Cosmic radio pulses repeating every few minutes or hours, known as long-period transients, have puzzled astronomers since their discovery in 2022. Our new study, published in Nature Astronomy today, might finally add some clarity.

Radio astronomers are very familiar with pulsars, a type of rapidly rotating neutron star. To us watching the skies from Earth, these objects appear to pulse because powerful radio beams from their poles sweep our telescopes—much like a cosmic lighthouse.

The slowest pulsars rotate in just a few seconds—this is known as their period. But in recent years, long-period transients have been discovered as well. These have periods from 18 minutes to more than six hours.