Melotte 66

(Collinder 147; MWSC 1222; OCL 739; ESO 208 12; FSR 1396; FoF 4)

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1.0 UTI
1.0
CN
1.0
Cdens
1.0
CC3
1.0
Clit
1.0
Cdup
C3 classification AA
Number of members (P>50%) 1800
Radius (P>50% members) 5.2 [arcmin]
  • 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
πŸ“₯ Members πŸ“Š Colab πŸ”¬ Bayestar19 πŸ” CDS πŸ” Simbad πŸ” CDS (Ξ±, Ξ΄) πŸ” Simbad (Ξ±, Ξ΄)

Overview
ℹ️
Melotte 66 is a very rich, very dense object of very high C3 quality. Its parallax locates it at a large distance, well below the mid-plane, affected by low extinction. It is catalogued as a very massive, near-solar metallicity, old cluster (see Parameters). It is very well-studied in the literature.

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

Distant Low extinction Very massive Near-solar metallicity Old

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

Cavallo et al. (2024)
Gold sample.

Rain et al. (2024)
BSSs appear in two distinct, parallel sequences, both well aligned with binary evolution tracks of different donor masses. This resembles double BSS sequences seen in other clusters. Existing evidence suggests mass transfer may contribute to both sequences, but the detailed origin remains uncertain.

Data
πŸ” Search references for Melotte 66 in: SciX Simbad
ℹ️
Reference Year RA [deg] DEC [deg] Plx [mas] pmRA [mas/yr] pmDE [mas/yr] Rv [km/s]
UCC – 111.581 -47.684 0.193 -1.431 2.772 21.659
Li et al. 2025 111.573 -47.685 0.183 -1.474 2.745 –
Hu & Soubiran 2025 111.577 -47.684 – – – –
Carrasco-Varela et al. 2025 111.701 -47.749 – – – –
Almeida et al. 2025 111.567 -47.682 – – – –
Hunt & Reffert 2024 111.583 -47.693 0.195 -1.435 2.775 21.411
Cavallo et al. 2024 111.577 -47.684 0.193 – – –
Hunt & Reffert 2023 111.583 -47.693 0.195 -1.435 2.775 21.411
Just et al. 2023 111.547 -47.666 – – – –
Jaehnig et al. 2021 111.572 -47.682 0.211 -1.486 2.739 –
Rain et al. 2021 111.573 -47.685 0.183 -1.474 2.745 –
Dias et al. 2021 111.567 -47.682 0.189 -1.485 2.735 18.295
Cantat-Gaudin et al. 2020 111.573 -47.685 0.183 -1.474 2.745 –
SΓ‘nchez et al. 2020 111.596 -47.667 – -1.273 2.531 –
Cantat-Gaudin & Anders 2020 111.573 -47.685 0.183 -1.474 2.745 –
Liu & Pang 2019 111.558 -47.694 0.258 -1.476 2.74 –
Soubiran et al. 2018 111.573 -47.685 – – – 21.94
Bica et al. 2019 111.601 -47.666 – – – –
Cantat-Gaudin et al. 2018 111.573 -47.685 0.183 -1.474 2.745 –
Loktin & Popova 2017 111.555 -47.666 – -5.385 3.903 23.5
Kharchenko et al. 2016 111.547 -47.666 – – – –
Dias et al. 2014 111.596 -47.667 – -3.09 3.26 –
Kharchenko et al. 2013 111.55 -47.668 – -4.37 6.78 23.5
Gozha et al. 2012 111.596 -47.667 – – – –
Kharchenko et al. 2007 111.6 -47.67 – 0.12 – –
van den Bergh 2006 111.596 -47.667 – – – –
Chen et al. 2003 111.595 -47.657 – – – –
Dias et al. 2002 111.596 -47.667 – -3.09 3.26 22.1

πŸ’‘ 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
Li et al. 2025 4.76 0.59 – 3790 -0.366 – – –
Hu & Soubiran 2025 – – – – -0.400* – – –
Carrasco-Varela et al. 2025 4.69 0.58 – 4487 -0.400 – – 0.10*
Almeida et al. 2025 4.69 0.58 – 4487 – 8876 – –
Hunt & Reffert 2024 – – – – – 5794* – –
Cavallo et al. 2024 3.70 0.66 – 7244 -0.630 – – –
Hunt & Reffert 2023 4.70 0.21 1.05 2472 – – – –
Just et al. 2023 – – – 2317 – 3828 – –
Jaehnig et al. 2021 4.78* – – – – – – –
Rain et al. 2021 4.72 0.46 – 3388 – – – 14
Dias et al. 2021 4.69 0.58 – 4487 -0.325 – – –
Cantat-Gaudin et al. 2020 4.83 0.25 – 4266 – – – –
Cantat-Gaudin & Anders 2020 4.72 – – – – – – –
Liu & Pang 2019 – – – 2690 0.000 – – –
Soubiran et al. 2018 4.72 – – – – – – –
Cantat-Gaudin et al. 2018 4.72 – – – – – – –
Loktin & Popova 2017 4.30 0.44 – 2897 – – – –
Kharchenko et al. 2016 4.49 0.39 – 2317 – – – –
Kharchenko et al. 2013 4.49 0.39 – 2317 -0.330 – – –
Gozha et al. 2012 4.31 – – 2786 -0.330 – – –
van den Bergh 2006 4.31 0.43 – 2754 – – – –
Chen et al. 2003 4.31 0.44 – 2780 -0.350* – – –
Dias et al. 2002 4.70 0.46 – 3388 -0.330 – – –

(*): Indicates that this parameter is assigned more than one value in the corresponding reference.

Cluster % RA DEC Plx pmRA pmDE Rv UTI
OC 0462 1.4 111.58 -47.71 0.26 -1.42 2.77 22.1 0.0

πŸ’‘ Note: The % column shows the percentage of members that Melotte 66 shares with each listed object.

Visualization
ℹ️
Melotte 66 UCC
Melotte 66 HUNT23
Melotte 66 CANTAT20
Galactocentric position diagram