A team of French scientists from the CNRS, Inria and ENS-PSL have published an article in the journal Science on January 20, 2023, explaining why the hearts of stars rotate more slowly than calculations predict.

Using simulations that model the flow of plasma in the deep layers of a star, the team discovered that an internal magnetic field could be responsible for this phenomenon.

The simulations show that the plasma flow can amplify a magnetic field, which in turn generates strong turbulent movements that could further amplify the magnetic field and cause the star’s core to slow down. These results are in agreement with observations of many stars.

The simulations indicate that this magnetic field would be occulted by the outer layers of the star, which is why it has not yet been detected by current measurement techniques.