A breakthrough simulation reveals how magnetars form and evolve, solving a key mystery about their magnetic origins.

Magnetars are a rare type of neutron star.

A neutron star is the collapsed core of a large (between 10 and 29 solar masses) star. Neutron stars are the smallest and densest stars known to exist. Though neutron stars typically have a radius on the order of just 10 — 20 kilometers (6 — 12 miles), they can have masses of about 1.3 — 2.5 that of the Sun.