Astronomers have, for the first time, traced radio signals directly to a planet outside our solar system. And no, it is not aliens.

Using the MeerKAT radio telescope, researchers localised natural auroral radio emissions to the exoplanet Beta Pictoris b. The planet is about 63 light-years from Earth.

The signals come from the planet's aurora, similar to the northern lights on Earth. Charged particles from the star interact with the planet's magnetic field and produce radio waves.

This is a milestone because it shows scientists can directly detect a planet's magnetic field from light-years away. Magnetic fields are important: they can protect a planet's atmosphere and are one factor in whether a world could support life.

The findings are in a preprint paper and have not yet been peer-reviewed. Researchers will now look for similar signals from other planets.

The team stressed the signal is natural. It is a strong reminder that strange cosmic signals usually have ordinary explanations.