J/ApJ/803/90ivo://CDS.VizieR/J/ApJ/803/90doi:10.26093/cds/vizier.18030090CDSPagano M.Truitt A.Young P.A.Shim S.-H.2015-09-25T08:57:31Z2015-09-03T08:51:50ZCDS support team

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

cds-question@unistra.frmultiple-starssolar-system-planetsline-intensities{tau} Ceti (HD10700), a G8 dwarf with mass 0.78M_{sun}_, is a close (3.65pc) Sun-like star where five possibly terrestrial planet candidates (minimum masses of 2, 3.1, 3.5, 4.3, and 6.7M_{Earth}_) have recently been discovered. We report abundances of 23 elements using spectra from the MIKE spectrograph on Magellan. We find [Fe/H]=-0.49 and T_eff_=5387K. Using stellar models with the abundances determined here, we calculate the position of the classical habitable zone (HZ) with time. At the current best fit age, 7.63_-1.5_^+0.87^Gyr, up to two planets (e and f) may be in the HZ, depending on atmospheric properties. The Mg/Si ratio of the star is found to be 1.78, which is much greater than for Earth (~1.2). With a system that has such an excess of Mg/Si ratio it is possible that the mineralogical make-up of planets around {tau} Ceti could be significantly different from that of Earth, with possible oversaturation of MgO, resulting in an increase in the content of olivine and ferropericlase compared with Earth. The increase in MgO would have a drastic impact on the rheology of the mantles of the planets around {tau} Ceti.2015ApJ...803...90Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/803/90CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/576/A89 : Oxygen abundances from HARPS (Bertran de Lis+, 2015)J/AJ/148/54 : The Hypatia Catalog ((Hinkel+, 2014)J/ApJ/770/90 : Candidate planets in the habitable zones (Gaidos, 2013)J/ApJ/767/95 : Improved parameters of smallest KIC stars (Dressing+, 2013)J/A+A/551/A79 : RV periodic variations in {tau} Ceti (Tuomi+, 2013)J/A+A/547/A36 : Chemical abundances of 87 KOIs (Adibekyan++, 2012)J/ApJS/199/8 : Interstellar column density compilation (Gudennavar+, 2012)J/MNRAS/414/1227 : Mg/Fe ratio of MILES stars (Milone+, 2011)J/ApJ/735/41 : Carbon and oxygen abundances in FGK stars (Petigura+, 2011)J/ApJ/725/2349 : C/O vs Mg/Si of planetary systems (Delgado Mena+, 2010)J/ApJ/715/1050 : Predicted abundances for exoplanets. I. (Bond+, 2010)J/A+A/497/563 : Chemical abundances of 451 stars (Neves+, 2009)J/PASJ/59/335 : Properties of 160 F-K disk dwarfs/subgiants (Takeda+, 2007)J/MNRAS/370/163 : Abundance distribution of stars with planets (Bond+, 2006)J/A+A/449/723 : Atmospheres of stars with planets (Gilli+, 2006)J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005)J/A+A/398/363 : Statistical properties of exoplanets II (Santos+, 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/803/90https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/803/90http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/803/90https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/803/90https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/803/90http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/803/90GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/ApJ/803/90/table2Complete line listElElement identifiermeta.id;phys.atmol.elementcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[4773/6858] Wavelength; Angstroms0.1nmem.wlfloatExPot[0/10.8] Lower excitation potentialeVphys.atmol.excitation;stat.minfloatlog(gf)[-9.8/0.6] Oscillator strengthphys.atmol.oscStrengthfloatEWsun[4/133] Solar equivalent width (m{AA})1e-13mspect.line.eqWidthfloatEW[1.5/114.6] {tau} Ceti equivalent width (m{AA})1e-13mspect.line.eqWidthfloat