Meet the Neighbors
November 17th, 2008 by timbotron
(artists’ concepts of Fomalhaut b. Left image by David A. Hardy)
A few days ago a team from UC Berkeley, NASA Goddard Space Flight Center, Lawrence Livermore Labs, and NASA JPL announced in Science that they have taken a photograph of a planet outside of our own solar system. Though numerous planets outside our solar system have been discovered in recent years, this is a rare example of an extrasolar planet identified through photographs. This planet - between one and a half to three times the mass of Jupiter - orbits the star Fomalhaut (25 light years away) in the constellation Piscis Australis (”The Southern Fish”). The star Fomalhaut is about twice the size of our Sun, but 15 times as bright, glowing bright blue-white. Remarkably, this young star has features similar to our early solar system: it has a large disk of debris surrounding it, serving as a “nursery” for young planets.
Several years ago, scientists noticed that this debris ring has a sharp inner edge (as if something large is shaping the inner edge) and that it is not entirely centered around the star (as if some other mass is pulling the ring slightly off-center). A comparison of photographs taken by the Hubble Space Telescope in 2004 and 2006 revealed an object in orbit around Fomalhaut on the inside of the star’s debris ring - this planet moves at a pace of 872 years for one complete orbit around the star.
This planet is named Fomalhaut b: it’s one and a half to three times the size of Jupiter, it appears to be a giant ball of gas (much like Jupiter or Saturn), and may have a large ring system of its own (and much larger than Saturn’s).
