Somewhere more than 5,000 light-years away, two stars turn around one another in a quiet dance that has been running far longer than any human record: a collapsed white dwarf, the spent ember of a once-burning star, spinning with a regularity of eight minutes, and a yellow companion much like our own sun. Astronomers, working across Australia, South Africa and Hawaii, have now traced a rhythmic radio pulse to this pair, a pairing unlike those where such signals were usually found. It is a small addition to the long human effort to read the sky, yet it shows how faint messages from distant deat
Radio Pulses Every Eight Minutes Traced to Unusual Star Pair 5,000 Light-Years Away
Storms on a star over 5,000 light-years away
Mark
Start with the basics. Why does it matter that this star is sun-like?
Mimi
Because these pulsing systems had mostly shown up with red dwarfs, the smallest, coolest stars. This is the first with a G-type companion, similar to our sun.
Mark
And the eight minutes is the white dwarf's spin?
Mimi
Yes, the white dwarf spins every eight minutes, and the pulses follow that rhythm.
Luke
Careful, though. Do we know the white dwarf is the source?
Mimi
Not entirely. McSweeney says the pulses come from a region close to the white dwarf, or possibly from the white dwarf itself. That's a real distinction.
Mark
So what did the new data actually show?
Mimi
The pulses were clear enough to watch the white dwarf move in its orbit around its companion. That's what localises the source near it.
Luke
And earlier systems?
Mimi
Researchers knew about objects that switch radio signals on and off, but couldn't tell which star was producing them. About a dozen such systems have been found since 2021.
Mark
What about the flares?
Mimi
The pulses let the team detect flares on the sun-like star, similar to those behind Earth's auroras. Hurley-Walker called it amazing that radio can reveal storms 5,000 light-years away.
Luke
Worth noting the source gives no explanation of what physically makes the pulses. That remains open.
Der Puls
- A radio signal arriving every eight minutes has long puzzled astronomers, and now its source is pinned to a rare and unexpected pair of stars.
- The white dwarf at its heart spins with clockwork precision, and the team has managed to watch it move within its orbit for the first time.
- Confirming the picture demanded more than 100 hours of supercomputer processing, with telescopes in Western Australia, South Africa and Hawaii each filling in a piece.
- The sun-like companion is also erupting with flares, and the same radio data has revealed these stellar storms across more than 5,000 light-years.
- With about a dozen comparable systems now under suspicion, researchers are poised to scrutinise each one with the same method.
Somewhere more than 5,000 light-years away, two stars turn around one another in a quiet dance that has been running far longer than any human record: a collapsed white dwarf, the spent ember of a once-burning star, spinning with a regularity of eight minutes, and a yellow companion much like our own sun. Astronomers, working across Australia, South Africa and Hawaii, have now traced a rhythmic radio pulse to this pair, a pairing unlike those where such signals were usually found. It is a small addition to the long human effort to read the sky, yet it shows how faint messages from distant death and life can still be heard and understood.
On Friday, astronomers at Curtin University and the International Centre for Radio Astronomy Research announced that a radio signal pulsing every eight minutes has been traced to a pair of stars more than 5,000 light-years away. The system is catalogued as GPM J071507−114153.
One member is a white dwarf, the dead core of a once-active star, spinning once every eight minutes. Its companion is a G-type star, a yellow dwarf like our sun. Until now, such pulses had mostly turned up around red dwarfs, so this is the first time the signal has been linked to a star of this kind.
Dr. Sam McSweeney, who led the discovery, said the pulses are clear enough for the first time to show the white dwarf moving through its orbit. That motion helps reveal whether the signal comes from near the white dwarf or from the star itself. Confirming it took more than 100 hours of computing at the Pawsey Supercomputing Research Centre in Western Australia.
The search crossed three continents. The Murchison Widefield Array in Western Australia first caught the system while scanning the Milky Way, South Africa's MeerKAT pinpointed its position, and the W.M. Keck Observatory in Hawai'i confirmed the companion's identity.
The pulses also exposed flares on the sun-like star, similar to those that create auroras on Earth. Natasha Hurley-Walker of Curtin called it amazing that radio waves can reveal storms on a star so far away. The result points toward more work: the roughly dozen known systems of this kind now become candidates for similar scrutiny.
On Friday, astronomers at Australia's Curtin University and the International Centre for Radio Astronomy Research announced that a radio signal pulsing every eight minutes has been traced to a pair of stars more than 5,000 light-years from Earth. The system carries the catalogue name GPM J071507−114153.
The pair is an unusual one. One member is a white dwarf, the dead core of a star that was once active, and it spins once every eight minutes. Its companion is a G-type star, a yellow dwarf of the same general kind as our sun. According to the researchers, this is the first time such pulses have been detected from a system with a star like that. Until now, they have typically turned up in systems with red dwarfs, the smallest and coolest stars in space.
The discovery was made by Dr. Sam McSweeney, who said in a statement released alongside the new research that the pulses are clear enough, for the first time, to show the white dwarf moving in its orbit around its companion. That motion matters because it tells the team where the pulses originate: from a region close to the white dwarf, or possibly from the white dwarf itself.
Pinning that down took heavy computing. McSweeney and his colleagues processed more than 100 hours of data at the Pawsey Supercomputing Research Centre in Western Australia to confirm the white dwarf's movement within the system.
The finding fills a gap. Researchers had already found systems containing similar objects, with radio signals that switch on and off, but it was not clear which star in each system was producing the pulses. Around a dozen comparable systems have been found since the first, in 2021.
The work drew on telescopes across three continents. GPM J071507−114153 was first detected with the Murchison Widefield Array in Western Australia, which was scanning the Milky Way. Natasha Hurley-Walker, an associate professor at Curtin, said the team then used South Africa's MeerKAT radio telescope to determine the system's precise position. To confirm that the companion really was a G-type star, they turned to the W.M. Keck Observatory in Hawai'i.
The pulses also yielded something the team was not necessarily looking for. They allowed the scientists to detect stellar flares on the sun-like star, similar to the flares that produce auroras on Earth. Hurley-Walker said it was amazing that radio wavelengths can be used to detect storms on a star over 5,000 light-years away.
What the result points toward is more of the same kind of work: with the pulsing source now tied to a specific orbiting pair, and radio data shown capable of picking up stellar storms at that distance, the roughly dozen known systems become candidates for similar scrutiny.
Bemerkenswerte Zitate
The pulses are clear enough, for the first time, to see the white dwarf moving in its orbit, so they come from near the white dwarf or possibly from it.— Dr. Sam McSweeney, Curtin University (paraphrased)
It's amazing that using radio wavelengths we can detect storms on a star over 5,000 light-years away.— Natasha Hurley-Walker, associate professor, Curtin University
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Das Original lesen bei The Independent ↗