'Past-prime' star may be creating planets

A star considered to have passed the age at which it can form planets may, in fact, be creating new worlds, European and U.S. astronomers say. Using the European Space Agency's Herschel space observatory, astronomers have accurately "weighed" the disk of material surrounding the star TW Hydrae and determined it still has enough mass to spawn 50 Jupiter-sized planets, several million years after most other stars its age have already given birth. TW Hydrae, relatively close to Earth by astronomical standards, is relatively young but in theory it is past the age at which giant planets already may have formed, they said. "We didn't expect to see so much gas around this star," study leader Edwin Bergin of the University of Michigan said in a release from ESA's Paris headquarters. "Typically stars of this age have cleared out their surrounding material, but this star still has enough mass to make the equivalent of 50 Jupiters." Planets are born out of material swirling around young stars, and the mass of this material is a key factor controlling their formation. "This star has significantly more mass than required to make our own Solar System and could make a much more exotic system with planets more massive than Jupiter," Bergin said.