DUST RELEASE RATES AND DUST-TO-GAS MASS RATIOS OF 8 COMETS

Mass release rates of dust and mass ratios of dust-to-gas release rates of Comets Thiele (1985m), Wilson (19861), P/Borrelly (1987p), Liller (1988a), Bradfield (1987s), Hartley-Good (19851), P/Giacobini-Zinner (1984e), and P/Halley (1982i) are estimated from the analysis of continuum flux measurements at optical wavelengths. An attempt is made to estimate the size of each comet nucleus on the basis of water-ice sublimation (vaporization), assuming that the nucleus is spherical and only a fraction of its surface area is active. Where possible, we compare the dust mass release rates with those obtained by other investigators in the optical and infrared wavelength regions. We find good agreement with results based on infrared observations.