R. G. West1, D. R. Anderson2, M. Gillon3,4, L. Hebb5, C. Hellier2, P. F. L. Maxted2, D. Queloz3, B. Smalley2, A. H. M. J. Triaud3, D. M. Wilson2, S. J. Bentley2, A. Collier Cameron5, B. Enoch5, K. Horne5, J. Irwin6, T. A. Lister7, M. Mayor3, N. Parley5, F. Pepe3, D. Pollacco8, D. Segransan3, M. Spano3, S. Udry3 and P. J. Wheatley9
1
Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK
2
Astrophysics Group, Keele University, Staffordshire ST5 5BG, UK
3
Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
4
Institut d'Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août, 17, Bat. B5C, Liège 1, Belgium
5
School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife KY16 9SS, UK
6
Department of Astronomy, Harvard University, 60 Garden Street, MS 10, Cambridge, MA 02138, USA
7
Las Cumbres Observatory, 6740 Cortona Dr. Suite 102, Santa Barbara, CA 93117, USA
8
Astrophysics Research Centre, School of Mathematics & Physics, Queen's University, University Road, Belfast BT7 1NN, UK
9
Department of Physics, University of Warwick, Coventry CV4 7AL, UK
R. G. West et al 2009 The Astronomical Journal 137 4834
We report the discovery of a low-density exoplanet transiting an 11th magnitude star in the Southern hemisphere. WASP-15b, which orbits its host star with a period P = 3.7520656 ± 0.0000028 d, has a mass M p = 0.542 ± 0.050 M J and radius R p = 1.428 ± 0.077 R J, and is therefore one of the least dense transiting exoplanets so far discovered (ρp = 0.247 ± 0.035 g cm–3). An analysis of the spectrum of the host star shows it to be of spectral type around F5, with an effective temperature T eff = 6300 ± 100 K and [Fe/H] = –0.17 ± 0.11.
binaries: eclipsing; planetary systems; stars: individual (WASP-15); techniques: photometric; techniques: radial velocities; techniques: spectroscopic
97.82.-j Extrasolar planetary systems
97.10.Cv Stellar structure, interiors, evolution, nucleosynthesis, ages
97.10.Wn Proper motions and radial velocities (line-of-sight velocities); space motions
97.10.Ri Luminosities; magnitudes; effective temperatures, colors, and spectral classification
Issue 6 (2009 June)
Received 2009 February 11 , accepted for publication 2009 March 16
Published 2009 April 29
R. G. West et al 2009 The Astronomical Journal 137 4834