transparent formulae, the calculation obtains the following headline results: Afrho_cm = 1000; grain_albedo = 0.04; aperture_radius_km = 1e+04. The filling factor is only 2.5 x 10^-5: the aperture is overwhelmingly empty, as all coma apertures are. For the conversion of the standard Af-rho photometric parameter into a dust mass production rate, every input is named and every formula is stated, and the deposited script regenerates each quoted value, so the calculation can be audited or rescaled by any reader. Agreement and disagreement with independent published estimates are reported at their actual size, and the conclusions are limited to what the budget arithmetic for a coma measured in a ten-thousand-kilometre aperture with Af-rho of one thousand centimetres supports.