A conceptual diagram of the interaction between an exoplanet and its host star/Alice Kitterman/National Science Foundation
2023.04.05 Wed posted at 21:00 JST
（ＣＮＮ） A team of US astronomers announced by Wednesday that they had detected repeating radio signals from an Earth-sized exoplanet and its parent star 12 light-years from Earth. The results suggest that the planet may have a magnetic field and atmosphere.
On Earth, the magnetic field repels energetic particles and plasma from the sun and protects the atmosphere. Atmospheres are necessary for life to exist, and finding atmospheres on extrasolar planets could help us find other worlds that could support life.
Strong radio waves were detected from YZ Cetus and the rocky planet YZ Cetus b that revolves around it. It was detected using the Very Large Interferometric Radio Telescopes in New Mexico. Researchers believe that the radio signals originate from interactions between the planet’s magnetic field and the star.
The results of the study were published on the 3rd in the scientific journal Nature Astronomy.
“When I saw the first burst, it looked beautiful. When I saw it again, I knew this was something,” said lead author Sebastian Pineda, an astrophysicist at the University of Colorado Boulder. . A planet’s magnetic field plays a role in preventing star particle emissions from depleting and depleting the atmosphere, he said.
However, when it comes to radio waves that can be detected from the earth, a very strong one is required.
Scientists have previously detected magnetic fields on Jupiter-sized exoplanets, but have had difficulty detecting them on smaller planets.
“We were looking for a way to find it,” said study co-author Jackie Viladsen, an assistant professor at Bucknell University in Pennsylvania, in a statement.
“We’re looking for planets that are really close to a star, similar in size to Earth, because they’re too close to a star to live in, but because they’re so close, they’re going through a lot of the stuff that comes from the star. “If a planet has a magnetic field and is burrowing through large amounts of stellar matter, bright radio waves will be emitted from the star.”
Planet b, which was the object of observation this time, revolves around a fixed star in two days. During that time, the plasma from the star collides with the magnetic field of the planet, and the interaction creates a powerful radio wave that can be detected on Earth.
Researchers measured this radio wave to determine the strength of the planet’s magnetic field. “This gives us new information about the stellar environment, which we call ‘extrasolar space weather,'” Pineda said.
More research will be needed to get a stronger confirmation of the radio waves coming from the planets, however, Viladsen said. The authors hope that new radio telescopes that will begin operating in the next decade will be able to detect more signals suggesting the presence of a magnetic field.
