Astronomers have detected a repeating radio signal near a rocky, Earth-sized exoplanet that suggests a key factor that makes the world habitable: a magnetic field.
known as planets YZ Ceti bAnd it’s orbiting a small red dwarf star about 12 light-years from Earth.
“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.” Joe Pace saidprogram director of the US National Science Foundation’s National Radio Astronomy Observatory, which supported the work.
“This study does not show that this particular rocky exoplanet likely has a magnetic field, but it does provide a promising method to find more.”
A magnetic field that prevents a planet’s atmosphere from being blown away by strong stellar winds.
For example, Mars had an atmosphere and was a warm and wet planet before it lost its magnetic field, and without its protection, its atmosphere was slowly eroded by plasma from our Sun.
Jupiter, Saturn, Uranus and Neptune Our solar system still has a magnetic field. And in the past, astronomers have Evidence of larger exoplanets with their own magnetic fields has been found.
But until now We have not been able to detect magnetic fields on small, rocky worlds Outside our solar system. In fact, we didn’t even have a reliable way to track them down.
As it turns out, repeating radio signals may be all we need. The team believes this is caused by interactions with the planet’s magnetic field YZ CetiThey circle that.
Before you get too excited, it’s unlikely that YZ Ceti b is teeming with life as we know it, even if it has a magnetic field. The rocky exoplanet is so close to YZ Ceti that its orbit is only two days (for comparison: the planet closest to our Sun, Mercury, takes 88 days to complete one full orbit).
But if the planet’s magnetic field is confirmed by further observations, it means we’ll have a way to detect more life-friendly worlds like this in the future, which is incredibly exciting in the search for habitable planets.
Picked up the signal Carl G. Jansky Very large arrays in New Mexico and was detected while astronomer Jackie Viladsen of Bucknell University in Pennsylvania was watching the data at home over the weekend.
“I’m seeing things that no one has seen before.” Viladsen told Jason Stoughton In a press release for the National Science Foundation.
“We saw the initial explosion and it was beautiful to see,” adds astronomer Sebastian PinedaAnother researcher on the paper, from the University of Colorado, Boulder.
“When we looked at it again, it was very suggestive that, OK, maybe we really have something here.”
So what causes the signal? The current hypothesis is that the planet’s magnetic field barges through the plasma produced by its star, creating powerful radio waves.
For this reason, YZ Ceti b – with its very short orbit – is a prime candidate for picking up a magnetic field, interacting with its star more frequently and violently to allow radio waves strong enough to be detected from Earth.
“We’re looking for planets that are really close to their star and about the same size as Earth. These planets are close enough to their star that you can live on, but because they’re so close, the planet is kind of plowing through a bunch of stuff from their star.” Viladsen said.
“If the planet has a magnetic field and plows through enough of the star, the star will emit bright radio waves.”
That’s essentially what the team saw: Over the course of five observations, Viladsen and Pineda found strong radio signals emitted by YZ Ceti, roughly aligned with the orbit of YZ Ceti b, indicating that it was an interaction between the planet and the star. make them
Based on the strength of the radio waves, the team was able to show that they could be explained by planets having a magnetic field. If confirmed, it would be the first rocky, Earth-sized exoplanet to be shown in one.
But while the evidence so far is compelling, it’s not enough to rule out that something else is causing the stellar radio waves.
It is also true that radio waves were “almost” (but not perfectly) aligned with the orbital period of the planet to consider.
This may be caused by a tilt in the planet’s magnetic field, team Explain them on paper, corresponding to the tilt of Jupiter’s magnetic field. But more observations are needed before we’re sure what we’re seeing.
“It’s going to take a lot of follow-up work before really strong confirmation of a planet-caused radio wave comes out,” Viladsen told the National Science Foundation.
“Once we show that it’s really happening, we’ll be able to do it more systematically. We’re at the beginning of that.”
Fortunately there is New radio facility coming online All the time and so our ability to ‘hear’ the stars is getting better. It’s only a matter of time before we spot a planet that has what we’re looking for—a magnetic field that reminds us of home.
The study was published Nature Astronomy.