Editing Magnetar (section)

{{Short description|Type of neutron star with a strong magnetic field}}
[[Image:Artist’s impression of the magnetar in the star cluster Westerlund 1.jpg|thumb|Artist's conception of a powerful magnetar in a [[star cluster]]]]

A '''magnetar''' is a type of [[neutron star]] with an extremely powerful [[magnetic field]] (~10<sup>9</sup> to 10<sup>11</sup> [[Tesla (unit)|T]], ~10<sup>13</sup> to 10<sup>15</sup> [[Gauss (unit)|G]]).<ref>{{Cite journal |last1=Kaspi |first1=Victoria M. |last2=Beloborodov |first2=Andrei M. |date=2017|title=Magnetars|journal=Annual Review of Astronomy and Astrophysics |volume=55 |issue=1 |pages=261–301 |doi=10.1146/annurev-astro-081915-023329 |arxiv=1703.00068 |bibcode=2017ARA&A..55..261K}}</ref> The magnetic-field decay powers the emission of high-[[photon energy|energy]] [[electromagnetic radiation]], particularly [[X-ray]]s and [[gamma ray]]s.<ref name="Ward">Ward; Brownlee, p.286</ref>

The existence of magnetars was proposed in 1992 by [[Robert C. Duncan (astrophysicist)|Robert Duncan]] and [[Christopher Thompson (astronomer)|Christopher Thompson]]<ref name="duncan_thompson">{{cite journal |doi=10.1086/186413 |bibcode=1992ApJ...392L...9D |title=Formation of Very Strongly Magnetized Neutron Stars: Implications for Gamma-Ray Bursts |last1=Duncan |first1=Robert C. |authorlink1=Robert C. Duncan (astrophysicist) |last2=Thompson |first2=Christopher |journal=[[Astrophysical Journal Letters]] |volume=392 |page=L9 |year=1992}}</ref> following earlier work by Katz<ref>{{cite journal | doi=10.1086/160262 | bibcode=1982ApJ..260...371K | title=Physical Processes in Gamma-Ray Bursts | last1=Katz | first1=Jonathan I. | journal=[[Astrophysical Journal]] | volume=260 | page=371 | year=1982}}</ref> on the Soft Gamma Repeater SGR 0525-66, then called a gamma-ray burst. 

Their proposal sought to explain the properties of transient sources of gamma rays, now known as [[soft gamma repeater]]s (SGRs).<ref name="journal"/><ref name="sokol">{{cite journal |last1=Thompson |first1=Christopher |last2=Duncan |first2=Robert C. |date=July 1995 |title=The soft gamma repeaters as very strongly magnetized neutron stars - I. radiative mechanisms for outbursts |journal=Monthly Notices of the Royal Astronomical Society |volume=275 |issue=2 |pages=255–300 |bibcode=1995MNRAS.275..255T |doi=10.1093/mnras/275.2.255 |doi-access=free }}</ref> Over the following decade, the magnetar hypothesis became widely accepted, and was extended to explain [[anomalous X-ray pulsar]]s (AXPs). {{As of|2021|07}}, 24 magnetars have been confirmed.<ref name=mcgill/>

It has been suggested that magnetars are the source of [[fast radio burst]]s (FRB), in particular as a result of findings in 2020 by scientists using the [[Australian Square Kilometre Array Pathfinder]] (ASKAP) radio telescope.<ref name="SA-20200601">{{cite news |last=Starr |first=Michelle |title=Astronomers Just Narrowed Down The Source of Those Powerful Radio Signals From Space |url=https://www.sciencealert.com/we-re-starting-to-figure-out-where-fast-radio-bursts-come-from |date=1 June 2020 |work=ScienceAlert.com |access-date=2 June 2020 }}</ref>