Irritating Planet Heats Up Parent Star
(From the March/April 2004 issue of StarDate
magazine)
A giant planet may be irritating the skin of its parent star, creating a
“hot spot” on the star’s surface. This bright blister provides the first
evidence that a planet outside our own solar system is generating a magnetic
field, according to Evgenya Shkolnik, a graduate student at the University
of British Columbia, who has studied the star for more than a year.
The star is known as HD 179949. It’s about 90 light-years away, and it’s
somewhat similar to the Sun. Another team of astronomers had already
discovered that a planet about 80 percent as massive as Jupiter orbits the
star at a distance of about 3.4 million miles.
Shkolnik found that a hot spot in the star’s lower atmosphere rotates into
view every three days — the same time it takes the planet to complete one
orbit. The hot spot may be caused by the planet’s magnetic field. The planet
is almost as massive as Jupiter, which generates a powerful magnetic field
that extends far into space. The magnetic field of the planet orbiting HD
179949 could be disturbing the star’s outer layers, producing storms similar
to the sunspots and flares seen on the Sun. -- Damond Benningfield
» More information about extrasolar planets
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