On the Relationship Between Gas and Dust in Comets: an Application to Comet 85P/Boethin

Resumo

Except for some narrowband photometric observations obtained by A´Hearn et al. (1995), in literature there is no other information available about Comet 85P/Boethin´s activity, such as mass loss and nuclear size for this shortperiod (~11.2 years) comet. In an effort to find more information about this object, we have used visual magnitude measurements available from International Comet Quarterly (ICQ) to obtain the water production rates (in molecules s-1) related to its perihelion passage of 1986 by applying the Semi-Empirical Method of Visual Magnitudes-SEMVM (de Almeida et al., 1997; Sanzovo et al., 2001). When associated to Delsemme’s (1982) water vaporization theory, these rates allowed for the calculus of the dimension of the effective minimum nuclear radius of the comet. The water production rates were then converted into gas production rates (in g s-1) so that, applying the correlation between gas and dust found for eleven periodic and three non-periodic comets deduced by Trevisan Sanzovo (2006), we have obtained the dust loss rates (in g s-1), its behavior with the heliocentric
distance and the dust-to-gas ratios for this little-known comet.