J/AJ/148/64ivo://CDS.VizieR/J/AJ/148/64doi:10.26093/cds/vizier.51480064CDSShkolnik E.L.Barman T.S.2017-11-29T11:48:53Z2015-01-05T13:09:15ZCDS support team

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

cds-question@unistra.frearly-type-starsm-starsstellar-spectral-typesultraviolet-astronomystellar-distanceThe spectral energy distribution, variability, and evolution of the high-energy radiation from an M dwarf planet host is crucial in understanding the planet's atmospheric evolution and habitability and in interpreting the planet's spectrum. The star's extreme-UV (EUV), far-UV (FUV), and near-UV (NUV) emission can chemically modify, ionize, and erode the atmosphere over time. This makes determining the lifetime exposure of such planets to stellar UV radiation critical for both the evolution of a planet's atmosphere and our potential to characterize it. Using the early M star members of nearby young moving groups, which sample critical ages in planet formation and evolution, we measure the evolution of the GALEX NUV and FUV flux as a function of age. The median UV flux remains at a "saturated" level for a few hundred million years, analogous to that observed for X-ray emission. By the age of the Hyades Cluster (650Myr), we measure a drop in UV flux by a factor of 2-3 followed by a steep drop from old (several Gyrs) field stars. This decline in activity beyond 300Myr follows roughly t^-1^. Despite this clear evolution, there remains a wide range, of 1-2 orders of magnitude, in observed emission levels at every age. These UV data supply the much-needed constraints to M dwarf upper-atmosphere models, which will provide empirically motivated EUV predictions and more accurate age-dependent UV spectra as inputs to planetary photochemical models.2014AJ....148...64Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/148/64CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/312 : GALEX-DR5 (GR5) sources from AIS and MIS (Bianchi+ 2011)J/MNRAS/431/2063 : UV/X-ray activity of M dwarfs within 10pc (Stelzer+, 2013)J/ApJ/766/9 : GALEX observations of exoplanet host stars (Shkolnik, 2013)J/ApJ/758/56 : Young M dwarfs within 25pc. II. Kinematics (Shkolnik+, 2012)J/AJ/142/138 : All-sky catalog of bright M dwarfs (Lepine+, 2011)J/ApJ/699/649 : Young M dwarfs within 25pc. I. (Shkolnik+, 2009)J/ApJS/173/673 : M dwarf UV flares in GALEX (Welsh+, 2007)J/other/ARA+A/42.685 : Young stars near the Sun (Zuckerman+, 2004)J/A+A/331/81 : Hyades membership (Perryman+ 1998)http://mastweb.stsci.edu/gcasjobs/ : CasJobshttp://galex.stsci.edu/galexview/ : GalexViewhttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/148/64https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/148/64http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/148/64https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/148/64https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/148/64http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/148/64GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/148/64/table1 (Target early M stars observed by GALEX)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/148/64/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/148/64/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/148/64/table1?GETtext/xml+votable180.050000true167.30754-30.027720.0055555555555555566/325 337 811 847 989 1035 1057 2545 2660 3715 3791 4158 5420 5534 6552 7103 7512 8023 8123 9585 9629 10027 10149 10448 12679 15311 15602 15686 15960 16391 16930 17058 17394 17502 17606 19163 19466 20100 20381 20473 21151 21180 21420 21953 22309 22535 23047 23094 23388 23523 23526 23527 23535 23539 23544 23545 23548 23549 23895 24227 24232 24233 24608 24629 24713 24740 24763 25009 26560 27201 27289 27392 27611 27792 28162 28341 28343 28646 28955 29684 31019 31191 32115 32335 32930 33006 33065 33170 33186 33342 33367 33382 33425 33456 33464 33468 33482 33501 33512 33513 33520 33523 33551 33583 33594 33666 33670 33689 33694 33706 33716 33718 33737 33756 33919 33965 33993 34127 34181 34380 34450 34486 34530 34733 34819 34830 34834 34843 34857 34959 34963 34998 35002 35027 35131 35147 35531 35670 35847 35885 36511 36614 38341 38347 38359 38363 38456 38551 38742 38936 39499 42054 42314 43571 43580 43670 44921 45073 45168 45322 45324 45336 45345 45378 45389 45394 45471 45472 45503 45510 45544 45852 45876 45977 46082 46207 46601 46632 46692 46718 46758 46922 48263 48274 485591.5062136169708525e-19 1.7003137259100215e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/148/64?format=asciiOpticalUVdefaultJ/AJ/148/64/table1Target early M stars observed by GALEXSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintYMGName of the Young Moving Group (1)meta.id.parentcharr_YMGReference for group membership (in refs.dat file)meta.ref;pos.framecharNameName of the star observed by GALEX (2)meta.id;meta.maincharf_Name[d] TWA 31 and TWA 30 B are both known to be accretors (3)meta.codecharRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainSpTPublished spectral typesrc.spTypecharJmag[4.2/15.4]? 2MASS J-band magnitudemagphot.mag;em.IR.Jfloatnullable2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlcharn_Dist[-] "-" indicates a photometric distance (4)meta.notecharDist[2/80] Hipparcos (cat. I/239) distance (4)pcpos.distance;pos.heliocentricfloatBinBinarity type (VB=visual binary, SB=spectroscopic binary, BD=brown dwarf)meta.codecharr_BinReference for binarity (in refs.dat file)meta.ref;pos.framecharSep[0/114.2]? Binary separation (5)arcsecpos.angDistancefloatnullablel_FFUV[<] Upper limit flag on FFUVmeta.code.errorcharFFUV[0.3/411]? GALEX far-UV (135-175nm) flux densityuJyphot.flux;em.UVfloatnullablee_FFUV? Error in FFUVuJystat.errorfloatnullablef_FFUV[NO] Indicates the star was not observed in FUVmeta.codecharl_FNUV[<] Upper limit flag on FNUVmeta.code.errorcharFNUV[1/2222]? GALEX near-UV (175-275nm) flux densityuJyphot.flux;em.UVfloatnullablee_FNUV? Error in FNUVuJystat.errorfloatnullablef_FNUV[NO] Indicates the star was not observed in NUVmeta.codecharGALEXSimbad column added by the CDSmeta.ref.urlcharJ/AJ/148/64/refsReferencesRef[1/27] Reference numbermeta.id;meta.mainintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBibCodeBibliographic Codemeta.bib.bibcodecharAutAuthor's namemeta.bib.authorcharCatCatalog in VizieR databasemeta.dataset;meta.tablechar