At the beginning of the mission, two out of four CCDs were assigned to asteroseismic observations of bright stars (apparent magnitude 6 to 9) in the so-called "seismo field" while the other CCDs were reserved for exoplanet hunting in the so-called "exo field". Albeit with a lower signal to noise ratio, interesting science on stars was also obtained from the exoplanets channel data, where the probe records several thousands of light curves from every observed field. Stellar activity, rotation periods, star spot evolution, star–planet interactions, multiple star systems are nice extras in addition to the main asteroseismic program. This exo field also turned out to be of incalculable richness in asteroseismic discoveries. During the first six years of its mission, CoRoT has observed about 150 bright stars in the "seismo field" and more than 150 000 weak stars in the "exo field". The figure shows where most of them are located in the Hertzsprung–Russell diagram together with some others observed from the ground.