Planet detected

The Corot orbiting space telescope has found the smallest terrestrial planet ever detected outside the Solar System.

The 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 the 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.

The development of the focal plane on board the spacecraft that detected the planet was created under the supervision of engineers at LESIA, who oversaw its development at EADS Sodern.

The focal plane itself is an array of four CCD imaging sensors developed under a CNES contract by Chelmsford-based e2v.

The CCDs are frame transfer matrices of 2048 x 4096 pixels, which work in visible light in an MPP (multi-phase pin) mode. This mode, associated with a temperature regulated at -40°C, reduces dark currents to a very low level.

'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 homogeneity and stability over more than 150 days of continuous observations,' said Michel Auvergne, instrument scientist, LESIA.

Brian McAllister, general manager of space and scientific imaging at e2v, said: 'Our 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.'