Scientists think they’ve detected radio emissions from an alien world
For the first time, scientists may have detected radio waves from a planet orbiting a star beyond our sun.
The new study used a radio telescope in the Netherlands to study three different stars believed to host exoplanets. The researchers compared what they saw to Jupiter observations that had been diluted as if seen from a star system thousands of light-years away. Tau Boötes, a star system with at least one exoplanet, stood out. If the detection holds up, it could open the door to a better understanding of the magnetic fields of exoplanets and therefore the exoplanets themselves, the researchers hope.
“We present one of the first hints of detecting an exoplanet in the radio realm,” Jake Turner, an astronomer at Cornell University and lead author of the new research, said in a statement. “We make the case for an emission by the planet itself. From the strength and polarization of the radio signal and the planet’s magnetic field, it is compatible with theoretical predictions.”
However, Turner and his colleagues aren’t yet positive that the signal they detected really is coming from the planet, dubbed Tau Boötes b; the researchers called for additional observations of the system, which is about 51 light-years away from Earth in the constellation Boötes.
The recent study started with Jupiter; the researchers had previously investigated the planet’s radio emissions and then modified those measurements to reflect the effect they believed closeness to the host star and distance from Earth would have on their observations of an exoplanet.
The scientists then consulted observations made by the Low Frequency Array (LOFAR) in the Netherlands in 2016 and 2017. In addition to the potential signal from Tau Boötes b, the researchers claim to have detected a signal from the star Upsilon Andromedae or its planet, however the detection was even fainter than the one from Tau Boötes b.
The researchers are interested in detecting radio emission from planets since such information could help scientists decipher what’s going on in the magnetic fields of the same worlds. These magnetic fields, in turn, influence conditions on the planet’s surface; for example, the Earth’s magnetic field protects the atmosphere that allows us to survive. Such magnetic fields can also reveal information about a world’s structure and history to scientists.
An artist’s depiction of the exoplanet Tau Boötes b displays a magnetic field, which scientists believe is responsible for the radio emissions they believe they have detected. (Image credit: Jack Madden/Cornell University)
Yet, despite the fact that nearly every planet in our solar system has had one at some point in its history, scientists have found it difficult to study those magnetic fields directly. Hence the interest in using radio emissions as an intermediate.
“We learned from our own Jupiter what this kind of detection looks like,” Turner said. “We went searching for it and we found it.”
But that’s just the beginning of the story, not the end of it, he emphasized, since the radio emissions could still be coming from the stars or another source instead of the planet. “There remains some uncertainty that the detected radio signal is from the planet. The need for follow-up observations is critical.”
The findings of the study are described in a manuscript that will be published in the journal Astronomy & Astrophysics and is already available online.