WASP-180Ab: Doppler tomography of a hot Jupiter orbiting the primary star in a visual binary
Bouchy, F.; Queloz, D.; Ségransan, D.; Collier Cameron, A.; Delrez, L.; Gillon, M.; Lendl, M.; Maxted, P. F. L.; Pollacco, D.; Udry, S.; Pepe, F.; Jehin, E.; Barkaoui, K.; Smalley, B.; Anderson, D. R.; Hellier, C.; McCormac, J.; Turner, O. D.; West, R. G.; Triaud, A. H. M. J.; Nielsen, L. D.; Brown, D. J. A.; Evans, D.; Burdanov, A.; Thompson, S.; Temple, L. Y.; Ducrot, E.; Murray, C.; Zouhair, B.
United Kingdom, Morocco, Belgium, Switzerland
Abstract
We report the discovery and characterization of WASP-180Ab, a hot Jupiter confirmed by the detection of its Doppler shadow and by measuring its mass using radial velocities. We find the 0.9 ± 0.1 MJup, 1.24 ± 0.04 RJup planet to be in a misaligned, retrograde orbit around an F7 star with Teff = 6500 K and a moderate rotation speed of vsin i⋆ = 19.9 km s-1. The host star is the primary of a V = 10.7 binary, where a secondary separated by ∼5 arcsec (∼1200 au) contributes ∼ 30 per cent of the light. WASP-180Ab therefore adds to a small sample of transiting hot Jupiters known in binary systems. A 4.6-d modulation seen in the WASP data is likely to be the rotational modulation of the companion star, WASP-180B.