Updated 24 March 2020
The Sun is the star at the center of the solar system. It is a nearly perfect sphere, or ball, of plasma, 1.391 million km in diameter (over 100 times the Earth's) and with a surface temperature of approximately 5,505°C. Its mass is about 1.989 × 1030 kg, which is about 330,000 times that of Earth, and accounts for about 99.86% of the entire mass of the solar system. About 73% of this mass is made up of hydrogen (H), with about another 25% coming from helium (He), and the remaining 2% from mainly oxygen (O), carbon (C), neon (Ne), and iron (Fe).