Astronomers have traced a mysterious radio signal repeating every eight minutes to a white dwarf star locked in orbit with a Sun-like companion.
Located 5,000 light-years away, the system—cataloged as GPM J071507-114153—is the first time a white dwarf has been observed emitting such long-period radio pulses while paired with a G-type star.
Detecting the Eight-Minute Pulse
The signal first emerged in late 2024, captured by the Murchison Widefield Array in Western Australia. Over the following months, between December 2024 and September 2025, researchers logged 214 individual radio pulses. This consistent rhythm places the object into the category of long-period transients, a class of radio sources defined by emission intervals significantly slower than those of traditional pulsars.
Mapping the Binary Dance
To confirm the origin of the signal, the research team processed more than 100 hours of radio data. By mapping the movement of the white dwarf, they successfully tied the pulses to its orbital path.
“The data on the pulses is clear enough to see the white dwarf orbiting its companion star,” said Sam McSweeney, lead author of the study published in Nature Astronomy, as reported by DonanımHaber.
The team used the MeerKAT radio telescope in South Africa to lock onto the source’s precise coordinates. Subsequent observations at the W.M. Keck Observatory in Hawaii confirmed that the white dwarf’s companion is a G-type main-sequence star. This specific pairing is notable, as previous research into similar objects has typically involved white dwarfs coupled with smaller, cooler red dwarfs.
Monitoring Distant Stellar Storms
“The ability to detect storms on a star 5,000 light-years away using radio wavelengths represents a significant advancement in observational astronomy,” said Natasha Hurley-Walker, a co-author of the study.
Mechanisms Still Under Review
While the discovery of GPM J071507-114153 shows that interactions in binary systems play a role in these transient emissions, researchers indicate that further observations are needed to fully understand the production mechanism of the signals.
Future observations must determine whether all long-period transients rely on this specific binary structure or if other celestial configurations can produce similar signatures. For now, researchers are focused on using these radio pulses to uncover a hidden population of white dwarfs, hoping to gain a clearer picture of stellar evolution and the complex dynamics of binary systems.
