Astronomers have observed a spot on the star HD179949 that travels around the star's surface at the same rate as a close-orbiting planet circles the star. The astronomers believe the planet's magnetic field is transferring energy to the star's chromosphere, heating it and causing the blemish. The planet, which is at least 270 times as massive as Earth, orbits the planet once every 3.09 days. The star and planet lie 90 light-years from us in the constellation Sagittarius.
Shane Erno / University of British Columbia