J/AJ/168/278ivo://CDS.VizieR/J/AJ/168/278doi:10.26093/cds/vizier/be-58-8pCDSChand K.Rao K.K.Vaidya K.Panthi A.2026-07-02T11:45:07Z2025-09-08T15:20:23ZCDS support team

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

cds-question@unistra.fropen-star-clustersinfrared-photometryvisible-astronomybroad-band-photometrypeculiar-variable-starsultraviolet-astronomyWe characterize blue straggler stars (BSSs) and yellow straggler stars (YSSs) of the open cluster (OC) Berkeley 39 using multiwavelength observations including the Swift/Ultraviolet and Optical Telescope (UVOT). Our analysis also makes use of ultraviolet (UV) data from Galaxy Evolution Explorer, optical data from Gaia DR3 and Panoramic Survey Telescope and Rapid Response System, and infrared data from Two Micron All Sky Survey, Spitzer/IRAC, and Wide-field Infrared Survey Explorer. Berkeley 39 is a ~6Gyr old Galactic OC located at a distance of ~4200pc. We identify 729 sources as cluster members utilizing a machine-learning algorithm, ML-MOC, on Gaia DR3 data. Of these, 17 sources are classified as BSS candidates and four as YSS candidates. We construct multiwavelength spectral energy distributions (SEDs) of 16 BSS and two YSS candidates, within the Swift/UVOT field, to analyze their properties. Out of these, eight BSS candidates and both the YSS candidates are successfully fitted with single-component SEDs. Five BSS candidates show marginal excess in the near-UV (NUV; fractional residual <0.3 in all but one UVOT filter), whereas three BSS candidates show moderate to significant excess in the NUV (fractional residual >0.3 in at least two UVOT filters). We present the properties of the BSS and YSS candidates, estimated based on the SED fits.2024AJ....168..278Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/168/278CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)II/311 : WISE All-Sky Data Release (Cutri+ 2012)II/312 : GALEX-DR5 (GR5) sources from AIS and MIS (Bianchi+ 2011)II/335 : Revised cat. of GALEX UV sources (GUVcat_AIS GR6+7) (Bianchi+ 2017)II/349 : The Pan-STARRS release 1 (PS1) Survey - DR1 (Chambers+, 2016)J/AJ/113/1723 : UBVI photometry in 4 open clusters (Kassis+, 1997)J/A+A/463/789 : Blue stragglers in open clusters (Ahumada+, 2007)J/A+A/523/A48 : Gaia photometry (Jordi+, 2010)J/ApJ/730/67 : Radial velocities of low-mass white dwarfs (Brown+, 2011)J/A+A/548/A122 : Berkeley 39 stars photometry & abundances (Bragaglia+, 2012)J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)J/AJ/158/35 : Swift UVOT Stars. III. Gal. open clusters (Siegel+, 2019)J/MNRAS/503/236 : UVIT catalog & membership of 6 open clusters (Jadhav+, 2021)J/A+A/650/A67 : Blue & yellow straggler stars in open clusters (Rain+, 2021)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/168/278https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/168/278http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/168/278https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/168/278https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/168/278http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/168/278GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/168/278/figs (The spatial distribution, proper motion distribution and parallax distribution of cluster members using ML-MOC algorithm on Gaia DR3 data)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/168/278/figs?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/168/278/figs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/168/278/figs?GETtext/xml+votable180.050000true116.7020524-4.66352880.005555555555555556Cone search capability for table J/AJ/168/278/table3 (*Coordinates & fluxes of BSS and YSS candidates across all utilized filters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/168/278/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/168/278/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/168/278/table3?GETtext/xml+votable180.050000true116.61005-4.662280.0055555555555555565/5429 6/3.036429446233786e-20 1.2058628298368645e-18https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/168/278?format=asciiUVOpticalInfrareddefaultJ/AJ/168/278/figsThe spatial distribution, proper motion distribution and parallax distribution of cluster members using ML-MOC algorithm on Gaia DR3 datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGaiaDR3Gaia DR3 (I/355) identifiermeta.id;meta.mainRA_ICRS[116.4/117] Right ascension (ICRS) at Ep=2016degpos.eq.ra;meta.mainDE_ICRS[-4.9/-4.4] Declination (ICRS) at Ep=2016degpos.eq.dec;meta.mainplx[0.1/0.41] Gaia DR3 parallaxmaspos.parallax.trigfloatSimbadSimbad column added by the CDSmeta.ref.urlchar_RA.icrsRight ascension (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.raindexed_DE.icrsDeclination (ICRS) at Epoch=J2000, proper motions taken into accountdegpos.eq.decindexede_plx[0.01/0.51] Standard error in plxmasstat.error;pos.parallaxfloatpmRA[-2.1/-1.4] Gaia DR3 proper motion in right ascensionmas/yrpos.pm;pos.eq.rafloate_pmRA[0.01/0.43] Standard error in pmRAmas/yrstat.error;pos.pm;pos.eq.rafloatpmDE[-1.9/-1.3] Gaia DR3 proper motion in declinationmas/yrpos.pm;pos.eq.decfloate_pmDE[0.009/0.32] Standard error in pmDEmas/yrstat.error;pos.pm;pos.eq.decfloatGmag[12.3/20] Gaia DR3 G-band (673nm) mean magnitudemagphot.mag;em.optdoublee_Gmag[0.002/0.005] Error in Gmagmagstat.error;phot.mag;em.optdoubleBPmag[13.2/20.7] Integrated Gaia DR3 BP (532nm) mean magnitudemagphot.mag;em.opt.Bdoublee_BPmag[0.002/0.12] Error in BPmagmagstat.error;phot.mag;em.opt.BdoubleRPmag[11.4/19.3] Gaia DR3 RP (797nm) mean magnitudemagphot.mag;em.opt.Rdoublee_RPmag[0.003/0.05] Error in RPmagmagstat.error;phot.mag;em.opt.RdoubleMm[0.21/0.98] Membership probabilitystat.probabilityfloatfCandFlag for the 18 BSS/YSS candidates (link to Table 3)meta.numberintnullableJ/AJ/168/278/table3*Coordinates & fluxes of BSS and YSS candidates across all utilized filterse_F(G)[1.1e-18/8.4e-18] F(G) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.opt.VdoubleF(RP)[3.4e-16/2.2e-15] Gaia RP (797nm) flux (I/355)cW.m**-2.nm**-1phot.flux;em.opt.RdoubleSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDName of the sourcemeta.idcharGaiaDR3Gaia DR3 identifier (I/355)meta.id;meta.mainRA_ICRS[116.6/116.8] Right ascension (ICRS) at Ep=2016.0degpos.eq.ra;meta.mainDE_ICRS[-4.8/-4.5] Declination (ICRS) at Ep=2016.0degpos.eq.dec;meta.mainF(UVW2)[1.4e-17/9.9e-16] Swift/UVOT UVW2 (180-260nm) flux (J/AJ/158/35)cW.m**-2.nm**-1phot.flux;em.UV.200-300nmdoublee_F(UVW2)[2.4e-18/1.9e-17] F(UVW2) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.UV.200-300nmdoubleF(UVM2)[1.1e-17/7.8e-16] Swift/UVOT UVM2 (200-280nm) flux (J/AJ/158/35)cW.m**-2.nm**-1phot.flux;em.UV.200-300nmdoublee_F(UVM2)[2.4e-18/1.91e-17] F(UVM2) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.UV.200-300nmdoubleF(UVW1)[5.3e-17/7.5e-16] Swift/UVOT UVW1 (220-400nm) flux (J/AJ/158/35)cW.m**-2.nm**-1phot.flux;em.UVdoublee_F(UVW1)[4.5e-18/1.4e-17] F(UVW1) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.UVdoubleF(NUV)[4.6e-17/1.3e-15]? GALEX NUV (177-273nm) flux (II/335)cW.m**-2.nm**-1phot.flux;em.UV.200-300nmdoublenullablee_F(NUV)[8.7e-19/2.9e-18]? F(NUV) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.UV.200-300nmdoublenullableF(BP)[5.4e-16/4.3e-15] Gaia BP (532nm) flux (I/355)cW.m**-2.nm**-1phot.flux;em.opt.Bdoublee_F(BP)[3.0e-18/1.5e-17] F(BP) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.opt.BdoubleF(G)[4.4e-16/3.2e-15] Gaia G (673nm) flux (I/355)cW.m**-2.nm**-1phot.flux;em.opt.Vdoublee_F(RP)[1.8e-18/8.4e-18] F(RP) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.opt.RdoubleF(g)[6.0e-16/4.97e-15] Pan-STARRS1 g (481nm) flux (II/349)cW.m**-2.nm**-1phot.flux;em.opt.Bdoublee_F(g)[1.3e-18/2.6e-16] F(g) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.opt.BdoubleF(r)[5.0e-16/3.5e-15] Pan-STARRS1 r (617nm) flux (II/349)cW.m**-2.nm**-1phot.flux;em.opt.Rdoublee_F(r)[6.4e-19/1.4e-16] F(r) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.opt.RdoubleF(i)[3.7e-16/2.4e-15] Pan-STARRS1 i (752nm) flux (II/349)cW.m**-2.nm**-1phot.flux;em.opt.Idoublee_F(i)[9.2e-19/7.7e-18] F(i) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.opt.IdoubleF(z)[2.8e-16/1.7e-15] Pan-STARRS1 z (866nm) flux (II/349)cW.m**-2.nm**-1phot.flux;em.opt.Idoublee_F(z)[8.2e-19/7.97e-18] F(z) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.opt.IdoubleF(y)[2.4e-16/1.5e-15] Pan-STARRS1 y (962nm) flux (II/349)cW.m**-2.nm**-1phot.flux;em.IR.Jdoublee_F(y)[1.2e-18/8.7e-18] F(y) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.IR.JdoubleF(J)[1.2e-16/7.6e-16] 2MASS J (1.24um) flux (II/246)cW.m**-2.nm**-1phot.flux;em.IR.Jdoublee_F(J)[7.8e-18/2.2e-17] F(J) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.IR.JdoubleF(H)[5.7e-17/3.5e-16] 2MASS H (1.66um) flux (II/246)cW.m**-2.nm**-1phot.flux;em.IR.Hdoublee_F(H)[6.4e-18/1.2e-17] F(H) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.IR.HdoubleF(Ks)[1.0e-17/1.4e-16] 2MASS Ks (2.16um) flux (II/246cW.m**-2.nm**-1phot.flux;em.IR.Kdoublee_F(Ks)[1.7e-18/6.4e-18] F(Ks) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.IR.KdoubleF(I1)[3.3e-18/1.95e-17]? Spitzer/IRAC I1 (3.6um) flux (cW.m**-2.nm**-1phot.flux;em.IR.3-4umdoublenullablee_F(I1)[2.1e-20/4.6e-20]? F(I1) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.IR.3-4umdoublenullableF(I2)[1.5e-18/9.1e-18]? Spitzer/IRAC I2 (4.5um) fluxcW.m**-2.nm**-1phot.flux;em.IR.4-8umdoublenullablee_F(I2)[2.0e-20/3.8e-20]? F(I2) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.IR.4-8umdoublenullableF(I3)[1.2e-18/3.5e-18]? Spitzer/IRAC I3 (5.8um) fluxcW.m**-2.nm**-1phot.flux;em.IR.4-8umdoublenullablee_F(I3)[4.1e-20/5.3e-20]? F(I3) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.IR.4-8umdoublenullableF(W1)[4.1e-18/2.9e-17]? WISE W1 (3.35um) flux (II/311)cW.m**-2.nm**-1phot.flux;em.IR.3-4umdoublenullablee_F(W1)[1.8e-19/1.6e-18]? F(W1) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.IR.3-4umdoublenullableF(W2)[1.1e-18/7.3e-18]? WISE W2 (4.60um) flux (II/311)cW.m**-2.nm**-1phot.flux;em.IR.4-8umdoublenullablee_F(W2)[1.3e-19/4.6e-19]? F(W2) uncertaintycW.m**-2.nm**-1stat.error;phot.flux;em.IR.4-8umdoublenullableSEDSED plot of this starmeta.ref.urlchar