We report the discovery of a planet transiting the star WASP-80 (1SWASP J201240.26-020838.2; 2MASS J20124017-0208391; TYC 5165-481-1; BPM 80815; V=11.9, K=8.4). Our analysis shows this is a 0.55 +/- 0.04 Mjup, 0.95 +/- 0.03 Rjup gas giant on a circular 3.07 day orbit around a star with a spectral type between K7V and M0V. This system produces one of the largest transit depths so far reported, making it a worthwhile target for transmission spectroscopy. We find a large discrepancy between the v sin i inferred from stellar line broadening and the observed amplitude of the Rossiter-McLaughlin effect. This can be understood either by an orbital plane nearly perpendicular to the stellar spin or by an additional, unaccounted for source of broadening.
@article{arxiv.1303.0254,
title = {WASP-80b: a gas giant transiting a cool dwarf},
author = {Amaury H. M. J. Triaud and D. R. Anderson and A. Collier Cameron and A. P. Doyle and A. Fumel and M. Gillon and C. Hellier and E. Jehin and M. Lendl and C. Lovis and P. F. L. Maxted and F. Pepe and D. Pollacco and D. Queloz and D. Segransan and B. Smalley and A. M. S. Smith and S. Udry and R. G. West and P. J. Wheatley},
journal= {arXiv preprint arXiv:1303.0254},
year = {2013}
}
Comments
Accepted in A&A, five pages, three figures and one table. RV and photometric data available at the CDS