Glossary term: Star

Description: A star is a ball of gas (more precisely, plasma) that is held together by its own gravity and prevented from collapse by inner pressure that is the consequence of nuclear fusion processes in the star's core. The star closest to Earth is the Sun. In a more general sense, the word is also used for stellar remnants such as neutron stars or white dwarfs, which are two possibilities (depending on mass) for what stars turn into once they have exhausted the fuel for their nuclear fusion. Stars are among the most obvious objects in the night sky. In the cosmos, they are typically found within galaxies, each star generally accompanied by one or more planets. The study of how stars form and evolve is an important part of astrophysics.

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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".

Related Media

On the outskirts of a cluster of galaxies is an arc of light. On this arc is a dot, an image of one of the first stars

A gravitational lens magnifies one of the first stars

Caption: This image zooms in on a star formed within the first billion years after the birth of the Universe (at a redshift of 6.2). The Hubble Space Telescope detected this light using a technique called gravitational lensing. A massive galaxy cluster between the observer and the imaged star creates a distorted and warped image of the parent galaxy and reveals its features.
Credit: NASA, ESA, B. Welch (JHU), D. Coe (STScI), A. Pagan (STScI) credit link
License: CC-BY-4.0 Creative Comments Attribution 4.0 International (CC BY 4.0) icons