Long-Period Transients

Long-period transients are a recently discovered class of radio sources that pulse every tens of minutes to hours, far slower than any ordinary pulsar, and are almost invisible in X-rays. Our simulations suggest they could be magnetars that bloom late. If a star’s strong field is anchored in its core, it can stay dormant and cool quietly for up to a million years. Once the crust is cold enough, the field starts to reorganise, and occasional crustal failures twist the magnetosphere, switching on radio emission and braking the star’s rotation until it reaches these extreme periods. In this picture, long-period transients are “late-blooming magnetars”.