spacetoday.net: Astronomers confirm discovery of rocky exoplanet

Posted: Thu, Sep 17, 2009, 9:01 AM ET (1301 GMT)
CoRoT-7b illustration (ESO)

Astronomers announced Wednesday that they have confirmed that an extrasolar planet closely orbiting another star is likely a "super-Earth" with a rocky surface. Astronomers used a telescope at the European Southern Observatory to examine CoRoT-7b, an exoplanet discovered earlier this year by the French astronomy satellite CoRoT. At the time astronomers knew that the planet completed one orbit in just 20.4 hours, and assumed that it was likely a terrestrial body, but had no direct information about its mass. The new radial velocity observations of CoRoT-7b found that the planet has a mass five times that of Earth, and a radius 80 percent larger, giving it a density similar to that of Earth. The planet is the smallest exoplanet discovered to date, and also the closest to orbit its parent star.