J/MNRAS/483/1125ivo://CDS.VizieR/J/MNRAS/483/1125doi:10.26093/cds/vizier.74831125CDSJackson R.J.Jeffries R.D.Deliyannis C.P.Sun Q.Douglas S.T.2024-08-19T20:15:33Z2022-08-10T14:28:04ZCDS support team

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

cds-question@unistra.fropen-star-clusterspre-main-sequence-starsstellar-massesstellar-radiiapparent-magnituderadial-velocityvisible-astronomyRotation periods from Kepler K2 are combined with projected rotation velocities from the WIYN 3.5m telescope to determine projected radii for fast-rotating, low-mass (0.1<=M/M_{sun}_<=0.6) members of the Praesepe cluster. A maximum likelihood analysis that accounts for observational uncertainties, binarity, and censored data yields marginal evidence for radius inflation - the average radius of these stars is 6+/-4 per cent larger at a given luminosity than predicted by commonly used evolutionary models. This overradius is smaller (at 2{sigma} confidence) than was found for similar stars in the younger Pleiades using a similar analysis; any decline appears due to changes occurring in higher mass (>0.25M_{sun}_) stars. Models incorporating magnetic inhibition of convection predict an overradius, but do not reproduce this mass dependence unless superequipartition surface magnetic fields are present at lower masses. Models incorporating flux blocking by starspots can explain the mass dependence but there is no evidence that spot coverage diminishes between the Pleiades and Praesepe samples to accompany the decline in overradius. The fastest rotating stars in both Praesepe and the Pleiades are significantly smaller than the slowest rotators for which a projected radius can be measured. This may be a selection effect caused by more efficient angular momentum loss in larger stars leading to their progressive exclusion from the analysed samples. Our analyses assume random spin-axis orientations; any alignment in Praesepe, as suggested by Kovacs, is strongly disfavoured by the broad distribution of projected radii.2019MNRAS.483.1125Jhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/483/1125CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/134/2340 : Membership of Praesepe and Coma Berenices clustersJ/ApJ/842/83 : Praesepe members rotational periods from K2 LCsIV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)I/337 : Gaia DR1 (Gaia Collaboration, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/483/1125https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/483/1125http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/483/1125https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/483/1125https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/483/1125http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/483/1125GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/483/1125/table2 (Properties of observed science targets in Praesepe)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/483/1125/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/483/1125/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/483/1125/table2?GETtext/xml+votable180.050000true128.96697520.266336110.0055555555555555565/1174 6/4685 4687 4690 4709 4720-4722https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/483/1125?format=asciiOpticaldefaultJ/MNRAS/483/1125/table2Properties of observed science targets in PraeseperecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDTarget name (2MASS JHHMMSSss+DDMMSSs)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainKmag2MASS K-band magnitudemagphot.mag;em.IR.KfloatV-KV-K color excess (1)magphot.color;em.opt.V;em.IR.Kfloatn_V-KV-K estimation sourcemeta.notecharPeriodRotation period from Douglas et al. (2017ApJ...842...83D, Cat. J/ApJ/842/83)dtime.periodfloatBCKmagK-band bolometric correction (2)magphot.mag.bcfloatlogLstarStar luminosity (2)log(solLum)phys.luminosityfloatMstarStar mass (2)solMassphys.massfloatRstarStar radius (2)solRadphys.size.radiusfloatvsiniProjected equatorial velocity (3)km/sphys.velocfloatSimbadSimbad column added by the CDSmeta.ref.urlcharJ/MNRAS/483/1125/table4Estimated values of relative RV, vsini, and RsinirecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDTarget name (2MASS JHHMMSSss+DDMMSSs)meta.id;meta.maincharKMagK-band absolute magnitudemagphot.magfloatlogLstarStar luminositylog(solLum)phys.luminosityfloatPeriodRotation period from Douglas et al. (2017ApJ...842...83D, Cat. J/ApJ/842/83)dtime.periodfloatSNRSignal to noise ratiostat.snrintRVrel? Relative radial velocitykm/sphys.veloc;arith.difffloatnullablee_RVrel? Error on RVrelkm/sstat.errorfloatnullablevsiniProjected equatorial velocitykm/sphys.velocfloate_vsiniError on vsinikm/sstat.error;phys.veloc.rotatfloatl_RsiniUpper limit in Rsini (1)meta.code.errorcharRsini? Projected radius (2)solRadphys.size.radiusfloatnullable