Introduction

CoRoT, (Convection, Rotation and Transits), is a small space telescope dedicated to photometry with extremely high precision in observations of large duration. The mission has two main objectives, which will be attained with observations of adjacent regions in the sky:

• Asteroseismology
• Detection of Extrasolar Planets

From its lauch th 27th of December 2006, the asteroseismology program is performing observations of large durations on individual stars to characterize their oscillations. In the 'central' program some solar-like stars are studied in detail with continuous observations lasting 5 months. Also, an 'exploratory' program is taking place, in which some stars from a large range of types are studied with shorter observations of about 2o days.

For the extrasolar planet program, CoRoT is intended to detect planets when they happen to pass ('transit') in front of their central star, which causes an observable diminution in the brightness of the star. CoRoT has found extrasolar planets that are significantly the smallest known today.

Physically, CoRoT is a small space telescope with a main mirror of 27cm diameter and a camera of 4 CCD detectors with a field of view of 3 by 3 degrees. CoRoT was launched in 2006, and the mission is still in space in 2012.

CoRoT is developed under leadership of the French space agency CNES, with participations by Spain, Austria, Belgium, and the European Space Agency (ESA). The Spanish participation begun in 1999. Its major contribution is the construction of a receiver station, whose antennas are in Villafranca near Madrid. Also Spanish scientists perform ground based observations for the definition of the stellar sample and contribute to the development of the data analysis software.