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: http://www.space.vsi.ru/sune.htm
Дата изменения: Sat Oct 14 21:13:07 2000 Дата индексирования: Mon Oct 1 19:33:24 2012 Кодировка: Поисковые слова: dark nebula |
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Our Sun is a typical star-dwarf of a spectrum class G2 - this is the great shining gas sphere with complicated internal structure without strict boarder - its density is decreasing step by step. But owing to photosphere (Greek “the light sphere” the thickness) of which is less than 300 km, the observer thinks that the Sun has a "surface".
The chemical composition taken from the solar spectrum: hydrogen is about 90%, helium - 10%, the rest elements - less than 0,1% (according to the number of atoms). The Solar energy sourse is the core transformation of the Sun, where temperature is 15 000 000 K. The energy from inside is carried by irradiation and then in the external layer with 0,2 Ra of thikness - by convection. With the convective movement of plasma many space occurences are connected such as: photosphere gravitation, the Solar spots etc. The intensity of plasma processes on the Sun is periodically changed (11-year period; see the item "The Solar activity").The Earth, situating far from the Sun (149 mil km), receives about 2.1017 W of the Solar beam energy (see item "The Solar constant"). The Sun is the main sourse of energy for all the terrestrial processes. The corpuscule Sun radiation influences all the biosphere (see "the Solar-terrestrial connections").