Radio pulses every 7.9 minutes traced to a white dwarf circling a Sun-like star

The radio pulses from GPM J071507−114153 repeat every 474 seconds and switch on in a window that returns every 1.35 days, which the team reads as the orbit of a white dwarf around a G-type star more than 5,000 light-years away.

Peer reviewed · Radio and optical observations of one system · Orbit inferred from radio timing

A team led by the International Centre for Radio Astronomy Research (ICRAR) in Australia has traced a radio source that pulses every 7.9 minutes to a white dwarf, the burnt-out core of a star, circling a star much like the Sun. Reported in Nature Astronomy on 12 November, GPM J071507−114153 is the first object of its class known to have a Sun-like partner; the confirmed earlier cases pair a white dwarf with a small, cool red dwarf. The catch: the 1.35-day orbit comes from radio timing alone and has not yet been checked with optical spectra.

Evidence at a glance

Is this a big deal?

It is a solid step for a young field, not a final answer. Finding a new partner type matters because it tells theorists which ingredients these systems need. Seeing an orbit written into the pulse timing is also new. But it is one system, and the orbit still needs an independent check.

What scientists found

Long-period transients are radio sources that flash on a cycle of minutes to hours, far slower than ordinary pulsars, and their bursts are strongly polarized. About a dozen are known. According to the paper’s abstract, optical follow-up has shown that at least 4 of the 12 known before this one are pairs of a white dwarf and an M dwarf, a small red star.

J0715−1141 breaks that pattern. Its partner is a G-type star, the same broad class as the Sun, identified from its optical spectrum. The other star is a white dwarf, the dense core a Sun-like star leaves behind when it dies (our guide to the life cycle of a star covers that stage). The team interprets the 7.9-minute radio period as the white dwarf’s spin.

The pulses do not arrive all the time. They appear inside an “activity window” that comes back every 1.35 days, and the team reads that cycle as the orbit. Their timing analysis suggests the G-type star is not swollen enough to spill gas onto the white dwarf; in astronomers’ terms, it does not fill its Roche lobe.

How they found it

The system turned up in the GPM survey, which uses the MWA in Western Australia to scan the part of the Milky Way visible from Australia. Csanád Horváth designed the detection method and Samuel McSweeney spotted the pulses, according to the paper’s contribution statement. Natasha Hurley-Walker, who leads the survey, then used the MeerKAT telescope in South Africa to fix the source’s precise position.

Antonio Rodriguez then took spectra of the matching star with the Keck I telescope in Hawaiʻi. The light matched a G-type star. Two spectra taken 40 minutes apart showed no shift in the star’s calcium lines, the supplementary information says, which fits the 7.9-minute period being a spin rather than an orbit.

The orbit came from the radio clock itself. Think of a lighthouse on a boat circling an island: when the boat is on the far side, each flash has farther to travel and reaches you a little late. McSweeney’s team saw the same kind of drift in the pulse arrival times, lined up with the 1.35-day cycle. In the peer review file, the authors estimate the orbit spans a few to several light-seconds, so the delays are seconds long, which the short pulses make measurable. The analogy has a limit: a lighthouse’s beam source is known, while here the drift shows only that the pulses come from something moving around the G-type star.

“This is the first time the pulses are clear enough to see the white dwarf moving in its orbit around its companion, so we know that the pulsations are coming from a region close to the white dwarf, or possibly even from the white dwarf itself,” McSweeney said in the Curtin University release. The team processed more than 100 hours of radio data at the Pawsey Supercomputing Research Centre.

Why it matters to you

This won’t change anything in daily life. The pulses are natural and pose no hazard; repeating radio signals sometimes prompt talk of aliens, but here both stars have been identified. The payoff is understanding: a white dwarf is what the Sun will become, and this system lets astronomers watch one interact with a Sun-like star.

What the evidence does not show

The orbit is not yet confirmed. The MWA could only watch when the source was high in its sky, and that sampling creates false periods in the data. One reviewer re-ran the period search and found the same signals as the authors, but still wrote that “a small amount of uncertainty remains regarding the true periodicity,” because a period of about 0.68 days also fit.

The exact source of the radio emission is open. The timing places it close to the white dwarf, possibly on the white dwarf itself, but does not say how the beam is made.

The polarization changes near the point where the white dwarf passes behind its partner fit radio waves crossing the star’s hot outer atmosphere, its corona. Hurley-Walker said in the release that the team also saw the white dwarf move behind a strongly magnetic region, “most likely a ‘stellar prominence'”, a loop of plasma above a star’s surface. A reviewer noted that a one-off eruption from the star could produce a similar change, and the authors added that caveat.

The white dwarf’s mass is not pinned down either. The abstract calls it low-mass, and a reviewer pointed out that the mass limit depends on assumptions in the orbital model.

How this fits what we already knew

The ICRAR group reported the first long-period transient, and the class has grown to around a dozen, says the Curtin release. The confirmed white dwarf systems so far all had red dwarf partners, which left open whether a red dwarf’s strong magnetic activity was a requirement.

In the abstract, the authors conclude that in white dwarf systems the pulsed radio emission depends on the white dwarf’s interaction with its partner, and that the partner can be a G-type star in a day-long orbit. That conclusion rests on the 1.35-day orbit being right.

Outside views from peer review

SciQuest has not yet reached an independent astronomer for comment. The open peer review file gives the closest outside view. Reviewer 1 called the work “a very elegant result.” Reviewer 2 wrote in an earlier round that much of the paper was “highly speculative” because it leaned on the 1.35-day signal, and asked for more optical spectroscopy before publication. The journal lists Sanne Bloot and Boris Gänsicke as the reviewers but does not say who wrote which report.

How other headlines framed it

• Gizmodo framed it as a mystery solved, saying astronomers “finally know” what is behind the signal; its body text is more careful about where the pulses originate.
• Tech Times called it the “first proof” that these sources are not limited to red dwarf pairs, a stronger claim than one system with an unconfirmed orbit supports.
• Phys.org carried ICRAR’s own text, which leads with a “rare star system” and the eight-minute rhythm.

What happens next

The decisive test is optical. Spectra taken across a full orbit should show the G-type star moving towards and away from us on a 1.35-day cycle, or on a 0.68-day one. One reviewer estimated a swing of roughly 93 km/s for typical masses, large enough to measure. During review, the authors wrote that the source was a daytime object and would not be observable for several months. Larger surveys will come from the SKA telescopes now under construction in Australia and South Africa, for which the MWA and MeerKAT serve as precursors.

In one sentence

A white dwarf that pulses in radio every 7.9 minutes appears to circle a Sun-like star every 1.35 days, showing that these slow radio clocks are not limited to red dwarf partners, if optical checks confirm the orbit.

Read next

• White dwarf colours: what these dead stars would look like up close.
• Life cycle of a star: how a Sun-like star ends as a white dwarf.
• How long it takes to travel one light-year: why 5,000 light-years is beyond any spacecraft.

Sources and disclosure

1. McSweeney SJ, Hurley-Walker N, Bahramian A, Horváth C, Rea N, Rodriguez AC, Pelisoli I. “A long-period transient with a Sun-like companion.” Nature Astronomy, published 12 November 2026 (received 19 January 2026, accepted 5 October 2026). doi:10.1038/s41550-026-03016-z. Abstract, author contributions and supplementary information read.
2. Peer Review File for the same paper, Nature Astronomy, CC BY 4.0 (source of the 474-second period, the 1.352998 ± 0.000045-day and 0.676427-day periods, the orbit-size estimate and the reviewer comments).
3. Curtin University. “Researchers discover rare star system that emits radio signals every eight minutes,” 12 November 2026 (source of the quotes, the 5,000 light-year distance and the 100-hour figure).
4. Coverage read for framing: Gizmodo, Tech Times and Phys.org, 12 November 2026.

Disclosure: This article was drafted with AI assistance and checked against the sources above. The full paper is paywalled, so details beyond the abstract, supplementary information, peer review file and Curtin release are not reported. SciQuest calculations: 1.352998 days × 86,400 s = 116,899 s, about 32.5 hours; 116,899 s ÷ 474 s ≈ 247 pulses per orbit. The graphic is a SciQuest original. Spotted an error? See our corrections policy.