Koposov 12

(FSR 0802; MWSC 701; Alessi J0601.6+35b; MWSC 702)

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0.96 UTI
0.79
CN
1.0
Cdens
1.0
CC3
1.0
Clit
1.0
Cdup
C3 classification AA
Number of members (P>50%) 219
Radius (P>50% members) 4.7 [arcmin]
  • CN 0.79 Rich
  • Cdens 1.0 Very dense
  • CC3 1.0 Very high quality
  • Clit 1.0 Very well-studied
  • Cdup 1.0 Unique
📥 Members 📊 Colab 🔬 Bayestar19 🔍 SciX 🔍 Simbad 🔍 CDS (α, δ) 🔍 Simbad (α, δ)

Overview
Koposov 12 is a rich, very dense object of very high C3 quality. Its parallax locates it at a moderate distance, above the mid-plane, affected by moderate extinction. It is catalogued as a near-solar metallicity, intermediate-age cluster, but with a large variance across recent sources for the metallicity and mass parameters (see Parameters). It is very well-studied in the literature.

Note: This object shares a small percentage of members with 2 later reported entries. See table with shared members information.

Relatively close Moderate extinction Near-solar metallicity Intermediate age

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

Cavallo et al. (2024): Gold sample.

Data
Reference Year RA [deg] DEC [deg] Plx [mas] pmRA [mas/yr] pmDE [mas/yr] Rv [km/s]
UCC – 90.25 35.291 0.394 0.648 -1.743 19.666
Almeida et al. 2025 90.235 35.295 – – – –
Zhang et al. 2024 90.247 35.266 – – – –
Hunt & Reffert 2024 90.247 35.266 0.401 0.652 -1.742 17.077
Cavallo et al. 2024 90.249 35.301 0.401 – – –
Hunt & Reffert 2023 90.247 35.266 0.401 0.652 -1.742 17.077
Just et al. 2023 90.251 35.277 – – – –
Dias et al. 2021 90.235 35.295 0.409 0.704 -1.711 –
Cantat-Gaudin et al. 2020 90.245 35.287 0.396 0.699 -1.732 –
Bossini et al. 2019 90.245 35.287 – – – –
Soubiran et al. 2018 90.245 35.287 – – – 20.31
Bica et al. 2019 90.261 35.277 – – – –
Cantat-Gaudin et al. 2018 90.245 35.287 0.396 0.699 -1.732 –
Kharchenko et al. 2016 90.251 35.277 – – – –
Kharchenko et al. 2013 90.261 35.277 – 0.92 -1.8 13.6
Kharchenko et al. 2012 90.261 35.277 – 0.92 -1.8 –
Glushkova et al. 2010 90.234 35.277 – – – –
Koposov et al. 2008 90.234 35.277 – – – –
Froebrich et al. 2007 90.254 35.279 – – – –
Dias et al. 2002 90.233 35.277 – 0.44 -1.82 –

💡 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] Bfr BSS
Almeida et al. 2025 2.06 1.68 – 500 – 506 – –
Zhang et al. 2024 – – – – -0.275* – – –
Hunt & Reffert 2024 – – – – – 1702* – –
Cavallo et al. 2024 2.43 1.58 – 417 0.500 – – –
Hunt & Reffert 2023 2.28 1.57 0.97 281 – – – –
Just et al. 2023 – – – 813 – 167 – –
Dias et al. 2021 2.06 1.68 – 500 0.012 – – –
Cantat-Gaudin et al. 2020 2.47 1.43 – 389 – – – –
Bossini et al. 2019 2.63 1.53 – 348 0.000 – – –
Soubiran et al. 2018 2.35 – – – – – – –
Cantat-Gaudin et al. 2018 2.35 – – – – – – –
Kharchenko et al. 2016 1.90 1.40 – 813 – – – –
Kharchenko et al. 2013 1.90 1.40 – 813 – – – –
Kharchenko et al. 2012 1.90 1.40 – 813 – – – –
Glushkova et al. 2010 2.05 0.93 – 794 – – – –
Koposov et al. 2008 2.05 0.93 – 794 – – – –
Dias et al. 2002 2.00 1.58 – 603 – – – –

💡 Note: The parameters are sometimes transformed from their original values to match the format of the columns shown here, see FAQ. The columns DAv, Bfr, BSS correspond to differential extinction, binary fraction, and blue stragglers, respectively. BSS values can be listed as fractions or integers.
(*): indicates that this parameter is assigned more than one value in the corresponding reference.

Cluster % RA DEC Plx pmRA pmDE Rv UTI
UBC 1579 21.0 90.31 35.4 0.49 0.64 -1.74 56.82 0.19
Alessi J0601.6+3531 9.1 90.35 35.5 0.56 0.63 -1.74 26.3 0.27

💡 Note: The % column shows the percentage of members that Koposov 12 shares with each listed object.

Visualization
Koposov 12 UCC
Koposov 12 HUNT23
Koposov 12 CANTAT20
Galactocentric position diagram

💡 Note: How are the galactocentric plots generated? See FAQ.