http://news.xinhuanet.com/english/2007-09/13/content_6718428.htm
*Discovery: 1st planet to survive "red-giant" phase* BEIJING, Sept. 13 (Xinhuanet) -- The discovery by astronomers of a gas-giant planet three times the size of Jupiter that is the first known planet to survive its "red-giant" phase reveals a glimpse of our own solar system's future and what will happen to Earth when the sun grows cold and collapses. A red-giant phase is when an aging star expands and engulfs bodies orbiting it. Scientists discovered the planet some 4,500 light-years from Earth. It once orbited its star at the same distance as the Earth is now from the sun -- about eight light-minutes -- but then drifted away, the researchers said in the journal Nature. "At present, (the) discovery is the only planetary system known to have survived its red-giant phase," Jonathan Fortney, a NASA researcher, wrote in a commentary in Nature, where the international team published its findings on Wednesday. "This will shed light not only on our own solar system, in which Mercury, Venus and perhaps Earth will eventually be engulfed by the red-giant sun but also the diverse array of planetary systems that are our galactic neighbors." Scientists have identified some 250 planets orbiting other stars. Most are detected by indirect measurements such as tiny variations in the wobble of a star. The team found this planet by accident while studying its parent star V 391 Pegasi, Don Kurtz, astrophysicist at the University of Lancashire who worked on the study, told Reuters. The team found that during its time as a middle-aged star, V 391 Pegasi had a mass similar to the sun before it expanded its radius by more than 100 times when it entered its red-giant phase -- something the sun is expected to do in 5 billion years. The researchers said the planet stayed intact because the parent star lost mass, reducing its gravitational pull just enough to let the planet drift away a bit. [Non-text portions of this message have been removed]
