Possible Radio Emissions Detected From Exoplanet Beta Pictoris b

Approximately 63 light-years away, Beta Pictoris is a very young planetary system—less than 1 percent as old as our solar system. Astronomers believe it contains a star more massive than the Sun, three giant planets, and a vast disk of dust and debris.

The system’s central planet, Beta Pictoris b, is a gas giant several times more massive than Jupiter. Because it is a gas giant, it is unlikely to have a solid surface on which to “land.” At only tens of millions of years old, it is considered a newborn planet in astronomical terms.

Beta Pictoris b is also one of the most extensively studied exoplanets through direct observations. Its youth keeps it hot and bright, while its orbit—roughly comparable to the distance between the Sun and Saturn—makes it possible to distinguish the planet from its star with a sufficiently powerful telescope.

Astronomers trace radio waves to an exoplanet

A new study by researchers at Harvard University and the University of Oregon claims that Beta Pictoris b is a source of something never before clearly detected on another world: radio radiation.

The signal was recorded by the MeerKAT radio telescope in South Africa. The researchers say it is likely natural in origin—not evidence of aliens. Their preprint has not yet been peer-reviewed, but the authors present evidence that the radio source may be linked to strong magnetic activity on the young gas giant.

The properties of the radio waves match theoretical predictions for magnetic fields produced by young giant planets. Charged particles can become trapped in a planet’s powerful magnetic field. As the planet rotates, those particles can accelerate and release energy as radio waves.

This phenomenon is known as auroral radio emission. In a sense, it is the soundless equivalent of Earth’s magnetosphere “screaming” into space.

Why the signal matters

For the first time, the research team says it was able to detect these radio emissions and trace their source directly to an exoplanet. That is an observation scientists have been working toward for many years.

An image of the debris disk around Beta Pictoris taken in 1984.

Photo: Bradford A. Smith / Richard J. Terrill / NASA-JPL