Starquakes triggered on the surface of the magnetar disturb the magnetic field which encompasses it, often leading to extremely powerful gamma ray flare emissions which have been recorded on Earth in 1979, 1998, and 2004.
Teoretični koncept magnetarja sta leta 1992 predstavila ameriška astrofizika Robert Duncan in Christopher Thompson, dejanske žarke gama iz magnetarja pa naj bi prvič zaznali že 5. marca 1979.