NGC 5999

(Melotte 137; Collinder 293; VDBH 178; MWSC 2326; OCL 946; vdBergh-Hagen 178; ESO 178 01; FSR 1706)

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0.95 UTI
0.9
CN
1.0
Cdens
1.0
CC3
0.94
Clit
1.0
Cdup
N50 (P>50% members) 495
Stellar density (N50/rad) 72.6 [N/pc2]
C3 classification AA
  • CN 0.9 Very rich
  • Cdens 1.0 Very dense
  • CC3 1.0 Very high quality
  • Clit 0.94 Very well-studied
  • Cdup 1.0 Unique
đŸ“Ĩ Members 📊 Colab đŸ”Ŧ Bayestar19 MOCAMOCA 🔍 CDS 🔍 Simbad 🔍 CDS (Îą, δ) 🔍 Simbad (Îą, δ)

Overview
ℹī¸
NGC 5999 is a very rich, very dense object of very high C3 quality. Its parallax locates it at a moderate distance, below the mid-plane, affected by moderate extinction. It is catalogued as a massive, near-solar metallicity, intermediate-age cluster, but with a large variance across recent sources for the age 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.

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

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).

Ahumada & Lapasset (2007)
All the cluster parameters except the apparent diameter are from (2005, unpublished data). The diagram up to 2.5' from the cluster centre was examined.

Data
🔍 Search references for NGC 5999 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– 238.045 -56.483 0.345 -3.411 -4.22 -31.119
Li et al. 2025 238.046 -56.482 0.326 -3.389 -4.216 –
Almeida et al. 2025 238.047 -56.482 – – – –
Hunt & Reffert 2024 238.044 -56.479 0.349 -3.421 -4.211 -33.152
Cavallo et al. 2024 238.049 -56.486 0.348 – – –
Hunt & Reffert 2023 238.044 -56.479 0.349 -3.421 -4.211 -33.152
Almeida et al. 2023 238.048 -56.484 – – – –
Just et al. 2023 238.031 -56.466 – – – –
Jaehnig et al. 2021 238.054 -56.481 0.36 -3.372 -4.226 –
Rain et al. 2021 238.046 -56.482 0.326 -3.389 -4.216 –
Dias et al. 2021 238.047 -56.482 0.329 -3.389 -4.21 -30.883
Cantat-Gaudin et al. 2020 238.046 -56.482 0.326 -3.389 -4.216 –
Cantat-Gaudin & Anders 2020 238.046 -56.482 0.326 -3.389 -4.216 –
Soubiran et al. 2018 238.046 -56.482 – – – -30.78
Bica et al. 2019 238.03 -56.468 – – – –
Ferreira et al. 2019 238.047 -56.488 – -3.374 -4.216 –
Cantat-Gaudin et al. 2018 238.046 -56.482 0.326 -3.389 -4.216 –
Dias et al. 2018 – – – -3.15 -4.08 –
Dib et al. 2018 238.042 -56.467 – – – –
Sampedro et al. 2017 238.033 -56.473 -1.47 -3.25 – –
Joshi et al. 2016 238.042 -56.467 – – – –
Kharchenko et al. 2016 238.031 -56.466 – – – –
Netopil et al. 2016 238.043 -56.467 – – – –
Dias et al. 2014 238.033 -56.473 – -0.72 -2.79 –
Kharchenko et al. 2013 238.042 -56.467 – 0.8 0.25 –
Ahumada & Lapasset 2007 238.05 -56.483 – – – –
van den Bergh 2006 238.05 -56.467 – – – –
Dias et al. 2002 238.033 -56.473 – -0.72 -2.74 –
Lynga 1987 238.056 -56.47 – – – –
van den Bergh & Hagen 1975 237.05 -56.317 – – – –
Sulentic et al. 1973 238.048 -56.491 – – – –

💡 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– 2.29 1.545 1.39 398 0.070 1144 0.6 2
Li et al. 2025 2.24 1.59 – 468 0.061 – – –
Almeida et al. 2025 2.19 1.87 – 196 – 1086 – –
Hunt & Reffert 2024 – – – – – 4448(1) – –
Cavallo et al. 2024 2.42 2.12 – 219 0.140 – – –
Hunt & Reffert 2023 2.56 1.78 1.39 137 – – – –
Almeida et al. 2023 2.29 1.94 – 163 0.135 1203(1) 0.60 –
Just et al. 2023 – – – 398 – 102 – –
Jaehnig et al. 2021 2.80(1) – – – – – – –
Rain et al. 2021 2.81 1.42 – 398 – – – 0
Dias et al. 2021 2.19 1.87 – 196 0.079 – – –
Cantat-Gaudin et al. 2020 2.75 1.40 – 200 – – – –
Kounkel et al. 2020 2.81 1.50 – 347 – – – –
Cantat-Gaudin & Anders 2020 2.81 – – – – – – –
Soubiran et al. 2018 2.81 – – – – – – –
Ferreira et al. 2019 1.82 2.02 – 316 -0.200 – – –
Cantat-Gaudin et al. 2018 2.81 – – – – – – –
Dib et al. 2018 1.63 – – 398 – – – –
Joshi et al. 2016 1.63 1.38 – 398 – – – –
Kharchenko et al. 2016 1.63 1.38 – 398 – – – –
Netopil et al. 2016 6.39 – – 400 – – – –
Kharchenko et al. 2013 1.63 1.38 – 398 – – – –
Ahumada & Lapasset 2007 – 1.96 – 251 – – – 4
van den Bergh 2006 2.05 1.42 – 398 – – – –
Dias et al. 2002 2.05 1.42 – 398 0.000 – – –

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

Visualization
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NGC 5999 UCC
NGC 5999 HUNT23
NGC 5999 CANTAT20
Galactocentric position diagram