TY - JOUR
T1 - WASP-128b
T2 - a transiting brown dwarf in the dynamical-tide regime
AU - Hodžić, Vedad
AU - Triaud, Amaury H. M. J.
AU - Anderson, David R.
AU - Bouchy, François
AU - Cameron, Andrew Collier
AU - Delrez, Laetitia
AU - Gillon, Michaël
AU - Hellier, Coel
AU - Jehin, Emmanuël
AU - Lendl, Monika
AU - Maxted, Pierre F. L.
AU - Pepe, Francesco
AU - Pollacco, Don
AU - Queloz, Didier
AU - Ségransan, Damien
AU - Smalley, Barry
AU - Udry, Stéphane
AU - West, Richard
PY - 2018/12/21
Y1 - 2018/12/21
N2 - Massive companions in close orbits around G dwarfs are thought to undergo rapid orbital decay due to runaway tidal dissipation. We report here the discovery of WASP-128b, a brown dwarf discovered by the WASP survey transiting a G0V host on a 2.2 d orbit, where the measured stellar rotation rate places the companion in a regime where tidal interaction is dominated by dynamical tides. Under the assumption of dynamical equilibrium, we derive a value of the stellar tidal quality factor logQ′⋆=6.96 ± 0.19. A combined analysis of ground-based photometry and high-resolution spectroscopy reveals a mass and radius of the host, M⋆ = 1.16 ± 0.04 M⊙, R⋆ = 1.16 ± 0.02 R⊙, and for the companion, Mb = 37.5 ± 0.8Mj, Rb = 0.94 ± 0.02Rj, placing WASP-128b in the driest parts of the brown dwarf desert, and suggesting a mild inflation for its age. We estimate a remaining lifetime for WASP-128b similar to that of some ultra-short period massive hot Jupiters, and note it may be a propitious candidate for measuring orbital decay and testing tidal theories.
AB - Massive companions in close orbits around G dwarfs are thought to undergo rapid orbital decay due to runaway tidal dissipation. We report here the discovery of WASP-128b, a brown dwarf discovered by the WASP survey transiting a G0V host on a 2.2 d orbit, where the measured stellar rotation rate places the companion in a regime where tidal interaction is dominated by dynamical tides. Under the assumption of dynamical equilibrium, we derive a value of the stellar tidal quality factor logQ′⋆=6.96 ± 0.19. A combined analysis of ground-based photometry and high-resolution spectroscopy reveals a mass and radius of the host, M⋆ = 1.16 ± 0.04 M⊙, R⋆ = 1.16 ± 0.02 R⊙, and for the companion, Mb = 37.5 ± 0.8Mj, Rb = 0.94 ± 0.02Rj, placing WASP-128b in the driest parts of the brown dwarf desert, and suggesting a mild inflation for its age. We estimate a remaining lifetime for WASP-128b similar to that of some ultra-short period massive hot Jupiters, and note it may be a propitious candidate for measuring orbital decay and testing tidal theories.
KW - Methods: data analysis
KW - Brown dwarfs
KW - Binaries: eclipsing
KW - Planets and satellites: dynamical evolution and stability
UR - http://adsabs.harvard.edu/abs/2018MNRAS.tmp.2403H
U2 - 10.1093/mnras/sty2512
DO - 10.1093/mnras/sty2512
M3 - Article
SN - 0035-8711
VL - 481
SP - 5091
EP - 5097
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -