New Study: Magnetic Field Detected on Exoplanet YZ Ceti b, Revealing Promising Clues for Finding More Extraterrestrial Magnetic Fields

SPACE — On Earth, we often underestimate our planet’s magnetic field. In fact, the magnetic field protects living things from sunlight, pulls the compass needle north, and even creates beautiful auroras.

Other worlds in our solar system also have magnetic fields, but what about Earth-like planets around other stars? New research may have revealed promising clues.

Recent observations from the Very Large Array (VLA) radio telescope in New Mexico revealed evidence of a magnetic field on the rocky exoplanet, YZ Ceti b. It orbits a star 12 light years from Earth. This is the first magnetic field detected on a planet outside our solar system, according to a study published Monday, April 3, 2023 in the journal Nature Astronomy.

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“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,” said study author Joe Pesce in a statement. He is the director

National Radio Astronomy Observatory (NRAO).

Magnetic fields are of great interest to astronomers because they are an important part of making a planet habitable. Without a magnetic field, energetic particles from a star can erode a planet’s atmosphere, stripping away layers of gas that could support life.

“The search for potentially habitable or life-sustaining worlds in other solar systems depends in part on being able to determine whether rocky, Earth-like exoplanets actually have magnetic fields,” Pesce said.

YZ Ceti b, however, is not a habitable planet. To detect radio waves from the magnetic field of a small and distant exoplanet, astronomers have to find very extreme examples. YZ Ceti b is quite close to its star, too close to make temperatures favorable for life. It also orbits at such a speed that its year is only two Earth days.

So close, according to the researchers, YZ Ceti b is capable of ‘hijacking’ material that is detached from its parent star. The planet’s magnetic field pushes the electrically charged plasma back toward the star, which then interacts with the star’s own magnetic field, emitting bright flashes of energy.

Basically, the radio waves the research team observed were auroras on their host stars, most likely created by interactions with planets. “There should also be auroras on this planet if it had an atmosphere of its own,” said Sebastian Pineda, a University of Colorado Boulder astronomer and co-author on the study.

Pineda said the latest facts provide new information about the environment around the star. “We call this idea ‘extrasolar space weather’,” he said.

The research team isn’t 100 percent sure whether the stellar auroras were caused entirely by YZ Ceti b. Further observations are needed to confirm that it is actually caused by the rocky planet’s magnetic field, and not just a feature of the star itself. However, the team remains optimistic their findings could be a breakthrough in the future in the search for habitable alien planets.

Study co-author Jackie Villadsen said it made perfect sense for their findings to be the first detection of a magnetic field on a rocky exoplanet. “But I think it will take a lot of follow-up work before very strong confirmation of radio waves being caused by a planet,” said the astronomer at Bucknell University in Lewisburg, Pennsylvania. Source: LiveScience