Solar System
The principal component of the Solar System is the Sun, a G2 main-sequence star that contains 99.86% of the system's known mass and dominates it gravitationally. The Sun's four largest orbiting bodies, the giant planets, account for 99% of the remaining mass, with Jupiter and Saturn together comprising more than 90%. The remaining objects of the Solar System (including the four terrestrial planets, the dwarf planets, moons, asteroids, and comets) together comprise less than 0.002% of the Solar System's total mass.
Solar phenomena
The Sun is a G-type main-sequence star (G2V) based on spectral class and it is informally designated as a "yellow dwarf" because its visible radiation is most intense in the yellow-green portion of the spectrum. It is actually white, but from the Earth's surface it appears 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 via fusing hydrogen into helium. In its core, the Sun fuses about 620 million metric tons of hydrogen each second.