Astronomers have reported the first convincing direct detection of radio emissions localized to a planet outside the solar system. The signal comes from the giant exoplanet Beta Pictoris b, located about 63 light-years from Earth, and is most likely generated by powerful auroras in its magnetic field.
The discovery is not related to the search for artificial signals from an extraterrestrial civilization. The radio waves are naturally occurring and give scientists something equally valuable: the ability to directly measure the strength of an exoplanet's magnetic field for the first time.
The study was led by Kevin Ortiz Ceballos, Edo Berger, and Yvette Sendes of the Harvard-Smithsonian Center for Astrophysics and the University of Oregon. It was published as a preprint on arXiv on September 15, 2026, and is still awaiting peer review.
The team used the South African radio interferometer MeerKAT and recorded fast, repetitive, and highly circularly polarized radio bursts, as well as more persistent emission between 0.85 and 3.5 GHz.
Scientists have picked up radio signals from an exoplanet for the first time ever. The source is Beta Pictoris b, a gas giant around 63 light-years away and about 10 times Jupiter’s mass. It isn’t aliens: the emissions are natural, caused by charged particles hitting the planet’s… pic.twitter.com/iGooeacDK2
— SNN Finland (@snnfinalnd) September 25, 2026
The key result is the location of the source. After precise astrometric correction, the radio emission coincides with the position of Beta Pictoris b. According to the analysis, it is inconsistent with the position of the star Beta Pictoris at 4.4 sigma and with that of the inner planet Beta Pictoris c at 4.8 sigma. This is what distinguishes the observation from earlier candidate signals from other exoplanet systems, where it was not possible to conclusively determine whether the radio waves came from the planet or its star.
The characteristics of the signal point to the so-called electron cyclotron maser instability, or ECMI. The same physical mechanism is behind some of the powerful auroral radio emission from planets in the solar system.
Magnetic field at least 2,500 times stronger than Earth's
The frequency of this radio emission is directly related to the strength of the magnetic field in the area where it is generated. Observations show that in Beta Pictoris b it is at least about 1.25 kilogauss, or 1,250 gauss. For comparison, the Earth's magnetic field at the surface is on the order of half a gauss.
This means that the measured field in the radio emission region is at least about 2500 times stronger than the characteristic Earth field. It is also over 100 times stronger than the characteristic values for Jupiter.
The result is important because magnetic fields contain information about the internal structure and dynamo of planets. They also affect the interaction with the stellar wind and the loss of atmosphere. Until now, astronomers have relied mostly on theoretical estimates of the magnetic fields of exoplanets.
The extremely strong field of Beta Pictoris b is actually consistent with expectations for a young, massive, and rapidly rotating gas giant.
Beta Pictoris b was discovered by direct imaging in 2008. The planet is a gas giant with a mass of approximately 9 to 12 times that of Jupiter and orbits its star at a distance of about 10 astronomical units. One of its years lasts approximately 24 Earth years.
Of particular interest is the speed at which the planet rotates on its axis. Previous spectroscopic measurements give a period of about 8–9 hours, despite its enormous size. Some of the new radio bursts are also separated by roughly eight hours, raising the possibility that the polar radio sources periodically appear and disappear from view as the planet rotates.
But this is where scientists remain cautious. Astronomer Joe Cullingham, who was not involved in the study, told Science News that the evidence is compelling, but seeing a clear, repeating modulation associated with the roughly eight-hour rotation would make the auroral interpretation even stronger.
The Beta Pictoris system is one of nature's most valuable “laboratory experiments” for studying young planetary systems. The star is significantly younger than the Sun and is surrounded by a huge disk of dust and debris left over from planet formation.
In July 2026, astronomers also announced the discovery of a third planet in the system, Beta Pictoris d. It is a gas giant with a mass about 2.4 times that of Jupiter and orbits approximately 26 astronomical units from the star. The planet is about 100 times fainter in brightness than Beta Pictoris b and is among the faintest exoplanets directly imaged by ground-based telescopes. The discovery was also independently confirmed by spectroscopic observations with the James Webb Space Telescope.
Therefore, today three planets are known around Beta Pictoris: b, c and d. Beta Pictoris b is already of particular interest to astronomy not only because it can be observed directly, but also because radio waves allow its magnetic environment to be probed.
If the result is confirmed by independent observations and peer-reviewed, radio astronomy could become a new way to study the magnetic fields of distant worlds. This would allow scientists to study the internal structure, rotation, and interactions of exoplanets with their stars through a characteristic that has so far been virtually impossible to measure directly.