At the heart of a monstrous magnet

1 Magnetic field

Magnetars are known for their extremely powerful magnetic fields, which produce high-energy X-ray and gamma-ray bursts. These magnetic fields are hundreds of millions times stronger than any humanmade magnet on Earth.

2 Outburst

The fireball, produced by magnetic field decay, ejects intense flashes of high-energy electromagnetic radiation. These giant flares leave the surface of the magnetar at the speed of light, and their radiation has even been recorded on Earth.

3 Solid crust

This outer layer is often only 500 metres (1,640 feet) thick. Eventually it fractures under the extreme magnetic stress. After all, a magnetar placed at the distance of the Moon could wipe all the credit cards on Earth. X-rays are then released by the resulting fireball.

4 The fluid layer

Extending out from the core over a distance of approximately six kilometres (3.7 miles), this heavy fluid interior is mostly made of neutrons, with a scattering of other atomic particles. Here the process of convection carries heat away from the core.

5 The solid core

Measuring just three kilometres (1.8 miles) across, the central core of a magnetar is made of subatomic particles called quarks – the same building blocks from which protons and neutrons are constructed.