Haffner 21

(MWSC 1411; OCL 677; ESO 494 11; FoF 1425)

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0.88 UTI
0.72
CN
1.0
Cdens
1.0
CC3
0.84
Clit
1.0
Cdup
Nm (P>50%) 95
Core radius and density 1.0 [pc], 8.1 [pc-2]
C3 classification AA
  • CN 0.72 Moderately populated
  • Cdens 1.0 Very dense
  • CC3 1.0 Very high quality
  • Clit 0.84 Well-studied
  • Cdup 1.0 Unique
đŸ“Ĩ Members 📊 Colab đŸ”Ŧ Bayestar19 MOCAMOCA 🔍 CDS 🔍 Simbad 🔍 CDS (Îą, δ) 🔍 Simbad (Îą, δ)

Overview
ℹī¸
Haffner 21 is a moderately populated, very dense object of very high C3 quality. Its parallax locates it at a moderate distance, above the mid-plane, affected by low extinction. It is catalogued as a near-solar metallicity, intermediate-age cluster (see Parameters). It is well-studied in the literature.

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

Cavallo et al. (2024)
Gold sample.

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

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 1.00 (50th percentile).

Hu et al. (2021)
Ellipticities (core, all): e_core=0.0888, e_all=0.0369.

Rain et al. (2021)
This cluster was include in (Dias et al., 2002A&A...389..871D, Cat. B/ocl) however, parameters log(t)=8.478, Av=0.686, [Fe/H]=0.00 were taken from Bossini et al. (2019A&A...623A.108B, Cat. J/A+A/623/A108). The distance d=2409.5 (dmode+01) of Cantat-Gaudin et al. (2018A&A...618A..93C, Cat. J/A+A18/A93) was use to fit the isochrone.

Data
🔍 Search references for Haffner 21 in: SciX Simbad
ℹī¸
Reference Year RA [deg] DEC [deg] Plx [mas] pmRA [mas/yr] pmDE [mas/yr] Rv [km/s]
UCC 99999– 120.289 -27.212 0.29 -1.429 1.593 –
Li et al. 2025 120.288 -27.212 0.286 -1.432 1.563 –
Almeida et al. 2025 120.29 -27.218 – – – –
Hunt & Reffert 2024 120.29 -27.211 0.282 -1.432 1.6 –
Cavallo et al. 2024 120.294 -27.216 0.283 – – –
Hunt & Reffert 2023 120.29 -27.211 0.282 -1.432 1.6 –
Almeida et al. 2023 120.296 -27.217 – – – –
Just et al. 2023 120.272 -27.21 – – – –
Jaehnig et al. 2021 120.286 -27.209 0.327 -1.434 1.564 –
Rain et al. 2021 120.288 -27.212 0.286 -1.432 1.563 –
Dias et al. 2021 120.29 -27.218 0.283 -1.424 1.566 –
Cantat-Gaudin et al. 2020 120.288 -27.212 0.286 -1.432 1.563 –
Cantat-Gaudin & Anders 2020 120.288 -27.212 0.286 -1.432 1.563 –
Liu & Pang 2019 120.283 -27.205 0.27 -1.719 1.907 –
Bossini et al. 2019 120.288 -27.212 – – – –
Bica et al. 2019 120.288 -27.204 – – – –
Cantat-Gaudin et al. 2018 120.288 -27.212 0.286 -1.432 1.563 –
Loktin & Popova 2017 120.285 -27.216 – -4.942 2.668 –
Sampedro et al. 2017 120.287 -27.217 – -3.35 2.81 –
Kharchenko et al. 2016 120.272 -27.21 – – – –
Dias et al. 2014 120.287 -27.217 – -5.01 3.38 –
Kharchenko et al. 2013 120.277 -27.213 – -4.69 1.62 –
Bukowiecki et al. 2011 120.275 -27.212 – – – –
Ahumada & Lapasset 2007 120.275 -27.217 – – – –
van den Bergh 2006 120.3 -27.167 – – – –
Dias et al. 2002 120.287 -27.217 – -5.01 3.38 –
Lynga 1987 120.289 -27.168 – – – 0.0

💡 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– 2.975 0.66 0.68 301 -0.010 327 0.72 0
Li et al. 2025 2.99 0.80 – 383 0.032 – – –
Almeida et al. 2025 2.74 0.85 – 286 – 327 – –
Hunt & Reffert 2024 2.96 0.44 0.68 301 – 475(1) – –
Cavallo et al. 2024 2.78 0.85 – 372 -0.060 – – –
Hunt & Reffert 2023 2.96 0.44 0.68 301 – – – –
Almeida et al. 2023 2.68 0.37 – 637 -0.020 270(1) 0.72 –
Just et al. 2023 – – – 422 – 160 – –
Jaehnig et al. 2021 3.08(1) – – – – – – –
Rain et al. 2021 3.17 0.69 – 295 – – – 0
Dias et al. 2021 2.74 0.85 – 286 -0.089 – – –
Cantat-Gaudin et al. 2020 3.15 0.59 – 269 – – – –
Kounkel et al. 2020 3.36 0.69 – 275 – – – –
Cantat-Gaudin & Anders 2020 3.17 – – – – – – –
Liu & Pang 2019 – – – 562 0.500 – – –
Bossini et al. 2019 3.05 0.69 – 301 0.000 – – –
Cantat-Gaudin et al. 2018 3.17 – – – – – – –
Loktin & Popova 2017 3.06 0.36 – 86 – – – –
Kharchenko et al. 2016 2.44 0.66 – 422 – – – –
Kharchenko et al. 2013 2.44 0.66 – 422 – – – –
Bukowiecki et al. 2012 – – – – – 4750 – –
Bukowiecki et al. 2011 4.89(1) 1.01 – 141 – – – –
Ahumada & Lapasset 2007 – 0.35 – 83 – – – 0
van den Bergh 2006 2.95 0.35 – 83 – – – –
Dias et al. 2002 2.95 0.33 – 83 – – – –
Lynga 1987 – – – 316 – – – –

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

Visualization
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Haffner 21 UCC
Haffner 21 HUNT23
Haffner 21 CANTAT20
Galactocentric position diagram