Possible Distortion of the Interplanetary Magnetic Field by the Dust Trail of Comet 122P/de Vico

Abstract

Interplanetary field enhancements are unexplained localized increases in the heliospheric magnetic field magnitude. Four such enhancements, detected by the Pioneer Venus Orbiter and Ulysses spacecraft, have been found to be very close to the orbital plane of comet 122P/de Vico. Analysis of the magnetic field during these events reveals that the field perturbations were close to those expected if the interplanetary magnetic field draped at the comet's orbit and that the field enhancements represent crossings of a sheet of disturbed solar wind in the comet's orbital plane. The results suggest that a dense dust stream may occupy at least part of the orbit of de Vico and that its effects on the solar wind are apparent almost 1.4 AU downstream. One field enhancement suggests the existence of an annulus of dust extending sunward of the dust trail itself.