J/AJ/156/178ivo://CDS.VizieR/J/AJ/156/178doi:10.26093/cds/vizier.51560178CDSZhang Z.Zhou Y.Rackham B.V.Apai D.2019-04-08T14:40:45Z2019-04-02T07:05:27ZCDS support team

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

cds-question@unistra.frexoplanetseffective-temperatureinfrared-astronomyspectroscopymultiple-starsThe seven approximately Earth-sized transiting planets in the TRAPPIST-1 system provide a unique opportunity to explore habitable- and nonhabitable-zone small planets within the same system. Its habitable-zone exoplanets - due to their favorable transit depths - are also worlds for which atmospheric transmission spectroscopy is within reach with the Hubble Space Telescope (HST) and James Webb Space Telescope (JWST). We present here an independent reduction and analysis of two HST Wide Field Camera 3 (WFC3) near-infrared transit spectroscopy data sets for six planets (b through g). Utilizing our physically motivated detector charge-trap correction and a custom cosmic-ray correction routine, we confirm the general shape of the transmission spectra presented by de Wit et al. (2016Natur.537...69D). Our data reduction approach leads to a 25% increase in the usable data and reduces the risk of confusing astrophysical brightness variations (e.g., flares) with instrumental systematics. No prominent absorption features are detected in any individual planet's transmission spectra; by contrast, the combined spectrum of the planets shows a suggestive decrease around 1.4 {mu}m similar to an inverted water absorption feature. Including transit depths from K2, the SPECULOOS-South Observatory, and Spitzer, we find that the complete transmission spectrum is fully consistent with stellar contamination owing to the transit light source effect. These spectra demonstrate how stellar contamination can overwhelm planetary absorption features in low-resolution exoplanet transit spectra obtained by HST and JWST and also highlight the challenges in combining multi-epoch observations for planets around rapidly rotating spotted stars.2018AJ....156..178Zhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/156/178CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/549/A10 : Transits of GJ 1214 (Harpsoe+, 2013)J/A+A/563/A21 : GJ 1214 Trappist and Spitzer light curves (Gillon+, 2014)J/ApJ/799/180 : Radii of 430 KOI Earth- to Neptune-sized planetshttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/156/178https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/156/178http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/156/178https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/156/178https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/156/178http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/156/178GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/156/178/planets (Parameters used as input in transit profile fitting from Gillon et al. (2016Natur.533..221G, 2017Natur.542..456G) (table 5) and planetary parameters for water absorption calculations (table 8))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/156/178/planets?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/156/178/planets?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/156/178/planets?GETtext/xml+votable180.050000true346.6223333-5.04144440.0055555555555555566/18726https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/156/178?format=asciiInfrareddefaultJ/AJ/156/178/table13Transmission spectraPl[bcdefg] TRAPPIST-1 planetmeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTrans[1/7] Transit numbermeta.numberintWave[11377/16613]? Wavelength ({AA}) (only in Table 13) (1)0.1nmem.wlintnullableDepth[0.00356/0.00824] Transit depthphys.absorption.opticalDepthdoubleE_Depth[9e-05/0.00037] Upper limit uncertainty in Depthstat.error;stat.maxdoublee_Depth[9e-05/0.00038] Lower limit uncertainty in Depthstat.error;stat.mindoubleJ/AJ/156/178/table14Transmission spectra in the interpolated binsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTrans[1/7] Transit numbermeta.numberintPl[bcdefg] TRAPPIST-1 planetmeta.id;meta.maincharDepth[0.00356/0.00824] Transit depthphys.absorption.opticalDepthdoubleE_Depth[9e-05/0.00037] Upper limit uncertainty in Depthstat.error;stat.maxdoublee_Depth[9e-05/0.00038] Lower limit uncertainty in Depthstat.error;stat.mindoubleJ/AJ/156/178/planetsParameters used as input in transit profile fitting from Gillon et al. (2016Natur.533..221G, 2017Natur.542..456G) (table 5) and planetary parameters for water absorption calculations (table 8)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPl[bcdefg] TRAPPIST-1 planetmeta.id;meta.maincharprimarymoreindicates transmission spectra data in Tables 13-14 for this planetmeta.ref.urlcharIncl[89.65/89.86] Inclination (1)degsrc.orbital.inclinationfloatE_Incl[0.025/0.22] Upper limit uncertainty in Incldegstat.error;stat.maxfloate_Incl[0.025/0.27] Lower limit uncertainty in Incldegstat.error;stat.minfloatT[1.5109/12.35294] Orbital period (2)dtime.perioddoublea[20.5/83.2] Semimajor axis, expressed in units of stellar radiusphys.angSize.smajAxisfloatMass[0.24/1.63] Planet mass(5.97236x10+24kg)phys.massfloatE_Mass[0.0038/0.63] Uperr limit uncertainty in Mass(5.97236x10+24kg)stat.error;stat.maxfloate_Mass[0.0038/0.63] Lower limit uncertainty in Mass(5.97236x10+24kg)stat.error;stat.minfloatTeff[198.6/400.1] Effective temperatureKphys.temperature.effectivefloate_Teff[3.8/7.7] Uncertainty in TeffKstat.error;phys.temperature.effectivefloatDeltad[-413/77] Transit depth {Delta}d(10-6)phot.flux.density;arith.ratiointe_Deltad[113/266] Uncertainty in Deltad(10-6)stat.errorintRad[0.772/1.127] Planet radius(6.3781x10+6m)phys.size.radiusfloate_Rad[0.03/0.041] Uncertainty in Rad(6.3781x10+6m)stat.errorfloatAH[-11.1/2.5] Water absorption amplitude A_H_ (see Equation (5))src.var.amplitudefloate_AH[1/13.6] Uncertainty in AHstat.error;stat.minfloatE_AH[3.2/29.7] 3{sigma} upper bound of AHstat.error;stat.maxfloatTrans[1/7] Transit numbermeta.numberintspTransmission spectrummeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main