Distribution Law For Particle Fragmentation Times In A Theory For Striated Tails Of Dust Comets: Application To Comet Hale-Bopp (C/1995 O1)

Sekanina and Farrell's model for the striated dust tails of comets describes the formation of striae as a two-step fragmentation process that is characterized by an ejection time t_e of parent particles, by their radiation pressure acceleration β_p, and by their fragmentation time t_f. Of these three, t_f is the weakest parameter in that a range oft_f offers a set of nearly equivalent solutions. In this context, we comment on Nishioka et al.'s finite-lifetime model, which is a modification of the fragmentation model. We propose a truncated Gaussian function as a first-approximation distribution law for particle fragmentation times. We apply this generalized model to a stria in comet Hale-Bopp detected on March 5–15, 1997 and analyzed by Pittichová et al. in a recent paper. We find that in order to fit the stria's estimated width of ∼150 000 km, the fragmentation times cannot be distributed over a period of more than approximately 2 to 3 days. This revised version was published online in July 2006 with corrections to the Cover Date.