Glossary term: Neutron Star

Description: A neutron star is a very dense and compact stellar remnant that is left following the collapse of a massive star's core. Stars with masses of about eight solar masses or more end their stellar evolution with their cores collapsing, triggering a supernova explosion. The collapsed core has a density larger than that of most atomic nuclei and is comprised primarily of neutrons. This latter point is due to protons and electrons combining to form neutrons in the extremely hot and dense collapsed core of the massive star. The lower mass limit of a neutron star is 1.4 solar masses, and the upper limit is about 3 solar masses – above this the object would collapse to a black hole. Highly magnetic neutron stars are known as magnetars. The vast majority of known neutron stars are observed as radio pulsars.

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Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

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".

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A neutron star appears as a blue spot surrounded by shells of material which appear as red and green rings

Death of a massive star

Caption: A multi-wavelength image taken with telescopes on the Earth and in space of a neutron star within our neighbouring Small Magellanic Cloud galaxy. A neutron star (seen here as the blue spot surrounded by a red ring) is the final product of gravitational collapse, compression and explosion of a massive star, left embedded in its supernova remnant (in green).
Credit: ESO/NASA, ESA and the Hubble Heritage Team (STScI/AURA)/F. Vogt et al. credit link

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