Detection of the secondary eclipse of WASP-10b in the Ks-band⋆
Astronomy & Astrophysics EDP Sciences 574 (2015) a103
Carbon monoxide and water vapor in the atmosphere of the non-transiting exoplanet HD 179949 b⋆
Astronomy & Astrophysics EDP Sciences 565 (2014) a124
Fast spin of the young extrasolar planet β Pictoris b.
Nature 509:7498 (2014) 63-65
Abstract:
The spin of a planet arises from the accretion of angular momentum during its formation, but the details of this process are still unclear. In the Solar System, the equatorial rotation velocities and, consequently, spin angular momenta of most of the planets increase with planetary mass; the exceptions to this trend are Mercury and Venus, which, since formation, have significantly spun down because of tidal interactions. Here we report near-infrared spectroscopic observations, at a resolving power of 100,000, of the young extrasolar gas giant planet β Pictoris b (refs 7, 8). The absorption signal from carbon monoxide in the planet's thermal spectrum is found to be blueshifted with respect to that from the parent star by approximately 15 kilometres per second, consistent with a circular orbit. The combined line profile exhibits a rotational broadening of about 25 kilometres per second, meaning that β Pictoris b spins significantly faster than any planet in the Solar System, in line with the extrapolation of the known trend in spin velocity with planet mass.WTS-2 b: a hot Jupiter orbiting near its tidal destruction radius around a K dwarf
Monthly Notices of the Royal Astronomical Society Oxford University Press (OUP) 440:2 (2014) 1470-1489
Abstract:
We report the discovery of WTS-2 b, an unusually close-in 1.02-d hot Jupiter (MP = 1.12MJ, RP = 1.30RJ) orbiting a K2V star, which has a possible gravitationally bound M-dwarf companion at 0.6 arcsec separation contributing ∼20 per cent of the total flux in the observed J-band light curve. The planet is only 1.5 times the separation from its host star at which it would be destroyed by Roche lobe overflow, and has a predicted remaining lifetime of just ∼40 Myr, assuming a tidal dissipation quality factor of Q′⋆=106. Q′⋆ is a key factor in determining how frictional processes within a host star affect the orbital evolution of its companion giant planets, but it is currently poorly constrained by observations. We calculate that the orbital decay of WTS-2 b would correspond to a shift in its transit arrival time of Tshift ∼ 17 s after 15 yr assuming Q′⋆=106. A shift less than this would place a direct observational constraint on the lower limit of Q′⋆ in this system. We also report a correction to the previously published expected Tshift for WASP-18 b, finding that Tshift = 356 s after 10 yr for Q′⋆=106, which is much larger than the estimated 28 s quoted in WASP-18 b discovery paper. We attempted to constrain Q′⋆ via a study of the entire population of known transiting hot Jupiters, but our results were inconclusive, requiring a more detailed treatment of transit survey sensitivities at long periods. We conclude that the most informative and straightforward constraints on Q′⋆ will be obtained by direct observational measurements of the shift in transit arrival times in individual hot Jupiter systems. We show that this is achievable across the mass spectrum of exoplanet host stars within a decade, and will directly probe the effects of stellar interior structure on tidal dissipation.Identifying new opportunities for exoplanet characterisation at high spectral resolution
Astronomy & Astrophysics EDP Sciences 561 (2014) a150