J/ApJ/888/L5ivo://CDS.VizieR/J/ApJ/888/L5doi:10.26093/cds/vizier.18889005CDSYee S.W.Winn J.N.Knutson H.A.Patra K.C.Vissapragada S.Zhang M.M.,Holman M.J.Shporer A.Wright J.T.2021-10-25T10:19:53Z2021-07-21T14:26:35ZCDS support team

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

cds-question@unistra.frexoplanetsinfrared-photometryradial-velocityWASP-12b is a transiting hot Jupiter on a 1.09 day orbit around a late-F star. Since the planet's discovery in 2008, the time interval between transits has been decreasing by 29+/-2ms/yr. This is a possible sign of orbital decay, although the previously available data left open the possibility that the planet's orbit is slightly eccentric and is undergoing apsidal precession. Here, we present new transit and occultation observations that provide more decisive evidence for orbital decay, which is favored over apsidal precession by a {Delta}BIC of 22.3 or Bayes factor of 70000. We also present new radial-velocity data that rule out the Romer effect as the cause of the period change. This makes WASP-12 the first planetary system for which we can be confident that the orbit is decaying. The decay timescale for the orbit is P/{dot}P=3.25+/-0.23Myr. Interpreting the decay as the result of tidal dissipation, the modified stellar tidal quality factor is Q_*_^'^=1.8x10^5^.2020ApJ...888L...5Yhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/888/L5CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/692/L9 : Tidal evolution of transiting exoplanets (Levrard+, 2009)J/ApJ/709/168 : Eccentric orbits in exoplanets (Anglada-Escude+, 2010)J/ApJ/720/872 : A spectropolarimetric analysis of WASP-12 (Fossati+, 2010)J/ApJ/727/125 : Two secondary eclipses of WASP-12b with Spitzer (Campo+, 2011)J/A+A/528/A65 : WASP-12b transits (Maciejewski+, 2011)J/A+A/529/A75 : Limb-darkening coefficients (Claret+, 2011)J/AJ/141/179 : Transits of TrES-4b, HAT-P-3b and WASP-12b (Chan+, 2011)J/ApJ/745/77 : Photochemical model for planet WASP-12b (Kopparapu+, 2012)J/ApJ/757/18 : RVs for 16 hot Jupiter host stars (Albrecht+, 2012)J/ApJ/757/161 : Spectroscopy of 56 exoplanet host stars (Torres+, 2012)J/A+A/551/A108 : Multi-site obs. of WASP-12 b transit (Maciejewski+, 2013)J/ApJ/785/126 : HIRES radial velocity measurements (Knutson+, 2014)J/A+A/588/L6 : WASP-12 transit light curves (Maciejewski+ 2016)J/A+A/602/A107 : 231 transiting planets eccentricity and mass (Bonomo+, 2017)J/AJ/154/4 : Times of transits and occultations of WASP-12b (Patra+, 2017)J/AJ/155/165 : Dissipation in planet hosts from tidal spin-up (Penev+, 2018)J/AJ/156/28 : Exoplanets with Spitzer light curves (Adams+, 2018)J/AcA/68/371 : WASP and KELT planet transits (Maciejewski+, 2018)J/MNRAS/486/5867 : Simulated Transit depths of 12 Hot Jupiters (Singh+, 2019)J/A+A/628/A115 : WASP-12, CoRoT-1 and TrES-3 light curves (von Essen+, 2019)J/A+A/630/A89 : WASP-12b and WASP-43b griz light curves (Parviainen+, 2019)J/AJ/158/190 : MS hot Jupiter hosts with good astrometry (Hamer+, 2019)J/AJ/159/150 : Transit times of 11 hot Jupiters (Patra+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/888/L5https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/888/L5http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/888/L5https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/888/L5https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/888/L5http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/888/L5GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapInfrareddefaultJ/ApJ/888/L5/table2New occultation midpoints and depthsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateUT datetime.epochnullableOrbit[1341/2026] Orbit numbermeta.idintBJD[57769.5/58517.3] Midpoint in Barycentric Julian Date TDB; BJD-2400000dtime.epochdoublee_BJD[0.00074/0.0014] Timing uncertaintydstat.errordoubleDepth[1089/4720] Eclipse depth(10-6)phot.mag;stat.mininte_Depth[71/279] Depth negative uncertainty(10-6)stat.error;phys.absorption.opticalDepthintE_Depth[72/289] Depth positive uncertainty(10-6)stat.error;stat.maxintSourceInstrument or referencemeta.id;instrcharr_Source[ab] Eclipse observed in another paper (1)meta.ref;pos.framecharBandObserved photometric bandinstr.bandpasscharAp[2/2.4]? Aperture radiuspixphys.angSize;srcfloatnullableBin[14/22]? Bin size (exposures)time.intervalintnullableLCInteractive occultation LCs plotmeta.ref.urlcharJ/ApJ/888/L5/table1Photometric timeseriesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric Julian Date; TDBdtime.epochdoubleNFlux[0.96/1.03] Normalized fluxphot.flux;arith.ratiofloate_NFlux[0.001/0.005] The 1{sigma} uncertainty in NFluxstat.errorfloatTelTelescope code (1)meta.code;instr.telcharOrbit[1397/2026] Orbit numbermeta.idintJ/ApJ/888/L5/table4HIRES radial velocity measurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBJDBarycentric Julian Date; TDBdtime.epochdoubleRVel[-216/231] Radial velocitym/sphys.veloc;pos.heliocentricdoublee_RVel[2/5] The 1{sigma} uncertainty in RVelm/sstat.error;spect.dopplerVelocfloatJ/ApJ/888/L5/table5WASP-12b transit and occultation timesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEventEvent identifier (1)meta.codecharBJDBarycentric Julian date (TDB) of mid-observationdtime.epochdoublee_BJD[0.0001/0.003] The 1{sigma} uncertainty in BJDdstat.errordoubleOrbit[-1640/2026] Orbit number (2)meta.idintRefSource code(s) (3)meta.codechar