WASP-120 b, WASP-122 b, AND WASP-123 b: Three Newly Discovered Planets from the WASP-South Survey

We present the discovery by the WASP-South survey of three planets transiting moderately bright stars (V ≈ 11). WASP-120 b is a massive (4.85 M _Jup) planet in a 3.6-day orbit that we find likely to be eccentric (e={0.059}_-0.018^+0.025) around an F5 star. WASP-122 b is a hot Jupiter (1.28 M _Jup, 1.74 R _Jup) in a 1.7-day orbit about a G4 star. Our predicted transit depth variation caused by the atmosphere of WASP-122 b suggests it is well suited to characterization. WASP-123 b is a hot Jupiter (0.90 M _Jup, 1.32 R _Jup) in a 3.0-day orbit around an old (∼7 Gyr) G5 star.