Sun has a layered structure.In each layer there are processes that allow this star to allocate energy and support life on Earth.The Sun is composed mainly of two elements: hydrogen and helium.There are others, but in very small quantities.Their mass fraction of less than 1%.


In the center of the core of the Sun is located.It consists of plasma density is 150 g / cm3.Its temperature is about 15 million degrees.At the core there is a continuous fusion reaction in which hydrogen (or rather, its super-heavy isotope - tritium) is converted into helium, and vice versa.As a result of this reaction produces a tremendous amount of energy, which ensures the flow of all other processes inside stars.Scientists estimate that even if the reaction is stopped suddenly, the sun will emit the same amount of
energy a million years.

thermonuclear reaction can occur only at very high values ​​of the kinetic energy of the nuclei of hydrogen and helium.That is why the temperature in the core of the sun so high.In this case, the nucleus of atoms can approach a distance sufficient for the reactions, despite the powerful forces of Coulomb repulsion.In other parts of the sun, these processes can not be performed because the temperature there is significantly lower.

radiant zone

It is the largest layer of the Sun, extending from the outer boundary of the core to tachocline.It measures up to 70% of the radius of the star.There is carried out the transfer of the energy released by the fusion reaction to the outer shell.This transfer is achieved using photons (light).That's why the area is called the radiant.At the boundary of the radiative zone temperature of 2 million degrees.


It is very thin (for solar standards) layer separating the radiant and convective zone.There are carried out the processes of forming the solar magnetic field.The plasma particles "pull" the magnetic field lines, increasing its strength a hundred times.

convection zone

convective zone begins at a depth of approximately 200 thousand kilometers from the surface of the sun.The temperature here is pretty high, but it is not enough for a full ionization of the small part of the atoms of heavy elements.All these are present in this zone.Their presence explains the opacity of the sun.

Deep convective zone is absorbed radiation coming from the lower layers of the sun.It is heated and convection approaches the surface.As we approach the temperature and density drops sharply.They are respectively 5,700 Kelvin and 0.0000002 g / cm3.This low density allows the substance to move freely in space.