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Decades-Long Changes of the Interstellar Wind Through Our Solar System

McComas, D. J.; Frisch, P. C.; Schwadron, N. A. +8 more

The journey of the Sun through the dynamically active local interstellar medium creates an evolving heliosphere environment. This motion drives a wind of interstellar material through the heliosphere that has been measured with Earth-orbiting and interplanetary spacecraft for 40 years. Recent results obtained by NASA's Interstellar Boundary Explor…

The Sun and Heliosphere at Solar Maximum

Krupp, N.; Balogh, A.; Geiss, J. +9 more

Recent Ulysses observations from the Sun's equator to the poles reveal fundamental properties of the three-dimensional heliosphere at the maximum in solar activity. The heliospheric magnetic field originates from a magnetic dipole oriented nearly perpendicular to, instead of nearly parallel to, the Sun's rotation axis. Magnetic fields, solar wind,…

Deflection of the local interstellar dust flow by solar radiation pressure.

Grün, E.; Landgraf, M.; Augustsson, K. +1 more

Interstellar dust grains intercepted by the dust detectors on the Ulysses and Galileo spacecrafts at heliocentric distances from 2 to 4 AU show a deficit of grains with masses from 1×10^-17 to 3×10^-16kg relative to grains intercepted outside 4 AU. To divert grains out of the 2- to 4-AU region, the solar radiation pressure must…

ULYSSES Laps Sun, Inspires New Missions

Hellemans, Alexander

Solar Wind Magnetic Field Bending of Jovian Dust Trajectories

Forsyth, R.; Hamilton, D. P.; Phillips, J. L. +5 more

From September 1991 to October 1992, the cosmic dust detector on the Ulysses spacecraft recorded 11 short bursts, or streams, of dust. These dust grains emanated from the jovian system, and their trajectories were strongly affected by solar wind magnetic field forces. Analyses of the on-board measurements of these fields, and of stream approach di…

The Heliospheric Magnetic Field Over the South Polar Region of the Sun

Balogh, A.; Tsurutani, B. T.; Horbury, T. S. +3 more

Magnetic field measurements from the Ulysses space mission over the south polar regions of the sun showed that the structure and properties of the three-dimensional heliosphere were determined by the fast solar wind flow and magnetic fields from the large coronal holes in the polar regions of the sun. This conclusion applies at the current, minimu…

The Southern High-Speed Stream: Results from the SWICS Instrument on Ulysses

Livi, S.; Balsiger, H.; Geiss, J. +8 more

The high-speed solar wind streaming from the southern coronal hole was remarkably uniform and steady and was confined by a sharp boundary that extended to the corona and chromosphere. Charge state measurements indicate that the electron temperature in this coronal hole reached a maximum of about 1.5 million kelvin within 3 solar radii of the sun. …

Ulysses Solar Wind Plasma Observations at High Southerly Latitudes

McComas, D. J.; Goldstein, B. E.; Bame, S. J. +7 more

Solar wind plasma observations made by the Ulysses spacecraft through -80.2^circ solar latitude and continuing equatorward to -40.1^circ are summarized. Recurrent high-speed streams and corotating interaction regions dominated at middle latitudes. The speed of the solar wind was typically 700 to 800 kilometers per second poleward of -35^circ. Coro…

Cosmic Ray and Solar Particle Investigations Over the South Polar Regions of the Sun

Sierks, H.; Kunow, H.; Muller-Mellin, R. +17 more

Observations of galactic cosmic radiation and anomalous component nuclei with charged particle sensors on the Ulysses spacecraft showed that heliospheric magnetic field structure over the south solar pole does not permit substantially more direct access to the local interstellar cosmic ray spectrum than is possible in the equatorial zone. Fluxes o…

Corotating Variations of Cosmic Rays Near the South Heliospheric Pole

Jokipii, J. R.; Kota, J.

Three-dimensional simulations of the heliospheric modulation of galactic cosmic ray protons show that corotating variations in the intensity can persist to quite high heliographic latitudes. Variations are seen at latitudes considerably higher than the maximum latitude extension of the heliographic current sheet, in regions where the solar wind ve…