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WASP-1b and WASP-2b: two new transiting exoplanets detected with SuperWASP and SOPHIE

Collier Cameron, A.; Bouchy, F.; Hebrard, G.; Maxted, P.; Pollacco, D.; Pont, F.; Skillen, I.; Smalley, B.; Street, R. A.; West, R. G.; Wilson, D. M.; Aigrain, S.; Christian, D. J.; Clarkson, W. I.; Enoch, B.; Evans, A.; Fitzsimmons, A.; Fleenor, M.; Gillon, M.; Haswell, C. A.; Hebb, L.; Hellier, C.; Hodgkin, S. T.; Horne, K.; Irwin, J.; Kane, S. R.; Keenan, F. P.; Loellet, B.; Lister, T. A.; Mayor, M.; Moutou, C.; Norton, A. J.; Osborne, J.; Parley, N.; Queloz, D.; Ryans, R.; Triaud, A. H. M. J.; Udry, S. and Wheatley, P. J. (2007). WASP-1b and WASP-2b: two new transiting exoplanets detected with SuperWASP and SOPHIE. Monthly Notices of the Royal Astronomical Society, 375(3) pp. 951–957.

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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 RJup, whereas WASP-2b has a radius in the range 0.65-1.26 RJup.

Item Type: Journal Item
ISSN: 1365-2966
Extra Information: Click here to view other publications available on this repository relating to the SuperWASP Project.
Keywords: data analysis; photometric; radial velocities; planetary systems
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Item ID: 8287
Depositing User: Andrew Norton
Date Deposited: 02 Jul 2007
Last Modified: 07 Dec 2018 09:04
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