β Hydri is a sun-like star close to us that is gradually approaching its transformation into a red giant. It was expected to have a relatively weak and calm magnetic field, but new research has found that this is not the case.
β Hydri
A group of astrophysicists from scientific institutions in Spain and Portugal recently studied the nearby star β Hydri and discovered something very unusual about its magnetic field. This discovery is particularly interesting given that this star is considered to be a twin of the Sun, which is approaching the final stage of its existence.
β Hydri is a bright star in the southern sky. It is actually quite close to us and is a yellow subgiant. Slightly heavier than the Sun, it is undergoing accelerated evolution and has already begun to depart from its main sequence, although it will be hundreds of millions of years before it turns into a red giant.
The scientists used the HARPSpol instrument, located on the 3.6-meter telescope at the European Southern Observatory in Chile, and then compared the results with data from TESS (Transiting Exoplanet Survey Satellite).
Excessively strong magnetic field
Scientists expected β Hydri to have a weak and inactive magnetic field. This follows from the general theory of the evolution of medium-mass stars, and it is expected that the same will happen to the Sun. However, the magnetic field detected turned out to be several times more active than that of our sun.
And in fact, it’s not as unexpected as it seemed. The main source of each star’s magnetic field is a dynamo — electrically conductive currents deep within the star, which we do not fully understand yet. It is generally believed that they should weaken over time.
However, when a star transitions to the subgiant stage, the thermonuclear reactions within it may change, allowing the dynamo to be reborn. It is quite possible that the same fate awaits our luminary.
According to phys.org
