Astronomers for the first time directly recorded a radio signal from an exoplanet

Astronomers have for the first time directly recorded a radio signal from an exoplanet. Researchers have for the first time unequivocally linked radio emission to a planet outside the Solar System — gas giant Beta Pictoris b. This is stated in the preprint of astrophysicists from the Harvard-Smithsonian Center for Astrophysics and the University of Oregon on the arXiv platform.

Observations were carried out on the MeerKAT radio telescope array in South Africa during four sessions from 2025 to 2026 in the frequency range from 0.85 to 3.5 GHz. Astronomers recorded two types of signals: constant background radiation and fast repeating bursts with circular polarization. With the help of distant quasars, scientists accurately determined the coordinates of the source and confirmed that the signal comes from the planet Beta Pictoris b, and not from its parent star Beta Pictoris, located about 63 light-years from Earth.

The physical reason for the radio signal, scientists called electron-cyclotron maser instability (ECMI), which generates radio radiation of polar aurorae, similar to processes on Earth and Jupiter. Based on the maximum frequency of the signal, astronomers for the first time directly measured the intensity of the exoplanet's magnetic field — it was at least 1250 gauss (1.25 kilogauss), which is more than 2000 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 revolution around its axis in 8-9 hours. Fast rotation supports the generation of a powerful field. The authors of the work identified seven more planets in five neighboring systems that can be studied in the same way using next-generation radio telescopes.