We report the discovery of a new transiting planet in the Southern Hemisphere .
It has been found by the WASP-south transit survey and confirmed photometrically and spectroscopically by the 1.2m Swiss Euler telescope , LCOGT 2m Faulkes South Telescope , the 60 cm TRAPPIST telescope and the ESO 3.6m telescope .
The orbital period of the planet is 2.94 days .
We find it is a gas giant with a mass of 0.88 \pm 0.10 M _ { \mathrm { J } } and a radius estimated at 0.96 \pm 0.05 R _ { \mathrm { J } } .
We have also obtained spectra during transit with the HARPS spectrograph and detect the Rossiter-McLaughlin effect despite its small amplitude .
Because of the low signal to noise of the effect and of a small impact parameter we can not place a constraint on the projected spin-orbit angle .
We find two conflicting values for the stellar rotation .
Our determination , via spectral line broadening gives v \sin I = 2.2 \pm 0.3 km s ^ { -1 } , while another method , based on the activity level using the index \log R ^ { \prime } _ { HK } , gives an equatorial rotation velocity of only v = 1.35 \pm 0.20 km s ^ { -1 } .
Using these as priors in our analysis , the planet could either be misaligned or aligned .
This should send strong warnings regarding the use of such priors .
There is no evidence for eccentricity nor of any radial velocity drift with time .