A magnetar is a special type of neutron star that has an enormous magnetic field.
In 2336, a binary system within a nebula contained a magnetar, one which spun so fast that it generated an intense magnetic field. It drew gas and matter from the heliosphere of a brown star and triggered massive solar flares. The two stars were 0.03 AU apart and had an orbital period of three days. When the shuttle T'Pol went to warp near the magnetar, it interfered with the gravity well, igniting flares that destroyed the planets in the system. (DS9 - The Lost Era novel: Well of Souls)
The neutron star Qul Tuq was a magnetar in the Qul Tuq system, with a massive magnetic field, a quadrillion times stronger than fields in a majority of systems. The field was so strong in a magnetar that it slowed the star’s spin, resulting in starquakes that emitted ion storms, Berthold rays, gamma radiation, delta rays, and other forms of radiation. (TOS novel: Excelsior: Forged in Fire)