WASP-3b: A strongly irradiated transiting gas-giant planet
journal contributionposted on 24.10.2012, 09:22 by D. Pollacco, N. P. Gibson, Y. C. Joshi, R. A. Street, D. J. Christian, A. Fitzsimmons, F. P. Keenan, R. Ryans, E. Simpson, I. Skillen, C. R. Benn, S. Hickey, M. Hrudková, S. R. Kane, Collier Cameron A., H. C. Stempels, L. Hebb, A. M. S. Smith, K. Alsubai, V. A. Bruce, K. Horne, T. A. Lister, B. Loeillet, C. Moutou, F. Bouchy, G. Hébrard, I. McDonald, B. Smalley, D. M. Wilson, A. Evans, C. Hellier, P. Maxted, S. Udry, M. Mayor, F. Pont, D. Queloz, R. G. West, J. P. Osborne, P. J. Wheatley, S. Aigrain, S. T. Hodgkin, J. Irwin, W. I. Clarkson, B. Enoch, C. A. Haswell, A. J. Norton, N. Parley
We report the discovery of WASP-3b, the third transiting exoplanet to be discovered by the WASP and SOPHIE collaboration. WASP-3b transits its host star USNO-B1.0 1256−0285133 every 1.846 834 ± 0.000 002 d. Our high-precision radial velocity measurements present a variation with amplitude characteristic of a planetary-mass companion and in phase with the light curve. Adaptive optics imaging shows no evidence for nearby stellar companions, and line-bisector analysis excludes faint, unresolved binarity and stellar activity as the cause of the radial velocity variations. We make a preliminary spectroscopic analysis of the host star and find it to have Teff= 6400 ± 100 K and log g= 4.25 ± 0.05 which suggests it is most likely an unevolved main-sequence star of spectral type F7-8V. Our simultaneous modelling of the transit photometry and reflex motion of the host leads us to derive a mass of 1.76+0.08−0.14MJ and radius 1.31+0.07−0.14RJ for WASP-3b. The proximity and relative temperature of the host star suggests that WASP-3b is one of the hottest exoplanets known, and thus has the potential to place stringent constraints on exoplanet atmospheric models.