Fig6_14 Magneatic spiral

Fig6_14 Magneatic spiral

Fig. 6.14 . The trajectory of flare electrons in interplanetary space as viewed from above the Sunís polar regions using the Ulysses spacecraft. The squares and crosses show Ulysses radio measurements of type III radio bursts. As the high-speed electrons move out from the Sun into progressively more tenuous plasma, they excite radiation at successively lower plasma frequencies. The numbers denote the observed frequency in kiloHertz, abbreviated kHz. Since the flaring electrons are forced to follow the interplanetary magnetic field, they do not move in a straight line out from the Sun, but instead travel along the spiral pattern of the interplanetary magnetic field, shown by the solid curved lines. The magnetic fields are drawn out into space by the radial solar wind, and attached at one end to the rotating Sun. The locations of the orbits of Mercury, Venus and the Earth are shown as circles. [Courtesy of Michael J. Reiner/Ulysses is a project of international collaboration between ESA and NASA.]

Copyright 2010, Professor Kenneth R. Lang, Tufts University