HR: 0800h
AN: SH51A-1184 [Abstracts]
TI: Characteristics of the Heliosheath from Voyager 1 Observations
AU: * Cummings, A C
EM: ace@srl.caltech.edu
AF: California Institute of Technology, Mail Code 220-47, Pasadena, CA 91125
United States
AU: Stone, E C
EM: ecs@srl.caltech.edu
AF: California Institute of Technology, Mail Code 220-47, Pasadena, CA 91125
United States
AU: McDonald, F B
EM: fm27@umail.umd.edu
AF: University of Maryland, Computer and Space Sci Bldg 3245, College Park, MD 20742
United States
AU: Heikkila, B C
EM: bryant@mail630.gsfc.nasa.gov
AF: Goddard Space Flight Center, Code 612.4, Greenbelt, MD 20771
United States
AU: Lal, N
EM: Nand.Lal@nasa.gov
AF: Goddard Space Flight Center, Code 612.4, Greenbelt, MD 20771
United States
AU: Webber, W R
EM: bwebber@nmsu.edu
AF: New Mexico State University, P.O. Box 30001/Dept. 4500, Las Cruces, NM 88003
United States
AB:
Voyager 1 crossed the termination shock of the solar wind on
December 16, 2004 at a distance of 94.0 AU from the Sun.
The low-energy energetic particle component, which dominates
the observed energy spectrum below ~30 MeV for protons
and which had been observed since mid-2002, has become
much less variable and much less anisotropic in
the heliosheath than it had been in the solar wind.
The energy spectra of the classic anomalous cosmic rays
(ACRs) were relatively unaffected at the crossing, being
heavily modulated and indicating a source region remote
from the crossing point of the termination shock at 34 N
in heliolatitude. However, the ACR spectra appear
to be evolving towards the expected source spectra
as Voyager 1 continues into the heliosheath. The intensity
of galactic cosmic rays and ~10 MeV electrons are also
increasing. In addition, Voyager 2 appears to be observing
termination shock particle precursors, suggesting it too
will likely cross the termination shock in the next few years.
This work was supported by NASA under contract NAS7-03001.
DE: 2104 Cosmic rays
DE: 2114 Energetic particles (7514)
DE: 2124 Heliopause and solar wind termination
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005