By Ron Cowen
It’s a topsy-turvy world out there and astronomers have new evidence to prove it. Researchers have for the first time documented that a star other than the sun flips its magnetic poles. The magnetic reversal observed on the nearby star tau Bootis may shed light on the origin of the sun’s 11-year magnetic cycle, which can affect Earth’s climate. The finding also highlights the role that massive, close-in planets may play in regulating a star’s magnetic activity.
Every 11 years, the sun reverses the direction of its magnetic field, heralding the peak of the solar cycle. That’s when the number of sunspots—regions where bundled loops of magnetic fields concentrate—reaches its maximum, and the sun is more likely to hurl billion-ton clouds of charged particles into space. Those eruptions can harm spacecraft and damage power grids on Earth.