Crossing the Termination Shock into the Heliosheath: Magnetic Fields

@article{Burlaga2005CrossingTT,
  title={Crossing the Termination Shock into the Heliosheath: Magnetic Fields},
  author={Leonard F. Burlaga and Norman F. Ness and Mario H. Acuna and Ronald P. Lepping and John E. P. Connerney and Edward C. Stone and Frank B. Mcdonald},
  journal={Science},
  year={2005},
  volume={309},
  pages={2027 - 2029}
}
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. An estimate of the compression ratio of the magnetic field strength B (± standard error of the mean) across the shock is B2/B1 = 3.05 ± 0.04, but ratios in the range from 2 to 4 are admissible. The average B in the heliosheath from day 1 through day 110 of 2005 was 0.136 ± 0.035 nanoteslas, ∼4.2 times that predicted by Parker's… 

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References

SHOWING 1-10 OF 16 REFERENCES

Voyager 1 exited the solar wind at a distance of ∼85 au from the Sun

The outer limit of the Solar System is often considered to be at the distance from the Sun where the solar wind changes from supersonic to subsonic flow. Theory predicts that a termination shock

Search for the heliosheath with Voyager 1 magnetic field measurements

The magnetic field measured by Voyager 1 (V1) near 85 AU from 2002.0 to 2003.17 has the expected properties for the heliospheric magnetic field at that distance and epoch of the solar cycle. These V1

Enhancements of energetic particles near the heliospheric termination shock

TLDR
A significant increase in the numbers of energetic ions and electrons that persisted for seven months beginning in mid-2002 is reported, arguing that the radial anisotropy of the cosmic rays is expected to be small in the foreshock region, as is observed.

Voyager 1 Explores the Termination Shock Region and the Heliosheath Beyond

TLDR
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.

Voyager 1 in the Foreshock, Termination Shock, and Heliosheath

TLDR
Observations from Voyager 1 are interpreted as evidence that V1 was crossed by the TS on 2004/351 (during a tracking gap) at 94.0 astronomical units, evidently as the shock was moving radially inward in response to decreasing solar wind ram pressure, and that V 1 has remained in the heliosheath until at least mid-2005.

News from the Edge of Interstellar Space

Auroral activity and magnetic storms that occasionally disrupt electric power grids are caused by the supersonic solar wind that sweeps past Earth as it blows radially away from the Sun. This

Electron Plasma Oscillations Upstream of the Solar Wind Termination Shock

TLDR
Electron plasma oscillations have been detected upstream of the solar wind termination shock by the plasma wave instrument on the Voyager 1 spacecraft, consistent with the spacecraft having crossed the termination shock into the heliosheath.

Solar wind speed and coronal flux-tube expansion

The hypothesis that the solar wind speed at 1 AU and the rate of magnetic flux-tube expansion in the corona are inversely correlated is shown to be consistent with observations extending over the

Motion of the termination shock in response to an 11 Year variation in the solar wind

A two-dimensional hydrodynamic numerical model has been used to study the motion of the termination shock in response to an 11 year variation in the solar wind ram pressure. We find that for a total

Solar cycle induced variations of the outer heliospheric structures

The solar wind undergoes complicated but typical changes during the solar activity cycle which are especially strongly pronounced in the inner heliosphere. In the outer heliosphere, as the main