Magnetism and Its Magnetic Fields – The Spectrum of Science

Magnetic stars are neutron stars with magnetic fields 100 to 1,000 times stronger than those of typical pulsars (see “Vortex Around a Magnetic Star”). They can cause mysterious short radio flashes and provide energy for exotic supernovae. However, the origin of their extreme domains is controversial. With a new paradigm, it is now possible to show how, when fast spinning neutron stars form, an initially weak magnetic field grows into a magnetic force.

Massive stars heavier than about nine solar masses collapse at the end of their lives into a neutron star or stellar black hole. This implosion could lead to a supernova-shaped massive explosion of core collapse, which ejects the outer layers of the dying star into surrounding space (see SuW 3/2020, p. 30). Most neutron stars develop dipole magnetic fields with a flux density (“force”) of about one billion Tesla. This exceeds the Earth’s field by more than ten billion times. In an estimated ten percent of all cases, the dipole fields are up to 100 times stronger. These highly magnetized neutron stars are called magnetic stars. Under what conditions and processes could their giant domains arise is a heated topic of debate with great relevance to current questions in supernova physics.