Wikipedia:Today's featured article/March 20, 2025
The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating energy from its surface mainly as light and infrared radiation. It is a G-type main-sequence star (G2V), informally called a yellow dwarf, though its light is actually white. It formed about 4.6 billion years ago and is by far the most important source of energy for life on Earth. From Earth the Sun is 1 astronomical unit (1.496×108 km) or about 8 light-minutes away. Its diameter is about 1,391,400 km (864,600 mi), 109 times that of Earth. Its mass is about 330,000 times that of Earth, making up about 99.86% of the total mass of the Solar System. Every second, the Sun fuses about 600 billion kilograms (kg) of hydrogen into helium and converts 4 billion kg of matter into energy. Venerated in many cultures, it is a central subject for astronomical research since antiquity. (This article is part of a featured topic: Solar System.)