News Excerpt:
Stars create elements through nuclear fusion in their cores.
About Nucleosynthesis:
- Stellar nucleosynthesis is the process by which stars forge elements inside their cores through nuclear fusion.
- Hydrogen, the most abundant and lightest element in the universe, is the only element not formed through stellar nucleosynthesis. It was formed in the aftermath of the Big Bang.
- The cores of stars have extremely high pressures and temperatures, such as
- The Sun's core temperature is about 15 million degrees Celsius.
- These harsh conditions allow for nuclear fusion of atomic nuclei.
- The hydrogen nucleus consists of a single proton. In the core, these nuclei fuse to form helium nuclei, which contain two protons and two neutrons. This process is known as the proton-proton (p-p) chain.
- More massive stars follow the carbon-nitrogen-oxygen (CNO) cycle, where the nuclei of these elements come together in different ways to form elements starting from helium.
- As a star runs out of nuclei to fuse, its core contracts, increasing the temperature and triggering further nuclear fusion. This process repeats until the star starts producing iron in its core.
- Iron is the lightest element for which fusion consumes more energy than it releases.
- Elements heavier than iron can only be synthesized when a star goes supernova, outside of the star itself.
Supernovae
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