The mission's two objectives were to search for extrasolar planets with short orbital periods, particularly those of large terrestrial size, and to perform asteroseismology by measuring solar-like oscillations in stars.

[14] The satellite, built in the Cannes Mandelieu Space Center, had a launch mass of 630 kg, was 4.10 m long, 1.984 m in diameter and was powered by two solar panels.

Both these "eyes" of CoRoT have been studied in preliminary observations carried out between 1998 and 2005,[15] allowing the creation of a database, called CoRoTsky,[16] with data about the stars located in these two patches of sky.

In fact, stellar targets brighter than 11 saturated the exoplanets CCD detectors, yielding inaccurate data, whilst stars dimmer than 16 do not deliver enough photons to allow planetary detections.

CoRoT was sensitive enough to detect rocky planets with a radius two times larger than Earth, orbiting stars brighter than 14;[18] it is also expected to discover new gas giants in the whole magnitude range.

The mission began on 27 December 2006 when a Russian Soyuz 2-1b rocket lifted the satellite into a circular polar orbit with an altitude of 827 km .

The CoRoT equipment bay, which houses the data acquisition and pre-processing electronics, was constructed by the LESIA Laboratory at the Paris Observatory and took 60 person-years to complete.

According to the press release announcing the first results, CoRoT's instruments are performing with higher precision than had been predicted, and may be able to find planets down to the size of Earth with short orbits around small stars.

Candidate detections have been obtained for about 2.3% of all CoRoT targets, but finding periodic transit events isn't enough to claim a planet discovery, since several configurations could mimic a transiting planet, such as stellar binaries, or an eclipsing fainter star very close to the target star, whose light, blended in the light curve, can reproduce transit-like events.

For the brighter targets, the prism in front of the exoplanets CCDs provides photometry in 3 different colors, enabling to reject planet candidates that have different transit depths in the three channels, a behaviour typical of binary stars.

These tests allow to discard 83% of the candidate detections,[24] whilst the remaining 17% are screened with photometric and radial velocity follow-up from a network of telescopes around the world.

Photometric observations, required to rule out a possible contamination by a diluted eclipsing binary in close vicinity of the target,[25] is performed on several 1 m-class instruments, but also employs the 2 m Tautenburg telescope in Germany and the 3,6 m CFHT/Megacam in Hawaii.

The radial velocity follow-up allows to discard binaries or even multiple star system and, given enough observations, provide the mass of the exoplanets found.

[26] Once the planetary nature of the candidate is established, high-resolution spectroscopy is performed on the host star, in order to accurately determine the stellar parameters, from which further exoplanet characteristics can be derived.

Sometimes the faintness of the target star or its characteristics, such as a high rotational velocity or strong stellar activity, do not allow to determine unambiguously the nature or the mass of the planetary candidate.

Each of these modes can be mathematically represented by a spherical harmonic of degree l and azimuthal order m. Some examples are presented here below with a color scheme in which blue (red) indicates contracting (expanding) material.

Helioseismology analyses have also unveiled the solar internal rotational profile, the precise extent of the convective envelope and the location of the helium ionization zone.

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.

This additional mixing has very important consequences since it involves longer time scales for nuclear burning phases and may in particular affect the value of the stellar mass at the transition between those stars which end up their life as white dwarfs and those which face a final supernova explosion.

A major success of CoRoT has been the discovery of radial and long-lived non-radial oscillations in thousands of red giants in the exo field.

Massive variable main sequence stars have frequency spectra dominated by acoustic modes excited by the κ mechanism at work in layers where partial ionization of iron group elements produce a peak in opacity.

As in lower mass stars the extent of the fully or partially mixed region located just above the convective core (extra-mixed zone) is one of the main uncertainties affecting theoretical modeling.

At such a young age, the cluster is an ideal target to investigate many different scientific questions connected to the formation of stars and early stellar evolution.

The Canadian space mission MOST targeted the brightest stars in the cluster in the optical light, while CoRoT observed the fainter members.

[82] Exciting insights into the earliest phases of stellar evolution also come from the comparison of the variability present in the optical light to that in the infrared and the X-ray regime.

[84] The eclipse phenomenon plays a key role since global parameters can immediately follow, bringing invaluable constraints, in addition to the seismic ones, to stellar modeling.

The Kepler mission (NASA) has continuously observed the same field for many years and thus had the ability to detect Earth sized planets located farther from their stars.

The moderate number of exoplanets discovered by CoRoT (34 during the 6 years of operation), is explained by the fact that a confirmation should absolutely be provided by ground-based telescopes, before any announcement is made.

In consequence, the CoRoT exoplanet science team has decided to publish confirmed and fully characterized planets only and not simple candidate lists.

On the other hand, the approach also increases the scientific return of the mission, as the set of published CoRoT discoveries constitute some of the best exoplanetary studies carried out so far.