Radio pulses traced to white dwarf and Sunlike star

Astronomers have linked radio pulses recurring about every eight minutes to a binary star system containing a white dwarf and a Sunlike star, a pairing not previously reported for these signals. The system, named GPM J071507114153, is classified as a long-period transient, a rare type of object whose radio emissions switch on and off over minutes or hours.

The research team identified the system through radio observations and follow-up optical measurements. The Murchison Widefield Array in Australia detected the pulses, and the MeerKAT radio telescope in South Africa was used to determine the source’s position. Optical observations with the W. M. Keck Observatory confirmed the companion’s association with a G-type star.

The study reports that this is the first detected radio-pulsing white dwarf orbiting a Sunlike star. Previously reported examples of these pairings involved red-dwarf companions. The system’s white dwarf is the dense stellar remnant left after a star dies, while the companion is similar to the Sun.

Lead author Sam McSweeney said the team could track the white dwarf’s movement in its orbit for the first time in a system of this kind. That motion places the pulses...