The Sun as a Dynamo The Sun is also part of a dynamo system called the heliosphere. The heliosphere is a bubble similar to a magnetosphere. Although electrically neutral atoms from interstellar space can penetrate the heliosphere bubble, virtually all material in the heliosphere emanates from the Sun itself.  The solar wind leaves the Sun in all directions at speeds of several hundred kilometers per seconds or at about 1,000,000 miles per hour. This supersonic wind slows down to subsonic speed when it meets the gases in interstellar space, which is quite a distance from the Sun and well beyond the orbit of Pluto. This subsonic flow region is called the helio-sheath. The outer surface of the helio-sheath, where the heliosphere meets the interstellar medium, is called the heliopause. The solar wind consists of particles, ionized atoms from the solar corona, and magnetic fields. As the Sun rotates, once in about 27 days, its magnetic field gets wrapped into a spiral. Variations in the Sun's magnetic field are carried outward by the solar wind and can produce magnetic storms in Earth's magnetosphere. Our Solar System, Chapter 2 Magnetosphere, Chapter 3 Radiation Belts, Chapter 4 Magnetic Fields, Chapter 5 Earth’s Dynamo, Chapter 6 Dynamo Systems, Chapter 7 The Sun as a Dynamo, Chapter 8 Auroras Chapter 9 Space Weather Chapter 10 References |