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Glossary term: Nucleus

Description: All the matter that we see around us consists of atoms, and each atom in turn consists of electrons surrounding a small, central nucleus. Atomic nuclei consist of protons and neutrons bound tightly together by nuclear interactions. Nuclei with the same number of protons form atoms that belong to the same chemical element. In the interior of stars, energy is set free as lighter nuclei (starting with hydrogen, whose nucleus is a single proton) fuse to form successively heavier nuclei. Shortly after the Big Bang, a brief phase of "Big Bang nucleosynthesis" had hydrogen nuclei fusing to helium and traces of other elements. Both stellar winds and cosmic rays contain some atomic nuclei, stripped of their electrons.

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Term and definition status: This term and its definition is still awaiting approval

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".