Let me preface this next story with an important caveat: the story you are about to hear is not about aliens. I repeat: this story is NOT about aliens.

But it is about a radio signal from an exoplanet.

A team of researchers led by Jake Turner of Cornell University recently published a new paper in Astronomy & Astrophysics that explains how they detected a radio emission from an exoplanet in the Tau Boötes system, some 51 light-years away. This detection is another of those “the observation matched the theory” bits of science we delight in around here.

Turner explains: The signal is from the Tau Boötes system, which contains a binary star and an exoplanet. 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.

To make this detection, the team first turned their radio eyes toward Jupiter to observe our largest planet’s radio emissions. Then they scaled up those emissions to give themselves a baseline for detecting a similar planet in a distant system, between 40 and 100 light-years away. With that information in hand, Turner and his colleagues poured through almost 100 hours worth of observations from the Low Frequency Array (LOFAR) in the Netherlands, eventually finding the signature of a hot Jupiter in Tau Boötes.

Turner goes on to explain: Observing an exoplanet’s magnetic field helps astronomers decipher a planet’s interior and atmospheric properties, as well as the physics of star-planet interactions. The magnetic field of Earth-like exoplanets may contribute to their possible habitability by shielding their own atmospheres from solar wind and cosmic rays, and protecting the planet from atmospheric loss.

I should note, of course, that there is some uncertainty with this detection, and follow-up observations are planned using multiple radio telescopes. Good luck, team!

More Information

Cornell University press release 

“The search for radio emission from the exoplanetary systems 55 Cancri, upsilon Andromedae, and tau Boötis using LOFAR beam-formed observations,” J.D. Turner et al, to be published in Astronomy & Astrophysics (preprint)