Artist impression of a magnetar with a ‘magnetic loop’. This is the interpretation of data collected by ESA’s XMM-Newton space telescope of the magnetar known as SGR 0418, which boasts one of the strongest magnetic fields in the Universe. In order to maintain such a strong magnetic field, the magnetar must have a twisted internal magnetic field, which manifests itself as a small region on the star’s surface, somewhat similar to the localised magnetic fields anchored in sunspots on the Sun.