Taken from a
post on Phil Plait's Bad Astronomy site. The star is listed as 1RXS J160929.1-210524 (Phil calls it 1RXS 1609 for 'short.'); it's a sun-like star about 500 light years from our solar system. The planet is about 8 times the mass of Jupiter and relatively young. Since it's still cooling down from its formation, it is hot enough to be imaged in near-infrared.
The object was actually first imaged by the 8-meter Gemini North telescope in Hawaii, in 2008. At the time, astronomers were not certain if it was an orbiting planet or another star or galaxy. More recent images confirm that it's a planet. See the discussion on
Bad Astronomy, complete with diagrams.
Some news stories are incorrectly calling this: "The first direct image of a planet orbiting an alien star." Actually, it's just the first such planet imaged from a ground-based telescope.
First, it’s not the first exoplanet even seen directly. That distinction belongs to the planet 2M1207b, which orbits a brown dwarf about 230 light years away. Brown dwarfs are smaller and cooler than the Sun, and are not fusing hydrogen into helium in their cores, so some people don’t consider them to be real stars. So while the object seen is a planet, it’s not orbiting a sun-like star.
OK, but a planet already has been directly imaged orbiting the star Fomalhaut. That star is hotter and more massive than the Sun, but is far more sun-like than a brown dwarf. The first image of the planet Fomalhaut b was taken in 2004 using Hubble Space Telescope, and the second confirming image in 2006. It took two more years to make sure everything was correct, and the news announced in 2008. So while this was announced after the image of 1RXS 1609b was first taken in 2008, the first image of Fomalhaut b was taken in 2004, four years earlier.
So, at the most recent count, we now have 3 (count 'em!) planets around other stars that have been imaged directly, not just inferred by the motion of the star or the dimming of the star as the planet passed in front of it. It's an amazing time we live in, even with all the horrible news about the economy and the ecological disaster in the gulf.