The Sun is the center of our solar system. Like most stars, it is a huge fireball, made up of glowing hydrogen gas.
The Sun has no solid surface. It is surrounded by the photosphere, which is the part visible to us and which borders on the chromosphere and the corona. Spectacular events occur in these layers. The Sun is made up of 71% hydrogen, 27% helium and 2% heavier elements.
Temperatures in the interior of the Sun reach 16 million degrees Celsius. Nuclear reactions that produce energy are made possible by this heat. Here, the nuclei of hydrogen atoms ( protons ) fuse together.
Four protons from several individual reactions fuse together to form a helium nucleus. This causes energy to be released in the form of gamma_radiation. Several hundred million tons of hydrogen atoms react to form helium every second.
Energy produced in the core of the Sun expands outwards in the form of radiation. The area it passes through is termed the radiative_zone. This borders on a convection_zone, where the energy is transported by gases until it appears as heat and light in the photosphere. Temperatures here are only around 5500┬░ Celsius.
