J/AJ/169/326 Identifying open clusters members using Gaia DR3 (Liu+, 2025)
Revisiting Open Clusters within 200pc in the Solar Neighborhood with Gaia DR3.
Liu P., Fang M., Tsai Y.-L.S., Pang X., Wang F., Fu X.
<Astron. J., 169, 326 (2025)>
=2025AJ....169..326L 2025AJ....169..326L
ADC_Keywords: Clusters, open; Photometry; Optical; Positional data; Reddening;
Stars, ages; Stars, distances; Parallaxes, trigonometric
Keywords: Open star clusters ; Star clusters ; Stellar evolutionary tracks
Abstract:
In this study, we develop a membership identification method and apply
it for 30 open clusters (OCs) within 200pc of the Sun using
astrometric data of Gaia DR3. By accounting for projection effects
that distort apparent stellar motions, our approach converts
astrometric data into accurate five-dimensional positions and
velocities. This approach enables better identification of members in
nearby OCs. We then compare our refined membership lists with previous
catalogs, revealing more members in most OCs, but also the
identification of elongated structures in Melotte 25 (Hyades), NGC
2632 (Praesepe), Melotte 111 (Coma Berenices), Platais 3, Melotte 22
(Pleiades), NGC 2451A, Platais 9, IC 2391, Platais 8, UPK 640, and HSC
2986, which we studied in detail. An analysis of the ages of their
members reveals that the members within and outside of the tidal
radius are distinctly coeval, further validating our methodology. This
study suggests that for OCs in the solar neighborhood, correcting for
the projection effect is very important for the identification of OC
members.
Description:
We identify cluster member stars based on the OC catalog from
Hunt+2023 (J/A+A/673/A114) and limit our cluster selection within
200pc of the Sun. Hunt+2023 performed a blind all-sky search for OCs
based on the latest Gaia DR3 (I/355) data, using an improved OC census
approach. For our chosen range of distances, OCs are strongly affected
by the projection effect. We select only those labeled "o" (the OCs)
but remove those labeled "m" (the moving groups) in the catalog. We
remove the OCs Chamaleon I and HSC 2919 because they are relatively
young and located in star-forming regions, resulting in poor
performance of the reddening correction method. Note that we selected
only those OCs with a number of members greater than 100 because these
clusters are statistically significant. In total, we have 30 OCs in
the sample. Among them, six OCs have been also studied in
Tarricq+2022 (J/A+A/659/A59), and 13 OCs have been investigated in
Cantat-Gaudin+2020 (J/A+A/640/A1).
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
clusters.dat 115 30 Selected OCs in this work (PDF version of Table 1)
members.dat 161 16601 Parameters of all members identified in this study
(MRT version of Table 1)
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See also:
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
I/339 : Hot Stuff for One Year (HSOY) (Altmann+, 2017)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)
J/ApJ/723/492 : Physical properties of GRS molec. clouds (Roman-Duval+, 2010)
J/MNRAS/416/3108 : Membership of Sco OB2 moving group (Rizzuto+, 2011)
J/A+A/616/A10 : 46 open clusters GaiaDR2 HR diagrams (Gaia Collaboration, 2018)
J/A+A/615/A49 : TGAS stars membership in 128 open clust. (Cantat-Gaudin+, 2018)
J/A+A/618/A59 : Gaia DR2 confirmed new nearby op. clust. (Castro-Ginard+, 2018)
J/ApJ/856/23 : BANYAN. XI. The BANYAN Σ algorithm (Gagne+, 2018)
J/A+A/615/A12 : 24 nearby open clusters TGAS and HSOY reanalysis (Yen+, 2018)
J/A+A/627/A35 : New open clusters in Gal. anti-centre (Castro-Ginard+, 2019)
J/A+A/624/L11 : Coma Berenices neighbor moving group (Fuernkranz+, 2019)
J/AJ/158/122 : Local structure & star form. history of the MW (Kounkel+, 2019)
J/ApJS/245/32 : Newly identified star clusters in Gaia DR2 (Liu+, 2019)
J/A+A/621/L3 : Hyades tidal tails with Gaia DR2 (Meingast+, 2019)
J/A+A/621/L2 : Hyades tidal tails revealed by Gaia DR2 (Roeser+, 2019)
J/ApJ/877/12 : Coma Ber and a Neighbor Stellar Group tidal tails (Tang+, 2019)
J/A+A/640/A1 : Portrait Galactic disc (Cantat-Gaudin+, 2020)
J/ApJ/889/99 : Gaia DR2 Blanco 1 member candidates (Zhang+, 2020)
J/MNRAS/504/356 : Updated parameters of 1743 open clusters (Dias+, 2021)
J/A+A/646/A104 : Improving the open cluster census. I. (Hunt+, 2021)
J/A+A/647/A137 : 800pc tidal tail of Hyades (Jerabkova+, 2021)
J/ApJ/917/23 : SPYGLASS. I. Mapping young stellar structures (Kerr+, 2021)
J/A+A/645/A84 : Coronae of nearby star clusters (Meingast+, 2021)
J/ApJ/912/162 : Open clusters in solar neighborhood (Pang+, 2021)
J/MNRAS/503/3279 : GALAH survey. Gal. disc with open clusters (Spina+, 2021)
J/A+A/661/A118 : 628 new open clust. found with OCfinder (Castro-Ginard+, 2022)
J/ApJS/260/8 : 541 new open cluster candidates (He+, 2022)
J/ApJ/939/94 : New associations in Gaia DR3 solar neighborh. (Moranta+, 2022)
J/A+A/659/A59 : Structural param. of 389 local open clusters (Tarricq+, 2022)
J/A+A/677/A163 : A Gaia astrometric view of 3 open clusters (Alfonso+, 2023)
J/AJ/165/108 : Propert. of 600 bona fide stars in the Hyades (Brandner+, 2023)
J/A+A/673/A114 : Improving the open cluster census. II. (Hunt+, 2023)
J/A+A/675/A68 : ML tool for open cluster membership (van Groeningen+, 2023)
J/A+A/686/A42 : Improving the open cluster census. III. (Hunt+, 2024)
Byte-by-byte Description of file: clusters.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name Main name of the open cluster
13- 26 A14 --- OName Other name
28- 31 I4 --- NstarH23 [103/1721] Number of member stars from
Hunt+2023 (J/A+A/673/A114)
33- 38 F6.2 deg RAdeg [10/358.47] Right ascension (J2000)
40- 45 F6.2 deg DEdeg [-64.39/79.32] Declination (J2000)
47- 52 F6.2 mas/yr pmRA [-42.07/104.14] Proper motion in right
ascension direction (pmRA*cosDE)
54- 59 F6.2 mas/yr pmDE [-45.46/23.27] Proper motion in declination
direction
61- 66 F6.2 pc Dist [47.19/198.3] Distance
68- 71 F4.2 --- logAgeH23 [6.67/8.82] Log of age from Hunt+2023
(J/A+A/673/A114)
73- 77 F5.2 --- e_logAgeH23 [-0.41/-0.16] Lower uncertainty giving the
16th percentile of logAgeH23
79- 83 F5.2 --- E_logAgeH23 [0.12/0.33] Upper uncertainty giving the
84th percentile of logAgeH23
85- 88 I4 --- Nstar [87/2544] Number of member stars from this
study
90- 92 A3 --- Flag Indicates whether the elongated morphology
of the cluster can be seen based on our
membership (1)
94- 97 F4.2 [Gyr] logAge [6.99/8.89] Log of age from this study
99- 103 F5.2 [Gyr] e_logAge [-0.17/-0.01] Lower uncertainty giving the
16th percentile of logAge
105- 109 F5.2 [Gyr] E_logAge [0/0.19] Upper uncertainty giving the 84th
percentile of logAge
111- 115 A5 --- Ref References to which our membership has been
compared (2)
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Note (1): Flag as follows:
No = The elongated morphology of the cluster cannot be seen based on our
membership (19 occurrences)
Yes = The elongated morphology of the cluster can be seen based on our
membership (11 occurrences)
Note (2): References as follows:
1 = Hunter+2023 (J/A+A/673/A114); 30 occurrences
2 = Tarricq+2022 (J/A+A/659/A59); 6 occurrences
3 = Cantat-Gaudin+2020 (J/A+A/640/A1); 13 occurrences
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Byte-by-byte Description of file: members.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Name Name of open cluster
13- 31 I19 --- GaiaDR3 Gaia DR3 unique source identifier
33- 44 F12.8 deg RAdeg Right ascension of source (J2000)
46- 57 F12.8 deg DEdeg Declination of source (J2000)
59- 69 F11.8 mas plx [2.9/47.3] Parallax of source
71- 82 F12.8 mas/yr pmRA [-70.37/420.21] Proper motion in right
ascension direction
84- 96 F13.8 mas/yr pmDE [-120.3/96.9] Proper motion in
declination direction
98- 103 F6.3 mag BP-RP [-0.41/4.77] BP-RP color
105- 114 F10.7 mag GMag [-3.25/17.72] Observed absolute
magnitude in G-band
116- 121 F6.3 mag (BP-RP)0 [-0.48/4.74] De-reddened BP-RP color
123- 132 F10.7 mag G0Mag [-3.31/17.71] De-reddened absolute
magnitude in G-band
134- 143 F10.6 pc rpgeo [21.11/336.42] Median of photogeometric
distance from Bailer-Jones+2021 (I/352)
145- 154 F10.8 --- FidelityV2 [0.51/1] V2 fidelity parameter from
Rybizki+2022 (2022MNRAS.510.2597R 2022MNRAS.510.2597R)
156 I1 --- Memb [0/2] Member in or outside tidal radius
(1)
158- 161 F4.2 --- Prob [0.5/1] Membership probability
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Note (1): Flag as follows:
0 = not in elongated open cluster (7286 occurrences)
1 = in tidal radius (5069 occurrences)
2 = outside tidal radius (4246 occurrences)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Robin Leichtnam [CDS] 18-Mar-2026