How a Star's Past Shapes Its Magnetic Field
Researchers at the Institute of Science and Technology Austria (ISTA) have made a new discovery about stars. They found that a star's past can affect its magnetic field strength, which is crucial for understanding stellar evolution.
The team used highly precise telescopes to measure tiny changes in a star's brightness, caused by vibrations or oscillations. These changes give insights into the star's internal structure.
The researchers focused on red giants, sun-like stars in a late phase of their lives. They found that some of these stars have a specific oscillation mode that is barely visible, which could be caused by strong magnetic fields.
However, the team's models suggested that the magnetic fields needed to explain this suppression would have to be extremely strong. To solve this puzzle, they considered an alternative explanation: a star may have 'stolen' mass from a companion star during its evolution.
This mass gain would alter the star's internal structure, making it more sensitive to magnetic fields. The team simulated this scenario using the open-source stellar evolution code MESA and found that a weaker magnetic field could explain the suppressed oscillations.
The study suggests that many red giants with strong magnetic fields may have gained mass from another star. This finding can help researchers create more accurate models of stellar evolution, which is essential for understanding the behavior of stars like our sun.
