For decades, astronomers had listened.
Nothing came back.
A peculiar class of young neutron stars known as central compact objects could be seen glowing brightly in X-rays inside the remains of exploded stars, yet repeated searches failed to find the regular radio pulses normally associated with pulsars.
That silence helped build a scientific assumption: perhaps these neutron stars simply did not produce radio emission.
South Africa’s MeerKAT telescope has now found one that does.
An international team detected faint, repeating radio pulses from the neutron star 1E 1207.4−5209, overturning the idea that central compact objects are necessarily radio-silent and suggesting that astronomers may have been overlooking a population of unusually quiet young pulsars. The study was published in Nature Astronomy on 25 June 2026.
The signal repeats roughly every 424 milliseconds.
That is the same rotation period previously measured from the star’s X-rays.
The object had been pulsing all along.
Astronomers simply needed an instrument sensitive enough to hear it.
The remains of a dead star
Neutron stars form when sufficiently massive stars reach the end of their lives and collapse during a supernova.
What remains is extraordinary: roughly a star’s worth of matter compressed into an object only tens of kilometres across.
Many neutron stars become pulsars.
Their magnetic fields channel radiation into beams that sweep through space as the star rotates. When one of those beams repeatedly crosses Earth, radio telescopes detect a remarkably regular pulse.
Central compact objects have been difficult to place within that picture.
They sit near the centres of young supernova remnants, making their youth obvious, and emit thermal X-rays. Yet major radio searches had repeatedly failed to detect them. Their magnetic fields also appear unusually weak compared with many young pulsars.
That created a puzzle.
Were they a fundamentally different kind of neutron star?
Or were they ordinary pulsars behaving in an unusual way?
MeerKAT has provided the strongest evidence yet for the second possibility.
Finding an extraordinarily faint pulse
The researchers used MeerKAT to conduct deep observations of several central compact objects.
During a four-hour observation on 5 January 2024, 60 MeerKAT dishes observed 1E 1207.4−5209 at radio frequencies between 544 and 1,088 MHz. Further observations followed in October 2025 using both MeerKAT’s UHF and L-band receivers.
The team then searched the data for repeating signals.
A faint pulse appeared at precisely the expected rotation period.
Polarisation measurements provided another important piece of evidence. They indicated that Earth’s line of sight passes relatively close to the neutron star’s magnetic pole. That makes it less likely that astronomers had previously missed the signal simply because its radio beam pointed elsewhere.
The star really is extremely faint at radio wavelengths.
That helps explain why previous telescopes failed to detect it.
A young star that can look incredibly old
The discovery also exposes an unusual problem in how astronomers estimate the ages of pulsars.
A pulsar gradually slows as it rotates. Astronomers can use its current rotation and the rate at which that rotation is slowing to calculate a characteristic age.
For ordinary pulsars, that estimate can provide useful information about their evolutionary stage.
This object breaks the neat relationship.
It sits inside a young supernova remnant, yet its weak magnetic field and slow rate of rotational change could make it appear billions of years old if astronomers discovered it after the surrounding remnant had faded away.
A genuinely young neutron star could therefore be hiding in a catalogue among apparently ancient pulsars.
And if one exists, others may too.
The authors argue that the extreme faintness of central compact objects could help explain another astronomical mystery: why many known supernova remnants contain no detectable radio pulsar at their centres.
Some may not be empty.
Their pulsars may simply be whispering.
Did the star recently switch on?
There is still an unresolved possibility.
1E 1207.4−5209 experienced an unusual rotational glitch around 2015 — a sudden small change in the way the neutron star spins.
Researchers have raised the possibility that this event changed the star’s magnetosphere and either activated or strengthened its radio emission.
At present, that remains a hypothesis.
There are no sufficiently sensitive radio observations from before the glitch capable of demonstrating whether the star was already transmitting.
Continued monitoring will be needed to determine whether central compact objects are permanently faint radio pulsars or whether their emission can change during their evolution.
A discovery made possible in South Africa
There is a particularly direct South African connection to this result.
MeerKAT is operated by the South African Radio Astronomy Observatory, a facility of the National Research Foundation under the Department of Science and Innovation. South African astronomer Fernando Camilo of SARAO was also part of the international research team.
The discovery illustrates what extreme telescope sensitivity can change.
For years, the absence of a detectable signal helped shape the scientific model of an entire class of neutron stars.
MeerKAT did not find a louder universe.
It listened more carefully to the one that was already there.
And in doing so, it revealed that some supposedly silent stars may simply be much harder to hear than astronomers realised.
Source Information
Study Title: Pulsed radio emission from a central compact object
Authors: Lei Zhang, Alessandro Ridolfi, Di Li, Erbil Gügercinoğlu, Fernando Camilo, Wynn C. G. Ho, Matthew Bailes, Ping Zhou, Craig O. Heinke and Marcus E. Lower
Journal: Nature Astronomy
Published: 25 June 2026
DOI: 10.1038/s41550-026-02899-2
