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 WHERE DO STARS GET THEIR ENERGY FROM?

To turn on a light, a telephone or a computer, to move a car, to warm ourselves in winter and refresh in summer, to walk, or even read these lines, we need energy. So, where does this energy come from? There are different sources. We can burn some fuel to warm up or move, or take advantage of the wind or the falling water on a waterfall to turn it into kinetic energy useful for other purposes. We can also take the solar light and turn it into chemical energy, keep it within batteries, and then use them to run our electronic devices. Even plants can transform solar light, air, water, and minerals into sugars to generate energy through other chemical processes, but how is the energy that comes from the Sun produced?

The Sun is mainly made up of hydrogen and helium, the most lightweight and common elements in the whole Universe, besides small quantities of chemical components such as carbon, nitrogen, oxygen, iron, sodium, calcium, and magnesium, among others.

In contrast to the Earth conditions, the Sun possess an enormous gravity due to its gigantic mass, which makes its core particularly hot. Also, it is very dense. There is an immense pressure and, under these extreme conditions, a phenomenon known as nuclear fusion occurs. Nuclear fusion is the process in which small and lightweight atoms, such as hydrogen, come together to create larger and heavier ones such as helium. In fact, it is needed four hydrogen atoms to fuse into one helium, but the process is much more complicated than just put atoms together. • • • 23