spacetoday.net: Astronomers find first carbon-rich exoplanet

Posted: Fri, Dec 10, 2010, 7:47 AM ET (1247 GMT)
WASP-12b exoplanet illustration (NASA)

Astronomers announced this week the discovery of the first extrasolar planet dominated by carbon, a world whose interior may be filled with graphite and diamonds. The planet, WASP-12b, is about 1.4 times as massive as Jupiter and orbits a star 1,200 light-years away. Astronomers used NASA's Spitzer Space Telescope to observe the system as the planet moved behind the star to determine the composition of the planet. The planet was the first found with a ratio of carbon to oxygen greater than one, indicating the presence of excess carbon. The observations also confirmed that the exoplanet is among the hottest yet discovered, with a temperature on the star-facing side of 2,600 kelvin.