The discovery of a "super-Earth" orbiting a red dwarf star 9,000 light-years away suggests that such worlds are three times more common than Jupiter-sized planets. (David Aguilar) |
Super-Earths may be three times more common than JupitersMarch 13, 2006Astronomers have discovered a new "super-Earth" orbiting a red dwarf star located about 9,000 light-years away. This newfound world weighs about 13 times the mass of the Earth and is probably a mixture of rock and ice, with a diameter several times that of Earth. It orbits its star at about the distance of the asteroid belt in our solar system, 250 million miles out. Its distant location chills it to -330 degrees Fahrenheit, suggesting that although this world is similar in structure to the Earth, it is too cold for liquid water or life. Orbiting almost as far out as Jupiter does in our solar system, this "super-Earth" likely never accumulated enough gas to grow to giant proportions. Instead, the disk of material from which it formed dissipated, starving it of the raw materials it needed to thrive. "This is a solar system that ran out of gas," says Harvard astronomer Scott Gaudi of the Harvard-Smithsonian Center for Astrophysics (CfA), a member of the MicroFUN collaboration that spotted the planet. The discovery was reported March 13, 2006 in a paper posted online at http://arxiv.org/abs/astro-ph/0603276 and submitted to The Astrophysical Journal Letters for publication. |
