The Corot orbiting space telescope has discovered the smallest terrestrial planet ever detected outside the Solar System.
The planet, which is less than twice the size of Earth, was identified using image sensors developed in the UK by e2v.
LESIA (Paris Observatory) oversaw the development of the Corot focal plane by EADS Sodern, which is an array of four e2v CCD imaging sensors.
“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,” said Michel Auvergne, Instrument scientist, from LESIA.
“This accuracy is achieved essentially due to the unique properties of the CCDs, and in particular their space homogeneity and stability over more than 150 days of continuous observations”, said Auvergne.
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).
“This 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,” said Brian McAllister, General Manager of Space & Scientific Imaging at e2v
Launched in 2006, the Corot mission is led by the French space agency (CNES) with contributions from ESA, Austria, Belgium, Germany, Spain and Brazil.