Three transiting planet discoveries from the Wide Angle Search for Planets: WASP-85 A b; WASP-116 b, and WASP-149 b

Abstract: (abridged) We report the discovery of three new transiting planets: WASP-85 A b, WASP-116 b, and WASP-149 b. WASP-85 b orbits its host star every 2.66 days, and has a mass of 1.25 M_Jup and a radius of 1.25 R_Jup. The host star is of G5 spectral type, with magnitude V = 11.2, and lies 141 pc distant. The system has a K-dwarf binary companion, WASP-85 B, at a separation of ~1.5". The close proximity of this companion leads to contamination of our photometry, decreasing the apparent transit depth that we account for during our analysis. Analysis of the Ca II H+K lines shows strong emission that implies that both binary components are strongly active. WASP-116 b is a warm, mildly inflated super-Saturn, with a mass of 0.59 M_Jup and a radius of 1.43 R_Jup. It was discovered orbiting a metal-poor ([Fe/H] = -0.28 dex), cool (T_eff = 5950 K) G0 dwarf every 6.61 days. WASP-149 b is a typical hot Jupiter, orbiting a G6 dwarf with a period of 1.33 days. The planet has a mass and radius of 1.05 M_Jup and 1.29 R_Jup, respectively. The stellar host has an effective temperature of T_eff = 5750 K and has a metallicity of [Fe/H] = 0.16 dex. WASP photometry of the system is contaminated by a nearby star; we therefore corrected the depth of the WASP transits using the measured dilution. WASP-149 lies inside the 'Neptune desert' identified in the planetary mass-period plane by Mazeh, Holczer & Faigler (2016). We model the modulation visible in the K2 lightcurve of WASP-85 using a simple three-spot model consisting of two large spots on WASP-85 A, and one large spot on WASP-85 B, finding rotation periods of 13.1+/-0.1 days for WASP-85 A and 7.5+/-0.03 days for WASP-85 B. We estimate stellar inclinations of I_A = 66.8+/-0.7 degrees and I_B = 39.7+/-0.2 degrees, and constrain the obliquity of WASP-85 A b to be psi<27 degrees. We therefore conclude that WASP-85 A b is very likely to be aligned.