CoRoT-22 b: a validated 4.9 R-circle plus exoplanet in 10-d orbit

The CoRoT satellite has provided high-precision photometric light curves for more than 163 000 stars and found several hundreds of transiting systems compatible with a planetary scenario. If ground-based velocimetric observations are the best way to identify the actual planetsamong many possible configurations of eclipsing binary systems, recent transit surveys have shown that it is not always within reach of the radial-velocitydetection limits. In this paper, we present a transiting exoplanetcandidate discovered by CoRoT whose nature cannot be established from ground-based observations, and where extensive analyses are used to validate the planetscenario. They are based on observing constraints from radial-velocityspectroscopy, adaptive optics imaging and the CoRoT transit shape, as well as from priors on stellar populations, planetand multiple stellar systems frequency. We use the fully Bayesian approach developed in the PASTIS ( PlanetAnalysis and Small Transit Investigation Software) analysis software, and conclude that the planetscenario is at least 1400 times more probable than any other false-positive scenario. The primary star is a metallic solar-like dwarf, with M-s = 1.099 +/- 0.049 M-circle dot and R-s = 1.136(-0.090)(+0.038) R-circle dot. The validated planethas a radius of R-p = 4.88(-0.39)(+0.17) R-circle plus and mass less than 49 M-circle plus. Its mean density is smaller than 2.56 g cm(-3) and orbital periodis 9.7566 +/- 0.0012 d. This object, called CoRoT-22 b, adds to a large number of validated Kepler planets. These planetsdo not have a proper measurement of the mass but allow statistical characterization of exoplanetspopulation.