Discovery and characterization of WASP-6b, an inflated sub-Jupiter mass planet transiting a solar-type star

M. Gillon, D. R. Anderson, A. H M J Triaud, C. Hellier, P. F L Maxted, D. Pollaco, D. Queloz, B. Smalley, R. G. West, D. M. Wilson, S. J. Bentley, A. Collier Cameron, B. Enoch, L. Hebb, K. Horne, J. Irwin, Y. C. Joshi, T. A. Lister, M. Mayor, F. PepeN. Parley, D. Segransan, S. Udry, P. J. Wheatley

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We report the discovery of WASP-6b, an inflated sub-Jupiter mass planet transiting every 3.3610060+0.0000022 -0.0000035 days a mildly metal-poor solar-type star of magnitude V = 11.9. A combined analysis of the WASP photometry, high-precision followup transit photometry and radial velocities yield a planetary mass Mp = 0.503+0.019 -0.038 Mj and radius Rp = 1.224 +0.051-0.052 Rj, resulting in a density ρp = 0.27 ± 0.05 ρj. The mass and radius for the host star are M* = 0.88+0.05 -0.08 M and R* = 0.870+0.025 -0.036 R⊙. The non-zero orbital eccentricity e = 0.054 +0.018 -0.015 that we measure suggests that the planet underwent a massive tidal heating ∼1 Gyr ago that could have contributed to its inflated radius. High-precision radial velocities obtained during a transit allow us to measure a sky-projected angle between the stellar spin and orbital axis β = 11+14 -18 deg. In addition to similar published measurements, this result favors a dominant migration mechanism based on tidal interactions with a protoplanetary disk.

Original languageEnglish
Pages (from-to)785-792
Number of pages8
JournalAstronomy and Astrophysics
Issue number2
Publication statusPublished - 1 Jul 2009
Externally publishedYes



  • Binaries: eclipsing
  • Planetary systems
  • Stars: individual: WASP-6
  • Techniques: photometric
  • Techniques: radial velocities
  • Techniques: spectroscopic

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Gillon, M., Anderson, D. R., Triaud, A. H. M. J., Hellier, C., Maxted, P. F. L., Pollaco, D., Queloz, D., Smalley, B., West, R. G., Wilson, D. M., Bentley, S. J., Cameron, A. C., Enoch, B., Hebb, L., Horne, K., Irwin, J., Joshi, Y. C., Lister, T. A., Mayor, M., ... Wheatley, P. J. (2009). Discovery and characterization of WASP-6b, an inflated sub-Jupiter mass planet transiting a solar-type star. Astronomy and Astrophysics, 501(2), 785-792.