  We report the discovery of a 7.3 Mjup exoplanet WASP-14b, one of the most
massive transiting exoplanets observed to date. The planet orbits the
tenth-magnitude F5V star USNO-B1 11118-0262485 with a period of 2.243752 days
and orbital eccentricity e = 0.09. A simultaneous fit of the transit light
curve and radial velocity measurements yields a planetary mass of 7.3+/-0.5
Mjup and a radius of 1.28+/-0.08 Rjup. This leads to a mean density of about
4.6 g/cm^3 making it densest transiting exoplanets yet found at an orbital
period less than 3 days. We estimate this system to be at a distance of
160+/-20 pc. Spectral analysis of the host star reveals a temperature of
6475+/-100 K, log g = 4.07 cm/s^2 and vsin i = 4.9+/-1.0 km/s, and also a high
lithium abundance, log N(Li} = 2.84+/-0.05. The stellar density, effective
temperature and rotation rate suggest an age for the system of about 0.5-1.0
Gyr.

Astrophysics