By Ron Cowen
Astronomers have found evidence suggesting that a rare group of ultradense stars are magnetars–the objects with the strongest magnetic fields known in the universe.
According to theory, these enormous fields–100 trillion to 1 quadrillion gauss–are generated within ultradense neutron stars. A neutron star’s gravity is so strong that it squeezes protons and electrons into a fluidlike core of neutrons inside a solid crust. Swirling motions within the core may dramatically amplify the already strong magnetic field there, creating a magnetar.