[en] We report the detection of a 0.6 M-J extrasolar planet by WASP-South, WASP-25b, transiting its solar-type host star every 3.76d. A simultaneous analysis of the WASP, FTS and Euler photometry and CORALIE spectroscopy yields a planet of R[SUB]p[/SUB] = 1.22 R[SUB]J[/SUB] and M[SUB]p[/SUB] = 0.58 M[SUB]J[/SUB] around a slightly metal-poor solar-type host star, [Fe/H] = - 0.05 +/- 0.10, of R[SUB]*[/SUB] = 0.92 R[SUB]solar[/SUB] and M[SUB]*[/SUB] = 1.00 M[SUB]solar[/SUB]. WASP-25b is found to have a density of ρ[SUB]p[/SUB] = 0.32 ρ[SUB]J[/SUB], a low value for a sub-Jupiter mass planet. We investigate the relationship of planetary radius to planetary equilibrium temperature and host star metallicity for transiting exoplanets with a similar mass to WASP-25b, finding that these two parameters explain the radii of most low-mass planets well.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Enoch, B.; School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS
Cameron, A Collier; School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS
Anderson, D. R.; Astrophysics Group, Keele University, Staffordshire ST5 5BG
Lister, T. A.; Las Cumbres Observatory, 6740 Cortona Drive Suite 102, Goleta, CA 93117, USA
Hellier, C.; Astrophysics Group, Keele University, Staffordshire ST5 5BG
Maxted, P. F. L.; Astrophysics Group, Keele University, Staffordshire ST5 5BG
Queloz, D.; Observatoire astronomique de l'Universitén de Genéve, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
Smalley, B.; Astrophysics Group, Keele University, Staffordshire ST5 5BG
Triaud, A H M J; Observatoire astronomique de l'Universitén de Genéve, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
West, R. G.; Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH
Brown, D. J. A.; School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS
Gillon, Michaël ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique et traitement de l'image
Hebb, L.; Vanderbilt University, Department of Physics and Astronomy, Nashville, TN 37235, USA
Lendl, M.; Observatoire astronomique de l'Universitén de Genéve, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
Parley, N.; School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS
Pepe, F.; Observatoire astronomique de l'Universitén de Genéve, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
Pollacco, D.; Astrophysics Research Centre, School of Mathematics & Physics, Queen's University, University Road, Belfast BT7 1NN
Segransan, D.; Observatoire astronomique de l'Universitén de Genéve, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
Simpson, E.; Astrophysics Research Centre, School of Mathematics & Physics, Queen's University, University Road, Belfast BT7 1NN
Street, R. A.; Las Cumbres Observatory, 6740 Cortona Drive Suite 102, Goleta, CA 93117, USA
Udry, S.; Observatoire astronomique de l'Universitén de Genéve, 51 Chemin des Maillettes, 1290 Sauverny, Switzerland
