J/AJ/170/288 MiMO: 1232 Gaia DR3 open clusters param. & mass funct. (Li+, 2025)
The MiMO catalog: Physical parameters and stellar mass functions of 1232 open
clusters from Gaia DR3.
Li Lu, Shao Z., Li Z., Fu X.
<Astron. J., 170, 288 (2025)>
=2025AJ....170..288L 2025AJ....170..288L
ADC_Keywords: Clusters, open; Photometry; Optical; Models; Abundances, [Fe/H];
Proper motions; Parallaxes, trigonometric; Stars, ages
Keywords: Open star clusters ; Mixture model ; Hertzsprung Russell diagram ;
Stellar mass functions ; Bayesian statistics ; Binary stars ;
Stellar ages
Abstract:
We present a homogeneous catalog of 1232 open clusters with precisely
determined ages, metallicities, distances, extinctions, and stellar
mass function (MF) slopes, derived from Gaia DR3 data. The parameters
are inferred using the Mixture Model for Open clusters (MiMO), a novel
Bayesian framework for modeling clusters in the color-magnitude
diagram. By explicitly accounting for field-star contamination as a
model component, MiMO removes the conventional need for stringent
membership preselection, allowing for a more complete inclusion of
member stars, and thereby enhancing both precision and robustness. Our
results broadly agree with existing catalogs but offer improved
precision. For each cluster, we provide the best-fit age, metallicity,
distance, extinction, and MF slope, along with their full likelihood
chains and photometric membership probabilities for individual stars.
We further identify an "MF Prime" subsample of 163 clusters with high-
quality data, for which the MF estimates are considered most reliable.
The catalog and an open-source implementation of MiMO are made
publicly available to the community.
Description:
Our analysis is based on the input sample of 1743 clusters from
Dias+2021 (J/MNRAS/504/356), which provides a high-confidence list of
existing OCs. Using this as our target list, we apply the Mixture
Model for Open clusters (MiMO; Li+, 2022ApJ...930...44L 2022ApJ...930...44L), a novel
Bayesian framework for modeling clusters in the color-magnitude
diagram, with Gaia DR3 (I/355) data to produce a homogeneous catalog.
After a thorough process of visual inspection and quality assessment
of the fitting results, we produced a final, reliable catalog of 1232
clusters. We further identify an "MF Prime" subsample of 163 clusters
with high-quality data, for which the mass function (MF) estimates are
considered most reliable.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 104 1232 Fitting sample selection criteria
table3.dat 171 1232 Catalog of inferred parameters
table4.dat 109 511735 Photometric membership probabilities for individual
stars in each open cluster
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See also:
B/ocl : Optically visible open clusters and Candidates (Dias+ 2002-2015)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
J/A+A/438/1163 : Catalogue of Open Cluster Data (COCD) (Kharchenko+, 2005)
J/A+A/558/A53 : MW global survey of star clusters. II. (Kharchenko+, 2013)
J/A+A/585/A150 : On the metallicity of open clusters. III. (Netopil+, 2016)
J/A+A/623/A108 : Age of 269 GDR2 open clusters (Bossini+, 2019)
J/A+A/623/A80 : Open clusters in APOGEE and GALAH surveys (Carrera+, 2019)
J/A+A/627/A35 : New open clusters in Gal. anti-centre (Castro-Ginard+, 2019)
J/ApJS/245/32 : Newly identified star clusters in Gaia DR2 (Liu+, 2019)
J/A+A/633/A99 : Gaia DR2 open clusters in Milky Way. II (Cantat-Gaudin+, 2020)
J/A+A/640/A1 : Portrait Galactic disc (Cantat-Gaudin+, 2020)
J/AJ/159/199 : OCCAM. IV. Open clust. abund. using APOGEE DR16 (Donor+, 2020)
J/MNRAS/504/356 : Updated parameters of 1743 open clusters (Dias+, 2021)
J/A+A/649/A3 : Gaia EDR3 photometric passbands (Riello+, 2021)
J/MNRAS/503/3279 : GALAH surv. Galactic disc with open clusters (Spina+, 2021)
J/A+A/668/A4 : LAMOST open clusters (Fu+, 2022)
J/A+A/663/A131 : Parameters for 25 distant open clusters (Perren+, 2022)
J/A+A/673/A114 : Improving the open cluster census. II. (Hunt+, 2023)
J/AJ/167/12 : Open cluster parameters with ANN (Cavallo+, 2024)
J/AJ/169/116 : Gaia & 2MASS fitting for Pleiades members (Liu+, 2025)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Cluster Cluster name
19- 26 F8.4 deg RAdeg Right Ascension (J2000)
28- 35 F8.4 deg DEdeg Declination (J2000)
37- 43 F7.3 mas/yr pmRA [-36.09/22.87] Mean cluster proper motion
in RA
45- 51 F7.3 mas/yr pmDE [-45.51/23.32] Mean cluster proper motion
in DE
53- 57 F5.3 mas/yr e_pmRA [0.03/1.28] Dispersion (1σ) in pmRA
59- 63 F5.3 mas/yr e_pmDE [0.02/1.31] Dispersion (1σ) in pmDE
65- 70 F6.3 mas plx [0.05/11.6] Mean cluster parallax
72- 76 F5.3 mas e_plx [5e-3/0.4] Dispersion (1σ) in plx
78- 82 F5.3 deg r50 [0.01/3.12] Projected half-number radius
84- 86 F3.1 --- Nr50 [1/6] Multiplicative factor, characteristic
radius
88- 90 F3.1 --- Npm [2/8] Multiplicative factor, proper motion
dispersion
92- 95 F4.1 --- Nplx [1/99] Multiplicative factor, parallax
dispersion
97- 100 F4.1 --- Nplx-near [3/99] Multiplicative factor, upper
parallax limit to remove foreground stars
102- 104 F3.1 --- Npm-fs [8/8] Multiplicative factor, lower proper
motion limit used to select the field star
sample
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Cluster Cluster name
19- 24 F6.3 [yr] logAge [6.4/10.15] Best-fit, log Age
26- 31 F6.3 [yr] logAge-50 [6.46/10.04] Median, log Age
33- 37 F5.3 [yr] logAge-16 [6.32/9.91] 16th percentile, log Age
39- 44 F6.3 [yr] logAge-84 [6.51/10.13] 84th percentile, log Age
46- 51 F6.3 [-] [Fe/H] [-0.66/0.45] Best-fit, metallicity
53- 58 F6.3 [-] [Fe/H]-50 [-0.65/0.45] Median, metallicity
60- 65 F6.3 [-] [Fe/H]-16 [-0.67/0.43] 16th percentile, metallicity
67- 72 F6.3 [-] [Fe/H]-84 [-0.55/0.45] 84th percentile, metallicity
74- 79 F6.3 mag DM [5/14.67] Best-fit, distance modulus
81- 86 F6.3 mag DM-50 [5/14.69] Median, distance modulus
88- 93 F6.3 mag DM-16 [5/14.66] 16th percentile, distance modulus
95- 100 F6.3 mag DM-84 [5/14.71] 84th percentile, distance modulus
102- 106 F5.3 mag AVmag [1e-3/3] Best-fit, V band reddening
108- 112 F5.3 mag AVmag-50 [3e-3/3] Median, V band reddening
114- 118 F5.3 mag AVmag-16 [2e-3/2.99] 16th percentile, V band
reddening
120- 124 F5.3 mag AVmag-84 [9e-3/3] 84th percentile, V band reddening
126- 131 F6.3 --- alpha [-4.97/1.9] Best-fit, mass function slope
133- 138 F6.3 --- alpha-50 [-4.83/1.33] Median, mass function slope
140- 145 F6.3 --- alpha-16 [-4.95/0.77] 16th percentile, mass function
slope
147- 152 F6.3 --- alpha-84 [-4.62/1.76] 84th percentile, mass function
slope
154- 159 F6.3 --- avgPrior [-0.56/0.37] Mean, spectroscopic metallicity
prior
161- 165 F5.3 --- sigPrior [0/0.32] Standard Deviation, spectroscopic
metallicity prior
167- 171 F5.3 --- MFsamp [0/1] 1=Member of MF Prime sample of
high-quality clusters (1)
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Note (1): Membership flag as follows:
0.000 = Not a member (1069 occurrences)
1.000 = Member (163 occurrences)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- Cluster Cluster name
19- 37 I19 --- GaiaDR3 Gaia DR3 source_id
39- 61 F23.19 deg RAdeg Right ascension (J2000)
63- 86 F24.20 deg DEdeg Declination (J2000)
88- 109 E22.16 --- Pmemb [0/1] Membership probability
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Robin Leichtnam [CDS] 18-Aug-2026