Astrophysics - Earth and Planetary Astrophysics; planetary systems
Abstract :
[en] 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 (T[SUB]eff[/SUB] = 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 main-sequence star we estimate that the planet has a mass M [SUB]p[/SUB] = 0.56 ± 0.02M [SUB]Jup[/SUB] and a radius R [SUB]p[/SUB] = 1.12 ± 0.04R [SUB]Jup[/SUB]. In addition, there is a linear trend of 40 m s[SUP]–1[/SUP] yr[SUP]–1[/SUP] 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.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Maxted, P. F. L.; Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK
Anderson, D. R.; Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK
Gillon, Michaël ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique et traitement de l'image
Hellier, C.; Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK
Queloz, D.; Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
Smalley, B.; Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK
Triaud, A H M J; Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
West, R. G.; Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH, UK
Wilson, D. M.; Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK
Bentley, S. J.; Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK
Cegla, H.; Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK ; Physics and Astronomy Department, Vanderbilt University, 6301 Stevenson Center, Nashville, TN 37235, USA ; Astrophysics Research Centre, School of Mathematics and Physics, Queen's University, University Road, Belfast, BT7 1NN, UK
Collier Cameron, A.; School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK
Enoch, B.; School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK
Hebb, L.; School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK
Horne, K.; School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK
Irwin, J.; Department of Astronomy, Harvard University, 60 Garden Street, MS 10, Cambridge, MA 02138, USA
Lister, T. A.; Las Cumbres Observatory, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117, USA
Mayor, M.; Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
Parley, N.; School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK
Pepe, F.; Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
Pollacco, D.; Astrophysics Research Centre, School of Mathematics and Physics, Queen's University, University Road, Belfast, BT7 1NN, UK
Segransan, D.; Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
Udry, S.; Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
Wheatley, P. J.; Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
