Sun.

sun is a hot gaseous sphere with a diameter of about 1.39×10
6
km and a mass of about 2.2×l0
27
It is 3.32×10
5
times the mass of the Earth and 1.3×10
6
times larger than earth, with an average density of one-four times that of earth. Its main component gases are hydrogen (about 80%) and helium (about 19%). As hydrogen is continuously polymerized into helium in the sun's interior, it continuously releases huge amounts of energy and transfers heat from the core to the surface in a radiation and converged manner, and the temperature gradually decreases from the center to the surface. Nuclear fusion is known to produce a loss of 0.00729 per 1g mass when hydrogen is polymerized into helium, releasing huge amounts of energy. Based on current estimates of the rate at which the sun produces nuclear energy, its hydrogen reserves are sufficient to last 60 billion years, so solar energy can be said to be inshaustible.

In the area of the sun's average radius of 23% (0.23R) is the core of the sun, the temperature is about 8×10
6
to 4×10
7
K, density of water 80 to 100 times, accounting for 40% of the total mass of the sun, 15% of the total volume. This part of the energy produced accounts for 90% of the total energy generated by the sun. Hydrogen polymerization releases γ rays, which increase in wavelength as it passes through colder areas, becoming
X-rays
or ultraviolet and visible light due to energy consumption. From 0.23 to 0.7R, the temperature drops to 1.3×10
5
K and the density drops to 0.079g/cm
3
. Between 0.7 and 1.0R, known as the "tessolow zone", the temperature drops to 5×10
3
K and the density drops to 10
-8
g/cm
3
. The outer part of the sun is a layer of light, which is the surface of the sun as seen by the naked eye, with a temperature of 5762K, a thickness of about 500km and a density of 10
-6
g/cm
3
, which is made up of strongly ionizing gases, from which most of the solar energy is emitted into space. Outside the sphere of light is not only glowing, but also almost transparent in the sun's atmosphere, known as the "inverter layer", which is made up of extremely thin gases, about hundreds of kilometers thick, and absorbs
spectral
radiation from some visible light. On the outside of the "anti-variant" is the upper layer of the sun's atmosphere, known as the "color sphere", about 1 to 1.5×10
4
km thick, mostly composed of hydrogen and helium. Outside the "color sphere" is a silver-white corona extending into space, with temperatures of up to 1 million degrees and sometimes tens of solar radius.



visible from the structure of the sun, the sun is not a black body with a constant temperature, but a multi-layered radiation body with different wavelengths emitted and absorbed. However, in solar energy use, it is usually regarded as a black body with a temperature of 6000K and a wavelength of 0.3 to 3 m.