Subaru HDS Transmission Spectroscopy of the Transiting Extrasolar Planet HD 209458b

[摘要] WehavesearchedforabsorptioninseveralcommonatomicspeciesduetotheatmosphereorexosphereofthetransitingextrasolarplanetHD209458b,usinghighprecisionopticalspectraobtainedwiththeSubaruHighDispersionSpectrograph(HDS).Previouslywereportedanupperlimiton$$mathrm{H}alpha$$absorptionof0.1%($$3,sigma$$)withina5.1 Åband.Usingthesameprocedure,wenowreportupperlimitsonabsorptionduetotheopticaltransitionsofNaD,Li,$$mathrm{H}alpha$$,$$mathrm{H}eta$$,$$mathrm{H}gamma$$,Fe,andCa.The$$3,sigma$$upperlimitforeachtransitionisapproximately1%withina0.3 Åband(thecoreoftheline),andafewtenthsofapercentwithina2 Åband(thefulllinewidth).Thewide-bandresultsareclosetotheexpectedlimitduetophoton-counting(Poisson)statistics,althoughinthenarrow-bandcasewehaveencounteredunexplainedsystematicerrorsatafewtimesthePoissonlevel.Theseresultsareconsistentwithallpreviouslyreporteddetectionsandupperlimits,butaresignificantlymoresensitive.

[学科分类] 天文学(综合)

[关键词] "planetary systems: individual (HD 209458b)";"techniques: spectroscopic"