Evolution of the Sun

Evolution of a star depends on its mass which determines the amount of fuel available and the maximum central temperature attainable for its fusion reaction. Stars lose mass into space as they burn. The Sun releases proton and electrons generating a solar wind. This wind of energetic particles causes the auroras called the northern and southern lights, which are the result of solar flares that intensify the solar wind. As the hydrogen fusion ends, the fate of a star depends on its mass. 

All stars contradict the Aristotelian view of the eternal eighth sphere of the heavens that contains fixed and immutable stars. The Sun is a low mass star with a final stage of helium fusion that starts 5B years from now and will cause the sun luminosity to increase by a factor of 1000. In 1B years a 10% increase will cause water vapor on earth to be lost into space. As the luminosity increases it will cause the oceans to evaporate and scorch the earth. 

As a star gets older it becomes larger, cooler, and redder; increasing its energy output. The hydrogen fusion stag ends and it morphs to a red giant. Stars eight times larger than the Sun or smaller don't have the mass to explode into a supernova. Therefore the Sun will fade away.

There is hundreds of possible nuclear reaction occurring in stars at different stages in their evolution as well as the aftermath of a supernova explosion. These provided the answer to the profound question of the origin of the elements. The oxygen and nitrogen we breathe, the carbon in our bodies, the metals such as aluminum, silver, gold and platinum were all made from stellar processes. Without the life and death of stars the world could not exist, without the source of energy from the Sun, life could not have developed.