A magnetar just woke up after three years of silence

When stars reach the end of their main sequence, they undergo a gravitational collapse, ejecting their outermost layers in a supernova explosion. What remains afterward is a dense, spinning core primarily made up of neutrons (aka. a neutron star), of which only 3000 are known to exist in the Milky Way Galaxy. An even rarer subset of neutron stars are magnetars, only two dozen of which are known in our galaxy.

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Neutron Stars, Pulsars and Magnetars Explained.

 

Discovery of runaway companion star points to a mass-exchange during a supernova explosion; weird conditions that lead to the weird, violent object called a magnetar.

 

A spinning magnetar radiating away its bright emission.

 

magnetar SGR 0418.