A precessing magnetar model for GLEAM-X J162759.5-523504.3

We propose a precessing transient magnetar model for the recently discovered radio source GLEAM-X J162759.5-523504.3. We identify the observed period of ∼ 1 ks as the precession period of the magnetar deformed due to its strong (Bφ ∼ 1016 G) toroidal field. The resulting deformation of order 10−4 implies a spin period of Ps = 0.1 s. Assuming a strong dipole field of Bd ∼ 1014 G we predict a period derivative of Ṗs ∼ 10−11 s s−1. We also predict that the precession period of the magnetar can be observed in the hard X-ray band just as the other three galactic magnetars exhibit precession.