An orbital period of 0.94 days for the hot-Jupiter planet WASP-18b
. (2009) An orbital period of 0.94 days for the hot-Jupiter planet WASP-18b. Nature, Vol.460 (No.7259). pp. 1098-1100. ISSN 0028-0836 Full text not available from this repository.
Official URL: http://dx.doi.org/10.1038/nature08245
The 'hot Jupiters' that abound in lists of known extrasolar planets are thought to have formed far from their host stars, but migrate inwards through interactions with the proto-planetary disk from which they were born(1,2), or by an alternative mechanism such as planet-planet scattering(3). The hot Jupiters closest to their parent stars, at orbital distances of only similar to 0.02 astronomical units, have strong tidal interactions(4,5), and systems such as OGLE-TR-56 have been suggested as tests of tidal dissipation theory(6,7). Here we report the discovery of planet WASP-18b with an orbital period of 0.94 days and a mass of ten Jupiter masses (10 M-Jup), resulting in a tidal interaction an order of magnitude stronger than that of planet OGLE-TR-56b. Under the assumption that the tidal-dissipation parameter Q of the host star is of the order of 10 6, as measured for Solar System bodies and binary stars and as often applied to extrasolar planets, WASP-18b will be spiralling inwards on a timescale less than a thousandth that of the lifetime of its host star. Therefore either WASP-18 is in a rare, exceptionally short-lived state, or the tidal dissipation in this system (and possibly other hot-Jupiter systems) must be much weaker than in the Solar System.
|Item Type:||Journal Article|
|Divisions:||Faculty of Science > Physics|
|Journal or Publication Title:||Nature|
|Publisher:||Nature Publishing Group|
|Date:||27 August 2009|
|Number of Pages:||3|
|Page Range:||pp. 1098-1100|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||UK's Science and Technology Facilities Council|
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