J/ApJ/872/17ivo://CDS.VizieR/J/ApJ/872/17doi:10.26093/cds/vizier.18720017CDSRichey-Yowell T.Shkolnik E.L.Schneider A.C.Osby E.Barman T.,Meadows V.S.2021-09-07T13:10:14Z2020-08-13T09:59:51ZCDS support team

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

cds-question@unistra.frk-starsultraviolet-photometryx-ray-sourcesstellar-massesstellar-agesstellar-distanceKnowing the high-energy radiation environment of a star over a planet's formation and evolutionary period is critical in determining if that planet is potentially habitable and if any biosignatures could be detected, as UV radiation can severely change or destroy a planet's atmosphere. Current efforts for finding a potentially habitable planet are focused on M stars, yet K stars may offer more habitable conditions due to decreased stellar activity and more distant and wider habitable zones (HZs). While M star activity evolution has been observed photometrically and spectroscopically, there has been no dedicated investigation of K star UV evolution. We present the first comprehensive study of the near-UV, far-UV, and X-ray evolution of K stars. We used members of young moving groups and clusters ranging in age from 10 to 625Myr combined with field stars and their archived GALEX UV and ROSAT X-ray data to determine how the UV and X-ray radiation evolve. We find that the UV and X-ray flux incident on an HZ planet is 5-50 times lower than that of HZ planets around early-M stars and 50-1000 times lower than those around late-M stars, due to both an intrinsic decrease in K dwarf stellar activity occurring earlier than for M dwarfs and the more distant location of the K dwarf HZ.2019ApJ...872...17Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/872/17CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toIX/10 : ROSAT All-Sky Bright Source Catalogue (1RXS) (Voges+ 1999)II/335 : Revised catalog of GALEX UV sources (GUVcat_AIS GR6+7) (Bianchi+ 2017)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/A+A/331/81 : Hyades membership (Perryman+ 1998)J/MNRAS/328/45 : Late-type stars members of young groups (Montes+, 2001)J/AJ/134/2340 : Praesepe & Coma Berenices cluster memberships (Kraus+, 2007)J/ApJ/761/166 : Terrestrial exoplanet atmospheres. I. (Hu+, 2012)J/MNRAS/422/2024 : X-ray-age relation & exoplanet evaporation (Jackson+, 2012)J/A+A/559/A43 : Pan-STARRS1 (PS1) obs. of the Hyades (Goldman+, 2013)J/ApJ/762/88 : Young stellar kinematic group cand. members (Malo+, 2013)J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)J/MNRAS/431/2063 : UV/X-ray activity of M dwarfs within 10pc (Stelzer+, 2013)J/AJ/147/146 : Spectroscopy of Tuc-Hor candidate members (Kraus+, 2014)J/AJ/148/64 : HAZMAT. I. FUV & NUV in early M stars (Shkolnik+, 2014)J/MNRAS/454/593 : Young moving groups in solar neighbourhood (Bell+, 2015)J/A+A/588/A103 : 2nd ROSAT all-sky survey (2RXS) source cat. (Boller+, 2016)J/AJ/154/67 : HAZMAT. II. Low-mass stars with GALEX UV obs. (Miles+, 2017)J/AJ/154/69 : ACRONYM II. {beta} Pictoris Moving Group (Shkolnik+, 2017)J/ApJS/239/2 : Simulated exoplanets from TESS targets (Barclay+, 2018)J/AJ/155/122 : HAZMAT. III. Low-mass stars GALEX photom. (Schneider+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/872/17https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/872/17http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/872/17https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/872/17https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/872/17http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/872/17GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/872/17/table2 (Number of K stars in each group or cluster)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/872/17/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/872/17/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/872/17/table2?GETtext/xml+votable180.050000true165.475-34.70.005555555555555556Cone search capability for table J/ApJ/872/17/table3 (Observed flux densities, fluxes, and model photospheric flux densities of the stars used in this analysis)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/872/17/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/872/17/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/872/17/table3?GETtext/xml+votable180.050000true165.4662716667-34.70473138890.0055555555555555565/1174 1177 6/60 78 100 129 137 181 307 309 311 320 323 326 334 339 357 381 383 427 477 478 540 674 684 719 835 889 917 940 993 1025 1026 1035 1036 1038 1044 1058 1096 1098 1113 1260 1530 1827 1839 2014 2328 2374 2622 3256 3372 3509 3915 3979 4017 4118 4278 4336 4468 4555 4620 4685 4686 4687 4691 4702 4720 4721 4937 5034 5207 5309 5434 5474 5622 5824 5853 5899 5919 5970 6049 6066 6073 6137 6209 6287 6316 6489 6752 7126 7129 7264 7745 7874 7908 7989 8003 8016 8132 8219 8357 8424 8773 8887 8993 9128 9150 9199 9609 9811 9843 9873 10062 10089 10211 10313 10325 10431 10439 10518 10983 11053 11103 11126 11142 11177 11391 11405 11412 11633 11713 11806 12340 12388 12654 12770 12889 13203 13323 13450 13568 13693 14438 14982 15101 15505 16069 16274 16342 16393 16502 16692 16853 16930 17017 17288 17314 17777 17783 18115 18135 18139 18299 18641 18758 18802 19185 19327 19701 19816 19888 19912 20372 20374 20457 20655 21038 21125 21136 21450 21546 21726 21838 22490 22566 22598 22606 22663 22708 22761 22813 22959 23017 23023 23026 23028 23276 23286 23321 23329 23368 23383 23400 23408 23413 23437 23450 23453 23505 23507 23509 23511 23515 23517 23518 23522 23523 23529 23535 23538 23539 23545 23548 23597 24099 24114 24126 24192 24194 24201 24202 24203 24204 24206 24209 24211 24212 24219 24232 24234 24248 24252 24266 24608 24831 25046 25091 25139 25238 25306 25342 25820 25880 26016 26183 26379 26394 26429 26492 27109 27176 27335 27374 27772 27954 28018 28395 28400 29357 29665 29756 31031 31087 31399 31545 31606 32055 32211 32224 32318 32509 32520 32757 32912 32937 33116 33145 33210 33270 33442 33500 33583 33662 33694 33725 33813 33832 33850 33895 33996 34058 34067 34074 34147 34450 34481 34508 34733 34758 34829 34830 34850 34947 35005 35123 35147 35375 35576 35690 35802 35861 36078 36152 36182 36261 36288 36308 36412 36697 36735 36758 37419 38382 38936 39044 39500 39597 39658 40830 41463 42577 42595 43296 43366 43696 43704 43804 44151 44262 44439 44715 44751 44792 44891 44967 45013 45120 45336 45351 45412 45475 45542 45544 45902 45941 45982 46010 46082 46321 46351 46692 46776 46785 46925 46997 47335 47390 47416 48061 48553 48606 491137.447298006782415e-19 1.4134638842407062e-18https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/872/17?format=asciiX-rayUVdefaultJ/ApJ/872/17/table2Number of K stars in each group or clusterSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterGroup/Cluster designation as in Table 3meta.id;meta.maincharprimaryu_Age[~] Uncertainty flag on Agemeta.code.error;time.agecharAgeAgeMyrtime.ageinte_Age[3/50]? Negative error on AgeMyrstat.error;time.ageintnullableE_Age[3/51]? Positive error on AgeMyrstat.error;stat.maxintnullabler_AgeAge reference (1)meta.ref;pos.framecharNin[3/310] Number of K stars in input samplemeta.numberintNnuv[1/229] Number of K stars observed in NUV by GALEXmeta.numberintDetNUV[1/169] Number of K stars detected in NUV by GALEXmeta.numberintNfuv[1/211] Number of K stars observed in FUV by GALEXmeta.numberintDetFUV[1/152] Number of K stars detected in FUV by GALEXmeta.numberintNx[0/107] Number of K stars detected in X-ray by ROSATmeta.numberintNsNumber of stars used in the analysis for this group (link to Table 3)meta.numberintnullable_RAPositions from SIMBAD (right ascension part)degpos.eq.ra;meta.mainnullable_DEPositions from SIMBAD (declination part)degpos.eq.dec;meta.mainnullableJ/ApJ/872/17/table3Observed flux densities, fluxes, and model photospheric flux densities of the stars used in this analysisSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterGroup/Clustermeta.notecharAge[10/5000] Age (1)Myrtime.ageintNameSimbad Name (2)meta.id;meta.maincharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainMass[0.5/1] Derived stellar masssolMassphys.massfloatDist[3.2/355.4] Distancepcpos.distance;pos.heliocentricfloatSJ[1870000/568000000] Observed J band flux densityuJyphot.flux.density;em.IR.JdoublesigJ[4760000/32400000] J band model photospheric flux density ({sigma}_J_)uJyphot.flux.density;meta.modelled;em.IR.Jdoublel_SNUVLimit flag on S-NUVmeta.code.errorcharSNUV[5/3460000]? Observed GALEX NUV (1771-2831{AA}) flux densityuJyphot.flux.density;em.UVdoublenullablee_SNUV[1/13200]? Uncertainty in S-NUVuJystat.errordoublenullablesigNUV[18.7/31100]? NUV model photospheric flux density ({sigma}_NUV_)uJyphot.flux.density;meta.modelled;em.UVdoublenullablel_SFUVLimit flag on S-FUVmeta.code.errorcharSFUV[2.5/165000]? Observed GALEX FUV (1344-1786{AA}) flux densityuJyphot.flux.density;em.UVdoublenullablee_SFUV[0.5/1850]? Uncertainty in S-FUVuJystat.errordoublenullablesigFUV[3.2e-5/3.1]? FUV model photospheric flux density ({sigma}_FUV_)uJyphot.flux.density;meta.modelled;em.UVdoublenullableFx[1e-13/2.4e-10]? Observed X-ray fluxmW.m**-2phot.flux;em.X-raydoublenullablee_Fx[1.4e-14/2.6e-11]? Uncertainty in FxmW.m**-2stat.errordoublenullable2RXSDisplay the 2RXS data (Boller+, 2016, J/A+A/588/A103) within 38"meta.ref.urlintnullablePM13Display data from Pecaut & Mamajek 2013, J/ApJS/208/9, within 1"meta.ref.urlintnullableGALEXDisplay data from GALEX GR6+7 (II/335) within 10"meta.ref.urlintnullable2MDisplay the 2MASS data (Cutri+ 2003, II/246) within 2"meta.ref.urlchar