Structure, deformations and gravitational wave emission of magnetars

Neutron stars can have, in some phases of their life, extremely strong magnetic fields, up to 10(15-16) G. These objects, named magnetars, could be powerful sources of gravitational waves, since their magnetic field could determine large deformations. We discuss the structure of the magnetic field of magnetars, and the deformation induced by this field. Finally, we discuss the prospects of detection of the gravitational waves emitted by these stars