heliosphere


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heliosphere

(hee -lee-ŏ-sfeer) The vast region around the Sun that is permeated by the solar wind and the weak interplanetary magnetic field, and in which the solar-wind plasma plays a dominant role. It is bounded by the heliopause, which is estimated to be 100 AU or more from the Sun's center but has not yet been encountered by any spacecraft. The heliosphere may be very elongated owing to the presence of an interstellar wind of neutral hydrogen flowing from the direction of the galactic center.

heliosphere

[′hē·lē·ə‚sfir]
(astronomy)
The region surrounding the sun where the solar wind dominates the interstellar medium. Also known as solar cavity.
(geophysics)
The region in the ionosphere where helium ions are predominant (sometimes there may be no region in which helium ions dominate).
References in periodicals archive ?
When charged particles from the inner solar system reach the boundary of the heliosphere, they sometimes undergo a series of charge exchanges with neutral gas atoms from the interstellar medium, dropping and regaining electrons as they travel through this vast boundary region.
Outside the heliosphere lies the interstellar medium, with plasma that has different speed, density, and temperature than solar wind plasma, as well as neutral gases.
Then last September, after months of speculation, mission scientists finally announced that Voyager 1 had exited the heliosphere on August 25, 2012 (SN Online: 9/12/13).
The scientists predicted that, in the next two years, Voyager 1 would cross the current sheet, the sprawling surface within the heliosphere where the polarity of the sun's magnetic field changes from plus to minus and if it would detect a reversal in the magnetic field, it would prove that it was still within the heliosphere.
25 last year, showing an abrupt drop in energetic charged particles, or cosmic rays, that are produced inside the heliosphere.
The observation frequency of 327 MHz (wavelength: 92 cm) is optimal for surveying the inner heliosphere, since it enables us to probe the solar wind plasma between 90.
The Solar Orbiter mission is conceived to perform a dose-up study of the sun and its inner heliosphere, the uncharted innermost regions of the solar system.
The telescope will also be used by scientists to study the sun's heliosphere during periods of strong solar activity and time-varying astronomical objects such as pulsars.
In light of Hamilton's profound and passionate engagement with Ulster and Scottish linguistic and cultural traditions, it quickly becomes apparent that her express dismay at the disappearance of the Scottish mixed schools testifies to her acute awareness of the invisibility of both sexual and cultural homogeneity from within the discursive heliosphere of the metropole.
A Christmas Galleon show is being held in Victoria Square and a Heliosphere aerial display in Centenary Square.
Some research areas explored are high-order finite difference solutions for MHD, kinetic modeling of interstellar hydrogen in the heliosphere, and self-similar evolution of cosmic-ray modified shocks.