EDGE-ON DUST DISKS IN PLANETARY NEBULAE

whilst the majority of planetary nebulae are (within certain limits) circular, some planetary nebulae have a strong asymmetric structure and seem to have bibolar outflow of matter. these nebulae show strong knots perpendicular to the apparent axis of the outflow. it is widely assumed that these objects are members of double star sytems. (see corradi and schwarz, 1993, a&a, 268, 714 and very recent discussions between h.e.scharz and s.kwok at the haifa conference 8.12.8.94). it seems that such systems consist of a pncs and a second highly evolved star in an agb or postagb state. gravitational forces drag highly evolved matter from far inside the central object(s) along the plane of the orbit. this proposal aims mainly at the study of the dust which builds from this higly evolved material. the objects were chosen to be nearly edgeon systems, to be able to model the observations. another criteria was an unusal hot iras 1225 color index. we intend to use angularily resolved color maps to model density and energy profiles within the disks of the systems. one target is a newly dicovered object of our own, which shows exactly the same optical characteristics. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]