In the cloud of molecular hydrogen in the heart of the nebula original, over the millennia, the nuclei of hydrogen compressed by gravity are transformed into helium, nuclear fusion starts, the gas ignites, the Sun was born in the darkness. This is how our Sun 1,392,000 km in diameter, appeared. These yellow dwarf is a pot nuclear hell, constantly buffeted by colossal explosions in space that send huge amounts of material. From 4.57 billion years, our aster in thermonuclear fusion in space sends a tremendous amount of energy, and it will last another 5 billion years. This plant is truly monstrous thermonuclear, it produces an enormous heat source and inexhaustible energy of 380 billion billion megawatts, equivalent to 3 800 billion times the power of our 439 nuclear reactors in operation (2011). Each square meter of the atmosphere receives 1,000 watts. In just one second, the Sun gives off unabated, more energy than the human civilization has produced since birth and it lasts for 4 billion years. However, 150 million km from Earth receives only a small amount of this energy, only 2 billionths of the emitted radiation. The mean temperature at Earth (15 ° C), is related to the average solar power received Earth and the distance between the Earth / Sun. The calculation of the power received on Earth in watts per square meter is 239 wm2. Consumption that is the loss of mass of the Sun is 4 million tons of hydrogen per second, in fact it transforms 564 million tons of hydrogen into 560 million tons of helium.
In addition the temperature of the center of the sun grows slowly over time. The Sun is composed primarily of hydrogen (74%) and helium (24%), the rest of the field consists of oxygen (0.77%), carbon (0.29%), iron (0 , 16%), neon (0.12%) of nitrogen (0.09%), silicon (0.07%), magnesium (0.05%) and sulfur (0.04%). This huge energy in the heart of the system, at a temperature of 15 million degrees, is isolated from interplanetary space by 700 000 km of material, which corresponds to the radius of the Sun. The heat and pressure so intense that matter is neither solid nor liquid, nor gas, it is so hot that it remains in the plasma state, the electrons are separated from the nuclei. The Sun ejects not only photons but also protons and electrons that make up the extremely energetic solar wind. This wind emerges from the surface layers, and spread in space. The Earth is not completely sheltered by his screen magnetic solar wind at a speed of 400 km/s, seeping through cracks polar to show us beautiful northern and southern lights, the lights white, green and reds. Subject to the solar wind, comets are decorated with a tail showing the direction of solar storms. It is this vast inexhaustible energy from the heart of the system, which must be the emergence of life on Earth.
Nota: The enormous power of the Sun. The Sun is really enormous, it has captured 99.86% of the total mass of dust and gas of the original nebula. Jupiter, the largest planet in the system, has captured 71% of the remainder. The other planets have shared the residue of the gravitational evolution.
The solar prominences are filaments of matter from the sun projected above the surface and characterize the activity of the Sun. These are coronal mass ejections (CME). The eruptive prominences of the Sun are huge geysers of solar material that appear on the chromosphere and that spring to hundreds of thousands of kilometers into space. Why the photons have to travel from the infernal solar core that carries the light rays to the Earth. The photons pass through the different layers of the Sun, the radiative zone and the convection zone, the photosphere, the chromosphere, and finally the solar corona. The transit time of a photon, the surface of the heart is between 10,000 and 170,000 years, according to the random collisions. At first the photon begins to penetrate the thick radiative zone of 300 000 km, the density is so high that the photon has trouble moving it from constantly colliding with other particles such as atoms and ionized hydrogen helium. The difficult progress of the photon is chaotic, it is called by scientists "photon random walk".
Video: A very long filament wound in the solar corona has finally exploded, December 6, 2010. The SDO (Solar Dynamics Observatory) NASA's filmed the explosion in ultraviolet light helium. This filament measured nearly a million miles long. The SDO has had time to film this event before the rotation of the sun does hide the view. Credit: NASA's GSFC, SDO AIA Team
Image: Extremely hot gas of solar spicule moving at a speed of 50 000 km/h in a tube of magnetic field. They are particularly evident around the spot visible at the bottom left of the image. The spicules have a shelf life of about 5 minutes, beginning in the form of long tubes of gas rising up quickly, then falling back towards the Sun. Credit: K. Reardon (Osservatorio di Arcetri Astrofisico, INAF) IBIS, DST, NSO