J/AJ/159/74ivo://CDS.VizieR/J/AJ/159/74doi:10.26093/cds/vizier.51590074CDSProtopapa S.Olkin C.B.Grundy W.M.Li J.-Y.Verbiscer A.,Cruikshank D.P.Gautier T.Quirico E.Cook J.C.Reuter D.,Howett C.J.A.Stern A.Beyer R.A.Porter S.Young L.A.Weaver H.A.,Ennico K.Dalle Ore C.M.Scipioni F.Singer K.2020-08-21T08:19:36Z2020-03-27T12:27:23ZCDS support team

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

cds-question@unistra.frsolar-systemphotometryvisible-astronomyinfrared-astronomyspectroscopyA multiwavelength regionally dependent photometric analysis of Pluto's anti-Charon-facing hemisphere using images collected by New Horizons' Multispectral Visible Imaging Camera (MVIC) reveals large variations in the absolute value and spectral slope of the single-scattering albedo. Four regions of interest are analyzed: the dark equatorial belt, Pluto's north pole, nitrogen-rich regions, and the mid-latitude terrains. Regions dominated by volatile ices such as Lowell Regio and Sputnik Planitia present single-scattering albedos of ~0.98 at 492nm, almost neutral across MVIC's visible wavelength range (400-910nm), indicating limited contributions from tholin materials. Pluto's dark equatorial regions, informally named Cthulhu and Krun Maculae, have single-scattering albedos of ~0.16 at 492nm and are the reddest regions. Applying the Hapke radiative transfer model to combined MVIC and Linear Etalon Imaging Spectral Array (LEISA) spectra (400-2500nm) of Cthulhu Macula and Lowell Regio successfully reproduces the spectral properties of these two regions of dramatically disparate coloration, composition, and morphology. Since this model uses only a single coloring agent, very similar to the Titan like tholin of Khare+ (1984Icar...60..127K), to account for all of Pluto's colors, this result supports the Grundy+ (2016Sci...351.9189G) conclusion that Pluto's coloration is the result of photochemical products mostly produced in the atmosphere. Although cosmic rays and extreme ultraviolet photons reach Pluto's surface where they can drive chemical processing, observations of diverse surface colors do not require different chemical products produced in different environments. We report a correction scaling factor in the LEISA radiometric calibration of 0.74{+/-}0.05.2020AJ....159...74Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/159/74CatalogResearchIsServedByTAP VizieR generic servicerelated-toVI/155 : Topocentric positions of Pluto (Eglitis+, 2018)J/A+AS/118/105 : Pluto 1991-1994 observations (Ryl'kov+, 1996)J/A+A/375/285 : Photometric observations of Near-Earth Objects (Szabo+, 2001)J/A+A/383/1054 : Astrometry of Pluto and Saturn in 1995-2001 (Rapaport+, 2002)J/A+A/486/613 : Observation of Pluto (Veiga+, 2008)J/A+A/515/A32 : Pluto, Charon, Nix, Hydra occultation 2008-15 (Assafin+, 2010)J/A+A/551/A102 : Photometry of 16 Flora family asteroids (Kryszczynska, 2013)J/A+A/553/A14 : Pluto's observations between 1997 and 2010 (Beauvalet+, 2013)J/AJ/149/22 : Astrometry of Pluto from 1930-1951 observations (Buie+, 2015)J/AJ/152/80 : Astrometry of Pluto & trans-Neptunian objects (Holman+, 2016)J/AJ/158/196 : Near-Earth Object Survey (MANOS) spectro. (Devogele+, 2019)J/ApJS/244/14 : Cassini CIRS observations of Titan 2004-2017 (Nixon+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/159/74https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/159/74http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/159/74https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/159/74https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/159/74http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/159/74GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/AJ/159/74/table2Multispectral Visible Imaging Camera (MVIC) observations of PlutorecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsIDRequest IDmeta.id;obscharMET[299104958/299178098] Mission elapsed time (1)time.durationlongDateUTC mid-time of observationstime.epochnullableScale[0.6/21] Image scalekm/pixinstr.scale;obs.imagefloatLong[161/197] Subsample-s/c longitude, Eastdegpos.framefloatLat[25/43] Subsample-s/c latitude, Northdegpos.framefloatJ/AJ/159/74/fig12cCombined New Horizons-MVIC and -LEISA mean radiance factor (RADF) spectrum of eastern Cthulhu (Data behind figure 12)lambda[0.49/2.4] Wavelengthumem.wldoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRADFC[0.05/0.39] Radiance factor of eastern Cthulhustat.fit.parame_RADFC[0.009/0.05] 1-{sigma} errorstat.errordoubleJ/AJ/159/74/fig12lrCombined New Horizons-MVIC and -LEISA mean RADF spectrum of Lowell Regio (Data behind figure 12)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[0.49/2.4] Wavelengthumem.wldoubleRADFL[0.04/0.77] Radiance factor of Lowell Regiostat.fit.parame_RADFL[0.01/0.08] 1-{sigma} errorstat.errordoubleJ/AJ/159/74/fig13aA Titan tholin optical constants (Data behind figure 13)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[0.38/2.5] Wavelengthumem.wldoublenA[1.6/1.8] The real part of the index of refraction for sample Ameta.code;spect.indexdoublekA[4.1e-4/0.1] The imaginary part of the index of refraction for sample Ameta.code;spect.indexdoubleJ/AJ/159/74/fig13bB Titan tholin optical constants (Data behind figure 13)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[0.38/2.5] Wavelengthumem.wldoublenB[1.6/1.8] The real part of the index of refraction for sample Bmeta.code;spect.indexdoublekB[4.1e-4/0.1] The imaginary part of the index of refraction for sample Bmeta.code;spect.indexdouble