(CNN) Astronomers have detected a repeating radio signal from an exoplanet 12 light-years from Earth and the star it orbits. The signal suggests that an Earth-sized planet may have a magnetic field and possibly an atmosphere.
Earth’s magnetic field protects the planet’s atmosphere, which life needs to survive, by deflecting energetic particles and plasma from the Sun. Detecting atmospheres around planets outside our solar system may point to other worlds capable of supporting life.
Carl G. in New Mexico. Scientists observed strong radio waves coming from the star YZ Ceti and the rocky planet orbiting it, YZ Ceti b, when observing using the Jansky Very Large Telescope. Researchers believe the radio signal is created by interactions between the planet’s magnetic field and the star.
There was a study describing the findings Published in the magazine on Monday Natural Astronomy.
“We saw the initial eruption and it was beautiful,” said lead study author Sebastian Pineda. An astrophysicist at the University of Colorado Boulder in a statement. “When we looked at it again, it was very indicative that, well, we might actually have something.”
Magnetic fields can prevent a planet’s atmosphere from depleting and, over time, from being bombarded by particles from the star, essentially eroding, Pineda said.
How strong are radio waves?
For radio waves to be detected on Earth, they have to be very strong, the researchers said.
“Whether or not a planet has an atmosphere depends on whether or not the planet has a strong magnetic field,” Pineda said.
Previously, researchers have detected magnetic fields on exoplanets the size of our solar system’s largest planet, Jupiter. But detecting magnetic fields on small Earth-sized planets is more difficult because magnetic fields are essentially invisible.
“What we’re doing is looking for a way to see them,” said Jackie Willetsen, an assistant professor of physics and astronomy at Bucknell University. Pennsylvania, in a statement.
“We’re looking for planets that are very close to their stars and similar in size to Earth,” he said. “These planets can’t be very close to their stars where you can live, but because they’re so close, it’s like the planet plows in material from the star. If the planet has a magnetic field, it plows in. If there’s enough stellar material, the star will emit bright radio waves.”
YZ Ceti b takes only two Earth days to complete a single orbit around its star. Meanwhile, the shortest orbit in our solar system is Mercury, which takes 88 Earth days to complete its orbit around the Sun.
As YZ Ceti b orbits its star, the plasma from the star collides with the planet’s magnetic field, bouncing off and interacting with the star’s magnetic field. All of these energetic reactions generate and emit strong radio waves that can be detected on Earth.
The researchers measured the radio waves they detected to determine the strength of the planet’s magnetic field.
“This tells us new information about the environment around stars,” Pineda said. “This idea is what we call ‘space weather’.”
In our solar system, the sun’s activity can create space weather that affects Earth. Energetic bursts from the Sun can disrupt satellites and global telecommunications and cause dazzling light displays near the Earth’s poles, such as the aurora borealis or northern lights.
Scientists imagine that interactions between YZ Ceti and its planet also create an aurora, but this light show actually takes place in the star itself.
“We’re actually seeing an aurora in the star — that’s this radio emission,” Pineda said. “If the planet has its own atmosphere then it must have an aurora.”
A rocky exoplanet candidate
Researchers consider YZ Ceti b to be the best candidate yet discovered for a rocky exoplanet with a magnetic field.
“It might actually be plausible,” Willetsen said. “But I think it will be a lot of follow-up work before strong confirmation of radio waves caused by a planet emerges.”
New radio telescopes set to become operational this decade will help astronomers further detect signals that indicate magnetic fields, the researchers said.
“The search for habitable or life-supporting worlds in other solar systems depends on being able to determine whether rocky, Earth-like exoplanets actually have magnetic fields,” said Joe Bess, program director at the National Radio Astronomy Observatory. A statement. “This research provides a promising method to find out if this particular rocky exoplanet not only has a magnetic field, but also more.”
