  We announce the discovery of the transiting planet CoRoT-13b. Ground based
follow-up in CFHT and IAC80 confirmed CoRoT's observations. The mass of the
planet was measured with the HARPS spectrograph and the properties of the host
star were obtained analyzing HIRES spectra from the Keck telescope. It is a hot
Jupiter-like planet with an orbital period of 4.04 days, 1.3 Jupiter masses,
0.9 Jupiter radii, and a density of 2.34 g cm-3. It orbits a G0V star with
Teff=5945K, M*=1.09 Msun, R*=1.01 Rsun, solar metallicity, a lithium content of
+1.45 dex, and an estimated age between 0.12 and 3.15 Gyr. The lithium
abundance of the star is consistent with its effective temperature, activity
level, and age range derived from the stellar analysis. The density of the
planet is extreme for its mass. It implies the existence of an amount of heavy
elements with a mass between about 140 and 300 Mearth.
