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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 which are red dwarfs. [30] [31] The Sun is a Population I, or heavy-element-rich, [b] star. [32]
Orbital speed. 720,000 km/h (450,000 mi/h) [10] Orbital period. ~230 million years [10] The Solar System [d] is the gravitationally bound system of the Sun and the objects that orbit it. [11] It was formed 4.6 billion years ago when a dense region of a molecular cloud collapsed, forming the Sun and a protoplanetary disc.
Taken on 20 October 1968 from Apollo 7. Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere as daylight when the Sun is above the horizon.
The position of the Sun in the sky is a function of both the time and the geographic location of observation on Earth 's surface. As Earth orbits the Sun over the course of a year, the Sun appears to move with respect to the fixed stars on the celestial sphere, along a circular path called the ecliptic .
Sun path, sometimes also called day arc, refers to the daily and seasonal arc -like path that the Sun appears to follow across the sky as the Earth rotates and orbits the Sun. The Sun's path affects the length of daytime experienced and amount of daylight received along a certain latitude during a given season.
The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun 's activity measured in terms of variations in the number of observed sunspots on the Sun's surface.
Solar core. The core of the Sun is considered to extend from the center to about 0.2 of solar radius (139,000 km; 86,000 mi). [1] It is the hottest part of the Sun and of the Solar System. It has a density of 150,000 kg/m 3 (150 g/cm 3) at the center, and a temperature of 15 million kelvins (15 million degrees Celsius; 27 million degrees ...
In SI base units. 1.9884 × 1030 kg [1] The solar mass ( M☉) is a standard unit of mass in astronomy, equal to approximately 2 × 1030 kg. It is approximately equal to the mass of the Sun. It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes.