HR: 14:05h
AN: SH43B-02    [Abstracts]
TI: Effect of the Interstellar Magnetic Field on the Termination Shock: Explaining the Voyager Results
AU: * Opher, M
EM: mopher@physics.gmu.edu
AF: George Mason University, Department of Physics and Astronomy, MSN 3F3 4400 University Drive, Fairfax, VA 22030-4444 United States
AU: Stone, E C
EM: ecs@srl.caltech.edu
AF: Caltech, 220-47 Downs, Caltech, 1200 East California Blvd., Pasadena, CA 91125 United States
AU: Liewer, P C
EM: paulett.liewer@jpl.nasa.gov
AF: Jet Propulsion Laboratory, MS 169-506 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AB: After a twenty-seven year journey, Voyager 1 crossed the termination shock, the first boundary separating the solar system from the rest of the galaxy, and is now on the other side exploring the heliosheath. Since mid-2002 Voyager 1 has been observing strong beams of energetic particles coming outward along the spiral magnetic field, the opposite of the direction expected for particles accelerated at the shock. This can be explained if the shock is non-spherical so that the interplanetary magnetic field lines cross the shock and reenters the solar wind before reaching Voyager 1. This configuration has been invoked recently (Jokipii et al. 2004; Stone et al. 2005) to reconcile the data recently collected and explain how Voyager 1 can detect energetic particles accelerated at the shock several years before crossing it. We show that the termination shock is, in fact, non-spherical due the distortion caused by an inclined interstellar magnetic field. We use the best values for the direction of the interstellar magnetic field (derived by Frisch 2003; and Lallement et al. 2005) showing that the shape of the termination shock depends strongly on the direction of the interstellar magnetic field. We also make predictions for Voyager 2 that will encounter the shock in the next couple of years.
DE: 2124 Heliopause and solar wind termination
DE: 2144 Interstellar gas
DE: 2164 Solar wind plasma
DE: 7524 Magnetic fields
DE: 7811 Discontinuities (2109)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005