A&A 389, 1039-1046 (2002)
Large-scale disturbance of the solar wind by a cometR. Wegmann
Max-Planck-Institut für Astrophysik, 85748 Garching, Germany
(Received 13 February 2002 / Accepted 26 March 2002)
Model calculations for the interaction of the solar wind with a comet are presented that extend 30 million km into the tail. It is shown that the disturbance of the interplanetary magnetic field (IMF) (the draping) is limited to timescales of 10 to 50 hours and length scales of 10 to 50 million km. This is supported by a theoretical argument about the acceleration of the cometary ions. The distribution of ions and protons at the end of the model tails agrees with measurements made by Ulysses far in the tail of comet Hyakutake. It is shown that the ion tail is concentrated in the current sheet between two flux lobes as long as the draping persists. The far tail, however, is flat and concentrated in a plane parallel to the IMF.
Key words: comets: general -- Sun: solar wind
© ESO 2002