HATS-4b: A Dense Hot Jupiter Transiting a Super Metal-rich G star

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 ≈ 2 . 5167 days, mass of M p ≈ 1 . 32 M Jup , radius of R p ≈ 1 . 02 R Jup , and density of ρ p = 1 . 55 ± 0 . 16 g cm − 3 ≈ 1 . 24 ρ Jup . The host star has a mass of 1 . 00 M , a radius of 0 . 92 R , 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 ⊕ . 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 v sin i and macroturbulence using high resolution spectra.