D. R. Anderson1, A. Collier Cameron2, C. Hellier1, M. Lendl3, T. A. Lister4, P. F. L. Maxted1, D. Queloz3, B. Smalley1, A. M. S. Smith1, A. H. M. J. Triaud3, R. G. West5, D. J. A. Brown2, M. Gillon6, F. Pepe3, D. Pollacco7, D. Ségransan3, R. A. Street4 and S. Udry3
Astrophysics Group, Keele University,
2 SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife KY16 9SS, UK
3 Observatoire de Genève, Université de Genève, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
4 Las Cumbres Observatory, 6740 Cortona Dr. Suite 102, Santa Barbara, CA 93117, USA
5 Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK
6 Institut d’Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 17, Bat. B5C, Liège 1, Belgium
7 Astrophysics Research Centre, School of Mathematics & Physics, Queen’s University, University Road, Belfast BT7 1NN, UK
Received: 25 November 2010
Accepted: 18 May 2011
We report the discovery of the low-density, transiting giant planet WASP-31b. The planet is 0.48 Jupiter masses and 1.55 Jupiter radii. It is in a 3.4-day orbit around a metal-poor, late-F-type, V = 11.7 dwarf star, which is a member of a common proper motion pair. In terms of its low density, WASP-31b is second only to WASP-17b, which is a more highly irradiated planet of similar mass.
Key words: binaries: eclipsing / planetary systems / stars: individual: WASP-31
Based in part on observations made with the HARPS spectrograph on the 3.6-m ESO telescope (proposal 085.C-0393) and with the CORALIE spectrograph and the Euler camera on the 1.2-m Euler Swiss telescope, both at the ESO La Silla Observatory, Chile.
The photometric time-series and radial-velocity data used in this work are available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (126.96.36.199) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/531/A60
© ESO, 2011