d.j.a.brown@warwick.ac.uk David Brown (University of Warwick), SuperWASP Consor>um Discovery of WASP-­‐85 Ab: A Hot Jupiter in a Visual Binary System Summary •  P = 2.66 days •  Mpl = 1.09 ± 0.03 MJup •  Rpl = 1.44 ± 0.02 Rjup •  WASP-­‐85 Ab is a hot Jupiter planet orbiAng the brighter component of BD+07o2474. •  Host star has super-­‐Solar metallicity. Companion is a cooler K-­‐dwarf of similar magnitude. •  Ca II H+K measurements suggest both are strongly acAve, parAcularly when compared to other hot Jupiter hosts. •  Prot = 14.6 ± 1.5 days •  vsinIA = 3.41 ± 0.89 km/s •  Teff = 5685 ± 65 K •  Photometry is strongly diluted by light from companion star, affecAng planet radius esAmate. •  HARPS radial velociAes are uncontaminated. •  b = 0.044 +0.037 -­‐0.028 •  iorb = 89.72 +0.18 -­‐0.24 •  e = 0 •  Joint MCMC fit of photometry (excluding K2) and HARPS spectroscopy. •  Bayesian priors placed on Teff, vsinIA, [Fe/H], and third light contribuAon. •  Analysis of K2 data ongoing. •  Our photometric observaAons contain light from both binary components. •  We add a third light component to the standard transit model to account for this. •  This level of contaminaAon is included as a addiAonal variables. •  Defined per wavelength. •  If we don’t account for contaminaAon, the Rpl decreases by 18%. •  BD+07o2474 has been observed as part of K2 campaign 1. •  The two stellar components are indisAnguishable in K2 data. •  The K2 long cadence lightcurve (top) clearly shows variability from stellar acAvity. •  Removing acAvity reveals a consistent transit shape. •  The depth is consistent with other lightcurves, accounAng for diluAon. •  CORALIE (blue squares) and SOPHIE (red circles) observaAons are also diluted by the stellar companion. •  Our HARPS (black triangles) observaAons are undiluted. •  We use only HARPS data in our modelling. •  The primary effect of diluAon is to decrease RV semi-­‐
amplitude for affected datasets. •  We detect rotaAonal modulaAon in the WASP lightcurve, indicaAng Prot = 14.6 ± 1.5 days for one of the stellar components. •  Binary posiAon angle shows a clear, long-­‐term, negaAve trend. •  This suggests a binary period of ≥3000 years. •  VariaAon in mean binary angular separaAon suggests the binary is inclined relaAve to our line of sight by ≈45o. •  The planet's orbit is thus misaligned with the binary plane.