J/ApJ/893/67ivo://CDS.VizieR/J/ApJ/893/67doi:10.26093/cds/vizier.18930067CDSMorris B.M.2023-08-16T13:43:23Z2021-09-28T14:41:44ZCDS support team

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

cds-question@unistra.frphotometryvisible-astronomystellar-associationsvariable-starsWe investigate starspot distributions consistent with space-based photometry of F, G, and K stars in six stellar associations ranging in age from 10Myr to 4Gyr. We show that a simple light-curve statistic called the "smoothed amplitude" is proportional to stellar age as t^-1/2^, following a Skumanich-like spin-down relation. We marginalize over the unknown stellar inclinations by forward modeling the ensemble of light curves for direct comparison with the Kepler, K2, and TESS photometry. We sample the posterior distributions for spot coverage with approximate Bayesian computation. We find typical spot coverages in the range 1%-10%, which decrease with increasing stellar age. The spot coverage is proportional to t^n^ where n=-0.37+/-0.16, also statistically consistent with a Skumanich-like t^-1/2^ decay of starspot coverage with age. We apply two techniques to estimate the spot coverage of young exoplanet-hosting stars likely to be targeted for transmission spectroscopy with the James Webb Space Telescope, and estimate the bias in exoplanet radius measurements due to varying starspot coverage.2020ApJ...893...67Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/893/67CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/133 : Kepler Input Catalog (Kepler Mission Team, 2009)IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)I/345 : Gaia DR2 (Gaia Collaboration, 2018)IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)J/ApJS/101/117 : UBVRIJHKLMNQ photometry in Taurus-Auriga (Kenyon+ 1995)J/ApJ/733/L9 : Stellar rotation for 71 NGC 6811 members (Meibom+, 2011)J/ApJ/736/19 : Kepler planetary candidates. II. (Borucki+, 2011)J/PASP/124/1279 : Q3 Kepler's combined photometry (Christiansen+, 2012)J/A+A/549/A134 : 4 new WASP transiting close-in giant planets (Hebrard+, 2013)J/ApJS/211/24 : Rotation periods of Kepler MS stars (McQuillan+, 2014)J/ApJ/795/167 : Transits of PH3b, c & d through January, 2019 (Schmitt+, 2014)J/MNRAS/452/2127 : Fundamental param. of Kepler stars (Silva Aguirre+, 2015)J/MNRAS/459/1060 : M67 var. stars from Kepler/K2-Campaign-5 (Gonzalez, 2016)J/MNRAS/461/794 : Scorpius-Centaurus K-Type Stars (Pecaut+, 2016)J/MNRAS/463/3513 : M67 Kepler/K2-Campaign-5 variable stars (Gonzalez, 2016)J/ApJ/842/83 : Praesepe members rot. periods from K2 LCs (Douglas+, 2017)J/MNRAS/472/1618 : Kepler study of starspot lifetimes (Giles+, 2017)J/ApJ/856/23 : BANYAN. XI. The BANYAN {Sigma} algorithm (Gagne+, 2018)J/A+A/612/L2 : Compilation of stellar rotation data (Kovacs, 2018)J/AJ/156/18 : APOGEE DR14:Bin. comp. of evolved stars (Price-Whelan+, 2018)J/A+A/622/L13 : Stellar stream in Gaia DR2 discovery (Meingast+, 2019)J/A+A/624/A15 : Kepler-411 mid-transit times (Sun+, 2019)J/ApJ/879/49 : Rot. periods for 171 Gaia members of NGC 6811 (Curtis+, 2019)J/AJ/158/77 : Cand. & members of the Pisces-Eridanus stream (Curtis+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/893/67https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/893/67http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/893/67https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/893/67https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/893/67http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/893/67GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/893/67/table1 (Smoothed amplitudes and rotation periods for all targets considered in this work)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/893/67/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/893/67/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/893/67/table1?GETtext/xml+votable180.050000true15.926136440.85436940.0055555555555555565/1174 1177 1180-1181 6/52 601 784 826 1762 2101 2374 2660 2966 4253 4255 4296 4298 4320 4679 4684-4685 4687 4690-4692 4694-4695 4701-4702 4716 4728 4730 4816-4817 4872 4896 14778-14779 14782 15120-15121 15124 16626 16670 16691 16736 16988 17009 17068 17092 17185 17292 17457 17552 17626 17656 17683 17691 17703 17713 17715 17733 17736 17859 17883 17987 17989 18438 18448 20505 21094 21172 21180 21195 21229 21231 21237 21386 21411 21420 22532 22542 22566 22580 22635 22639 22648 22667 22676 22685 22691 22707 22713 22720-22721 22728 22730 22736 22771 22776 22786 23047 23058 23060 23074 23094 23116 23140 23155 23471 23895 24189-24190 24278 27392 30826 33116 33193 33937 34074 34334 34410 34423 34610 35351 35390 35414 35640 35736 35853 36012 36031 36109 36118 36199 36215 36218 36261 36269 36285 36340 36342 36358 36371 36392 36449 36576 36588 36629 36660 36671 36713 36725 36799 36805 36816 36821 38950 39829 47095https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/893/67?format=asciiOpticaldefaultJ/ApJ/893/67/table1Smoothed amplitudes and rotation periods for all targets considered in this workPer[0.19/39.2] Perioddtime.periodfloat_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.mainrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource identifiermeta.id;meta.maincharAssocAssociation identifier (1)meta.id.assoccharSAmp[0.0001/0.15] Smoothed amplitude (2)src.var.amplitudefloatKICDisplay the KIC (V/133) data within 2"meta.ref.urlintnullableK2Display the K2 (IV/34) data within 2"meta.ref.urlintnullableTICDisplay the TIC (IV/38) data within 2"meta.ref.urlintnullableSimbadNameSimbad column added by the CDSmeta.idcharnullable_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main