Shells in the C2 coma of Comet P/Halley

We reanalyzed the CN images of Comet P/Halley, in which jets have been discovered for the first time, in search of shell structures. Shells were actually detected at the outer edges of the frames on those dates for which shells with radii small enough to be covered by the limited field of view of the CCD were predicted. The C2 images of the same data set were subjected to an analogous investigation which led to the discovery of shell structures in C2 as well. The morphology of the CN and the C2 shells is essentially equal on the same observational date. They have the same radii and show almost identical asymmetries which suggests that CN and C2 in the shells originate from the same general source. The comparison of the jets in both species before and after a two-dimensional continuum subtraction supports this supposition. The similar morphology of the jets indicates that both species are produced from the same bulk of precursor material which has been ejected in the form of jets from the same active area. However, similarly located and oriented jets in CN and C2 do not show similar relative intensities in most cases. These differences in the intensity distribution imply that the production rates of CN and C2 follow different laws.