Magnetars

 

Magnetars are another derivative of neutron stars besides pulsars. Their magnetic fields are 1000 times stronger than neutron stars.

Neutron stars have a crust until 1 kilometre from the outermost surface. This crust is locked together with the magnetic field, so any explosion or a "star-quake" that the crust experiences creates a ripple in the magnetic field. Due to the huge magnetic field, any ripple releases an enormous amount of energy as radiation.

In fact, a magnetar discovered in 1979 had such an explosion, and in one-tenth of a second, it released more energy than the sun has emitted in the last 100,000 years.