We report the discovery of WASP-34b, a sub-Jupiter-mass exoplanet transiting its 10.4-magnitude solar-type host star (1SWASP J110135.89-235138.4; TYC 6636-540-1) every 4.3177 days in a slightly eccentric orbit (e = 0.038 +/- 0.012). We find a planetary mass of 0.59 +/- 0.01 M_Jup and radius of 1.22 ^{+0.11}_{-0.08} R_Jup. There is a linear trend in the radial velocities of 55+/-4 m/s/y indicating the presence of a long-period third body in the system with a mass > 0.45 M_Jup at a distance of >1.2 AU from the host star. This third-body is either a low-mass star, white dwarf, or another planet. The transit depth ((R_P/R_*)^2 = 0.0126) and high impact parameter (b = 0.90) suggest that this could be the first known transiting exoplanet expected to undergo grazing transits, but with a confidence of only ~80%.
@article{arxiv.1012.2278,
title = {WASP-34b: a near-grazing transiting sub-Jupiter-mass exoplanet in a hierarchical triple system},
author = {B. Smalley and D. R. Anderson and A. Collier Cameron and C. Hellier and M. Lendl and P. F. L. Maxted and D. Queloz and A. H. M. J. Triaud and R. G. West and S. J. Bentley and B. Enoch and M. Gillon and T. A. Lister and F. Pepe and D. Pollacco and D. Segransan and A. M. S. Smith and J. Southworth and S. Udry and P. J. Wheatley and P. L. Wood and J. Bento},
journal= {arXiv preprint arXiv:1012.2278},
year = {2015}
}
Comments
5 pages, 6 figures, accepted on 9 December 2010 by A&A Main Journal, Section 10. Planets and planetary systems