J/ApJ/795/161ivo://CDS.VizieR/J/ApJ/795/161doi:10.26093/cds/vizier.17950161CDSDouglas S.T.Agueros M.A.Covey K.R.Bowsher E.C.Bochanski J.J.,Cargile P.A.Kraus A.Law N.M.Lemonias J.J.Arce H.G.Fierroz D.F.,Kundert A.2026-05-29T20:04:51Z2017-05-31T15:58:46ZCDS support team

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

cds-question@unistra.fropen-star-clustersstellar-spectral-typesinfrared-photometrystellar-massesstellar-distanceline-intensitiesOpen clusters are collections of stars with a single, well-determined age, and can be used to investigate the connections between angular-momentum evolution and magnetic activity over a star's lifetime. We present the results of a comparative study of the relationship between stellar rotation and activity in two benchmark open clusters: Praesepe and the Hyades. As they have the same age and roughly solar metallicity, these clusters serve as an ideal laboratory for testing the agreement between theoretical and empirical rotation-activity relations at ~600 Myr. We have compiled a sample of 720 spectra - more than half of which are new observations - for 516 high-confidence members of Praesepe; we have also obtained 139 new spectra for 130 high-confidence Hyads. We have also collected rotation periods (P_rot_) for 135 Praesepe members and 87 Hyads. To compare H{alpha} emission, an indicator of chromospheric activity, as a function of color, mass, and Rossby number R_o_, we first calculate an expanded set of {chi} values, with which we can obtain the H{alpha} to bolometric luminosity ratio, L_H{alpha}_/L_bol_, even when spectra are not flux-calibrated and/or stars lack reliable distances. Our {chi} values cover a broader range of stellar masses and colors (roughly equivalent to spectral types from K0 to M9), and exhibit better agreement between independent calculations, than existing values. Unlike previous authors, we find no difference between the two clusters in their H{alpha} equivalent width or L_H{alpha}_/L_bol_ distributions, and therefore take the merged H{alpha} and P_rot_ data to be representative of 600 Myr old stars. Our analysis shows that H{alpha} activity in these stars is saturated for R_O_<=0.11\-0.03_^+0.02^. Above that value activity declines as a power-law with slope {beta}=0.73_-0.12_^+0.16^, before dropping off rapidly at R_o_{approx} 0.4. These data provide a useful anchor for calibrating the age-activity-rotation relation beyond 600 Myr.2014ApJ...795..161Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/795/161CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/80/379 : Hyades cluster: motion, membership, & distance (Hanson+, 1975)J/A+A/310/879 : Hyades binaries (Barrado+, 1996)J/ApJ/521/682 : Binaries in the Praesepe and Coma clusters (Abt+, 1999)J/A+A/367/111 : A Hipparcos study of the Hyades cluster (de Bruijne+, 2001)J/A+A/375/989 : JHK photometry of Praesepe low-mass stars (Bouvier+, 2001)J/AJ/134/2340 : Membership of Praesepe & Coma Berenices clusters (Kraus+, 2007)J/A+A/531/A92 : Deep all-sky census of the Hyades (Roeser+, 2011)J/MNRAS/413/2218 : Stellar rotation in Hyades and Praesepe (Delorme+, 2011)J/A+A/559/A43 : Pan-STARRS1 (PS1) observations of the Hyades (Goldman+, 2013)J/MNRAS/434/3236 : Masses of Praesepe members (Khalaj+, 2013)J/ApJ/842/83 : Praesepe members rot. periods from K2 LCs (Douglas+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/795/161https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/795/161http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/795/161https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/795/161https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/795/161http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/795/161GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/795/161/table5 (Praesepe stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/795/161/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/795/161/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/795/161/table5?GETtext/xml+votable180.050000true125.507583320.3267750.005555555555555556Cone search capability for table J/ApJ/795/161/table6 (Hyades stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/795/161/table6?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/795/161/table6?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/795/161/table6?GETtext/xml+votable180.050000true28.336435323.44477250.0055555555555555564/293 5/80-81 84 87 256 261-262 265 1169-1171 1177 1180-1181 5869 5874-5875 5878 5880-5881 5883-5884 5886-5887 6050 6052 6058-6059 6/60 75 78 95 100 107 125 197 211 247 251 272-274 276 278 287 305 309 311 313 318 330 333-335 340-342 344-345 353 355 357-358 365 367-370 373 375 378-379 381 383 401 407 422 428 438 450 455-456 458 462 465 470 472 475 477-478 483 499 501 507 528 540 583 608 671 701 706 711-712 729 766 770 780 795 803 820 823 829 835 837 840 847 879 882 889-890 917 924 959 989 997 1009 1020 1029 1031-1033 1035-1038 1041-1043 1052 1056-1058 1064-1065 1074-1075 1077 1094 1096-1097 1113 1127 1146 1158-1159 1167 1180 1196 1198-1199 1206 1210-1211 1232 1234 1239 1272 1324 1342 1415 1451 1554 1564 1567 1577 1602 1609 1611 1614 1661 1676 1713 1720 1752 1817 1827 1839 2139 2328 2335 2350 2375 2383 2391 4335 4346-4347 4349 4351 4673-4675 4704-4705 4707 4712-4713 4715-4717 4719 4728-4730 4732-4734 4816-4817 4823 4866-4867 4872-4874 4896 4898-4899 17714 17857 17871 21156 21196 21221 21235 21275 21383 21391 21418 21440 21496 22558 22566 22598 22628 22663 22713 22760 22764 22769 22781 22811 22823 22827 22830 22837 22847 22882 22884 22892 22902 22904 22906-22907 22911 22916 22920 22949 22959 22970 22978 23011 23017 23022-23024 23026 23029 23035 23111 23140 23169 23256 23261 23276 23282-23283 23286 23288 23313 23315 23321 23324 23328-23329 23332 23335 23339 23344 23348 23355 23358-23359 23362 23364 23368-23370 23374-23375 23378 23383 23386-23387 23392 23395-23396 23399-23400 23403 23405-23406 23408 23410 23413 23415-23416 23418-23419 23421 23423 23437 23440 23443-23444 23449-23450 23453-23454 23463 23484 23487 23489-23494 23504-23505 23507-23509 23511 23517-23519 23529-23531 23540-23542 23597 23663 23680 23694 23704 23721-23722 23727 23738 23741 23748 23789 23794 24067-24068 24070 24075 24078 24097 24099 24102 24104 24106 24110 24114 24123-24124 24126 24129 24137 24162 24175 24192 24194-24196 24204 24206-24207 24212 24215-24216 24218-24220 24223-24226 24228-24230 24241-24242 24244 24246 24248-24249 24251-24252 24256 24266 24298 24310 24315 24319 24336 24344 24359-24360 24363 24382 24470 24482 24491 24502 24506 24552 24554 367587.952274030004205e-20 1.0188844282367877e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/795/161?format=asciiInfrareddefaultJ/ApJ/795/161/table5Praesepe starsSimbadNameSimbad column added by the CDSmeta.idcharnullableNameIdentifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Hour of Right Ascension (J2000) (4)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000) (4)pos.eq.dec;meta.mainPMem? Membership probability (1)%meta.code.memberintnullableSpTypeSpectral typesrc.spTypecharrmag? The r' band magnitude (1)magphot.mag;em.opt.Rfloatnullablee_rmag? Error in rmag (1)magstat.error;phot.magfloatnullabler_rmag[TUSC] Reference for rmag (2)meta.ref;pos.framecharKmag? The K band magnitude (1)magphot.mag;em.IR.Kfloatnullablee_Kmag? Error in Kmag (1)magstat.error;phot.magfloatnullableDist? Distancepcpos.distance;pos.heliocentricfloatnullabler_Dist[RH-] Reference for Dist (3)meta.ref;pos.framecharPMass? Mass from Agueros et al. (2011ApJ...740..110A) (1)solMassphys.massdoublenullableMass? Mass from this work (1)solMassphys.massfloatnullableRadius? RadiussolRadphys.angSize;srcdoublenullableBin?[YN] Possible binary systemmeta.codecharSpTypeHSpectral type from the output of the Hammer (only in table6.dat)src.spTypecharEW? H{alpha} equivalent width; Angstroms (1)0.1nmspect.line.eqWidthdoublenullablee_EW? Error in EW (1)0.1nmstat.error;spect.line.eqWidthdoublenullableLum? H{alpha} to bolometric luminosities ratio for stars with H{alpha} in emission (1)phys.luminositydoublenullablee_Lum? Error in Lum (1)stat.errordoublenullableJ/ApJ/795/161/table6Hyades starsSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameIdentifiermeta.id;meta.maincharRAJ2000Hour of Right Ascension (J2000) (4)pos.eq.raDEJ2000Degree of Declination (J2000) (4)pos.eq.decPMem? Membership probability (1)%meta.code.memberintnullableSpTypeSpectral typesrc.spTypecharrmag? The r' band magnitude (1)magphot.mag;em.opt.Rfloatnullablee_rmag? Error in rmag (1)magstat.error;phot.magfloatnullabler_rmag[TUSC] Reference for rmag (2)meta.ref;pos.framecharKmag? The K band magnitude (1)magphot.mag;em.IR.Kfloatnullablee_Kmag? Error in Kmag (1)magstat.error;phot.magfloatnullableDist? Distancepcpos.distance;pos.heliocentricfloatnullabler_Dist[RH-] Reference for Dist (3)meta.ref;pos.framecharPMass? Mass from Agueros et al. (2011ApJ...740..110A) (1)solMassphys.massdoublenullableMass? Mass from this work (1)solMassphys.massfloatnullableRadius? RadiussolRadphys.angSize;srcdoublenullableBin?[YN] Possible binary systemmeta.codecharSpTypeHSpectral type from the output of the Hammer (only in table6.dat)src.spTypecharEW? H{alpha} equivalent width; Angstroms (1)0.1nmspect.line.eqWidthdoublenullablee_EW? Error in EW (1)0.1nmstat.error;spect.line.eqWidthdoublenullableLum? H{alpha} to bolometric luminosities ratio for stars with H{alpha} in emission (1)phys.luminositydoublenullablee_Lum? Error in Lum (1)stat.errordoublenullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main