29 Apr 2009
CHELMSFORD, UK, 28 April 2009 – e2v Charge Couple Device (CCD) imaging sensors have enabled the Corot orbiting space telescope to find the smallest terrestrial planet ever detected outside the Solar System. The amazing planet is less than twice the size of Earth and orbits a Sun-like star. Its temperature is so high that it is possibly covered in lava or water vapour.
The Corot mission is led by the French space agency (CNES) with contributions from ESA, Austria, Belgium, Germany, Spain and Brazil. Since being launched into space on 27 December 2006, Corot has been studying the internal structure of stars to seek out extra solar planets around nearby stars.
LESIA (Paris Observatory) oversaw the development of the Corot focal plane by EADS Sodern, which is an array of 4 e2v CCD imaging sensors (developed under CNES contract): 2 to search for exoplanets and 2 to study the internal structure of stars. The CCDs are frame transfer matrices of 2048 x 4096 pixels and the technology used (13.5-µm thinned, back illuminated) works in visible light in the MPP (Multi Phase Pin) mode. This mode, associated with a temperature regulated at -40° C, reduces the dark currents to a very low level. The detectors also have a high quantum efficiency in the spectral range (370 nm, 950 nm).
"The photometric signal produced by the 'transit' of this very small planet in front of its parent star is as small as 200 parts per million. This accuracy is achieved essentially due to the unique properties of the e2v CCDs, and in particular their space homogeneity and stability over more than 150 days of continuous observations", says Michel Auvergne, Instrument scientist, from LESIA.
"This discovery is a very important step on the road to understanding the formation and evolution of our planet," said Malcolm Fridlund, ESA's COROT Project Scientist. "For the first time, we have unambiguously detected a planet that is 'rocky' in the same sense as our own Earth. We now have to understand this object further to put it into context, and continue our search for smaller, more Earth-like objects with Corot," he added.
Brian McAllister, General Manager of Space & Scientific Imaging at e2v said: "e2v's technology is used in many space applications for visible imaging and we are very excited that our imaging sensors have enabled Corot to make this important discovery, which is a big step forward in understanding the universe."