Astronomers Detect Radio Signals Directly From an Exoplanet for the First Time — And Its Magnetic Field Is Powerful

For decades, astronomers have studied planets beyond our solar system by observing how they affect their host stars. Now, scientists have achieved a major breakthrough: radio signals have been directly traced to an exoplanet itself for the first time.

The planet is β Pictoris b, a young and massive gas giant located about 64 light-years from Earth. Researchers detected faint, repeating radio bursts coming from the planet, providing a new way to study the invisible magnetic fields surrounding distant worlds.

The discovery could open an entirely new window into the interiors and environments of giant exoplanets.

A New Way to Study Distant Worlds

Exoplanets are planets that orbit stars beyond our Sun. Since the first confirmed discoveries in the 1990s, astronomers have identified thousands of these distant worlds.

However, studying an exoplanet directly is extremely difficult. Most are too far away and too faint to see clearly. Scientists often detect them indirectly by observing their effects on their host stars.

Radio observations provide another possibility.

Some planets produce radio waves through powerful auroras. On Earth, auroras such as the northern and southern lights occur when charged particles interact with the planet's magnetic field and upper atmosphere.

A similar process can occur on other planets—but on a much larger scale.

If scientists can detect those radio waves and determine exactly where they originate, they can potentially learn about the planet's magnetic field.

That is precisely what happened with β Pictoris b.

The Challenge: Where Did the Signal Come From?

Astronomers had previously detected radio emissions from some exoplanetary systems. However, there was an important problem: scientists couldn't confidently determine whether the radio waves were coming from the planet or from its host star.

The β Pictoris system presented an opportunity to solve that problem.

A team led by Kevin Ortiz Ceballos at the Center for Astrophysics | Harvard & Smithsonian used South Africa's MeerKAT radio telescope to observe the system.

MeerKAT consists of many radio antennas working together as a highly sensitive radio interferometer. By combining their observations, astronomers can determine the position of faint radio sources with great precision.

The researchers detected faint, repeating radio bursts from the β Pictoris system.

But detecting the signal was only the first step.

They needed to identify its exact source.

Using Distant Quasars as Cosmic Markers

To determine where the radio emission originated, the researchers used extremely distant objects called quasars as reference points.

Quasars are extraordinarily bright sources powered by material falling toward supermassive black holes in distant galaxies. Because they are extremely far away, their positions appear essentially fixed from our perspective.

The researchers used these distant quasars as cosmic reference markers to create an accurate map of the β Pictoris system.

They then compared the radio observations with the precise positions of the star and its known planet.

The result was striking.

When the researchers overlaid the radio data onto the positional map, the radio emission aligned with β Pictoris b rather than the parent star.

This allowed the team to identify the planet itself as the source of the radio emission.

The researchers described the observation as the first direct detection of auroral radio emission from an exoplanet.

What Is Creating the Radio Waves?

The discovery does not mean β Pictoris b is transmitting a message.

The radio waves are believed to be produced by auroral activity associated with the planet's magnetic field.

A magnetic field acts somewhat like an invisible shield and guide around a planet. Charged particles moving through space can become trapped or guided along magnetic field lines toward the planet's atmosphere.

When these energetic particles interact with gases in the upper atmosphere, they can produce auroras.

On Earth, this process creates spectacular displays such as the northern lights.

But auroral processes can also generate radio emission.

In the case of β Pictoris b, the detected radio bursts appear to provide evidence that the planet has an extremely strong magnetic environment.

A Surprisingly Powerful Magnetic Field

The radio observations allowed the researchers to estimate the strength of β Pictoris b's magnetic field.

Their calculations indicate a magnetic field of at least about 1,250 gauss in the region where the radio emission is produced.

For comparison, this is considerably stronger than the magnetic field of Jupiter, the most massive planet in our solar system.

The measurement is particularly important because magnetic fields are difficult to measure directly on exoplanets.

Scientists can estimate their existence through indirect effects, but actually connecting radio emission to a planet provides a powerful new method for investigating them.

The researchers described their result as the first direct measurement of magnetic field strength for an exoplanet.

Why β Pictoris b Is Special

β Pictoris b is not an ordinary gas giant.

It is a young, massive planet, and its youth makes it particularly interesting for scientists studying planetary evolution.

Young giant planets are expected to generate strong magnetic fields because their interiors can contain large amounts of hot, electrically conducting material.

The observed magnetic field strength is consistent with theoretical predictions for young, massive giant planets.

That agreement gives researchers an opportunity to test models describing how planetary magnetic fields are generated.

Magnetic fields are closely connected to what happens deep inside a planet. By studying them, scientists can potentially learn more about a planet's interior structure, temperature and evolution.

A New Tool for Exoplanet Science

The significance of this discovery goes beyond β Pictoris b.

If astronomers can detect similar radio emissions from other exoplanets, they could begin building a larger picture of how magnetic fields behave across different planetary systems.

That could help answer several important questions.

How do giant planets generate magnetic fields?

How does a planet's magnetic field change as it ages?

Why are some planetary magnetic fields stronger than others?

And how do magnetic fields protect or influence planetary atmospheres?

These questions are especially important when scientists study planets in environments very different from our own solar system.

Future radio observations could reveal more examples of auroral activity and allow researchers to compare magnetic fields across many different types of exoplanets.

Not an Alien Signal

The discovery may sound like something from science fiction, but there is no evidence that the radio emission is artificial or connected to extraterrestrial intelligence.

The signals are explained by a known natural process: auroras produced by interactions between charged particles, a planet's magnetic field and its atmosphere.

Nevertheless, the observation is remarkable because astronomers have now gained a direct radio view of a magnetic environment around a planet located dozens of light-years away.

A New Window Into Exoplanets

The discovery of radio emission directly from β Pictoris b represents an important step in the study of worlds beyond our solar system.

Instead of simply detecting an exoplanet through the shadow it creates or the gravitational effect it has on its star, astronomers can now study radio waves produced by the planet itself.

Those waves carry information about its magnetic field and potentially about its interior.

As radio telescopes become more sensitive, astronomers may be able to find similar signals from other distant planets. What began as a faint repeating radio burst could therefore become a powerful new technique for exploring the hidden magnetic environments of worlds across the galaxy.

Reference: Kevin N. Ortiz Ceballos et al., Discovery of radio emission from the exoplanet β Pictoris b, arXiv (2026), DOI: 10.48550/arxiv.2609.16720.