The browser you are using is not supported by this website. All versions of Internet Explorer are no longer supported, either by us or Microsoft (read more here:

Please use a modern browser to fully experience our website, such as the newest versions of Edge, Chrome, Firefox or Safari etc.

Alexander Mustill. Profile picture.

Alexander Mustill


Alexander Mustill. Profile picture.

WTS-2 b: a hot Jupiter orbiting near its tidal destruction radius around a K dwarf


  • J. L. Birkby
  • M. Cappetta
  • P. Cruz
  • J. Koppenhoefer
  • O. Ivanyuk
  • Alexander Mustill
  • S. T. Hodgkin
  • D. J. Pinfield
  • B. Sipocz
  • G. Kovacs
  • R. Saglia
  • Y. Pavlenko
  • D. Barrado
  • A. Bayo
  • D. Campbell
  • S. Catalan
  • L. Fossati
  • M. -C. Galvez-Ortiz
  • M. Kenworthy
  • J. Lillo-Box
  • E. L. Martin
  • D. Mislis
  • E. J. W. de Mooij
  • S. V. Nefs
  • I. A. G. Snellen
  • H. Stoev
  • J. Zendejas
  • C. del Burgo
  • J. Barnes
  • N. Goulding
  • C. A. Haswell
  • M. Kuznetsov
  • N. Lodieu
  • F. Murgas
  • E. Palle
  • E. Solano
  • P. Steele
  • R. Tata

Summary, in English

We report the discovery of WTS-2 b, an unusually close-in 1.02-d hot Jupiter (M-P = 1.12M(J), R-P = 1.30R(J)) orbiting a K2V star, which has a possible gravitationally bound M-dwarf companion at 0.6 arcsec separation contributing similar to 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 similar to 40 Myr, assuming a tidal dissipation quality factor of Q(*)' = 10(6).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 T-shift similar to 17 s after 15 yr assuming Q(*)' = 10(6). 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 T-shift for WASP-18 b, finding that T-shift = 356 s after 10 yr for Q(*)' = 10(6), 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.


  • Lund Observatory - Has been reorganised

Publishing year







Monthly Notices of the Royal Astronomical Society





Document type

Journal article


Oxford University Press


  • Astronomy, Astrophysics and Cosmology


  • surveys
  • planets and satellites: detection
  • planets and satellites:
  • dynamical evolution and stability
  • planets and satellites: fundamental
  • parameters
  • planets and satellites: individual: WTS-2 b




  • ISSN: 1365-2966