J/ApJ/814/91ivo://CDS.VizieR/J/ApJ/814/91doi:10.26093/cds/vizier.18140091CDSBarnes R.Meadows V.S.Evans N.2018-05-14T06:31:57Z2017-10-27T11:30:30ZCDS support team

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

cds-question@unistra.frmultiple-starssolar-system-planetsastronomical-modelsExoplanet habitability is traditionally assessed by comparing a planet's semimajor axis to the location of its host star's "habitable zone", the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS, and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an "eccentricity-albedo degeneracy" for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass-radius relationships, and, when available, constraints on eccentricity to compute a number we call the "habitability index for transiting exoplanets" that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler objects of interest and find that planets that receive between 60% and 90% of the Earth's incident radiation, assuming circular orbits, are most likely to be habitable. Finally, we make predictions for the upcoming TESS and James Webb Space Telescope missions.2015ApJ...814...91Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/814/91CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/133 : Kepler Input Catalog (Kepler Mission Team, 2009)J/ApJS/222/14 : Planetary cand. from 1st yr K2 mission (Vanderburg+, 2016)J/ApJ/809/77 : Transiting Exoplanet Survey Satellite (TESS) (Sullivan+, 2015)J/ApJ/807/45 : Potential habitable planets around M dwarfs (Dressing+, 2015)J/ApJS/210/20 : Small Kepler planets radial velocities (Marcy+, 2014)J/A+A/567/A133 : Habitable zone code (Valle+, 2014)J/ApJ/771/L45 : 3D climate models for exoplanet around M-star (Yang+, 2013)J/ApJ/771/107 : Spectroscopy of faint KOI stars (Everett+, 2013)J/ApJ/770/90 : Candidate planets in the habitable zones (Gaidos, 2013)J/ApJS/204/24 : Kepler planetary candidates. III. (Batalha+, 2013)J/A+A/549/A109 : HARPS XXXI. The M-dwarf sample (Bonfils+, 2013)J/ApJ/736/L25 : Habitability of Kepler planetary cand. (Kaltenegger+, 2011)J/ApJ/715/1050 : Predicted abundances for extrasolar planets. I. (Bond+, 2010)http://exoplanetarchive.ipac.caltech.edu/ : NASA exoplanet archivehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/814/91https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/814/91http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/814/91https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/814/91https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/814/91http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/814/91GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/814/91/table1 (Observed and derived parameters for potentially habitable KOIs)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/814/91/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/814/91/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/814/91/table1?GETtext/xml+votable180.050000true292.0020541.78696110.0055555555555555565/3647 3683 3694 3695 3706 3733 3741 3743 3777 3778 3784 3787 3792 6/14573 14579 14580 14581 14583 14584 14585 14586 14731 14744 14746 14751 14752 14755 14756 14757 14760 14762 14763 14764 14766 14767 14770 14771 14772 14773 14775 14792 14794 14817 14830 14915 14916 14919 14921 14923 14924 14925 14929 14930 14931 14937 14938 14939 14942 14944 14947 14948 14949 14950 14954 14957 14958 14960 14961 14963 14971 15040 15060 15061 15104 15107 15116 15118 15119 15122 15123 15125 15126 15127 15128 15129 15131 15132 15133 15142 15143 15145 15146 15147 15153 15155 15156 15158 15160 15161 15172 15173 15200 26977https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/814/91?format=asciidefaultJ/ApJ/814/91/table1Observed and derived parameters for potentially habitable KOIsStarmeta.id.parentcharSimbadNameSimbad column added by the CDSmeta.idcharL[0/3]? Flux boundary (2)meta.codeintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPlPlanet identifier (KNNNNN.NN, K2-3d or Kepler-NNa)meta.id;meta.maincharR*[0.1/2] Stellar radiussolRadphys.size.radiusfloatTeff[2661/6640] Effective stellar temperatureKphys.temperature.effectiveintlog(g)*[4/5.3] Log stellar surface gravitylog(cm.s**-2)phys.gravityfloatM*[0.09/1.4] Stellar masssolMassphys.massfloatL*[0.001/4.5] Stellar luminositysolLumphys.luminosityfloatPer[3.6/651.1] Orbital perioddtime.periodfloatDepth[52.5/37296] Transit depth(10-6)phys.absorption.opticalDepthfloatDur[0.8/34.2] Transit duration (D)htime.durationfloatb[0/0.97] Impact parametersrc.impactParamfloatRp[0.5/2.5] Planetary radius(6.3781x10+6m)phys.size.radiusfloatMp[0.1/28.3] Planetary mass(5.97236x10+24kg)phys.massfloatlog(g)p[4.3/44.4] Log planetary surface gravitylog(m.s**-2)phys.gravityfloatFmax[270.4/350] Runaway greenhouse fluxW.m**-2phot.fluxfloata[0.02/1.5] Semi-major axisAUphys.size.smajAxisfloatDc[0.3/20.8] Transit duration if orbit is circularhtime.durationfloatTDA[0.1/4] Transit Duration Anomaly (D/Dc)time.epochfloateminMinimum eccentricitysrc.orbital.eccentricityfloatemaxMaximum eccentricitysrc.orbital.eccentricityfloatScir[0.1/21.5] Incident stellar radiation (1)Earthstat.fit.paramfloatH[0/0.93] "habitability index for transiting exoplanets" (HITE)stat.likelihoodfloatH'[0/0.96] HITE primestat.likelihoodfloatJmag[9.4/14.7] Apparent J band magnitudemagphot.mag;em.IR.JfloatKmag[8.5/17.2] Apparent K band magnitudemagphot.mag;em.IR.KfloatNc[0/2] Number of adjacent planetary companionsmeta.numberintKICDisplay the KIC data (V/133) within 1.6"meta.ref.urlintnullable2MDisplay the 2MASS data (Cutri+, 2003, II/246) within 2"meta.ref.urlchar_RAPositions from the host star taken in Simbad or the KIC (V/133) (right ascension part)degpos.eq.ra;meta.main_DEPositions from the host star taken in Simbad or the KIC (V/133) (declination part)degpos.eq.dec;meta.main