An orbital period of 0.94days for the hot-Jupiter planet WASP-18b
Data(s) |
27/08/2009
|
---|---|
Resumo |
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 ~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 0.94days and a mass of ten Jupiter masses (10MJup), 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 106, 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. |
Identificador |
http://dx.doi.org/10.1038/nature08245 http://www.scopus.com/inward/record.url?scp=69349094770&partnerID=8YFLogxK |
Idioma(s) |
eng |
Direitos |
info:eu-repo/semantics/restrictedAccess |
Fonte |
Hellier , C , Anderson , D R , Cameron Collier , A , Gillon , M , Hebb , L , Maxted , P F L , Queloz , D , Smally , B , Triaud , A H M J , West , R G , Wilson , D G , Bentley , S J , Enoch , B , Horne , K , Irwin , J , Lister , T A , Mayor , M , Parley , N , Pepe , F , Pollacco , D , Segransan , D , Udry , S & Wheatley , P 2009 , ' An orbital period of 0.94days for the hot-Jupiter planet WASP-18b ' Nature , vol 460 , no. 7259 , pp. 1098-1100 . DOI: 10.1038/nature08245 |
Palavras-Chave | #/dk/atira/pure/subjectarea/asjc/1000 #General |
Tipo |
article |