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What causes the sun to vary?

We live in the extended atmosphere of a magnetic variable star that drives our solar system and sustains life on Earth. Our Sun varies in every way we can observe it. The Sun gives off light in the infrared, visible, ultraviolet, and at x-ray energies, and it gives off magnetic field, bulk plasma (the solar wind) and energetic particles moving up to nearly the speed of light, and all of these emissions vary. These variations occur on timescales from milliseconds to billions of years. Most of these variations are related to the solar magnetic field, which is caused by the moving plasma inside the rotating Sun, which make a dynamo.

Related missions:

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DivisionNameLaunch DatePhase
Heliophysics ACE
Advanced Composition Explorer (ACE) observes particles of solar, interplanetary, interstellar, and galactic origins, spanning the energy range from solar wind ions to galactic cosmic ray nuclei. This mission is part of SMD's Explorers Program. This mission is part of SMD's ...
19970825 August 25, 1997 3Operating
Heliophysics BARREL
The Balloon Array for Radiation-belt Relativistic Electron Losses mission is a balloon-based Mission of Opportunity to augment the measurements of NASA's RBSP spacecraft. This mission is part of SMD's LWS program.
2Development
Heliophysics IMP-8
IMP 8 has deepened understanding of the space environment near Earth in many ways. Observations from IMP 8 provided insight into plasma physics, the Earth's magnetic field, the structure of the solar wind and the nature of cosmic rays.
19731026 October 26, 1973 4Past
Heliophysics SOHO
Solar and Heliospheric Observatory (SOHO) is a solar observatory studying the structure, chemical composition, and dynamics of the solar interior. SOHO a joint venture of the European Space Agency and NASA. This mission is part of SMD's Heliophysics Research program.
19951202 December 02, 1995 3Operating
Heliophysics STEREO
The goal of STEREO is to understand the origin the Sun's coronal mass ejections (CMEs) and their consequences for Earth. The mission consists of two spacecraft, one leading and the other lagging Earth in its orbit. The spacecraft carries instrumentation ...
20061025 October 25, 2006 3Operating
Heliophysics Yohkoh
Yohkoh, an observatory for studying X-rays and gamma-rays from the Sun, is a project of the Institute for Space and Astronautical Sciences, Japan.
19910830 August 30, 1991 4Past