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Chemically, approximately three-quarters of the Sun's mass consists of hydrogen, while the rest is dominated by helium. The remainder of the mass (1.69%, equivalent to 5,629 times the mass of the Earth) consists of heavy elements such as oxygen, carbon, fluorescent, iron, and others. [15]

The sun formed about 4.6 billion years ago due to the gravitational decay of an area within a large molecular cloud. Most of the material is gathered in the middle, while the rest of it crops up into circulating disks that will become the Solar System. The central mass is getting hotter and denser and ultimately starts thermonuclear fusion at its core. It is alleged that almost all other stars are formed by a similar process. Classification of the Sun's stars, by their spectral class, is the main sequence star G (G2V) and is often classified as a yellow dwarf because radiation appears to be more intense in the yellow-red portion of the spectrum. Although the color is white, from the surface of the Earth the Sun appears yellow due to the mixing of blue light in the atmosphere. [16] According to the spectral class label, G2 denotes a surface temperature of about 5778 K (5505 ° C) and V indicates that the Sun, like other stars, is the main sequence star, so its energy is created by nuclear fusion of hydrogen nuclei into helium. In essence, the Sun fuses 620 million metric tons of hydrogen every second.

In the past, the Sun was viewed by astronomers as small and insignificant stars. Now, the Sun is considered brighter than about 85% of stars in the Milky Way dominated by red dwarfs. [17] [18] The absolute magnitude of the Sun is +4,83. However, as the closest star to the Earth, the Sun is the sunniest thing in the sky with an apparent magnitude of -26.74. [19] [20] The hot corona of the Sun continues to expand in outer space and create the Sun's wind, the flow of charged particles moving up to a heliopause of about 100 au. The bubbles in the interstellar medium formed by the solar wind, the heliosphere, are the largest concatenated structures in the Solar System. [21] [22]

The sun is currently moving through the Local Antarcross Cloud (near Cloud G) in the Local Bubble zone, precisely within the inner circle of the Orion Arms in the Milky Way galaxy. [23] [24] Of the nearest 50 star systems within 17 light years from Earth (the nearest star is a red dwarf named Proxima Centauri about 4.2 light-years away), the Sun has the fourth largest mass. [25] The Sun orbits the center of the Milky Way at a distance of approximately 24,000-26,000 light years from the center of the galaxy. When viewed from the north pole of the galaxy, the Sun completes one orbit clockwise in the period of about 225-250 million years. Because the Milky Way is moving relative to the cosmic microwave background radiation (CMB) toward the Hydra constellation at a speed of 550 km / s, the Sun's velocity relative to CMB is about 370 km / sec towards the Crater or Leo. [26]

The average distance of the Sun from the Earth is about 149.6 million kilometers (1 au), although the distance varies as the Earth moves away from perihelion in January to aphelion in July. [27] At this average distance, light moves from the Sun to Earth for 8 minutes 19 seconds. This solar energy helps the development of virtually every life form on Earth through photosynthesis [28] and alters Earth's climate and weather. The extraordinary impact of the Sun on Earth has been observed since prehistoric times. The sun is also considered by some civilizations as gods. An accurate scientific understanding of the Sun grew slowly. In the 19th century, some well-known scientists began to know little about the physical composition and sources of solar energy. This understanding is still developing today. There are a number of Sun behavioral anomalies that have not yet been scientifically explained