Astronomy Practice Exam

The primary energy source for the Sun's core is nuclear fusion. In the extreme conditions of temperature and pressure found in the core, hydrogen nuclei combine to form helium nuclei through a series of nuclear reactions. This process releases an enormous amount of energy in the form of gamma rays. The energy generated in the core is what powers the Sun and ultimately leads to the emission of light and heat that we receive on Earth. Thermal radiation refers to the energy emitted due to the temperature of an object, but it does not serve as the primary energy source in the Sun’s core. Instead, thermal radiation is a byproduct of the energy generated by nuclear fusion. Solar wind consists largely of charged particles ejected from the Sun's outer layers and is not the source of energy in the core. Magnetic fields, while significant in various solar phenomena and processes, do not generate energy by themselves within the core. They can, however, affect the movement of charged particles and contribute to solar activity.