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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 the energy mainly as light and infrared radiation. It is by far the most important source of energy for life on Earth. Its diameter is about 1.39 million kilometres (864,000 miles), or 109 times that of Earth, and its mass is about 330,000 times that of Earth. It accounts for about 99.86% of the total mass of the Solar System.
Roughly three quarters of the Sun's mass consists of hydrogen (~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.The Sun is a G-type main-sequence star (G2V) based on its spectral class. As such, it is informally and not completely accurately referred to as a yellow dwarf (its light is closer to white than yellow). It formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most of this matter gathered in the center, whereas the rest flattened into an orbiting disk that became the Solar System. The central mass became so hot and dense that it eventually initiated nuclear fusion in its core. It is thought that almost all stars form by this process.
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Fresno ( FREZ-noh; Spanish for '"ash tree"') is a city in and the county seat of Fresno County, California, United States. It covers about 112 square miles (290 km2) in the center of the San Joaquin Valley, the southern portion of California's Central Valley.
Named for the abundant ash trees lining the San Joaquin River, Fresno was founded in 1872 as a railway station of the Central Pacific Railroad before it was incorporated in 1885. The city has since become an economic hub of Fresno County and the San Joaquin Valley, with much of the surrounding areas in the Metropolitan Fresno region predominantly tied to large-scale agricultural production.
The population of Fresno grew from 134,000 in 1960 to 428,000 in 2000.
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Gurupi, Tocantins is a city and a municipality in the Brazilian state of Tocantins. The estimated...