J/A+A/707/A275 Rotation-based census of blue lurkers (Jadhav+, 2026)
A rotation-based census of blue lurker candidates in open clusters.
Jadhav V.V., Rao K.K., Reggiani E.
<Astron. Astrophys. 707, A275 (2026)>
=2026A&A...707A.275J 2026A&A...707A.275J (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Clusters, open ; Positional data ; Optical ;
Photometry ; Rotational velocities ; Proper motions ;
Parallaxes, trigonometric ; Infrared ; Ultraviolet ;
Stars, diameters ; Effective temperatures
Keywords: methods: observational - catalogs - binaries: general -
blue stragglers - stars: rotation -
open clusters and associations: general
Abstract:
We have compiled a list of blue lurker (BL) candidates in open
clusters using the available rotation catalogs. Blue lurkers are
rejuvenated main-sequence stars hidden among normal main-sequence
stars on color-magnitude diagrams of star clusters. In comparison to
BLs, blue straggler stars, which formed via similar mass transfers or
mergers, occupy a distinct space in color-magnitude diagrams.
Blue lurkers can be identified by their unusually faster rotation
compared to similar mass stars, which is a signature of recent
accretion, or by the presence of a companion (e.g., an extremely low
mass white dwarf), which can only be formed by mass donation. We
searched for fast-rotating stars on the main sequence of open clusters
using Kepler, TESS, and spectroscopic rotation indicators, such as
rotation periods and vsini measurements.
We identified 97 new BL candidates across 35 open clusters, almost
tripling the previously known sample of 36. Based on the estimated
completeness of ∼3%, thousands of BLs are likely hidden within the
cluster population. Detailed spectroscopic and time series analyses
will be essential to confirming their mass-transfer histories.
Description:
Astrometric, photometric and SED-based properties of blue lurker
candidates. The catalogue lists information for 36 previously known
and 97 newly identified blue lurker candidates is presented in
table1.dat.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
cluster.dat 40 40 Open cluster sample in our study
table1.dat 903 133 The catalog of new and previously known blue
lurker candidates
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See also:
J/A+A/688/A152 : UOCS. XIV. blue lurkers in NGC 752 (Jadhav+, 2024)
J/A+A/676/A47 : UOCS study of NGC 6791 (Jadhav+, 2023)
J/A+A/676/A129 : Gaia-ESO catalogue version 5.1 (Hourihane+, 2023)
J/A+A/674/A152 : Cool star rotation periods in NGC 2281 (Fritzewski+, 2023)
J/AJ/168/205 : WIYN open cl. XC. RVs & orbital param. in NGC 2506
(Linck+, 2024)
J/AJ/139/1383 : Radial velocities in M35 (NGC 2168) (Geller+, 2010)
J/ApJ/944/39 : Rot. vel. & inclinations in stars of open clusters
(Healy+, 2023)
J/ApJ/904/140 : Ruprecht 147 members & rot. data for 5 other cl.
(Curtis+,2020)
J/ApJ/879/100 : K2 rotation periods for Hyades & Praesepe members
(Douglas+, 2019)
J/MNRAS/503/236 : UVIT catalog and membership of 6 open clusters (Jadhav+,2021)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
II/389 : The Pan-STARRS release 1 (PS1) Survey - DR2 (Magnier+, 2025)
II/335 : Revised catalog of GALEX UV sources (GUVcat_AIS GR6+7)
(Bianchi+ 2017)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
Byte-by-byte Description of file: cluster.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- Cluster Host cluster name (Cluster)
15- 16 I2 h RAh Right ascension from simbad (J2000)
18- 19 I2 min RAm Right ascension from simbad (J2000)
21- 25 F5.2 s RAs Right ascension from simbad (J2000)
27 A1 --- DE- Declination sign from simbad (J2000)
28- 29 I2 deg DEd Declination from simbad (J2000)
31- 32 I2 arcmin DEm Declination from simbad (J2000)
34- 37 F4.1 arcsec DEs Declination from simbad (J2000)
39- 40 I2 --- Nbr Number of source occurences in table1.dat
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Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 source_id
21- 33 A13 --- Cluster Host cluster name
35- 48 A14 --- RefRot Reference for rotational info (1)
50- 64 A15 --- RefID Reference which identified the blue
lurker candidate (1)
66- 75 A10 --- Comment Comment indicating evidence from the
literature for UV excess emission or
radial velocities inconsistent with the
cluster
77- 82 F6.2 km/s vsini ? Mean v*sin(i); projected rotational
velocity
84- 88 F5.2 km/s e_vsini ? Error in vsini
90- 95 F6.4 d Prot ? Photometric rotation period
97-102 F6.4 d e_Prot ? Error in Prot
104-113 F10.6 deg RAdeg Right ascension (ICRS) at Ep=2016.0
115-124 F10.6 deg DEdeg Declination (ICRS) at Ep=2016.0
126-132 F7.4 mas Plx Parallax (Gaia)
134-141 F8.4 mas/yr pmRA Proper motion in R.A. direction
(pmRA*cosDE, Gaia)
143-150 F8.4 mas/yr pmDE Proper motion in Dec. direction (Gaia)
152-159 F8.4 km/s RV ? Radial velocity (Gaia)
161-193 A33 --- Simbad Simbad Identifier
195-250 A56 --- SimbadTypes Simbad object types
252-255 I4 Myr Age ? Age of the host cluster
257-260 F4.2 mag AV ? Cluster extinction in V band
262-265 F4.2 mag e_AV ? Error in the cluster AV
267-271 F5.2 --- [Fe/H] Cluster metallicity
273-291 F19.14 pc Dist Cluster distance
293-310 F18.14 pc e_Dist Error in the cluster distance
312-318 F7.4 mag Gmag Gaia DR3 G band magnitude (Gaia)
320-325 F6.4 mag e_Gmag Error in Gmag
327-333 F7.4 mag BPmag Gaia DR3 Gbp band magnitude (Gaia)
335-340 F6.4 mag e_BPmag Error in Gbpmag
342-348 F7.4 mag RPmag Gaia DR3 Grp band magnitude (Gaia)
350-355 F6.4 mag e_RPmag Error in Grpmag
357-363 F7.4 mag F606Wmag ? Synthetic Gaia DR3 HST/ACS/WFC F606W
band magnitude (Gaia)
365-370 F6.4 mag e_F606Wmag ? Error in F606Wmag
372-378 F7.4 mag F814Wmag ? Synthetic Gaia DR3 HST/ACS/WFC F814W
band magnitude (Gaia)
380-385 F6.4 mag e_F814Wmag ? Error in F814Wmag
387-393 F7.4 mag Umag ? Synthetic Gaia DR3 U band magnitude
(Gaia)
395-400 F6.4 mag e_Umag ? Error in Umag
402-408 F7.4 mag Bmag ? Synthetic Gaia DR3 B band magnitude
(Gaia)
410-415 F6.4 mag e_Bmag ? Error in Bmag
417-423 F7.4 mag Vmag ? Synthetic Gaia DR3 V band magnitude
(Gaia)
425-430 F6.4 mag e_Vmag ? Error in Vmag
432-438 F7.4 mag Rmag ? Synthetic Gaia DR3 R band magnitude
(Gaia)
440-445 F6.4 mag e_Rmag ? Error in Rmag
447-453 F7.4 mag Imag ? Synthetic Gaia DR3 I band magnitude
(Gaia)
455-460 F6.4 mag e_Imag ? Error in Imag
462-467 F6.3 mag W1mag ? WISE W1 band magnitude (WISE)
469-473 F5.3 mag e_W1mag ? Error in W1mag
475-480 F6.3 mag W2mag ? WISE W2 band magnitude (WISE)
482-486 F5.3 mag e_W2mag ? Error in W2mag
488-493 F6.3 mag W3mag ? WISE W3 band magnitude (WISE)
495-499 F5.3 mag e_W3mag ? Error in W3mag
501-507 F7.4 mag FUVmag ? GALEX FUV band magnitude (GALEX)
509-514 F6.4 mag e_FUVmag ? Error in FUVmag
516-522 F7.4 mag NUVmag ? GALEX NUV band magnitude (GALEX)
524-529 F6.4 mag e_NUVmag ? Error in NUVmag
531-537 F7.4 mag PS1gmag ? PanSTARRS DR1 g band magnitude
(PanSTARRS)
539-544 F6.4 mag e_PS1gmag ? Error in PS1_gmag
546-552 F7.4 mag PS1rmag ? PanSTARRS DR1 r band magnitude
(PanSTARRS)
554-559 F6.4 mag e_PS1rmag ? Error in PS1_rmag
561-567 F7.4 mag PS1imag ? PanSTARRS DR1 i band magnitude
(PanSTARRS)
569-574 F6.4 mag e_PS1imag ? Error in PS1_imag
576-582 F7.4 mag PS1zmag ? PanSTARRS DR1 z band magnitude
(PanSTARRS)
584-589 F6.4 mag e_PS1zmag ? Error in PS1_zmag
591-597 F7.4 mag PS1ymag ? PanSTARRS DR1 y band magnitude
(PanSTARRS)
599-604 F6.4 mag e_PS1ymag ? Error in PS1_ymag
606-612 F7.4 mag SDSSumag ? SDSS DR13 u band magnitude (SDSS)
614-619 F6.4 mag e_SDSSumag ? Error in SDSS_umag
621-627 F7.4 mag SDSSgmag ? SDSS DR13 g band magnitude (SDSS)
629-634 F6.4 mag e_SDSSgmag ? Error in SDSS_gmag
636-642 F7.4 mag SDSSrmag ? SDSS DR13 r band magnitude (SDSS)
644-649 F6.4 mag e_SDSSrmag ? Error in SDSS_rmag
651-657 F7.4 mag SDSSimag ? SDSS DR13 i band magnitude (SDSS)
659-664 F6.4 mag e_SDSSimag ? Error in SDSS_imag
666-672 F7.4 mag SDSSzmag ? SDSS DR13 z band magnitude (SDSS)
674-679 F6.4 mag e_SDSSzmag ? Error in SDSS_zmag
681-687 F7.4 mag Jmag ? 2MASS J band magnitude (2MASS)
689-693 F5.3 mag e_Jmag ? Error in Jmag
695-701 F7.4 mag Hmag ? 2MASS H band magnitude (2MASS)
703-707 F5.3 mag e_Hmag ? Error in Hmag
709-715 F7.4 mag Ksmag ? 2MASS Ks band magnitude (2MASS)
717-721 F5.3 mag e_Ksmag ? Error in Ksmag
723-728 F6.3 mag F148Wmag ? AstroSat/UVIT F148W band magnitude
730-734 F5.3 mag e_F148Wmag ? Error in F148Wmag
736-740 F5.2 mag F154Wmag ? AstroSat/UVIT F154W band magnitude
742-745 F4.2 mag e_F154Wmag ? Error in F154Wmag
747-752 F6.3 mag F169Mmag ? AstroSat/UVIT F169M band magnitude
754-758 F5.3 mag e_F169Mmag ? Error in F169Mmag
760-765 F6.3 mag N245Mmag ? AstroSat/UVIT N245M band magnitude
767-771 F5.3 mag e_N245Mmag ? Error in N245Mmag
773-778 F6.3 mag N263Mmag ? AstroSat/UVIT N263M band magnitude
780-783 F4.2 mag e_N263Mmag ? Error in N263Mmag
785-790 F6.3 mag UVOTUmag ? SWIFT/UVOT U band magnitude
792-796 F5.3 mag e_UVOTUmag ? Error in Umag
798-803 F6.3 mag UVOTUVW1mag ? SWIFT/UVOT UVW1 band magnitude
805-809 F5.3 mag e_UVOTUVW1mag ? Error in UVW1mag
811-816 F6.3 mag UVOTUVM2mag ? SWIFT/UVOT UVM2 band magnitude
818-822 F5.3 mag e_UVOTUVM2mag ? Error in UVM2mag
824-829 F6.3 mag UVOTUVW2mag ? SWIFT/UVOT UVW2 band magnitude
831-835 F5.3 mag e_UVOTUVW2mag ? Error in UVW2mag
837 I1 --- NuvEx ? Number of points whose UV flux leaves
more than 0.3 fractional residual
839-842 I4 K Teff ? SED based effective temperature
844-847 I4 K b_Teff ? Lower bound (16th perc.) of Teff
849-852 I4 K B_Teff ? Upper bound (84th perc.) of Teff
854-856 F3.1 [cm/s2] logg ? SED based surface gravity
858-861 F4.2 Rsun Rad ? SED based radius
863-866 F4.2 Rsun b_Rad ? Lower bound (16th percentile) of Rad
868-871 F4.2 Rsun B_Rad ? Upper bound (84th percentile) of Rad
873-877 F5.2 Lsun Lum ? SED based luminosity
879-883 F5.2 Lsun b_Lum ? Lower bound (16th percentile) of Lum
885-889 F5.2 Lsun B_Lum ? Upper bound (84th percentile) of Lum
891-897 F7.2 --- chi2r ? Reduced chi2 of the SED fit
899-903 F5.2 --- vgfb2 ? The vgfb2 value of the SED fit
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Note (1): References as follows:
Curtis2020 = 2020ApJ...904..140C 2020ApJ...904..140C, Cat. J/ApJ/904/140
Dattatrey2023 = 2023MNRAS.523L..58D 2023MNRAS.523L..58D
Douglas2019 = 2019ApJ...879..100D 2019ApJ...879..100D, Cat. J/ApJ/879/100
Fritzewski2023 = 2023A&A...674A.152F 2023A&A...674A.152F, Cat. J/A+A/674/A152
Geller2010 = 2010AJ....139.1383G 2010AJ....139.1383G, Cat. J/AJ/139/1383
GES = 2023A&A...676A.129H 2023A&A...676A.129H, Cat. J/A+A/676/A129
Healy2023 = 2023ApJ...944...39H 2023ApJ...944...39H, Cat. J/ApJ/944/39
Jadhav2019 = 2019ApJ...886...13J 2019ApJ...886...13J, Cat. J/MNRAS/503/236
Jadhav2023 = 2023A&A...676A..47J 2023A&A...676A..47J, Cat. J/A+A/676/A47
Jadhav2024 = 2024A&A...688A.152J 2024A&A...688A.152J, Cat. J/A+A/688/A152
Leiner2019 = 2019ApJ...881...47L 2019ApJ...881...47L
Linck2024 = 2024AJ....168..205L 2024AJ....168..205L, Cat. J/AJ/168/205
Narayan2025 = 2026AJ....171..102N 2026AJ....171..102N
Panthi2024 = 2024MNRAS.52710335P 2024MNRAS.52710335P
Sha2024 = 2024ApJ...977..103S 2024ApJ...977..103S
Subramaniam2020 = 2020JApA...41...45S 2020JApA...41...45S
VanLane2025 = 2025ApJ...986...59V 2025ApJ...986...59V
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Acknowledgements:
Vikrant V. Jadhav, vikrant-vinayak.jadhav(at)matfyz.cuni.cz
(End) Luc Trabelsi [CDS] 29-Jan-2026