Interplanetary magnetic field draping about fast coronal mass ejecta in the outer heliosphere

The possibility that the IMF becomes draped around coronal mass ejections (CMEs) propagating rapidly through the quiescent solar wind into the outer heliosphere is investigated theoretically. The results are presented in diagrams and graphs and discussed in detail. It is found that large sunward-directed structures analogous to the Venus and cometary magnetotails should form when the CME velocity exceeds the solar-wind velocity by more than the local Alfven speed; such structures could hang up swept-up IMF flux for as long as several days. Pioneer 11 magnetic-field measurements at 6.9-9.4 AU from three 20-d periods in 1978 are examined and shown to contain some features consistent with CME draping.