The Effects of a Local Interstellar Magnetic Field on Voyager 1 and 2 Observations

@article{Opher2006TheEO,
  title={The Effects of a Local Interstellar Magnetic Field on Voyager 1 and 2 Observations},
  author={Merav Opher and Edward C. Stone and Paulette C. Liewer},
  journal={The Astrophysical Journal Letters},
  year={2006},
  volume={640},
  pages={L71 - L74}
}
We show that an interstellar magnetic field can produce a north-south asymmetry in the solar wind termination shock. Using Voyager 1 and 2 measurements, we suggest that the angle α between the interstellar wind velocity and the magnetic field is 30° < α < 60°. The distortion of the shock is such that termination shock particles could have streamed outward along the spiral interplanetary magnetic field connecting Voyager 1 to the shock when the spacecraft was within ~2 AU of the shock. The shock… 

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References

SHOWING 1-10 OF 23 REFERENCES

Crossing the Termination Shock into the Heliosheath: Magnetic Fields

Magnetic fields measured by Voyager 1 show that the spacecraft crossed or was crossed by the termination shock on about 16 December 2004 at 94.0 astronomical units, and the cosmic ray intensity increased when B was relatively large in the heliosheath.

Heliosphere in the magnetized local interstellar medium' Results of a three-dimensional MHD

The results of a three-dimensional adaptive magnetohydrodynamic (MHD) model of the interaction of a magnetized solar wind with a magnetized very local interstellar medium in the presence of neutral

Probing the Edge of the Solar System: Formation of an Unstable Jet-Sheet

The Voyager spacecraft is now approaching the edge of the solar system. Near the boundary between the solar system and the interstellar medium we find that an unstable "jet-sheet" forms. The

Magnetic Effects at the Edge of the Solar System: MHD Instabilities, the de Laval Nozzle Effect, and an Extended Jet

To model the interaction between the solar wind and the interstellar wind, magnetic fields must be included. Recently, Opher et al. found that by including the solar magnetic field in a

Influence of the interstellar magnetic field direction on the shape of the global heliopause

In this paper we study the influence of the angle between the local interstellar medium velocity and magnetic field vectors on the interaction of this medium with the solar wind. Both winds are

Deflection of the Interstellar Neutral Hydrogen Flow Across the Heliospheric Interface

The neutral hydrogen flow is found to be deflected relative to the helium flow by about 4°, the most likely explanation of this deflection is a distortion of the heliosphere under the action of an ambient interstellar magnetic field.

Direction of the interstellar H atom inflow in the heliosphere : Role of the interstellar magnetic field

Recently Lallement et al. (2005, Science, 307, 1447) reported that the direction of the flow of interstellar neutral hydrogen in the heliosphere is deflected by ∼4° from the direction of the pristine

Physics of the outer heliosphere

Major advances in the physics of the outer heliosphere are reviewed for the 1987-1990 time frame. Emphasis is placed on five broad topics: the detailed structure of the solar wind at large

Voyager 1 Explores the Termination Shock Region and the Heliosheath Beyond

The intensity of anomalous cosmic ray (ACR) helium did not peak at the shock, indicating that the ACR source is not in the shock region local to Voyager 1, and the intensities of ∼10–megaelectron volt electrons, ACRs, and galactic cosmic rays have steadily increased since late 2004.