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

Birkby, J. L.; Cappetta, M.; Cruz, P.; Koppenhoefer, J.; Ivanyuk, O.; Mustill, Alexander LU ; Hodgkin, S. T.; Pinfield, D. J.; Sipocz, B. and Kovacs, G., et al. (2014) In Monthly Notices of the Royal Astronomical Society 440(2). p.1470-1489
Abstract
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.... (More)
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. (Less)
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keywords
surveys, planets and satellites: detection, planets and satellites:, dynamical evolution and stability, planets and satellites: fundamental, parameters, planets and satellites: individual: WTS-2 b
in
Monthly Notices of the Royal Astronomical Society
volume
440
issue
2
pages
1470 - 1489
publisher
Wiley-Blackwell
external identifiers
  • wos:000334742200040
  • scopus:84898972682
ISSN
1365-2966
DOI
10.1093/mnras/stu343
language
English
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yes
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6037cad5-c9b6-42e0-84a0-f2d603280c48 (old id 4482497)
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2014-06-19 14:22:52
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2017-11-12 03:11:57
@article{6037cad5-c9b6-42e0-84a0-f2d603280c48,
  abstract     = {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.},
  author       = {Birkby, J. L. and Cappetta, M. and Cruz, P. and Koppenhoefer, J. and Ivanyuk, O. and Mustill, Alexander and Hodgkin, S. T. and Pinfield, D. J. and Sipocz, B. and Kovacs, G. and Saglia, R. and Pavlenko, Y. and Barrado, D. and Bayo, A. and Campbell, D. and Catalan, S. and Fossati, L. and Galvez-Ortiz, M. -C. and Kenworthy, M. and Lillo-Box, J. and Martin, E. L. and Mislis, D. and de Mooij, E. J. W. and Nefs, S. V. and Snellen, I. A. G. and Stoev, H. and Zendejas, J. and del Burgo, C. and Barnes, J. and Goulding, N. and Haswell, C. A. and Kuznetsov, M. and Lodieu, N. and Murgas, F. and Palle, E. and Solano, E. and Steele, P. and Tata, R.},
  issn         = {1365-2966},
  keyword      = {surveys,planets and satellites: detection,planets and satellites:,dynamical evolution and stability,planets and satellites: fundamental,parameters,planets and satellites: individual: WTS-2 b},
  language     = {eng},
  number       = {2},
  pages        = {1470--1489},
  publisher    = {Wiley-Blackwell},
  series       = {Monthly Notices of the Royal Astronomical Society},
  title        = {WTS-2 b: a hot Jupiter orbiting near its tidal destruction radius around a K dwarf},
  url          = {http://dx.doi.org/10.1093/mnras/stu343},
  volume       = {440},
  year         = {2014},
}