Publication Date:
2009-08-29
Description:
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, or by an alternative mechanism such as planet-planet scattering. The hot Jupiters closest to their parent stars, at orbital distances of only approximately 0.02 astronomical units, have strong tidal interactions, and systems such as OGLE-TR-56 have been suggested as tests of tidal dissipation theory. 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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hellier, Coel -- Anderson, D R -- Cameron, A Collier -- Gillon, M -- Hebb, L -- Maxted, P F L -- Queloz, D -- Smalley, B -- Triaud, A H M J -- West, R G -- Wilson, D M -- Bentley, S J -- Enoch, B -- Horne, K -- Irwin, J -- Lister, T A -- Mayor, M -- Parley, N -- Pepe, F -- Pollacco, D L -- Segransan, D -- Udry, S -- Wheatley, P J -- England -- Nature. 2009 Aug 27;460(7259):1098-100. doi: 10.1038/nature08245.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK. ch@astro.keele.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19713926" target="_blank"〉PubMed〈/a〉
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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