[1] Institut d'Astrophysique de Paris, UMR 7095 CNRS, Université Pierre and Marie Curie, 98 bis blv Arago, 75014 Paris, France
[2] European Southern Observatory, Casilla 19001, Vitacura 19, Santiago, Chile
[3] University College of London, Deparment of Physics and Astronomy, Gower Street, London, WC1E 6BT, United Kingdom
[4] University of Notre Dame, Department of Physics, 225 Nieuwland Science Hall, Notre Dame, United States
[5] University of Tasmania, School of Mathematics and Physics, GPO, Private Bag 37, Hobart, TAS 7001, Australia
[6] Dipartimento di Fisica, Università Degli Studi di Roma Tor Vergata, Rome, Italy
[7] Department of Astronomy, 610 Space Sciences Building, Cornell University, Ithaca, NY 14853, United States
[8] Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540, United States
[9] Department of Astronomy, Ohio State University, 140 W. 18th Ave., Columbus, OH 43210, United States
[10] Department of Earth and Space Science, Osaka University, Osaka 560-0043, Japan
[11] Observatoire Midi-Pyrénées, UMR 5572, 14 avenue Edouard Belin, 31400 Toulouse, France
[12] Institute of Information and Mathematical Sciences, Massey University, North Shore Mail Centre, Private Bag 102-904, Auckland, New Zealand
[13] Department of Physics and Astrophysics, Faculty of Science, Nagoya University, Nagoya 464-8602, Japan
[14] Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland
[15] Laboratoire d'Astrophysique de Grenoble, UMR 5571 Université Joseph Fourier, CNRS, BP 53, 38051 Grenoble Cedex 9, France