Merrillville Community Planetarium
Bringing the Universe to the Merrillville Schools and Northwest Indiana

Stellar Magnetism

A team of astronomers using the Canada-France-Hawaii Telescope on Mount Kea, Hawaii has measured the magnetic field of the star Tau Bootis in the constellation Bootes (the Herdsman.) (It looks like an ice cream cone and can be seen in the summer.) Astronomers say the star has about 1.5 solar masses and is about 50 light years from Earth. Its magnetic field is slightly stronger than our sun’s magnetic field. Scientists believe stellar magnetism plays a role in producing hot, gas-giant planets. Tau Bootis has a hot, gas-giant planet orbiting extremely close to it. The planet weighs about 4.4 Jupiters and orbits only 4.6 million miles from the star! (Mercury orbits at a distance of 36 million miles.) After forming farther out, the star’s magnetic field may have pulled the planet closer, creating a hot gas-giant planet.