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Astronomers Detect Radio Waves From Exoplanet Beta Pictoris B
Confirmed
In Short: Astronomers have detected radio waves from an exoplanet, marking the first direct measurement of an exoplanet's magnetic field. The discovery was made using South Africa's MeerKAT radio telescope.
Astronomers have detected radio waves from an exoplanet, marking the first direct measurement of an exoplanet's magnetic field. The discovery was made using South Africa's MeerKAT radio telescope.
The radio signals originated from Beta Pictoris B, a gas giant roughly 12 times the mass of Jupiter, orbiting a young star about 63 light-years away.
Previously, radio signals from exoplanets were only inferred from their stars. This new detection directly links the signals to the planet itself.
The radio waves are believed to come from auroras on Beta Pictoris B, similar to Earth's Northern Lights, where charged particles interact with the planet's magnetic field.
Astronomer Yvette Cendes clarified, “When people see ‘radio signal from an exoplanet,’ they think aliens,” but emphasized that this finding is unrelated to extraterrestrial life.
The radio waves detected are highly circularly polarized, meaning they corkscrew through space rather than oscillate in a single plane.
This phenomenon, known as electron cyclotron maser instability (ECMI), occurs when energetic electrons spiral through a strong magnetic field, emitting coherent radio waves.
This discovery could lead to a better understanding of exoplanet environments and their potential to support life.
What this adds
The detection of radio waves from an exoplanet's auroras is a significant breakthrough in exoplanet research.
The circular polarization of the radio waves provides a unique signature that distinguishes them from other celestial phenomena.
What's confirmed
- But, the experts write, “no physical mechanism known to cause radio emission in early-type stars can explain the observed emission”.
What's still developing
- Astronomers have been listening for radio signals and other signs of life and activity for decades now.
- And while it’s not linked to life on another planet, a team from the Centre for Astrophysics Harvard & Smithsonian and the University of Oregon has announced an exciting first: they’ve picked up on radio signals that come directly from an exoplanet, or a planet beyond our solar system.
- The researchers found signals near Beta Pictoris B using South Africa’s MeerKAT radio telescope, and later narrowed its location down to the specific planet it likely belongs to by looking at active galaxy cores called quasars.
- That’s been a major hurdle for previous efforts to find radio waves from exoplanets.
- Auroras are the source of Earth’s northern lights, and they also occur on other planets in the solar system, including Saturn, Jupiter and Mars.
- The astrometric localization that separates this paper from all prior work required anchoring the radio image to an independent celestial reference frame.
- The 8-hour gap between the first and third radio bursts detected in the L-band session is consistent with the planet's rotation period, suggesting the rotationally modulated aurora bursts are spinning in and out of the line of sight as the planet turns.
- The research team — Ortiz Ceballos and Berger at the Center for Astrophysics | Harvard & Smithsonian and Cendes at the University of Oregon — used the MeerKAT radio telescope array in South Africa to observe the Beta Pictoris system on four MeerKAT observation sessions between February 2025 and May 2026.
- Because the highest-frequency radio waves a planet can emit are set by its peak magnetic field strength, the maximum detectable emission frequency functions as a direct read-out of field strength — no model required, no assumptions about interior structure needed.
- But that same feature can happen on other surfaces - famously gold has a “glint” when seen from the right angle.
- But most of what makes up exoplanets, like sand, and rock, and soil, doesn’t glint.
- When seen from straight above, light mostly penetrates straight down, or reflects weakly.