Letter to the Editor

WASP-43b: the closest-orbiting hot Jupiter

¹ Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK
e-mail: ch@astro.keele.ac.uk
² SUPA, School of Physics and Astronomy, University of St. Andrews, North Haugh, Fife, KY16 9SS, UK
³ Institut d’Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août, 17, Bât. B5C, Liège 1, Belgium
⁴ Observatoire astronomique de l’Université de Genève, 51 Ch. des Maillettes, 1290 Sauverny, Switzerland
⁵ Astrophysics Research Centre, School of Mathematics & Physics, Queen’s University, University Road, Belfast, BT7 1NN, UK
⁶ Department of Physics and Astronomy, University of Leicester, Leicester, LE1 7RH, UK

Received: 14 April 2011
Accepted: 1 November 2011

Abstract

We report the discovery of WASP-43b, a hot Jupiter transiting a K7V star every 0.81 d. At 0.6-M_⊙ the host star has the lowest mass of any star currently known to host a hot Jupiter. It also shows a 15.6-d rotation period. The planet has a mass of 1.8 M_Jup, a radius of 0.9 R_Jup, and with a semi-major axis of only 0.014 AU has the smallest orbital distance of any known hot Jupiter. The discovery of such a planet around a K7V star shows that planets with apparently short remaining lifetimes owing to tidal decay of the orbit are also found around stars with deep convection zones.