WASP-25b: A 0.6M planet in the Southern hemisphere
journal contributionposted on 24.10.2012, 09:06 by A. C. Cameron, D. J. A. Brown, N. Parley, D. R. Anderson, C. Hellier, P. F. L. Maxted, B. Smalley, T. A. Lister, R. A. Street, D. Queloz, A. H. M. J. Triaud, M. Gillon, M. Lendl, F. Pepe, D. Segransan, S. Udry, R. G. West, L. Hebb, D. Pollacco, E. Simpson
We report the detection of a 0.6 MJ extrasolar planet by WASP-South, WASP-25b, transiting its solar-type host star every 3.76 d. A simultaneous analysis of the WASP, FTS and Euler photometry and CORALIE spectroscopy yields a planet of Rp= 1.22 RJ and Mp= 0.58 MJ around a slightly metal-poor solar-type host star, [Fe/H]=− 0.05 ± 0.10, of R*= 0.92 R⊙ and M*= 1.00 M⊙. WASP-25b is found to have a density of ρp= 0.32 ρJ, 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.