Tau Bootis magnetic field

FLIPPING FIELD: An artist’s impression of the star Tau Boo, along with its magnetic field, and the exoplanet Tau Boo b.

Image: Karen Teramura/IfA

The relationship between stars and planets is usually rather one-directional—the star rules over its celestial subjects, blasting them with radiation, blessing them with warmth. The puny planets simply take what they get. But sometimes a planet is so massive, and so close to its star, that the smaller object can exert considerable influence on its stellar neighbor.

Such is the case with the planet orbiting the star Tau Boötis—Tau Boo for short. The giant world, six times the mass of Jupiter, was discovered in 1996 circling the bright star some 50 light-years from the sun. Tau Boo b, as the planet is known, passes so close to the star in its orbit—less than one twentieth the distance between Earth and the sun—that it drags the stellar surface along with it, thereby synchronizing the rotation of the star with the orbit of the planet.

via Star Entangled with Its Giant Planet Experiences Hyperactive Magnetic Cycle: Scientific American.