The only star in the Solar system, so, the closest to Earth, is the Sun. All planets make the movement around it and therefore the planetary system is called by the name of the star.
Instruction
1. The sun - one of hundred million stars of the galaxy the Milky Way, and in size is approximately in the 4th place among them. On spectral classification the Sun treats yellow dwarfs, and its age, according to approximate calculations, about 4.5 billion years. Now the Sun is in the middle of the life cycle. The star, next to the Sun, is called Proxima of the Centaur and is from it at distance of 4 light years. The distance from the planet Earth to the Sun is equal to 150 million km, light is distance passes in 8 minutes. The sun is at distance of 26 thousand light years from the center of the galaxy, and the speed of its rotation concerning the center is 1 turn for 200 million years.
2. When the Sun reaches age approximately in 7 billion years, this star will turn into the red giant. Its outer sheaths will extend and will reach an orbit of Earth or even Saturn, having removed these planets on a long distance. The star consists of hydrogen for 92% and of helium for 7%, having very complex structure. In the center of the Sun there is its center which radius is of about 150000 - 175000 km, these are about 25% of the general radius of a star. In the center of a kernel temperature reaches 14,000,000 K. Yadro rotates around own axis with the high speed which significantly exceeds indicators of outer sheaths of a star. Exactly here as a result of reaction, helium which marks out a large amount of energy is formed of 4 protons. It is also radiated from the photosphere as kinetic energy and light.
3. Over a kernel of the Sun there is a zone of radiant transfer with temperatures around 2-7 million To. This zone is followed by a convective zone about 200 thousand km in depth. In this zone there is no reradiation and transfer of energy, there is a plasma hashing here. Temperature of a surface of this layer reaches 5800 K. The photosphere making a visible surface of a star is the main part of the atmosphere of the Sun on an equal basis with the chromosphere. The crown which of external part there is solar wind - a stream of the ionized particles is considered the last outer sheath of a star.
4. Life on the planet Earth exists generally only thanks to the Sun. The planet rotates round its pivot-center, and dawn and a sunset, and at the night of a star in the dark sky can observe every day of people. Live on the planet sun has a huge impact on activity of all: the star participates in photosynthesis, promotes education in vitamin D human body. Penetration of solar wind into the atmosphere of Earth is visible to the naked eye. These northern lights which also cause geomagnetic storms. Approximately each 11 years the solar activity decreases or increases.