NGC 2204

(Melotte 44; Collinder 88; MWSC 822; OCL 572; ESO 556 07; FSR 1201; FoF 2)

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1.0 UTI
1.0
CN
1.0
Cdens
1.0
CC3
1.0
Clit
1.0
Cdup
N50 (P>50% members) 1095
Stellar density (N50/rad) 12.3 [N/pc2]
C3 classification AA
  • CN 1.0 Very rich
  • Cdens 1.0 Very dense
  • CC3 1.0 Very high quality
  • Clit 1.0 Very well-studied
  • Cdup 1.0 Unique
đŸ“Ĩ Members 📊 Colab đŸ”Ŧ Bayestar19 MOCAMOCA 🔍 CDS 🔍 Simbad 🔍 CDS (Îą, δ) 🔍 Simbad (Îą, δ)

Overview
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NGC 2204 is a very rich, very dense object of very high C3 quality. Its parallax locates it at a moderate distance, well below the mid-plane, affected by low extinction. It is catalogued as a massive, near-solar metallicity, old cluster, but with a large variance across recent sources for the absorption, metallicity, and mass parameters (see Parameters). It is very well-studied in the literature.

Note: This object contains blue stragglers according to at least one source.

Note: This object shares a very small percentage of members with a later reported entry. See table with shared members information.

Almeida et al. (2025)
Mass determination: good fit. Isochrone match: good fit.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 1.00 (50th percentile).

Ahumada & Lapasset (2007)
All the cluster parameters except the apparent diameter are from (2005, unpublished data). Reference (1976MNRAS.174..225H) draws attention to the strong central concentration of the blue stragglers, also observed in M67 and Melotte 66.

Data
🔍 Search references for NGC 2204 in: SciX Simbad
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Reference Year RA [deg] DEC [deg] Plx [mas] pmRA [mas/yr] pmDE [mas/yr] Rv [km/s]
UCC 99999– 93.886 -18.671 0.204 -0.578 1.953 92.424
Otto et al. 2026 93.885 -18.671 – -0.56 1.96 92.1
Li et al. 2025 93.882 -18.67 0.209 -0.56 1.964 –
Guerco et al. 2025 93.8 -18.6 0.22 -0.58 1.95 92.2
Hu & Soubiran 2025 93.873 -18.673 – – – –
Carrasco-Varela et al. 2025 94.057 -18.705 – – – –
Almeida et al. 2025 93.882 -18.679 – – – –
Hunt & Reffert 2024 93.885 -18.671 0.201 -0.579 1.957 93.888
Cavallo et al. 2024 93.873 -18.673 0.202 – – –
Hunt & Reffert 2023 93.885 -18.671 0.201 -0.579 1.957 93.888
Angelo et al. 2023 93.896 -18.652 – -0.57 1.95 –
Just et al. 2023 93.882 -18.659 – – – –
Jadhav & Subramaniam 2021 93.882 -18.67 – – – –
Jaehnig et al. 2021 93.882 -18.665 0.238 -0.554 1.974 –
Rain et al. 2021 93.882 -18.67 0.209 -0.56 1.964 –
Dias et al. 2021 93.882 -18.679 0.212 -0.556 1.978 92.492
Spina et al. 2021 93.882 -18.671 0.21 -0.555 1.977 –
Cantat-Gaudin et al. 2020 93.882 -18.67 0.209 -0.56 1.964 –
Donor et al. 2020 93.888 -18.66 – -0.58 1.95 91.9
Cantat-Gaudin & Anders 2020 93.882 -18.67 0.209 -0.56 1.964 –
Liu & Pang 2019 93.877 -18.691 0.252 -0.538 1.975 –
Soubiran et al. 2018 93.882 -18.67 – – – 92.42
Bica et al. 2019 93.902 -18.655 – – – –
Cantat-Gaudin et al. 2018 93.882 -18.67 0.209 -0.56 1.964 –
Loktin & Popova 2017 93.885 -18.665 – 1.26 0.42 89.0
Kharchenko et al. 2016 93.882 -18.659 – – – –
Dias et al. 2014 93.888 -18.665 – 1.26 0.42 –
Kharchenko et al. 2013 93.888 -18.66 – 0.5 3.36 89.0
Gozha et al. 2012 93.888 -18.665 – – – –
Bukowiecki et al. 2011 93.883 -18.667 – – – –
Kharchenko et al. 2007 93.88 -18.67 – 0.08 – –
Ahumada & Lapasset 2007 93.875 -18.667 – – – –
van den Bergh 2006 93.787 -18.643 – – – –
Chen et al. 2003 93.892 -18.659 – – – –
Dias et al. 2002 93.888 -18.665 – 1.26 0.42 92.35
Lynga 1987 93.921 -18.647 – – – –
Sulentic et al. 1973 93.923 -18.659 – – – –

💡 Note: The UCC values are estimated from its identified members.

Reference Year Dist [kpc] Av [mag] DAv [mag] Age [Myr] [Fe/H] [dex] Mass [Msun] Bfrac BSS
UCC 99999– 4.04 0.25 0.29 1950 -0.270 3699 – 6
Otto et al. 2026 – – – 2089 -0.270(15) – – –
Li et al. 2025 4.06 0.28 – 1976 -0.273 – – –
Guerco et al. 2025 – – – 2090 -0.260 – – –
Hu & Soubiran 2025 – – – – -0.410(5) – – –
Carrasco-Varela et al. 2025 4.11 0.18 – 2070 -0.150 – – 5(1)
Almeida et al. 2025 4.11 0.18 – 2070 – 3699 – –
Hunt & Reffert 2024 – – – – – 5225(1) – –
Cavallo et al. 2024 3.19 0.57 – 2291 -0.660 – – –
Hunt & Reffert 2023 4.55 0.05 0.29 1832 – – – –
Angelo et al. 2023 4.04 0.28 – 1995 -0.220 10(1) – –
Just et al. 2023 – – – 1950 – 998 – –
Spina et al. 2022 – – – – -0.260 – – –
Jadhav & Subramaniam 2021 4.00 0.01 – 2089 – 5985 – 6(1)
Jaehnig et al. 2021 4.23(1) – – – – – – –
Rain et al. 2021 4.20 0.25 – 776 – – – 7
Dias et al. 2021 4.11 0.18 – 2070 -0.175 – – –
Spina et al. 2021 4.32 – – 2089 -0.270(20) – – –
Cantat-Gaudin et al. 2020 4.00 0.01 – 2089 – – – –
Kounkel et al. 2020 4.36 0.31 – 1479 – – – –
Donor et al. 2020 – – – – -0.260 – – –
Cantat-Gaudin & Anders 2020 4.20 – – – – – – –
Liu & Pang 2019 – – – 1380 0.250 – – –
Soubiran et al. 2018 4.20 – – – – – – –
Cantat-Gaudin et al. 2018 4.20 – – – – – – –
Loktin & Popova 2017 2.81 0.32 – 851 – – – –
Kharchenko et al. 2016 3.79 0.07 – 1950 – – – –
Kharchenko et al. 2013 3.79 0.07 – 1950 -0.320 – – –
Gozha et al. 2012 2.63 – – 787 -0.320 – – –
Bukowiecki et al. 2011 3.98(1) 0.00 – 1585 – – – –
Ahumada & Lapasset 2007 – 0.38 – 1585 – – – 9
van den Bergh 2006 2.63 0.25 – 794 – – – –
Chen et al. 2003 2.63 0.27 – 780 -0.330(1) – – –
Dias et al. 2002 2.63 0.27 – 787 -0.230 – – –
Lynga 1987 3.10 – – 3020 -0.580 – – –

(N): Indicates that there are N extra values assigned to this parameter in the corresponding reference.

Cluster % RA DEC Plx pmRA pmDE Rv UTI
OC 0378 2.3 93.91 -18.72 0.26 -0.59 1.94 92.94 0.0

💡 Note: The % column shows the percentage of members that NGC 2204 shares with each listed object.

Visualization
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NGC 2204 UCC
NGC 2204 HUNT23
NGC 2204 CANTAT20
Galactocentric position diagram