The Planet With a Tail

Today there is a new tail to add to the tale of astronomical tails. This one belongs to a planet.Comet McNaught Credit: Robert McNaughtYou're all familiar with the beautiful tails that comets display as the go around the Sun. Energy from our star ionizes particles and strips dust away from the comet's nucleus to form these sometimes magnificent tails.Mira, one of the most famous variable stars, also sports a tail. Mira is an old evolved red giant star that is losing massive amounts of surface material as it hurdles along through space. This tail material, imaged for the first time in 2007, has been released over the past 30,000 years. Coincidentally, Mira happens to reside inside the tail of the constellation Cetus the Whale. Image credit: NASA/JPL-Caltech The common factor in the formation of these tails is a strong stellar wind emanating from the star; our Sun in the case of comets, and the wind from the red giant Mira in the case of the variable star.Now astronomers have discovered evidence for a planet sporting a tail caused by this same phenomena, the stellar wind of the star HD 209458. The gas giant planet, named HD 209458b, is orbiting so ...