Astronomers have identified the source of a mysterious, repeating radio signal in the Milky Way, solving a puzzle tied to a rare type of cosmic object known as a long-period radio transient (LPRT). The signal, named ASKAP J1745-5051, pulses every 84 minutes and occasionally disappears for hours before returning. Initially baffling, the pattern is now explained by a binary star system consisting of a white dwarf and a red dwarf orbiting each other in just 1.36 hours.

The white dwarf’s strong magnetic field pulls plasma from its companion, accelerating electrons to near-light speed and generating coherent radio bursts through a process called cyclotron emission. When the magnetic connection between the stars temporarily breaks, the system goes dark—explaining the intermittent signal seen from Earth. This mechanism confirms that some LPRTs originate from magnetic cataclysmic variables, not isolated neutron stars or pulsars.

The discovery, published in Nature Astronomy, redefines how scientists interpret transient radio sources. It highlights the role of accreting white dwarfs in producing detectable radio emissions and provides a new template for identifying similar systems. Future surveys using radio and X-ray telescopes will apply these findings to uncover more hidden binary interactions shaping stellar evolution.