J/A+A/641/A158ivo://CDS.VizieR/J/A+A/641/A158doi:10.26093/cds/vizier.36410158CDSMurgas F.Chen G.Nortmann L.Palle E.Nowak G.2021-04-27T11:11:03Z2020-09-24T08:18:53ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frmultiple-starssolar-system-planetsspectroscopyOne of the major atmospheric features in exoplanet atmospheres, detectable both from ground- and space-based facilities, is Rayleigh scattering. In hydrogen-dominated planetary atmospheres Rayleigh scattering causes the measured planetary radius to increase towards blue wavelengths in the optical range. We obtained a spectrophotometic time series of one transit of the Saturn-mass planet WASP-69b using the OSIRIS instrument at the Gran Telescopio Canarias. From the data we construct 19 spectroscopic transit light curves representing 20nm wide wavelength bins spanning from 515nm-905nm. We derive the transit depth for each curve individually by fitting an analytical model together with a Gaussian Processes to account for systematic noise in the light curves. We find that the transit depth increases towards bluer wavelengths, indicative of a larger effective planet radius. Our results are consistent with space-based measurements obtained in the near infrared using the Hubble Space telescope, which show a compatible slope of the transmission spectrum. We discuss the origin of the detected slope and argue between two possible scenarios: a Rayleigh scattering detection originating in the planet's atmosphere or a stellar activity induced signal from the host star.2020A&A...641A.158Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/641/A158CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/563/A41 : WASP-43 OSIRIS transmission spectroscopy (Murgas+, 2014)J/A+A/589/A62 : GTC transit light curves of CoRoT-29b (Palle+, 2016)J/A+A/594/A65 : GTC transit light curves of HAT-P-32b (Nortmann+, 2016)J/A+A/600/L11 : GTC transit light curves of WASP-52b (Chen+, 2017)J/A+A/605/A114 : GTC transit light curves of WASP-48b (Murgas+, 2017)J/A+A/616/A145 : GTC transit light curves of WASP-127b (Chen+, 2018)J/A+A/622/A172 : GTC transit light curves of HAT-P-11b (Murgas+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/641/A158https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/641/A158http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/641/A158https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/641/A158https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/641/A158http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/641/A158GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/641/A158/tablea2Results for the planet-to-star radius ratio for each of the 11 spectroscopic channels around the NaI doubletrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda1Wavelength of the center of the channelnmem.wlfloatlambda2Total width of the channelnminstr.bandwidthfloatRp/RsMeasured planet-to-star radius ratio Rp/Rsphys.size.radiusdoubleE_Rp/RsUpper 1-sigma uncertainty in Rp/Rsstat.error;stat.maxdoublee_Rp/RsLower 1-sigma uncertainty in Rp/Rsstat.errordoubleJ/A+A/641/A158/listList of light curve filesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRangeWavelength interval in nminstr.bandwidthcharlcShow the light curvesmeta.ref.urlcharFileNameName of the table with photometrymeta.id;phot;meta.tablecharJ/A+A/641/A158/gtcwlcn1WASP-69b GTC transit white light curve (2016/10/05)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric Julian Date (TDB standard)dtime.epochdoubleFluxRelative fluxphot.flux;arith.ratiodoublee_FluxUncertainty of relative fluxstat.error;phot.fluxdoubleposXDrift of star on CCD in spatial directionpixpos.cartesian.x;instr.detdoubleposYDrift of star on CCD in dispersion directionpixpos.cartesian.y;instr.detdoublefwhmXRelative change of full width at half maximum of the stellar absorption line profilepixarith.rate;spect.line.widthdoublefwhmYFull width at half maximum of the stellar spatial profilepixspect.line.widthdoubleAirmAirmass during observationobs.airMassdoubleRotAngTelescope rotator angle during observationsdeginstr.offsetdoubleJ/A+A/641/A158/tablea1Results for the planet-to-star radius ratio for each of the 19 spectroscopic channelsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda1Wavelength of the center of the channelnmem.wlfloatlambda2Total width of the channelnminstr.bandwidthfloatRp/RsMeasured planet-to-star radius ratio Rp/Rsphys.size.radiusdoubleE_Rp/RsUpper 1-sigma uncertainty in Rp/Rsstat.error;stat.maxdoublee_Rp/RsLower 1-sigma uncertainty in Rp/Rsstat.errordouble