In our endless search to understand the Universe and our place within it, small and precious data images can hint at new worlds.
Immersions in a star’s light levels can reveal the presence of planets in orbit, and now astronomers have taken the first steps toward using radio emission tracks to reveal new exoplanetary mysteries.
“Observing the emission of planetary auroral rays is the most promising method for detecting exoplanetary magnetic fields,” explained Cornell University astronomer Jake Turner and colleagues in their new article, “the whose knowledge will provide valuable insights into the inner structure of the planet, the atmospheric escape habitability. “
When the stellar wind – charged particles flowing from the host star – hits a planet’s magnetic field, its change in speed can be detected as startling variations in radio emissions, statistically described as ” explosives “.
The Earth’s own magnetic field howls and screams like alien birds as it channels the solar winds. We have also heard similar cries from other planets in our solar system.
Of course, to detect a murmur of these radio signals coming from an exoplanet, we first need a way to look beyond all the noise on Earth and elsewhere.
A few years ago, the team developed the BOREALIS piping program to do just that. They tested it on Jupiter and then calculated what Jupiter’s radio emissions would be like if they were much further away.
There have already been some tentative detections of new planets using these radio emissions, even earlier this year when astronomers related the activity of radio waves to the interactions between the star’s magnetic field. GJ 1151 and a potential planet the size of Earth. But these have not yet been confirmed by follow-up radio observations.
Thus, Turner’s team decided to test the technique he developed, using Netherland’s low-frequency matrix radio telescope (LOFAR) to examine three systems with known exoplanets: 55 Cancri, Upsilon Andromedae, and Tau Boötis.
Only the Tau Boötis system, located 51 light-years away, showed details of the radio data that matched researchers’ predictions of their tests with Jupiter. It was presented in the form of 14-21 MHz burst emissions and is within approximately three standard deviations of certainty (3.2 sigma).
In 1996, a hot exoplanet of Jupiter was discovered in an orbit of 3,3128 days around the scorching young F-type star and the smallest red dwarf that makes up the Tau Boötis binary system.
“We advocate a broadcast for the planet itself,” Turner said. “Based on the strength and polarization of the radio signal and the planet’s magnetic field, it is compatible with theoretical predictions.”
If their measurements are correct, they suggest that the intensity of the planet’s surface magnetic field ranges from 5 to 11 gauss (Jupiter ranges from 4 to 13 gauss, by comparison, and measurements of its magnetic field have revealed that the planet has a metallic hydrogen core). The emission force of the observed magnetic field also adapts to previous predictions.
“The magnetic field of Earth-like exoplanets can contribute to their possible habitability,” Turner explained, “protecting their own atmospheres from the solar wind and cosmic rays and protecting the planet from atmospheric loss.”
The signal they detected is weak and has yet to be verified by other low-frequency telescopes before researchers can confirm the actual origin of the detected radio emissions.
“We cannot rule out starbursts as a source of emissions,” the researchers warned, but emissions from the planet remain a possibility.
If other telescopes like LOFAR-LBA and NenuFAR can corroborate these findings, these detections of radio emissions from exoplanets will open up an exciting new field of research, which will provide us with a potential way to observe more of alien and distant worlds.
This research was published in Astronomy and astrophysics.