3 Apr. (EUROPE PRESS) –
Astronomers have identified a possible Earth-sized planet in another solar system as prime candidate to also have a magnetic field.
It is about YZ Ceti b, a rocky planet that orbits around a star located about 12 light years from Earth, as published in the journal ‘Nature Astronomy’.
Researchers Sebastián Pineda and Jackie Villadsen observed a repeating radio signal from the star YZ Ceti using the Karl G. Jansky Very Large Array, a radio telescope operated by the US National Science Foundation’s National Radio Astronomical Observatory.
Pineda and Villadsen’s research to understand magnetic field interactions between distant stars and their orbiting planets is supported by the NSF.
“The search for potentially habitable or life-bearing worlds in other solar systems depends in part on being able to determine whether rocky, Earth-like exoplanets actually have magnetic fields,” he says. it’s a statement Joe Pesce, program director of the National Radio Astronomy Observatory (NSF)–. This research shows not only that this particular rocky exoplanet probably has a magnetic field, rather it provides a promising method for finding more.”
“A planet’s magnetic field can prevent its atmosphere from being worn away over time by particles spewed out by its star,” said Pineda, an astrophysicist at the University of Colorado. Whether or not a planet survives with an atmosphere may depend on whether the planet has a strong magnetic field or not.”
“We saw the initial explosion and we thought it was beautiful,” Pineda explains. “When we saw it again, it was very indicative that, okay, maybe we really have something here.”
The researchers theorize that the stellar radio waves they detected are generated by interactions between the exoplanet’s magnetic field and the star it orbits. However, for these radio waves to be detectable over long distances, they must be very intense. Although magnetic fields have already been detected on massive Jupiter-sized exoplanets, doing it on a comparatively tiny exoplanet the size of Earth requires a different technique.
Because magnetic fields are invisible, it’s hard to tell if a distant planet has one, explains Villadsen, an astronomer at Bucknell University.
“What we are doing is looking for a way to see them,” he explains. “We are looking for planets that are very close to their stars and are similar in size to Earth. These planets are too close to their stars to be alive.” in them, but since they are so close, the planet is going through a lot of stuff coming out of the star.”
“If the planet has a magnetic field and it passes through enough stellar material, it will cause the star to emit bright radio waves,” he adds.
The small red dwarf star YZ Ceti and its known exoplanet, YZ Ceti b, provided an ideal match because the exoplanet is so close to the star that it completes a full orbit in just two days. (For comparison, the shortest planetary orbit in our solar system is that of Mercury, at 88 days.)
When YZ Ceti’s plasma breaks away from the planet’s magnetic “plough”, it interacts with the magnetic field of the star itself, which generates radio waves intense enough to be observed on Earth.
The intensity of these radio waves can be measured, allowing researchers to determine the strength of the planet’s magnetic field.
“This gives us new information about the environment that surrounds the stars,” Pineda points out. This idea is what we call ‘extrasolar space weather’.”
High-energy particles from the sun and sometimes huge explosions of plasma create closer solar weather around Earth. These ejections from the sun can disrupt global telecommunications and cause short circuits in the electronic components of satellites and even on the surface of the Earth. The interaction between the solar weather and the Earth’s magnetic field and atmosphere also creates the phenomenon of the aurora borealis.
Interactions between YZ Ceti and its star also produce an aurora, but with one significant difference: The aurora is produced on the star itself. “Actually, we are seeing the aurora on the star, that is what this radio emission is,” Pineda explains. There should also be aurora on the planet if it has its own atmosphere.”
Both researchers agree that although YZ Ceti b is the best candidate so far for a rocky exoplanet with a magnetic field, it is not a closed case. “It is very possible that it is this one,” says Villadsen, “but I think a lot of follow-up work will be needed before really solid confirmation of radio waves being caused by a planet comes out.”
“There are many new radio facilities in operation and planned for the future,” Pineda says of the possibilities for future research. “Once we show that this is actually happening, we will be able to do it more systematically. we are at the beginning“, he highlights.
