Illustration of the interaction between a candidate exoplanet and its star. Plasma emitted from the star is deflected by the exoplanet’s magnetic field and then interacts with the star’s magnetic field, producing aurorae on the star and emission of radio waves.
Nationalgeographic.co.id – Earth’s magnetic field does more than keep everyone’s compass needle pointing in the same direction. It also helps preserve a chunk of the atmosphere that sustains life on Earth by deflecting the high-energy particles and plasma that are regularly ejected from the sun.
Researchers have now identified an Earth-sized candidate in another solar system as a prime candidate for one with a magnetic field too—YZ Ceti b, a rocky planet orbiting a star about 12 light years from Earth.
Researchers Sebastian Pineda and Jackie Villadsen observed repeated radio signals coming 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 Astronomy Observatory.
Research by Pineda and Villadsen to understand magnetic field interactions between distant stars and planets orbiting them is supported by the NSF. The results of their research were published in a journal Nature Astronomy pada 3 April 2023 dengan judul “Coherent radio bursts from known M-dwarf planet-host YZ Ceti.”
“The search for potentially habitable or life-sustaining worlds in other solar systems hinges in part on being able to determine whether rocky, Earth-like exoplanets actually have magnetic fields,” said NSF’s Joe Pesce, program director for the National Radio Astronomy Observatory. .
“This research not only shows that this rocky exoplanet most likely has a magnetic field, but also provides a promising method for finding many more,” he added.
The Karl G. Jansky Very Large Array radio telescope in its most compact configuration.
A planet’s magnetic field can prevent that planet’s atmosphere from being eroded over time by particles spewed from its star, explains Pineda, an astrophysicist at the University of Colorado. “Whether a planet survives with an atmosphere or not depends on whether the planet has a strong magnetic field or not.”
“I saw things no one had ever seen before,” recalls Villadsen, an astronomer at Bucknell University, when he first isolated radio signals while filling in data at his home over the weekend.
“We saw the initial burst and it looked beautiful,” Pineda said. “When we look at it again, it really shows that, okay, maybe we really do have something here.”
The researchers theorized that the radio waves of the star they detected were generated by interactions between the exoplanet’s magnetic field and the star it orbits.
However, for such radio waves to be detected over long distances, they must be very strong. While magnetic fields have previously been detected on massive exoplanets the size of Jupiter, doing so for relatively small Earth-sized exoplanets requires a different technique.
