Astronomers have directly detected repeating auroral radio emissions from Beta Pictoris b, a young gas giant located roughly 63 light-years away, marking the first time radio signals have been unequivocally traced to a planet outside our solar system rather than its host star.
Researchers operating South Africa’s MeerKAT radio telescope array captured the historic signals after studying the planetary system across observing sessions through 2025 and early 2026. Led by Kevin N. Ortiz Ceballos of the Center for Astrophysics | Harvard & Smithsonian, alongside collaborators at the University of Oregon, the team detailed their findings in a preprint posted to arXiv on September 15, 2026.
MeerKAT Array Isolates Signals From Beta Pictoris b
For decades, radio searches for exoplanets faced an insurmountable hurdle: distinguishing faint signals from an orbiting world versus the blindingly bright emissions of its host star. The team surmounted this challenge by using the known coordinates of distant quasars as celestial lighthouses to triangulate the exact spatial origin of the radio waves.
By comparing these radio images against the stellar system, the analysis confirmed the source aligned precisely with the exoplanet at 4.4σ significance, ruling out the host star. The array’s 64 interlinked dishes recorded rapid, recurring bursts and persistent emission across frequencies ranging from 0.85 to 3.5 gigahertz.
“Here, we report the first direct detection of auroral radio emission from an exoplanet, the giant planet Beta Pictoris b, with the MeerKAT array.”
Kevin N. Ortiz Ceballos and research collaborators, via arXiv preprint
Magnetic Fields and Auroral Physics on a Distant Gas Giant
The captured radio waves exhibited strong circular polarization and rapid variability, signatures that physicists recognize as electron cyclotron maser radiation. This same coherent physical process drives auroral activity on Earth and each of the four giant planets in our solar system, where energetic electrons spiral along magnetic field lines to produce intense natural radio bursts.
Because higher emission frequencies correlate with stronger magnetic fields, the detected peak frequency allowed scientists to calculate a lower bound for the planet’s magnetism. Astronomers deduced that Beta Pictoris b possesses a magnetic field of at least 1,250 gauss at the radio-emitting region, which is more than 300 times as strong as that of Jupiter’s.
Harvard University physicist Avi Loeb noted that the phenomenon is entirely natural rather than artificial, comparing it directly to Earth’s northern lights where charged particles collide with upper atmospheric gases.
Implications for Planetary Habitability and Future Exoplanet Searches
While Beta Pictoris b itself is a massive, young gas giant orbiting a star only about 23 million years old and lacking a solid surface, establishing a direct measurement of exoplanetary magnetic strength provides a crucial missing variable in planetary science. Magnetospheres act as planetary shields, deflecting stellar winds and protecting atmospheres from being stripped away over geological time.
Astronomer Yvette Cendes pointed out that the measured field is much stronger than anything found in our solar system. Applying this observational method to smaller, rocky worlds in future studies will give researchers a new tool to assess whether distant exoplanets can retain atmospheres and sustain liquid water.
With seven other directly imaged giant planets located within roughly 147 light-years offering potential targets, astronomers anticipate that next-generation radio observatories—potentially five to seven times more sensitive than current arrays—will soon expand the catalog of detected exoplanetary magnetic fields.