The Sun

The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields. It has a diameter of about 1,392,684 km, about 109 times that of Earth, and its mass accounts for about 99.86% of the total mass of the Solar System. Chemically, about three quarters of the Sun's mass consists of hydrogen, while the rest is mostly helium. The remainder consists of heavier elements, including oxygen, carbon, neon and iron, among others. The Sun's stellar classification, based on spectral class, is G2V, and is informally designated as a yellow dwarf, because its visible radiation is most intense in the yellow-green portion of the spectrum and although its color is white, from the surface of the Earth it may appear yellow because of atmospheric scattering of blue light. In the spectral class label, G2 indicates its surface temperature of approximately 5778 K, and V indicates that the Sun, like most stars, is a main-sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei. The Sun is The Only Star That Contains Life.