WHAT DO STREAMERS IN THE DUST TAIL TELL ABOUT THE COMETARY NUCLEUS

The interrelations between the physical parameters of a cometary nucle us, and the morphology of the dust tail and its streamers are systemat ically investigated by means of a model developed by Bei ss er (1990a) , involving a rotating nucleus. The analysis of streamers in the tail, using direct modeling and synchrone grids, provides a suitable tool t o deduce substantial informations on the nucleus' state of rotation. O pportunities and limitations of this analysis are discussed. Dust emis sion parameters like the distribution of active regions on the nucleus , or the emission characteristics can only be determined if certain ot her physical properties of the nucleus have been independently measure d before.