J/MNRAS/517/2165ivo://CDS.VizieR/J/MNRAS/517/2165doi:10.26093/cds/vizier/bg-g5-23nCDSCao L.Pinsonneault M.H.2026-08-03T07:31:59Z2025-11-18T16:04:37ZCDS support team

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

cds-question@unistra.fropen-star-clustersstellar-activityspectroscopyinfrared-astronomyastrometryeffective-temperaturechemical-abundancesgalaxy-kinematicsmagnetic-fieldsx-ray-sourcesvisible-astronomyWe measure star-spot filling fractions for 240 stars in the Pleiades and M67 open star clusters using APOGEE high-resolution H-band spectra. For this work, we developed a modified spectroscopic pipeline which solves for star-spot filling fraction and star-spot temperature contrast. We exclude binary stars, finding that the large majority of binaries in these clusters (80 per cent) can be identified from Gaia DR3 and APOGEE criteria - important for field star applications. Our data agree well with independent activity proxies, indicating that this technique recovers real star-spot signals. In the Pleiades, filling fractions saturate at a mean level of 0.248 +/- 0.005 for active stars with a decline at slower rotation; we present fitting functions as a function of Rossby number. In M67, we recover low mean filling fractions of 0.030 +/- 0.008 and 0.003 +/- 0.002 for main sequence GK stars and evolved red giants, respectively, confirming that the technique does not produce spurious spot signals in inactive stars. Star-spots also modify the derived spectroscopic effective temperatures and convective overturn time-scales. Effective temperatures for active stars are offset from inactive ones by -109 +/- 11 K, in agreement with the Pecaut & Mamajek empirical scale. Star-spot filling fractions at the level measured in active stars changes their inferred overturn time-scale, which biases the derived threshold for saturation. Finally, we identify a population of stars statistically discrepant from mean activity-Rossby relations and present evidence that these are genuine departures from a Rossby scaling. Our technique is applicable to the full APOGEE catalogue, with broad applications to stellar, galactic, and exoplanetary astrophysics.2022MNRAS.517.2165Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/517/2165CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/513/5727 : Lithium study with GESiDR6's PMS stars clusterJ/MNRAS/476/908 : Chromospheric activity in 4 open clusters (Fang+, 2018)J/MNRAS/448/484 : MgII UV feature in T Tauri stars (Lopez-Martinez+, 2015)J/MNRAS/441/2361 : Stellar magnetism, age and rotation (Vidotto+, 2014)J/A+A/662/A41 : Magnetic fields in 292 M dwarfs. (Reiners+, 2022)J/A+A/657/A7 : Stellar and substellar companions from Gaia EDR3J/A+A/656/A103 : NGC 3532 stars chromospheric activity (Fritzewski+, 2021)J/A+A/627/A119 : Extended halo of NGC 2682 (M 67) (Carrera+ 2019)J/A+A/613/A63 : Lithium content for 148 Pleiades stars (Bouvier+, 2018)J/A+A/605/A102 : Stellar models. 0.85<M<6, Z=0.0001-0.014 (Charbonnel+, 2017)J/A+A/589/A113 : PMS stars in h Per (Argiroffi+, 2016)J/A+A/586/A52 : NGC 2264, NGC 2547 and NGC 2516 stellar radiiJ/A+A/541/A150 : Lithium in M67 and Hyades (Pace+, 2012)J/A+A/510/A46 : Pre-main sequence evolutionary tracks (Landin+, 2010)J/A+A/484/609 : BVI photometry and proper motions in M67 (Yadav+, 2008)J/A+A/397/147 : Activity-rotation relationship in stars (Pizzolato+ 2003)J/A+A/341/751 : ROSAT HRI observations of the Pleiades (Micela+ 1999)J/ApJ/931/45 : The factory & the beehive. IV. Praesepe & HyadesJ/ApJ/924/84 : {lambda} Orionis PMS stars with Gaia & SPOTS (Cao+, 2022)J/ApJ/921/53 : IGRINS YSO survey. I. PMS stars in Tau-AurJ/ApJ/916/66 : K2 LCs analysis of Sun-like stars in the PleiadesJ/ApJ/893/67 : Smoothed amplitudes from Kepler, K2 and TESS phot.J/ApJ/874/97 : Chemical abundances from APOGEE. II. M67 stars (Souto+,2019)J/ApJ/871/174 : Kepler rapid rotators and Ks-band excesses (Simonian+, 2019)J/ApJ/869/9 : Machine-learning investigation of the open cluster M67J/ApJ/834/85 : H{alpha} emission in nearby M dwarfs (Newton+, 2017)J/ApJ/794/125 : IN-SYNC. I. APOGEE stellar parameters (Cottaar+, 2014)J/ApJ/776/67 : Rotational tracks (van Saders+, 2013)J/ApJ/743/48 : Stars with rotation periods and X-ray luminositiesJ/ApJ/348/557 : X-ray studies of stars in the Pleiades (Micela+, 1990)J/ApJ/315/687 : X-Ray emission from solar-type stars: F and G (Maggio+,1987)J/ApJS/244/21 : Surface rotation & activity of Kepler stars. I.J/ApJS/208/9 : Intrinsic colors and temperatures of PMS starsJ/ApJS/91/625 : ROSAT survey of the Pleiades (Stauffer+ 1994)J/ApJS/85/315 : F, G and K dwarf stars of the Pleiades (Soderblom+ 1993)J/AJ/163/257 : Properties of 125 M-dwarfs in the southern CVZJ/AJ/161/190 : Radial Velocities of binary population in M67 (Geller+,2021)J/AJ/153/101 : Pleiades members stellar properties (Somers+, 2017)J/AJ/152/115 : Pleiades members with K2 light curves. III. (Stauffer+,2016)J/AJ/152/114 : Pleiades members with K2 light curves. II. (Rebull+, 2016)J/AJ/152/113 : Pleiades members with K2 light curves. I. PeriodsJ/AJ/151/144 : ASPCAP weights for the 15 APOGEE chemical elementsJ/AJ/106/1059 : Lithium in the Pleiades (Soderblom+, 1993)VII/233 : 2MASS All-Sky Extended Source Catalog (XSC)V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16)III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)II/335 : Revised catalog of GALEX UV sources (GUVcat_AIS GR6+7)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)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/517/2165https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/517/2165http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/517/2165https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/517/2165https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/517/2165http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/517/2165GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/517/2165/table1 (Physical, photometric and spectroscopic informations of Pleiades star sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/517/2165/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/517/2165/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/517/2165/table1?GETtext/xml+votable180.050000true56.3759124.312650.005555555555555556Cone search capability for table J/MNRAS/517/2165/table3 (Physical, photometric and spectroscopic informations of M67 star sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/517/2165/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/517/2165/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/517/2165/table3?GETtext/xml+votable180.050000true132.872262711.757667470.0055555555555555565/115 118 6/381 453 455 466-467 476 478 484-486 496 4253 4255 4296 4298 4320https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/517/2165?format=asciiX-rayOpticalInfrareddefaultJ/MNRAS/517/2165/table1Physical, photometric and spectroscopic informations of Pleiades star sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintAPOGEE-SDSSDisplay the APOGEE-2 and SDSS DR16 datameta.ref.urlcharl_logLX/LbolUpper limit flag in X-ray emission for logLx/Lbol values (l_log_Lx_Lbol)meta.code.errorcharr_logLX/LbolReference for X-ray data (Ref_log_Lx_Lbol) (4)meta.ref;pos.framecharlogR'Ha? Logarithm of the excess chromospheric H_{alpha}_ emission isolating activity emission as in Appendix B (log_R'Ha)phys.luminosity;arith.ratio;em.opt.Rfloatnullabler_logR'HaReference for logR'Ha (Ref_log_R'Ha) (5)meta.ref;pos.framecharlogR'CaIRT? Logarithm of th excess chromospheric Ca II infrared triplet isolated activity emission as in Appendix B (log_R'CaIRT)phys.luminosity;arith.ratio;em.opt.Ifloatnullabler_logR'CaIRTReference for logR'CaIRT (Ref_log_R'CaIRT) (5)meta.ref;pos.framecharSimbadSimbad column added by the CDSmeta.ref.urlcharGaiaDR3Display GaiaDR3 datameta.ref.urlcharRAJ2000Right ascension (J2000) (RA_J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (Dec_J2000)degpos.eq.dec;meta.mainProtRotation period (Prot) (1)dtime.periodfloatRo? Rossby number (Ro) (2)stat.param;arith.ratio;time.scaledoublenullableGlobGlobal binarity flag computed from section 2.3 Binary rejection (Bin_Flag)meta.codecharPhotPhotometric binary flag computed from section 2.3.1 Photometric binary cut (Bin_Photometric)meta.codecharGaiaRVGaia radial velocity DR3 variance flag for binarity from section 2.3.2 Gaia DR3 radial velocity cut (Bin_Gaia_RV)meta.codecharAPORVAPOGEE RV flag for binarity from section 2.3.2 APOGEE radial velocity cut (Binary_APOGEE_RV_Flag)meta.codecharRUWERUWE flag for binarity as defined in sec. 2.3.3 Gaia RUWE Cut (Bin_Gaia_RUWE)meta.codecharGaiaMultMultiple source flag for binarity from section 2.3.4 Gaia multiple source cut (Bin_Gaia_Multiple)meta.codecharTeff? Two-temperature effective temperature as defined in equation 1 of section 2.2 Grid construction (Teff)Kphys.temperature.effectivefloatnullablefspot? Two-temperature star-spot filling fraction as explicited in section 2.2 Grid construction (fspot)arith.factor;stat.filling;meta.modelledfloatnullablexspot? Two-temperature star-spot temperature contrast as explicited in section 2.2 Grid construction (xspot)phys.temperature;arith.diff;meta.modelledfloatnullablelogg? Logarithm of surface gravity dertived from two-temperature method explicited in section 2.2 Grid construction (logg)log(cm.s**-2)phys.gravityfloatnullable[M/H]? Metallicity derived from two-temperature method explicited in section 2.2 Grid construction ([M/H])phys.abund.Zfloatnullablevsini? Rotational velocity derived from two-temperature method explicited in section 2.2 Grid construction (vsini)km/sphys.veloc.rotatfloatnullableVt? Microturbulence velocity from two-temperature method explicited in section 2.2 Grid construction (vdop)km/sphys.veloc.microTurbfloatnullablee_Teff? Mean error in derived Teff (e_Teff)Kstat.error;phys.temperature.effectivefloatnullablee_fspot? Mean error in derived fspot (e_fspot)stat.errorfloatnullablee_xspot? Mean error in derived xspot (e_xspot)stat.errorfloatnullablee_logg? Mean error in derived logg (e_logg)log(cm.s**-2)stat.errorfloatnullablee_[M/H]? Mean error in derived [M/H] (e_[M/H])stat.error;phys.abundfloatnullablee_vsini? Mean error in derived vsini (e_vsini)km/sstat.error;phys.veloc.rotatfloatnullablee_Vt? Mean error in derived microturbulence (e_vdop)km/sstat.errorfloatnullableBmean? Derived surface mean equipartition B as defined in equation 7 of section 4.2.2 (B_eqp_mean)Gphys.magFieldfloatnullablee_Bmean? Mean error of Bmean (e_B_eqp_mean)Gstat.errorfloatnullableBmax? Derived equipartition magnetic field (B_eqp_max) (3)Gphys.magFieldfloatnullablee_Bmax? Mean error of Bmax (e_B_eqp_max)Gstat.errorfloatnullablelogLX/Lbol? Logarithm of the fractional X-ray emission as defined in section 4.2.3 Activity-Star-spot Relations (log_Lx_Lbol)phys.luminosity;arith.ratio;em.X-rayfloatnullablee_logLX/Lbol? Reported mean error in X-ray emission (e_log_Lx_Lbol)stat.errorfloatnullableF10/F90Fractional flux difference F_10_/F_90_ 10th to 90th percentile as in equation 8 of the section 4.2.3 (frac_flux_10_90)phot.flux;arith.ratiofloat2MASS2MASS designation as 2MHHMMSSss+DDMMSSs (APOGEE_ID)meta.id;meta.maincharJ/MNRAS/517/2165/table3Physical, photometric and spectroscopic informations of M67 star sourcesAPORVAPOGEE RV flag for binarity from section 2.3.2 APOGEE radial velocity cut (Binary_APOGEE_RV_Flag)meta.codecharRUWERUWE flag for binarity as defined in sec. 2.3.3 Gaia RUWE Cut (Bin_Gaia_RUWE)meta.codecharSLSingle-lined binary flag from spectroscopic selects of Geller et al. (2021AJ....161..190G, Cat. J/AJ/161/190) (Bin_Geller17_sl)meta.codecharSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASS2MASS designation as 2MHHMMSSss+DDMMSSs (APOGEE_ID)meta.id;meta.maincharAPOGEE-SDSSDisplay the APOGEE-2 and SDSS DR16 datameta.ref.urlcharGaiaDR3Display GaiaDR3 datameta.ref.urlcharRAJ2000Right ascension (J2000) (RA_J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (Dec_J2000)degpos.eq.dec;meta.mainStateEvolutionary state as defined in section 4.3 (Evstate) (1)src.classcharGlobGlobal binarity flag computed from section 2.3 Binary rejection (Bin_Flag)meta.codecharPhotPhotometric binary flag computed from section 2.3.1 Photometric binary cut (Bin_Photometric)meta.codecharGaiaRVGaia radial velocity DR3 variance flag for binarity from section 2.3.2 Gaia DR3 radial velocity cut (Bin_Gaia_RV)meta.codecharDLDouble-lined binary flag from spectroscopic selects of Geller et al. (2021AJ....161..190G, Cat. J/AJ/161/190) (Bin_Geller17_dl)meta.codecharTeff? Two-temperature effective temperature as defined in equation 1 of section 2.2 Grid construction (Teff)Kphys.temperature.effectivefloatnullablefspot? Two-temperature star-spot filling fraction as explicited in section 2.2 Grid construction (fspot)arith.factor;stat.filling;meta.modelledfloatnullablexspot? Two-temperature star-spot temperature contrast as explicited in section 2.2 Grid construction (xspot)phys.temperature;arith.diff;meta.modelledfloatnullablelogg? Logarithm of surface gravity dertived from two-temperature method explicited in section 2.2 Grid construction (logg)log(cm.s**-2)phys.gravityfloatnullable[M/H]? Metallicity derived from two-temperature method explicited in section 2.2 Grid construction ([M/H])phys.abund.Zfloatnullablevsini? Rotational velocity derived from two-temperature method explicited in section 2.2 Grid construction (vsini)km/sphys.veloc.rotatfloatnullableVt? Microturbulence velocity from two-temperature method explicited in section 2.2 Grid construction (vdop)km/sphys.veloc.microTurbfloatnullablee_Teff? Mean error in derived Teff (e_Teff)Kstat.error;phys.temperature.effectivefloatnullablee_fspot? Mean error in derived fspot (e_fspot)stat.errorfloatnullablee_xspot? Mean error in derived xspot (e_xspot)stat.errorfloatnullablee_logg? Mean error in derived logg (e_logg)log(cm.s**-2)stat.errorfloatnullablee_[M/H]? Mean error in derived [M/H] (e_[M/H])stat.error;phys.abundfloatnullablee_Vt? Mean error in derived microturbulence (e_vdop)km/sstat.errorfloatnullablee_vsini? Mean error in derived vsini (e_vsini)km/sstat.error;phys.veloc.rotatfloatnullable