J/ApJ/808/13ivo://CDS.VizieR/J/ApJ/808/13doi:10.26093/cds/vizier.18080013CDSRamirez I.Khanal S.Aleo P.Sobotka A.Liu F.Casagrande L.,Melendez J.Yong D.Lambert D.L.Asplund M.2017-01-23T22:00:00Z2015-12-14T13:18:35ZCDS support team

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

cds-question@unistra.frline-intensitiesmultiple-starsspectroscopyUsing high-quality spectra of the twin stars in the XO-2 binary system, we have detected significant differences in the chemical composition of their photospheres. The differences correlate strongly with the elements' dust condensation temperature. In XO-2N, volatiles are enhanced by about 0.015dex and refractories are overabundant by up to 0.090dex. On average, our error bar in relative abundance is 0.012dex. We present an early metal-depletion scenario in which the formation of the gas giant planets known to exist around these stars are responsible for a 0.015 dex offset in the abundances of all elements while 20M_{Earth}_ of non-detected rocky objects that formed around XO-2S explain the additional refractory-element difference. An alternative explanation involves the late accretion of at least 20M_{Earth}_of planet-like material by XO-2N, allegedly as a result of the migration of the hot Jupiter detected around that star. Dust cleansing by a nearby hot star as well as age or Galactic birthplace effects can be ruled out as valid explanations for this phenomenon.2015ApJ...808...13Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/808/13CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/801/L10 : XO-2N and XO-2S equivalent widths (Teske+, 2015)J/A+A/583/A135 : XO-2N and XO-2S spectra (Biazzo+, 2015)J/A+A/575/A111 : GAPS V: Global analysis of the XO-2 system (Damasso+, 2015)J/A+A/562/A71 : Abundances of solar neighbourhood dwarfs (Bensby+, 2014)J/A+A/561/A7 : Abundances for stars with planets (Ramirez+, 2014)J/A+A/558/A106 : Chemical abundances for 83 transit hosts (Mortier+, 2013)J/ApJ/770/36 : APOSTLE transits of XO-2 system (Kundurthy+, 2013)J/ApJ/768/L12 : Abundances in host stars XO-2S and XO-2N (Teske+, 2013)J/A+A/552/A6 : Abundances of F-G MS stars (Gonzalez Hernandez+, 2013)J/ApJ/757/161 : Spectroscopy of 56 exoplanet host stars (Torres+, 2012)J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)J/ApJ/732/55 : Abundances of stars with planets (Schuler+, 2011)J/ApJ/715/1050 : Predicted abundances for extrasolar planets. I. (Bond+, 2010)J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)J/ApJ/709/447 : Chemical composition of OGLE-2007-BLG-514S (Epstein+, 2010)J/AJ/137/4911 : Six transits of the exoplanet XO-2b (Fernandez+, 2009)J/A+A/508/L17 : Abundances in solar analogs (Ramirez+, 2009)J/A+A/465/271 : Oxygen abundances in nearby stars (Ramirez+, 2007)J/MNRAS/373/13 : Lower main-sequence stars param. (Casagrande+, 2006)J/ApJ/626/446 : Effective temperature scale of FGK stars (Ramirez+, 2005)J/A+A/275/101 : Chemical evolution of the galactic disk I. (Edvardsson+ 1993)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/808/13https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/808/13http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/808/13https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/808/13https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/808/13http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/808/13GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/808/13/table3Line listrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintf_lambda[-] -: no equivalent width valuesmeta.codecharlambda[4218.7/8092.7] Wavelength in Angstroms0.1nmem.wldoubleSp[6/106] Numeric species code (1)phys.atmol.ionStagefloatExPot[0/9.2] Excitation PotentialeVphys.atmol.excitationfloatlog(gf)[-6.3/0.6] Log of the oscillator strengthphys.atmol.oscStrengthfloatXO-2N[6/217]? Equivalent width in XO-2N (2)1e-13mspect.line.eqWidthfloatnullableXO-2S[7/210]? Equivalent width in XO-2S (2)1e-13mspect.line.eqWidthfloatnullableSun[3/158]? Equivalent width in the Sun (2)1e-13mspect.line.eqWidthfloatnullable