Abstract

We report the discovery by the HATSouth survey of HATS-4b, an extrasolar planet transiting a V = 13.46 mag G star. HATS-4b has a period of P approximate to 2.5167 days, mass of M-p approximate to 1.32 M-Jup, radius of R-p approximate to 1.02 R-Jup, and density of rho(p) = 1.55 +/- 0.16 g cm(-3) approximate to 1.24 rho(Jup). The host star has a mass of 1.00 M-circle dot, a radius of 0.92 R-circle dot, and a very high metallicity [Fe/H]= 0.43 +/- 0.08. HATS-4b is among the densest known planets with masses between 1 and 2 M-J and is thus likely to have a significant content of heavy elements of the order of 75 M-circle plus. In this paper we present the data reduction, radial velocity measurements, and stellar classification techniques adopted by the HATSouth survey for the CORALIE spectrograph. We also detail a technique for simultaneously estimating nu sin i and macroturbulence using high resolution spectra.