Sun

The Sun is the star at the center of the Solar System. The Earth and additional matter (including other planets, asteroids, meteoroids, comets and dust) orbit the Sun, which by itself accounts for about 99.8% of the solar system's mass. power from the Sun—in the form of sunlight—supports almost all life on Earth via photosynthesis, and drives the Earth's climate and weather.

The Sun is composed of hydrogen (about 74% of its mass, or 92% of its volume), helium (about 25% of mass, 7% of volume), and draw quantities of other elements. The Sun has a spectral class of G2V. G2 implies that it has a surface temperature of about 5,500 K (or approximately 9,600 degrees Fahrenheit / 5,315 Celsius), giving it a white color which, because of atmospheric scattering, appears yellow as seen from the surface of the Earth. This is a subtractive effect, as the preferential scattering of blue photons (causing the sky color) removes enough blue light to leave a residual reddishness that is perceived as yellow.