Astronomers have detected thousands of exoplanets, but we can only learn so many things from light-years away. A new study from Cornell University could help shed light on the conditions of exoplanets by analyzing radio emissions connected to their magnetic fields. Researchers say this marks the first time an exoplanet has been detected in radio bands.
This project began with the study of Jupiter, which has an extremely strong magnetic field. A few years ago, the study’s lead author, Jake Turner, performed an analysis of Jupiter’s magnetic field. In the new study, these data become the basis for exoplanet hunting. The team processed Jupiter data to simulate the radio frequency signal from a distant gas giant.
The results have become a template for similar planets that could be 40 to 100 light-years away from the observatory. Using the low frequency matrix (LOFAR), the team scanned several nearby solar systems that are known to host exoplanets. If the signals from one of these stars matched the pattern, this would indicate that it had found the emissions of an exoplanet in the radio spectrum.
It took more than 100 hours of observation, but a star known as Tau Boötes, 51 light-years away, showed exactly the type of signal the researchers hoped to find. Turner and colleagues even used other radio telescopes to repeat the analysis, and the signal is still there. And that makes sense – Tau Boötes has a well-known exoplanet, a gas giant called Tau Boötes b, which orbits very close to the star.
According to researchers, the signal is very poorly understood. There were a few other stars with radio pings that could have been planets, but the one in Tau Boötes was much more significant. The team is now turning to other researchers to confirm the findings – data on an exoplanet’s magnetic field may be invaluable, but it is still possible that the signal came from the star or another local source, rather than the planet.
Researchers say that a planet’s magnetic field can provide clues to its composition and habitability. For example, the Earth’s magnetic field is a product of the planet’s iron core, and the field helps deflect dangerous radiation that can damage living things and eliminate a planet’s atmosphere. The lack of a magnetic field on Mars is thought to be one of the reasons it is so inhospitable. After confirming and refining Turner’s results, astronomers may be able to learn about distant worlds by scanning radio frequency emissions.