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Why is the Sun's corona so much hotter than the Sun's surface? (more unsolved problems in astronomy) The temperature of the photosphere is approximately 6,000 K, whereas the temperature of the corona reaches 1,000,000–2,000,000 K. The high temperature of the corona shows that it is heated by something other than direct heat conduction from the photosphere. It is thought that the energy ...
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 about 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 .
Solar rotation varies with latitude. The Sun is not a solid body, but is composed of a gaseous plasma. Different latitudes rotate at different periods. The source of this differential rotation is an area of current research in solar astronomy. [1] The rate of surface rotation is observed to be the fastest at the equator (latitude φ = 0°) and ...
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 Kelvin (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.
Solar radius is a unit of distance used to express the size of stars in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun 's photosphere where the optical depth equals 2/3: [1] 695,700 kilometres (432,300 miles) is approximately 10 times the average radius of Jupiter, 109 times the radius ...