J/A+A/709/A20ivo://CDS.VizieR/J/A+A/709/A20CDSWang S.Wang J.Ma J.Wu Z.-Y.Zhou R.2026-05-19T14:14:26Z2026-04-28T12:00:47ZCDS support team

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

cds-question@unistra.fropen-star-clustersastrometryphotometryultraviolet-astronomyvisible-astronomystellar-massesOpen clusters are vital laboratories for studying stellar dynamics and evolution, with mass segregation-the preferential concentration of massive stars toward cluster cores-serving as a key indicator of internal dynamical processes. This study investigates four open clusters (NGC 7243, NGC 2301, NGC 1528, and NGC 2281; ages 100-650 Myr) using deep multicolor photometry from the Beijing-Arizona-Taiwan-Connecticut (BATC) Sky Survey, combined with Gaia Data Release 3 (DR3), to explore their mass functions and dynamical states. The work seeks to characterize mass segregation patterns across spatial scales to establish its origin (primordial vs. dynamical) and to provide the first conclusive evidence of mass segregation in NGC 2281. Additionally, we analyze how cluster relaxation timescales and evolutionary stages influence their dynamical architectures. Fundamental parameters were derived via Bayesian methods. The tidal radii were determined from the intersection of the observed cumulative mass profiles and theoretical tidal mass curves, and mass functions were analyzed through power-law fits ({Phi}(m){prop.to}m^{alpha}^) performed separately for the inner (bound) and outer (tidal) regions. All clusters exhibit signs of mass segregation. However, only NGC 2281 shows a statistically significant steepening of the mass function slope in its outer tidal region, indicating significant evaporation of low-mass stars and providing the first clear evidence of strong, dynamically evolved mass segregation in this cluster. For NGC 7243, NGC 2301, and NGC 1528, the derived {tau} values ({tau}=Age/t_relax_>3) suggest advanced dynamical evolution, yet their outer regions contain too few stars to robustly confirm the expected steepening of the mass function.2026A&A...709A..20Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/709/A20CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/558/A53 : Milky Way global survey of star clusters. II.J/A+A/543/A156 : Milky Way global survey of star clusters (Kharchenko+, 2012)J/A+A/531/A92 : Deep all-sky census of the Hyades (Roeser+, 2011)J/A+A/438/1163 : Catalogue of Open Cluster Data (COCD) (Kharchenko+, 2005)J/A+A/401/531 : Proper motions in NGC 7243 (Jilinski+, 2003)J/AJ/134/1368 : Proper motions in NGC 2244 and NGC 6530 (Chen+, 2007)J/AJ/132/1669 : Wide-field CCD phot. around nine open clusters (Sharma+, 2006)J/AJ/112/628 : BATC Color Survey of M67 (Fan+ 1996)J/A+A/656/A49 : Decoding the morphological evolution of open clustersJ/A+A/673/A114 : Improving the open cluster census. II. (Hunt+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/709/A20https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/709/A20http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/709/A20https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/709/A20https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/709/A20http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/709/A20GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/709/A20/tablea3 (Astrometric, photometry and SED fit masses of member stars of the four open clusters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/709/A20/tablea3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/709/A20/tablea3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/709/A20/tablea3?GETtext/xml+votable180.050000true333.79449.8750.0055555555555555565/482 1677 1679 1688 1690 1713 5530 6/1952 6764 6766 6801 6805 6848-6850 6857 6864 6866 14039 14045 14210-14211 14214 14216-14217 22124 22126 22209 222121.9867573869263685e-19 6.207084633206021e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/709/A20?format=asciiUVOpticaldefaultJ/A+A/709/A20/tablea3Astrometric, photometry and SED fit masses of member stars of the four open clusterskmag? BATC k-band magnitude the effective wavelength of 7546 {AA} and bandwidth FWHM of 192 {AA} (k_mag)magphot.mag;em.opt.Ifloatnullablemmag? BATC m-band magnitude the effective wavelength of 8023 {AA} and bandwidth FWHM of 255 {AA} (m_mag)magphot.mag;em.opt.IfloatnullableSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterName of the open cluster (Cluster) (1)meta.id.parentcharMWSCDisplay the Milky Way global survey of star open clusters parameters catalog of Kharchenko et al. (2013A&A...558A..53K, Cat. J/A+A/558/A53)meta.ref.urlintnullableHunt+23Display the Improving the member stars of open cluster census II of Hunt & Reffert (2023A&A...673A.114H, Cat. J/A+A/673/A114)meta.ref.urlintnullableRAJ2000Right ascension (J2000) (RA)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (Dec)degpos.eq.dec;meta.mainGaiaDR3Unique Gaia DR3 source identifier (Gaia_DR3_Source_ID)meta.id;meta.mainamag? BATC a-band magnitude the effective wavelength of 3360 {AA} and bandwidth FWHM of 360 {AA} (a_mag)magphot.mag;em.opt.Ufloatnullablebmag? BATC b-band magnitude the effective wavelength of 3890 {AA} and bandwidth FWHM of 340 {AA} (b_mag)magphot.mag;em.opt.Ufloatnullablecmag? BATC c-band magnitude the effective wavelength of 4194 {AA} and bandwidth FWHM of 309 {AA} (c_mag)magphot.mag;em.opt.Bfloatnullabledmag? BATC d-band magnitude the effective wavelength of 4540 {AA} and bandwidth FWHM of 332 {AA} (d_mag)magphot.mag;em.opt.Bfloatnullableemag? BATC e-band magnitude the effective wavelength of 4925 {AA} and bandwidth FWHM of 374 {AA} (e_mag)magphot.mag;em.opt.Bfloatnullablefmag? BATC f-band magnitude the effective wavelength of 5267 {AA} and bandwidth FWHM of 344 {AA} (f_mag)magphot.mag;em.opt.Vfloatnullablegmag? BATC g-band magnitude the effective wavelength of 5790 {AA} and bandwidth FWHM of 289 {AA} (g_mag)magphot.mag;em.opt.Vfloatnullablehmag? BATC h-band magnitude the effective wavelength of 6074 {AA} and bandwidth FWHM of 308 {AA} (h_mag)magphot.mag;em.opt.Rfloatnullableimag? BATC i-band magnitude the effective wavelength of 6656 {AA} and bandwidth FWHM of 491 {AA} (i_mag)magphot.mag;em.opt.RfloatnullableGmag? Gaia G-band magnitudemagphot.mag;em.optfloatnullablejmag? BATC j-band magnitude the effective wavelength of 7057 {AA} and bandwidth FWHM of 238 {AA} (j_mag)magphot.mag;em.opt.Rfloatnullablenmag? BATC n-band magnitude the effective wavelength of 8484 {AA} and bandwidth FWHM of 167 {AA} (m_mag)magphot.mag;em.opt.Ifloatnullableomag? BATC o-band magnitude the effective wavelength of 9182 {AA} and bandwidth FWHM of 247 {AA} (o_mag)magphot.mag;em.opt.IfloatnullableBPmag? Gaia BP-band magnitudemagphot.mag;em.opt.BfloatnullableRPmag? Gaia RP-band magnitudemagphot.mag;em.opt.RfloatnullableM*Stellar mass derived from SED fittingsolMassphys.mass;meta.modelled;arithfloat