Astronomers have detected radio emissions originating directly from a planet outside the solar system for the first time, according to a scientific preprint posted in September. Using the MeerKAT radio telescope array in South Africa, researchers traced the signals to Beta Pictoris b, a young gas giant located approximately 63 to 64 light-years from Earth.
The research team, which includes scientists from the University of Oregon and the Center for Astrophysics | Harvard & Smithsonian, identified persistent emissions and rapid, recurring radio bursts at frequencies between 0.85 and 3.5 gigahertz. The researchers determined the signals were not from an artificial source or an attempt at alien communication, but were instead produced by auroras associated with the planet’s magnetic field.
Locating the Radio Source
Distinguishing whether radio radiation comes from a planet or its host star has historically been difficult for scientists. To resolve this, the team utilized a method comparing radio images with the fixed positions of background quasars. By plotting the precise locations of the host star and the exoplanet against these markers, the researchers found that the signals aligned with the position of Beta Pictoris b.
Magnetic Field Measurements
The detected signals, which were strongly circularly polarised, allowed researchers to perform what they describe as the first direct measurement of magnetic-field strength for an exoplanet. They calculated that the field in the emission region is approximately 1,250 gauss (or 1.25 kilogauss).
Co-author Yvette Cendes of the University of Oregon described the field as “incredibly, incredibly strong,” noting it is much stronger than any found in our solar system, including those of Earth and Jupiter. This strength is attributed to the planet’s mass, which is roughly 10 times that of Jupiter, making it comparable to brown dwarfs.
Planet Characteristics and Status
Beta Pictoris b is a massive gas giant in a young planetary system characterized by a large disk of debris and dust. Due to its brightness, youth, and wide orbit, it has become one of the most extensively observed directly imaged exoplanets. The findings remain preliminary and have not yet undergone peer review or independent confirmation.
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