A low-magnetic-field Soft Gamma Repeater

Understand

Soft gamma repeaters and anomalous x-ray pulsars form a rapidly increasing group of x-ray sources exhibiting sporadic emission of short bursts.

• They are believed to be magnetars, i.e.
• neutron stars powered by extreme magnetic fields, B~10^{14}-10^{15} Gauss.
• We report on a soft gamma repeater with low magnetic field, SGR 0418+5729, recently detected after it emitted bursts similar to those of magnetars.