Astronomers directly detect exoplanet radio signal for first time

The observations were conducted on the MeerKAT radio telescope array in South Africa across four sessions between 2025 and 2026 in the frequency range of 0.85 to 3.5 GHz. The astronomers detected two types of signals: steady background emission and rapid, repeating bursts with circular polarization. Using distant quasars, the scientists precisely pinned down the coordinates of the source and confirmed that the signal originates specifically from the planet Beta Pictoris b, rather than from its host star Beta Pictoris, located about 63 light-years from Earth.

The scientists identified electron cyclotron maser instability (ECMI) as the physical cause of the radio signal, which produces auroral radio emissions similar to processes on Earth and Jupiter. Based on the maximum frequency of the signal, the astronomers directly measured the magnetic field strength of an exoplanet for the first time, finding it to be at least 1,250 gauss (1.25 kilogauss), which is more than 2,000 times stronger than Earth's.

The object under study is a young, massive gas giant about 10–12 times heavier than Jupiter, making a full rotation on its axis in 8–9 hours. The rapid rotation sustains the generation of the powerful field. The authors of the study identified another seven planets across five neighboring systems that could be investigated using this method with next-generation radio telescopes.