Staff Reporter
ASTRONOMERS have detected radio signals directly from an exoplanet for the first time, using South Africa’s MeerKAT radio telescope to identify auroral radio bursts from the giant planet Beta Pictoris b, located about 63 light-years from Earth.
The discovery provides the first direct measurement of a magnetic field on a planet outside our Solar System, with scientists estimating that Beta Pictoris b has a magnetic field of at least 1.25 kilogauss, several thousand times stronger than Earth’s.
Beta Pictoris b is a gas giant with a mass estimated at between nine and 13 times that of Jupiter. It was first discovered in 2008 by astronomers using the European Southern Observatory’s Very Large Telescope.
PICTURED: The MeerKAT radio telescope array in South Africa’s Northern Cape. Photo: MeerKAT
PICTURED: Short, repeated radio bursts detected from planet Beta Pictoris b. Credit: Ceballos et al., arXiv, 2026.
The planet orbits its star, Beta Pictoris, at a distance about ten times greater than the distance between Earth and the Sun. The system also contains at least two other planets and a large disc of gas and dust that could eventually develop into a belt of icy objects similar to the Kuiper Belt around our Solar System.
The Beta Pictoris system is located in the constellation Pictor and is estimated to be about 23 million years old, making it relatively young compared with our Solar System.
Using the MeerKAT radio telescope array in South Africa, the researchers detected rapid, repeated radio bursts from Beta Pictoris b, along with continuous radio emission. The signals were detected at frequencies between 0.85 and 3.5 GHz and were strongly circularly polarised.
The researchers linked the radio emission to a process known as electron cyclotron maser instability. This process is also responsible for auroral radio emissions from planets in our Solar System, including Earth, Jupiter, Saturn, Uranus and Neptune.
Auroras are produced when charged particles interact with a planet’s magnetic field and atmosphere. The radio signals therefore provide information about the planet’s magnetic field, which cannot be seen directly.
“The most massive planet in the system, Beta Pictoris b, reaches an angular separation of up to 0.55’’ across its 24-year orbit, and the host star is magnetically quiet, making the system an ideal target for radio observations,” said Kevin Ortiz Ceballos of the Harvard & Smithsonian Center for Astrophysics and his colleagues.
The researchers said the radio emission is caused by interactions between the planet’s magnetic field and its upper atmosphere.
Because the highest frequency of this type of radio emission is directly linked to the strength of the magnetic field, the detection allowed the researchers to estimate a minimum magnetic field strength of about 1.25 kilogauss for Beta Pictoris b.
“This constitutes the first direct measurement of magnetic field strength for an exoplanet, and is consistent with dynamo-scaling predictions for a young, massive giant planet,” the researchers said.
The findings were submitted on 15 September 2026 in a study titled “Discovery of radio emission from the exoplanet β Pictoris b” by Kevin N. Ortiz Ceballos, Edo Berger and Yvette Cendes.
