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.

DOI: https://doi.org/10.1111/j.1365-2966.2006.11350.x


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.

Viewing alternatives


Public Attention

Altmetrics from Altmetric

Number of Citations

Citations from Dimensions
No digital document available to download for this item

Item Actions