We report the discovery of a 7.3 M _ { J } 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 \pm 0.5 M _ { J } and a radius of 1.28 \pm 0.08 R _ { J } .
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 \pm 20 pc .
Spectral analysis of the host star reveals a temperature of 6475 \pm 100 K , log g = 4.07 cm s ^ { -2 } and v \sin i = 4.9 \pm 1.0 km s ^ { -1 } , and also a high lithium abundance , \log N ( { Li } ) = 2.84 \pm 0.05 .
The stellar density , effective temperature and rotation rate suggest an age for the system of about 0.5–1.0 Gyr .