J/ApJ/903/L7ivo://CDS.VizieR/J/ApJ/903/L7doi:10.26093/cds/vizier.19039007CDSCrossfield I.J.M.Dragomir D.Cowan N.B.Daylan T.Wong I.,Kataria T.Deming D.Kreidberg L.Mikal-Evans T.Gorjian V.,Jenkins J.S.Benneke B.Collins K.A.Burke C.J.Henze C.E.,McDermott S.Mireles I.Watanabe D.Wohler B.Ricker G.,Vanderspek R.Seager S.Jenkins J.M.2022-06-13T09:51:22Z2022-03-14T07:31:59ZCDS support team

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

cds-question@unistra.frexoplanetsinfrared-photometryeffective-temperaturePhase-curve measurements provide a global view of the composition, thermal structure, and dynamics of exoplanet atmospheres. Although most of the dozens of phase-curve measurements made to date are of large, massive hot Jupiters, there is considerable interest in probing the atmospheres of the smaller planets that are the more typical endproduct of the planet formation process. One such planet that is favorable for these studies is the ultrahot Neptune LTT9779b, a rare denizen of the Neptune desert. A companion paper presents the planet's secondary eclipses and dayside thermal emission spectrum; in this work we describe the planet's optical and infrared phase curves, characterized using a combination of Spitzer and Transiting Exoplanet Survey Satellite (TESS) photometry. We detect LTT9779b's thermal phase variations at 4.5{mu}m, finding a phase amplitude of 358{+/-}106ppm and no significant phase offset, with a longitude of peak emission occurring -10{deg}{+/-}21{deg} east of the substellar point. Combined with our secondary eclipse observations, these phase-curve measurements imply a 4.5{mu}m dayside brightness temperature of 1800{+/-}120K, a nightside brightness temperature of 700{+/-}430K (<1350K at 2{sigma} confidence), and a day-night brightness temperature contrast of 1110{+/-}460K. We compare our data to the predictions of 3D general circulation models calculated at multiple metallicity levels and to similar observations of hot Jupiters experiencing similar levels of stellar irradiation. Though not conclusive, our measurement of its small 4.5{mu}m phase offset, the relatively large amplitude of the phase variation, and the qualitative differences between our target's dayside emission spectrum and those of hot Jupiters of similar temperatures all suggest a supersolar atmospheric metallicity for LTT9779b, as might be expected given its size and mass. Finally, we measure the planet's transits at both 3.6{mu}m and 4.5{mu}m, providing a refined ephemeris (P=0.79207022{+/-}0.00000069days, T0=2458783.51636{+/-}0.00027, BJDTDB) that will enable efficient scheduling of future observations to further characterize the atmosphere of this intriguing planet.2020ApJ...903L...7Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/903/L7CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/328 : AllWISE Data Release (Cutri+ 2013)J/ApJ/754/136 : Light curves of HD 149026b in 3.6-16um (Stevenson+, 2012)J/ApJ/755/9 : Spitzer/IRAC light curves of GJ 436 system (Stevenson+, 2012)J/A+A/552/A16 : Limb-darkening for CoRoT, Kepler, Spitzer. II. (Claret+, 2013)J/ApJ/790/53 : Photometric data of HD 209458b (Zellem+, 2014)J/A+A/619/A1 : 55 Cnc radial velocities and photometry (Bourrier+, 2018)J/A+A/625/A136 : WASP-18b HST/WFC3 spectroscopic phase curves (Arcangeli+,2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/903/L7https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/903/L7http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/903/L7https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/903/L7https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/903/L7http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/903/L7GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/903/L7/fig12 (Derived parameters from all IRAC 4.5m phase curve measurements of planets on nearly-circular orbits)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/903/L7/fig12?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/903/L7/fig12?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/903/L7/fig12?GETtext/xml+votable180.050000true133.149213928.33082140.0055555555555555566/2335 5009 8825 9459 12644 12983 14667 15129 15950 16395 24409 26771 30466 31541 35210 38452 45372https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/903/L7?format=asciiInfrareddefaultJ/ApJ/903/L7/fig12Derived parameters from all IRAC 4.5m phase curve measurements of planets on nearly-circular orbitsSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDPlanet identifiermeta.id;meta.maincharRefReference (1)meta.ref;pos.framecharMode[4.5] Wavelength at which observation were madeumem.wlfloatMass[0.02/10.2]? Planetary mass(1.898187x10+27kg)phys.massdoublenullableSep[2.98/8.81] Planetary separation, stellar radiipos.angDistance;src.orbitalfloatRad[0.02/0.17] Planetary radius in stellar radiiphys.size.radiusdoubleTeff[3036/10170] Effective stellar temperatureKphys.temperature.effectiveintDF/F[0.0001/0.005] Flux contrast in phase curve (2)phot.flux;arith.ratiodoublee_DF/F[0.000001/0.06] Uncertainty in DF/Fstat.errordoubleOffset[-23/57.6] Eastward phase offsetpos;arith.diffdoublee_Offset[0.1/21] Uncertainty in Offsetstat.errordoubleecldep[0.0001/4140] Eclipse depth(10-6)phys.absorption.opticalDepthdoublee_ecldep[1e-6/220] Uncertainty in ecldep(10-6)stat.errordoubleTeqMax[1028/5176] Maximum equilibrium temperatureKphys.temperatureintTday[1031/5991] Planetary day side temperatureKphys.temperatureinte_Tday[2/1458] Uncertainty in TdayKstat.errorintTnight[481/4461] Planetary night side temperatureKphys.temperatureinte_Tnight[2/1217] Uncertainty in TnightKstat.errorintDeltaT[270/2490] Day-night temperature contrastphys.temperatureinte_DeltaT[4/1395] Uncertainty in DeltaTstat.errorintaobs[0.18/0.76] Normalized day-night temperature contrast (3)phys.temperaturefloate_aobs[0.002/0.3] Uncertainty in aobsstat.errorfloatAB[0.02/0.88]? Bond albedophys.albedofloatnullablee_AB[0/0.3]? Uncertainty in ABstat.errorfloatnullableepsilon[0.006/0.69]? Global heat recirculation efficiencyphys.mol.formationHeatfloatnullablee_epsilon[0/0.3]? Uncertainty in epsilonstat.errorfloatnullable_RAPosition from SIMBAD (right ascension part)degpos.eq.ra;meta.mainnullable_DEPosition from SIMBAD (declination part)degpos.eq.dec;meta.mainnullable