The Sun
The sun is a yellow dwarf star, a hot ball of glowing gases. Its gravity holds the solar system together, keeping everything from the biggest planets to the smallest particles of debris in its orbit. Electric currents in the Sun generate a magnetic field that is carried out through the solar system by the solar wind. ​
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The Sun is the largest object in our solar system. 99.8% of the mass of our solar system is the sun. Although the sun seems. tobe huge, there are many other stars that are larger.
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Earth orbits the sun from a distance of about 93 million miles. The sun affects the Earth's seasons, climate, radiation belts, and auroras. Although it may look special, there are billions of stars similar to the sun scattered across our solar system.
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The Anatomy of the Sun
The Sun's Core - Energy is generated via thermonuclear reactions creating extreme temperatures deep within the Sun's core.
The Radiative Zone - Energy moves slowly outward, taking more than 170,000 years to radiate through this layer of the Sun.
The Convection Zone - Energy continues to move toward the surface through convection currents of the heated and cooled gas.
The Chromosphere - This relatively thin layer of the Sun is sculpted by magnetic field lines that restrain the electrically charged solar plasma. Occasionally larger plasma features called prominences, form and extend far into the very tenuous and hot corona, sometimes ejecting material away from the Sun.
The Corona - The ionized elements within the corona (or solar atmosphere) glow in the x-ray and extreme ultraviolet wavelengths. NASA instruments can image the Sun's corona at these higher energies since the photosphere is quite dim in these wavelengths.
Coronal Streamers - The outward flowing plasma of the corona is shaped by magnetic field lines into tapered forms called coronal streamers, which extend millions of miles into space.
