WASP-43b (Hellier et al.)

Vol. 535
In section 1. Letters to the Editor

WASP-43b: The closest-orbiting hot Jupiter

by C. Hellier, D.R. Anderson, A. Collier Cameron, M. Gillon, E. Jehin, et al., A&A 535, L7

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Hellier et al. present the discovery by transit-search photometry of another exotic planet to be added to the menagerie of known exoplanets. With an orbital period of only 19 hours and 31 minutes, WASP-43b is the closest hot Jupiter known to date. Its mass is 1.8 and size 0.9 times that of Jupiter. Interestingly, its host star is only 0.6 times the mass of our Sun; i.e., it is the smallest one known to host a hot Jupiter. Is WASP-43b one of the rare cases of 'last Mohicans', i.e. planets that are falling onto their parent star due to tidal interactions? Or is it telling us instead that tidal interactions are much weaker than previously thought? Thanks to objects like this one, theoretical models of star-planet interactions will be put to the test, hopefully leading to a much clearer understanding of the dissipation processes in both stars and planets.