Illustration of a proton-proton reaction chain, from hydrogen forming deuterium, helium-3, and regular helium-4 The proton–proton chain occurs around 9.2 × 10 37 times each second in the core, converting about 3.7 × 10 38 protons into alpha particles (helium nuclei) every second (out of a total of ~8.9 × 10 56 free protons in the Sun), or about 6.… See more
The Sun is the star at the center of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to The … See more
The English word sun developed from Old English sunne. Cognates appear in other Germanic languages, including West Frisian sinne, Dutch zon, Low German Sünn, Standard German Sonne, Bavarian Sunna, Old Norse sunna, … See more
The Sun is a G-type main-sequence star that makes up about 99.86% of the mass of the Solar System. It has an absolute magnitude of +4.83, estimated to be brighter than about 85% of the stars in the Milky Way, most of whi… See more
The Sun consists mainly of the elements hydrogen and helium. At this time in the Sun's life, they account for 74.9% and 23.8%, respectively, of the mass of the Sun in the photosphere. All heavier elements, called … See more
The core of the Sun extends from the center to about 20–25% of the solar radius. It has a density of up to 150 g/cm (about 150 times the density of water) and a temperature of close to 15.7 million kelvin (K). By con… See more
The Sun has a stellar magnetic field that varies across its surface. Its polar field is 1–2 gauss (0.0001–0.0002 T), whereas the field is typically 3,000 gauss (0.3 T) in features on the Sun called sunspots and 10–100 ga… See more
The Sun today is roughly halfway through the main-sequence portion of its life. It has not changed dramatically in over four billion years and will remain fairly stable for about five billion more. However, after hydrogen fusion in it… See more
Web3 hours ago · Typically superficial, wedge-shaped, with the apex directed toward the ventricle. Commonly found in surgical series; the most common vascular malformation …