HR: 0800h
AN: SH51A-1190    [Abstracts]
TI: Interstellar Dust in the Heliosheath: Tentative Discovery of the Magnetic Wall of the Heliosphere
AU: * Frisch, P C
EM: frisch@oddjob.uchicago.edu
AF: Dept. Astronomy and Astrophysics University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 United States
AB: The evident identification of interstellar dust grains entrained in the magnetic wall of the heliosphere is reported. It is shown that the distribution of dust grains causing the weak polarization of light from nearby stars is consistent with polarization by small charged interstellar dust grains captured in the heliosphere magnetic wall (Tinbergen 1982, Frisch 2005). There is an offset between the deflected small charged polarizing dust grains, radius less than 0.2 microns, and the undeflected large grain population, radius larger than 0.2 microns. The region of maximum polarization is towards ecliptic coordinates lambda,beta = 295,0 deg, which is offset along the ecliptic longitude by about 35 deg from the heliosphere nose and extends to low ecliptic latitudes where the heliosphere magnetic wall is expected. An offset is also found between the best aligned dust grains, near lambda=281 deg to 220 deg, and the upwind direction of the undeflected inflow of large grains seen by Ulysses and Galileo. In the aligned-grain region, the polarization strength anti-correlates with ecliptic latitude, indicating that the magnetic wall was predominantly at negative ecliptic latitudes when these data were acquired. These data are consistent with model predictions for an interstellar magnetic field which is tilted by 60 deg with respect to the ecliptic plane, and parallel to the galactic plane. References: Tinbergen, 1982: AA, v105, p53; Frisch, 2005: to appear in ApJL.
DE: 2124 Heliopause and solar wind termination
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005