Fomalhaut has been a prime target for planet hunters ever since JPL’s Infrared Astronomy Satellite (IRAS) found a region of excessive dust around it in the early ’80s. This image was taken using the coronagraph in Hubble’s Advanced Camera for Surveys, which blocks out the bright light of the central star (here represented by the white dot). The radial streaks in the image are glare from the star, but the bright ring is real dust, and its off-center shape suggested to Kalas that a planet might be “shepherding” it. That planet, Fomalhaut b, is about one billion times fainter than its star, has a calculated orbital period of 872 years, and is roughly 18 billion kilometers from its star, or 10 times the distance from Saturn to the sun.

Planet, Ho!

A team of scientists including two Caltech alumni and a brace of JPL staffers have used the Hubble Space Telescope to take the first-ever visible-light photo of a planet orbiting another star—Fomalhaut, a bright star about 25 light-years from Earth. The planet, estimated to be no more than three times Jupiter’s mass, was found by comparing pictures of the debris ring around Fomalhaut taken two years apart. The first picture revealed several bright points in the ring that might have been planets; the second one showed one of them had moved.

The team includes UC Berkeley professors Paul Kalas, James Graham, and Eugene Chiang (PhD ’00), Berkeley grad student Edwin Kite, Mark Clampin of NASA’s Goddard Space Flight Center, Michael Fitzgerald of Lawrence Livermore National Laboratory, and JPL’s Karl Stapelfeldt (PhD ’91) and John Krist. —DS