SPACE/COSMOS
Sydney astronomers pinpoint the most distant fast radio burst ever detected
Record-breaking cosmic signal offers a rare glimpse of the early Universe
image:
Dr Manisha Caleb (left) and Dr Themiya Nanayakkara in a physics lecture hall at the University of Sydney.
view moreCredit: Stefanie Zingsheim/University of Sydney
Astronomers have detected and traced the most distant fast radio burst ever recorded, a powerful flash of radio waves that travelled for more than 10 billion years across the cosmos before reaching Earth.
Fast radio bursts (FRBs) are among the most mysterious objects in astronomy. Lasting only milliseconds, they release enormous amounts of energy but their origins remain uncertain.
The discovery, led by researchers Dr Manisha Caleb and Dr Themiya Nanayakkara from the University of Sydney, is published today in the prestigious journal Science.
The MeerTRAP project used South Africa’s MeerKAT radio telescope to detect the burst, designated FRB 20240304B, before identifying its host galaxy using observations from NASA’s James Webb Space Telescope.
The burst originated when the Universe was only about three billion years old, making it the most distant FRB yet detected and more than doubling the previous distance record. The finding gives astronomers a powerful new way to study both the evolution of galaxies and the vast, otherwise invisible matter that fills the space between them.
“This is an extraordinary glimpse into the distant Universe,” said Dr Caleb from the Sydney Institute for Astronomy in the School of Physics.
“We have caught a fast radio burst from a time when the Universe was only about three billion years old, and we have used that brief flash of radio light to learn about the matter it has travelled through over billions of years.”
By combining sensitive radio observations with powerful infrared imaging and spectroscopy, the team was able to detect not only the burst but also identify the galaxy that produced it.
The host galaxy turned out to be an unexpected source.
“The galaxy hosting this burst is surprisingly small, metal-poor and undergoing a very active episode of star formation,” said Dr Laura Driessen, a co-author at the University of Sydney.
“That gives us an important clue about the environments in which FRBs are born and shows that these brief radio flashes can tell us not only about the distant Universe, but also about how galaxies and their stellar populations evolve.”
The research provides fresh evidence that at least some FRBs may originate from young magnetars, highly magnetised neutron stars formed when massive stars explode in a supernova. The newly discovered host galaxy is young and vigorously forming stars, characteristics more consistent with magnetar formation than alternative theories involving the merger of older neutron stars.
The result pushes the boundaries of how far astronomers can use fast radio bursts as probes of the Universe.
“In principle, sufficiently powerful bursts could be detectable from the very early Universe,” said Kavya Shaji, a co-author and a PhD student in the School of Physics.
Dr Caleb said: “What is particularly exciting about our result is that we’ve now demonstrated that we can identify and study an FRB from when the Universe was young.”
Co-author Professor Ben Stappers from the University of Manchester is also Principal Investigator of the MeerTRAP project at the MeerKAT telescope. He said: “The next step is to push this frontier further and see how close we can get to the first generations of stars.”
The host galaxy was invisible to the largest ground-based telescopes, requiring the unique capabilities of the James Webb Space Telescope to pinpoint it and measure its distance.
“Our results further show the amazing capability of the Webb space telescope where we can push boundaries beyond what was previously possible,” said Dr Nanayakkara, who recently joined the University of Sydney.
Beyond setting a new distance record, the burst acted as a cosmic beacon, illuminating the vast reservoirs of gas and matter between galaxies. As the radio signal travelled across most of cosmic history, it carried information about the material it encountered along the way, allowing researchers to study structures that are otherwise difficult to observe directly.
The discovery further shows the University of Sydney’s international leadership in radio astronomy. In 2023, University astronomers were also involved in the discovery of what was then the most-distant fast radio burst, a record now surpassed by FRB 20240304B.
The finding was made using the MeerKAT telescope in South Africa, one of the world’s most powerful radio astronomy facilities and a precursor to the SKA Observatory under construction in Australia and South Africa. University of Sydney researchers are playing leading roles in the scientific programs that will be enabled by the SKA, which is expected to transform understanding of the Universe through unprecedented radio observations.
DOWNLOAD artwork, the research and photos of the researchers at this link.
INTERVIEWS
Dr Manisha Caleb | manisha.caleb@sydney.edu.au | +61 402 119 535
Dr Themiya Nanayakkara | themiya.nanayakkara@sydney.edu.au | +61 404 220 289
MEDIA ENQUIRIES
Marcus Strom | marcus.strom@sydney.edu.au | +61 474 269 459
Outside of work hours: please call +61 2 8627 0246 (directs to a mobile number) or email media.office@sydney.edu.au.
RESEARCH
Caleb, M. et al ‘A fast radio burst at redshift 2, three billion years after the Big Bang’ (Science 2026). DOI: 10.1126/science.adz2675
DECLARATION
The authors declare no competing interests.
The work was supported by funding from the Australian Research Council, European Research Council, Science and Technology Facilities Council (UK) and the National Science Foundation (USA). A full list of funders is available in the paper.
The MeerKAT telescope is operated by the South African Radio Astronomy Observatory (SARAO), which is a facility of the National Research Foundation, itself an agency of the Department of Science and Innovation. The MeerTRAP collaboration acknowledges funding from the European Research Council under the European Union's Horizon 2020 research and innovation program.
Artist's illustration representing the detection of FRB 20240304B
Credit
Carl Knox/OzGrav, Swinburne University of Technology
Dr Themiya Nanayakkara (left) and Dr Manisha Caleb in the School of Physics offices at the University of Sydney.
Credit
Stefanie Zingsheim/University of Sydney
Journal
Science
Method of Research
Observational study
Subject of Research
Not applicable
Article Title
A fast radio burst at redshift 2, three billion years after the Big Bang
Article Publication Date
8-Oct-2026
COI Statement
The authors declare no competing interests.
Discovery marks the first detection of variable water clouds outside of our solar system
University of Arizona
image:
Artist's concept of a brown dwarf. Brown dwarfs begin their lives like stars but they never accumulate enough mass to fuse atoms steadily at their cores and ignite with starlight.
view moreCredit: NASA/JPL-Caltech
A Jupiter-sized world just 7.5 light-years away is cloudy, chemically complex, and, it turns out, more like home than anyone expected.
Using the James Webb Space Telescope, Brittany Miles, assistant astronomer at University of Arizona Steward Observatory, led a team that spent 11 hours staring at WISE 0855, the coldest known brown dwarf, collecting a spectrum of its light every 15 minutes. The result is the most detailed time-series portrait ever taken of this frigid world – and the first direct confirmation that water clouds on another body are changing thickness over time, just like weather on Earth.
The study, published in The Astrophysical Journal, reveals that WISE 0855's atmosphere is shaped by at least two distinct processes playing out simultaneously: water clouds at high altitudes that grow thicker and thinner as the object rotates, and deep chemical gases being dredged upward by convection from far below. Untangling those two signals – previously impossible with older telescopes – is what makes JWST data so powerful.
"This is the first time we've been able to confirm that water clouds are becoming thinner and thicker on a nearby world," said Miles, a postdoctoral researcher at Steward Observatory. "Before JWST, we only had photometry, which mixed up the effects of clouds, chemistry, and temperature all together. Now we can actually distinguish them."
Brown dwarfs occupy a strange middle ground. Too massive to be planets, too small to ignite as stars, they glow dimly with leftover heat from their formation. WISE 0855, at roughly 265 Kelvin – colder than Earth's surface – sits at the very bottom of that category, blurring the line further. At about twice Jupiter's mass and nearly the same size, it looks and behaves, in many ways, like a free-floating giant planet.
Understanding its atmosphere requires looking at the world through what co-author Mark Marley, director and department head of the Lunar and Planetary Laboratory at U of A, describes as a kind of screen door. "The photons go through the atmosphere and escape to space," Marley said. "It's like looking at the world through a screen door, where the screen is filtering out some of the light. We're learning about the world on either side of the screen – but we also have to understand the screen itself."
In this case, the screen keeps changing. As WISE 0855 rotates, different patches of its surface rotate into view, each with slightly different cloud cover and temperature, like watching a slowly turning patchwork of warmer and cooler regions. JWST's medium-resolution spectrograph was sensitive enough to track those differences across individual molecular features – something no prior observatory could achieve for an object this cold. In addition to the variable temperatures that followed the rotation of the brown dwarf, the spectrograph also captured a rhythmic, wave-like signal tied to specific gases: carbon monoxide and phosphine. Those chemicals fluctuate because heat from deep inside the brown dwarf is constantly churning them upward toward the surface, the same way a pot of hot soup pushes warmer liquid up from the bottom.
This kind of chemical signal is familiar to planetary scientists. On Jupiter, convective mixing dredges gases from deep, hot layers up into the visible atmosphere. The same process, called disequilibrium chemistry, has been observed in brown dwarfs before – but watching it vary in real time, molecule by molecule, is new territory.
"We're seeing water clouds getting thicker and thinner, and deep gases rising and falling, and we can actually watch them change in real time," Miles said.
Miles says that the real value of this discovery isn't just what it tells us about WISE 0855 specifically, but what it suggests about planetary atmospheres more broadly. The basic physics of convection, clouds and chemistry that governs Jupiter also govern this cold, free-floating world more than seven light-years away. If that physics is universal, it applies to the gas giant exoplanets that astronomers are now beginning to study in earnest with JWST.
"Even though brown dwarfs are not true planets, they exhibit planet-like behavior," Miles said. "There is a spectrum of behaviors – not a hard line between brown dwarfs and planets. Jupiter and this object look distinctly different, but they have similar weather patterns. There are basic physics and chemistry that can be applied across all of these worlds."
For Miles, whose models were built on foundational work by theorists like Marley – whose atmospheric models were themselves benchmarked against Jupiter – the paper is as much a generational milestone as it is a discovery. "A lot of my physical intuition on what is missing from the models is because of Mark's mentorship and hard work," she said. "This is a multi-year project. A lot of people contributed to make sure this could be done right."
Miles looks ahead to logging more hours of baseline observations with JWST to pin down further details about WISE 0855's rotation and the three-dimensional nuances of its atmospheric movement. For now, the message is clear: weather happens everywhere, and some of our closest neighbors have skies worth watching.
Journal
The Astrophysical Journal
Method of Research
Computational simulation/modeling
Article Title
Water Cloud and Chemical Modulations in the Coldest Brown Dwarf
