Long-period radio transients are a new class of astronomical objects characterized by periods ranging from 18 to 54 minutes. They exhibit bursts highly polarized, beamed radio emission lasting only 10–100 seconds. The intrinsic nature of these objects is subject to speculation, with highly magnetized white dwarfs and neutron stars being the prevailing candidates. Lee et al. have reported in Nature Astronomy the discovery of ASKAP J183950.5−075635.0, which has the longest known period of this class at 6.45 hours. Discovered in a Rapid ASKAP Continuum Survey (RACS) observation, follow-up ovservations with the ATCA, MeerKAT, and ASKAP enabled the source to be characterised and the rotational period determined. The source exhibits both bright main pulses and weaker interpulses offset by about half a period that are indicative of an oblique or orthogonal rotator. This phenomenon, observed in a long-period radio transient, confirms that the radio emission originates from both magnetic poles and that the observed period corresponds to the rotation period. The spectroscopic and polarimetric properties of ASKAP J183950.5−075635.0 are consistent with a neutron star origin, and this object is a crucial piece of evidence in our understanding of long-period radio sources and their links to neutron stars. (Image credit: James Josephides)
