Long Period Radio Transients

Long-period radio transients (LPTs) are a class of Galactic radio sources that emit highly polarised, coherent bursts of radio emission that regularly repeat, with periods ranging few minutes to several hours. Unlike classical pulsars, which are neutron stars that rotate on timescales of milliseconds to seconds, LPTs have periods orders of magnitude longer — often exceeding conventional theoretical limits for radio-emitting neutron stars.

Source: Wikipedia — Long Period Radio Transients (CC BY-SA 4.0)