Astronomers have found evidence that some stars have unexpectedly strong surface magnetic fields; it’s a discovery that challenges existing models of their evolution.

In stars like our Sun, surface magnetism is associated with the rotation of the stars, a process similar to the inner workings of a flashlight. Strong magnetic fields are observed in the hearts of magnetic sunspot regions and cause various space weather phenomena. Until now, low-mass stars (celestial bodies with less mass than our Sun that can rotate very quickly or relatively slowly) were thought to exhibit very low levels of magnetic activity, making them ideal host stars for potentially habitable locations. planets

In a new study published today Astrophysical Journal LettersWhen a star’s surface and core begin to spin at the same speed and then separate from each other, there’s a new internal mechanism called core-shell segregation, say researchers at Ohio State University. – may be responsible for the strengthening of magnetic fields in cold stars; this process could increase their radiation over billions of years and affect the habitability of nearby exoplanets.

The study was made possible by a technique developed earlier this year by Lira Kao, the study’s lead author and a graduate student in astronomy at Ohio State, and co-author Marc Pinsonneau, professor of astronomy at Ohio State, earlier this year to make and characterize starspots. magnetic field measurements.

Cao said that although low-mass stars are the most common stars in the Milky Way and often host exoplanets, scientists know relatively little about them.

For decades, it was believed that the physical processes of lower-mass stars repeat the processes of solar-type stars. Because stars gradually lose their angular momentum as they spin downward, astronomers can use stellar rotation as a tool to understand the nature of the star’s physical processes and how they interact with their moons and surroundings. However, Cao said there are times when the star’s rotation clock stops.

Using public data from the Sloan Digital Sky Survey to examine 136 samples of stars in M44, a star bed also known as the Praesepe or Beehive Cluster, the team found that the magnetic fields of low-mass stars in the region were significantly visible. More powerful than current models.

While previous research has shown that the Beehive cluster is home to many stars that challenge current theories of rotational evolution, one of Cao’s team’s most exciting discoveries was the determination that the magnetic fields of these stars could be just as unusual; Much more powerful than modern thought. models.

“It was incredibly interesting to see the relationship between magnetic enhancement and rotational anomalies,” Cao said. Said. “This suggests that there may be some interesting physics at work.” The team also hypothesized that the process of synchronizing the star’s core and envelope could cause the magnetism found in these stars to have a fundamentally different origin than that seen on the Sun.

“We found evidence of another type of dynamo mechanism driving the magnetism of these stars,” Cao said. Said. “This work shows that stellar physics can have surprising implications for other fields.”

According to the research, these findings have important implications for our understanding of astrophysics, particularly regarding the search for life on other planets. “Stars that experience this enhanced magnetism are likely to blast their planets with high-energy radiation,” Cao said. “This effect is estimated to last for billions of years on some stars, so it’s important to understand how it might affect our concepts of habitability.”

But these discoveries should not hinder the search for extraterrestrial existence. With further research, the team’s discovery may help you better understand where to look for planetary systems that could host life. But here on Earth, Cao believes his team’s discoveries could lead to better simulations and theoretical models of stellar evolution.

“The next thing to do is to make sure that enhanced magnetism happens on a much larger scale,” Cao said. Said. “If we can understand what goes on inside these stars when they are subjected to shear-enhanced magnetism, it will take science in a new direction.” Source