spacetoday.net: Dozens of new exoplanets discovered

Dozens of new exoplanets discovered

Posted: Tue, Oct 20, 2009, 6:58 AM ET (1058 GMT)
Gliese 667 exoplanet illustration (ESO)

Astronomers announced Monday the discovery of over 30 new extrasolar planets, bringing the total number of such worlds found to date to 400. The discoveries, 32 in total, were made by a state-of-the-art instrument at the European Southern Observatory in Chile, which found the exoplanets by detecting minute, periodic shifts in stellar spectral lines caused by orbiting planets. A number of the discoveries are around stars that are "metal-deficient", setting constraints on the amount of heavy elements needed for planet formation. Astronomers now estimate that at least 40 percent of solar-type stars have low-mass planets.