Earth’s magnetic field protects its slim, life-sustaining atmosphere by reflecting high-energy particles from the sun.
A planet’s magnetic field can prevent the atmosphere from being exhausted by particles exhaled by the central star (the solar wind). This same “space weather” causes auroras on Earth.
With the discovery of Auroras, YZ Ceti b (YZ Ceti b, an Earth-sized exoplanet orbiting a red dwarf star 12 light-years from Earth in the constellation Ceti) is a terrestrial exoplanet with a magnetic field. became the leading candidate for
“Being able to determine whether rocky, Earth-like exoplanets have magnetic fields is important for finding habitable or life-bearing worlds in extrasolar systems,” said NSF. Science Foundation) and Program Director of the National Radio Astronomy Observatory, Joe Pesch, published in Nature Astronomylatest papertalked regarding “This study not only shows that this terrestrial planet may have a magnetic field, but offers a promising way to find out more.”
Using the Very Large Interferometry Radio Telescope constellation in New Mexico, the researchers detected strong radio waves that are thought to have been produced by YZ Ceti and interfered with the magnetic field of the planet YZ Ceti b.
“The radio waves give us new information regarding the surrounding environment of the star,” said co-lead author Sebastian Pineda of the paper, who called the detection “extrasolar space weather.” “We’re actually seeing auroras on stars. That’s this radio emission. And if a planet has an atmosphere, there should be aurorae there, too.”
Detecting the presence of magnetic fields around distant exoplanets is not easy. This is the first time that a magnetic field has been found around an Earth-sized exoplanet, and so far it has only been detected for a Jupiter-sized exoplanet.
In order for radio waves coming from 12 light-years away to be detected, not only are the radio waves very strong, but the exoplanet must orbit very close to the central star. YZ Cetus B takes only two days to orbit its central star. “We’re looking for Earth-sized planets orbiting very close to the central star,” says Peneda. “Such a planet is too close to its star to be inhabited, but so close that the planet seems to be wading through the masses of material coming from the star. If the planet has a magnetic field. And if we push through enough stellar material, it will cause the central star to emit strong radio waves.”
Additional work is needed to validate these findings, the researchers say.
