* Astronomy

Title: The first planet detected in the WTS: an inflated hot-Jupiter in a 3.35 day orbit around a late F-star
Authors: M. Cappetta, R. P. Saglia, J. L. Birkby, J. Koppenhoefer, D. J. Pinfield, S. T. Hodgkin, P. Cruz, G. Kovács, B. Sipöcz, D. Barrado, B. Nefs, Y. V. Pavlenko, L. Fossati, C. del Burgo, E. L. Martín, I. Snellen, J. Barnes, A. M. Bayo, D. A. Campbell, S. Catalan, M. C. Gálvez-Ortiz, N. Goulding, C. Haswell, O. Ivanyuk, H. Jones, M. Kuznetsov, N. Lodieu, F. Marocco, D. Mislis, F. Murgas, R. Napiwotzki, E. Palle, D. Pollacco, L. Sarro Baro, E. Solano, P. Steele, H. Stoev, R. Tata, J. Zendejas

We report the discovery of WTS-1b, the first extrasolar planet found by the WFCAM Transit Survey, which began observations at the 3.8-m United Kingdom Infrared Telescope. Light curves comprising almost 1200 epochs with a photometric precision of better than 1 per cent to J=16 were constructed for 60000 stars and searched for periodic transit signals. For one of the most promising transiting candidates, high-resolution spectra taken at the Hobby-Eberly Telescope allowed us to estimate the spectroscopic parameters of the host star, a late-F main sequence dwarf (V=16.13) with possibly slightly subsolar metallicity, and to measure its radial velocity variations. The combined analysis of the light curves and spectroscopic data resulted in an orbital period of the substellar companion of 3.35 days, a planetary mass of 4.01±0.35 Jupiter masses and a planetary radius of 1.49±0.17 Jupiter radii. WTS-1b has one of the largest radius anomalies among the known hot Jupiters in the mass range 3-5 Jupiter masses.

Read more (1994kb, PDF)