Wasp-22 b: A transiting "hot jupiter" planet in a hierarchical triple system

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

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    We report the discovery of a transiting planet orbiting the star TYC 6446-326-1. The star,WASP-22, is a moderately bright (V = 12.0) solar-type star (Teff = 6000±100 K, [Fe/H]= -0.05±0.08). The light curve of the star obtained with the WASP-South instrument shows periodic transit-like features with a depth of about 1% and a duration of 0.14 days. The presence of a transit-like feature in the light curve is confirmed using z-band photometry obtained with Faulkes Telescope South. High-resolution spectroscopy obtained with the CORALIE and HARPS spectrographs confirms the presence of a planetary mass companion with an orbital period of 3.533 days in a near-circular orbit. From a combined analysis of the spectroscopic and photometric data assuming that the star is a typical mainsequence star we estimate that the planet has a mass Mp = 0.56 ± 0.02MJup and a radius Rp = 1.12 ± 0.04RJup. In addition, there is a linear trend of 40 m s-1 yr-1 in the radial velocities measured over 16 months, from which we infer the presence of a third body with a long-period orbit in this system. The companion may be a low mass M-dwarf, a white dwarf, or a second planet.

    Original languageEnglish
    Pages (from-to)2007-2012
    Number of pages6
    JournalAstronomical Journal
    Issue number6
    Publication statusPublished - 1 Dec 2010



    • Planetary systems

    ASJC Scopus subject areas

    • Astronomy and Astrophysics
    • Space and Planetary Science

    Cite this

    Maxted, P. F. L., Anderson, D. R., Gillon, M., Hellier, C., Queloz, D., Smalley, B., Triaud, A. H. M. J., West, R. G., Wilson, D. M., Bentley, S. J., Cegla, H., Cameron, A. C., Enoch, B., Hebb, L., Horne, K., Irwin, J., Lister, T. A., Mayor, M., Parley, N., ... Wheatley, P. J. (2010). Wasp-22 b: A transiting "hot jupiter" planet in a hierarchical triple system. Astronomical Journal, 140(6), 2007-2012. https://doi.org/10.1088/0004-6256/140/6/2007