J/AJ/157/152ivo://CDS.VizieR/J/AJ/157/152doi:10.26093/cds/vizier.51570152CDSHsu A.I.Wong M.H.Simon A.A.2019-11-12T13:28:39Z2019-08-05T14:40:33ZCDS support team

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

cds-question@unistra.frsolar-systemsolar-system-planetshst-photometrystellar-evolutionary-modelsWe scoured the full set of blue-wavelength Hubble Space Telescope images of Neptune, finding one additional dark spot in new Hubble data beyond those discovered in 1989, 1994, 1996, and 2015. We report the complete disappearance of the SDS-2015 dark spot, using new Hubble data taken on 2018 September 9-10, as part of the Outer Planet Atmospheres Legacy (OPAL) program. Overall, dark spots in the full Hubble data set have lifetimes of at least one to two years, and no more than six years. We modeled a set of dark spots randomly distributed in time over the latitude range on Neptune that is visible from Earth, finding that the cadence of archival Hubble images would have detected about 70% of these spots if their lifetimes are only one year, or about 85%-95% of simulated spots with lifetimes of two or more years. Based on the Hubble data set, we conclude that dark spots have average occurrence rates of one dark spot every four to six years. Many numerical models to date have simulated much shorter vortex lifetimes, so our findings provide constraints that may lead to improved understanding of Neptune's wind field, stratification, and humidity.2019AJ....157..152Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/157/152CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)J/AJ/152/142 : Spitzer and WISE light curves of Neptune (Stauffer+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/157/152https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/157/152http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/157/152https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/157/152https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/157/152http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/157/152GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/AJ/157/152/table3Observation catalogInstInstrument on HubbleinstrcharDatasetDataset identifiermeta.id;meta.datasetcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateStart datetime.startnullableTimeStart time (hh:mm)time.epochnullableExp[8/130] Total exposure durationstime.duration;obs.exposureintFiltFilter/Gratingmeta.notecharOb-Lon[5.69/356.17] Sub-observer longitudedegpos.framefloatOb-Lat[-261/26.1] Sub-observer latitudedegpos.framefloatPID[5221/15262] Proposal IDmeta.id;obsintPIPrincipal Investigator last nameobs.observercharDSpot[Yes/No] Whether dark spot is detected in the imagemeta.codecharJ/AJ/157/152/table4Monte Carlo simulation for 1-year lifetimerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/8000] Dark spot identifiermeta.idintLS[1/6] Lifespan of this simulated dark spotyrtime.intervalintLat[-90/50] Latitude of dark spotdegpos.framefloatBirth[1988.51/2018.49] Time in years the dark spot is bornyrtime.epochfloatDrift[-448.97/289.44] Drift rate added to Sromovsky zonal windm/sobs.paramfloatNdet[0/81] Number of detectionsmeta.numberintJ/AJ/157/152/table5Monte Carlo simulation for 2-year lifetimerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/8000] Dark spot identifiermeta.idintLS[1/6] Lifespan of this simulated dark spotyrtime.intervalintLat[-90/50] Latitude of dark spotdegpos.framefloatBirth[1988.51/2018.49] Time in years the dark spot is bornyrtime.epochfloatDrift[-448.97/289.44] Drift rate added to Sromovsky zonal windm/sobs.paramfloatNdet[0/81] Number of detectionsmeta.numberintJ/AJ/157/152/table6Monte Carlo simulation for 3-year lifetimeNdet[0/81] Number of detectionsmeta.numberintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/8000] Dark spot identifiermeta.idintLS[1/6] Lifespan of this simulated dark spotyrtime.intervalintLat[-90/50] Latitude of dark spotdegpos.framefloatBirth[1988.51/2018.49] Time in years the dark spot is bornyrtime.epochfloatDrift[-448.97/289.44] Drift rate added to Sromovsky zonal windm/sobs.paramfloatJ/AJ/157/152/table7Monte Carlo simulation for 4-year lifetimerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/8000] Dark spot identifiermeta.idintLS[1/6] Lifespan of this simulated dark spotyrtime.intervalintLat[-90/50] Latitude of dark spotdegpos.framefloatBirth[1988.51/2018.49] Time in years the dark spot is bornyrtime.epochfloatDrift[-448.97/289.44] Drift rate added to Sromovsky zonal windm/sobs.paramfloatNdet[0/81] Number of detectionsmeta.numberintJ/AJ/157/152/table8Monte Carlo simulation for 5-year lifetimerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/8000] Dark spot identifiermeta.idintLS[1/6] Lifespan of this simulated dark spotyrtime.intervalintLat[-90/50] Latitude of dark spotdegpos.framefloatBirth[1988.51/2018.49] Time in years the dark spot is bornyrtime.epochfloatDrift[-448.97/289.44] Drift rate added to Sromovsky zonal windm/sobs.paramfloatNdet[0/81] Number of detectionsmeta.numberintJ/AJ/157/152/table9Monte Carlo simulation for 6-year lifetimerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[1/8000] Dark spot identifiermeta.idintLS[1/6] Lifespan of this simulated dark spotyrtime.intervalintLat[-90/50] Latitude of dark spotdegpos.framefloatBirth[1988.51/2018.49] Time in years the dark spot is bornyrtime.epochfloatDrift[-448.97/289.44] Drift rate added to Sromovsky zonal windm/sobs.paramfloatNdet[0/81] Number of detectionsmeta.numberint