methods: data analysis; techniques: photometric; techniques: radial velocities; planetary systems
Abstract :
[en] We have detected low-amplitude radial-velocity variations in two stars, USNO-B1.0 1219-0005465 (GSC 02265-00107 = WASP-1) and USNO-B1.0 0964-0543604 (GSC 00522-01199 = WASP-2). Both stars were identified as being likely host stars of transiting exoplanets in the 2004 SuperWASP wide-field transit survey. Using the newly commissioned radial-velocity spectrograph SOPHIE at the Observatoire de Haute-Provence, we found that both objects exhibit reflex orbital radial-velocity variations with amplitudes characteristic of planetary-mass companions and in-phase with the photometric orbits. Line-bisector studies rule out faint blended binaries as the cause of either the radial-velocity variations or the transits. We perform preliminary spectral analyses of the host stars, which together with their radial-velocity variations and fits to the transit light curves yield estimates of the planetary masses and radii. WASP-1b and WASP-2b have orbital periods of 2.52 and 2.15 d, respectively. Given mass estimates for their F7V and K1V primaries, we derive planet masses 0.80-0.98 and 0.81-0.95 times that of Jupiter, respectively. WASP-1b appears to have an inflated radius of at least 1.33 R[SUB]Jup[/SUB], whereas WASP-2b has a radius in the range 0.65-1.26 R[SUB]Jup[/SUB].
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Cameron, A Collier; School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS
Bouchy, F.; Institut d'Astrophysique de Paris, CNRS (UMR 7095) - Université Pierre & Marie Curie, 98bis bvd. Arago, 75014 Paris, France ; Observatoire de Haute-Provence, 04870 St Michel l'Observatoire, France
Hébrard, G.; Institut d'Astrophysique de Paris, CNRS (UMR 7095) - Université Pierre & Marie Curie, 98bis bvd. Arago, 75014 Paris, France
Maxted, P.; Astrophysics Group, Keele University, Staffordshire ST5 5BG
Pollacco, D.; ARC, Main Physics Building, School of Mathematics & Physics, Queen's University, University Road, Belfast BT7 1NN
Pont, F.; Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland
Skillen, I.; Isaac Newton Group of Telescopes, Apartado de Correos 321, E-38700 Santa Cruz de la Palma, Tenerife, Spain
Smalley, B.; Astrophysics Group, Keele University, Staffordshire ST5 5BG
Street, R. A.; ARC, Main Physics Building, School of Mathematics & Physics, Queen's University, University Road, Belfast BT7 1NN
West, R. G.; Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH
Wilson, D. M.; Astrophysics Group, Keele University, Staffordshire ST5 5BG
Aigrain, S.; Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA
Christian, D. J.; ARC, Main Physics Building, School of Mathematics & Physics, Queen's University, University Road, Belfast BT7 1NN
Clarkson, W. I.; Department of Physics and Astronomy, The Open University, Milton Keynes MK7 6AA ; STScI, 3700 San Martin Drive, Baltimore, MD 21218, USA
Enoch, B.; Department of Physics and Astronomy, The Open University, Milton Keynes MK7 6AA
Evans, A.; Astrophysics Group, Keele University, Staffordshire ST5 5BG
Fitzsimmons, A.; ARC, Main Physics Building, School of Mathematics & Physics, Queen's University, University Road, Belfast BT7 1NN
Fleenor, M.; Volunteer Observatory, 10305 Mantooth Lane Knoxville, TN 37932, USA
Gillon, Michaël ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique et traitement de l'image
Haswell, C. A.; Department of Physics and Astronomy, The Open University, Milton Keynes MK7 6AA
Hebb, L.; School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS
Hellier, C.; Astrophysics Group, Keele University, Staffordshire ST5 5BG
Hodgkin, S. T.; Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA
Horne, K.; School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS
Irwin, J.; Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA
Kane, S. R.; Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055, USA
Keenan, F. P.; ARC, Main Physics Building, School of Mathematics & Physics, Queen's University, University Road, Belfast BT7 1NN
Loeillet, B.; Laboratoire d'Astrophysique de Marseille, BP 8, 13376 Marseille Cedex 12, France
Lister, T. A.; School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS ; Astrophysics Group, Keele University, Staffordshire ST5 5BG
Mayor, M.; Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland
Moutou, C.; Laboratoire d'Astrophysique de Marseille, BP 8, 13376 Marseille Cedex 12, France
Norton, A. J.; Department of Physics and Astronomy, The Open University, Milton Keynes MK7 6AA
Osborne, J.; Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH
Parley, N.; Department of Physics and Astronomy, The Open University, Milton Keynes MK7 6AA
Queloz, D.; Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland
Ryans, R.; ARC, Main Physics Building, School of Mathematics & Physics, Queen's University, University Road, Belfast BT7 1NN
Triaud, A H M J; School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS
Udry, S.; Observatoire de Genève, Université de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland
Wheatley, P. J.; Department of Physics, University of Warwick, Coventry CV4 7AL
Bakos G. A. et al., 2006, ApJ, in press (astro-ph/0609369)
Baranne A. et al., 1996, A&AS, 119, 373
Blackwell D. E., Shallis M. J., 1977, MNRAS, 180, 177
Bouchy F., Pont F., Santos N. C., Melo C., Mayor M., Queloz D., Udry S., 2004, A&A, 421, L13
Bouchy F. et al., 2005, A&A, 444, L15
Bouchy F. et al. (the SOPHIE team), 2006, in Arnold L., Bouchy F., Moutou C., eds, Tenth Anniversary of 51 Peg-b: Status of and Prospects for Hot Jupiter studies, p. 319
Brown T. M., Charbonneau D., Gilliland R. L., Noyes R. W., Burrows A., 2001, ApJ, 552, 699
Castelli F., Gratton R. G., Kuracz R. L., 1997, A&A, 318, 841
Charbonneau D., Brown T. M., Latham D. W., Mayor M., 2000, ApJ, 529, L45
Charbonneau D., Brown T. M., Noyes R. W., Gilliland R. L., 2002, ApJ, 568, 377
Charbonneau D. et al., 2005, ApJ, 626, 523
Charbonneau D., Winn J. N., Everett M. E., Latham D. W., Holman M. J., Esquerdo G. A., O'Donovan F. T., 2006, ApJ, submitted (astro-ph/0610589)
Christian D. J. et al., 2006, MNRAS, 372, 1117
Claret A., 2000, A&A, 363, 1081
Collier Cameron A. et al., 2006, MNRAS, 373, 799
Deming D., Seager S., Richardson L. J., Harrington J., 2005, Nat, 434, 740
Deming D., Harrington J., Seager S., Richardson L. J., 2006, ApJ, 644, 560
