Stars in close binary systems can exhibit unexpectedly high levels of magnetic activity, according to Australian and international researchers. This activity, responsible for flares and sunspots, is usually powered by the star’s rotation, with magnetic activity higher in faster spinning stars, but only up to a known limit.
However, the team from The Australian National University, the University of Sydney and the University of Southern Queensland found that close binary stars break this rule, with unexpectedly high magnetic activity given their spin, and in the most extreme cases – where stars spin especially fast – magnetic activity begins to decline.
The researchers say this may be because of tidal forces between closely orbiting stars, affecting their magnetic activity. Understanding these effects could help us identify habitable exoplanets, the researchers conclude.