Melotte 186

(Collinder 359; MWSC 2773; OCL 84; Bull of Poniatowski)

Click to load Aladin Lite
0.79 UTI
0.62
CN
0.35
Cdens
1.0
CC3
1.0
Clit
1.0
Cdup
Nm (P>50%) 75
Core radius and density 1.4 [pc], 1.7 [pc-2]
C3 classification AA
  • CN 0.62 Moderately populated
  • Cdens 0.35 Loose
  • 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
ℹī¸
Melotte 186 is a moderately populated, loose object of very high C3 quality. Its parallax locates it at a close distance, above the mid-plane, affected by low extinction. It is catalogued as a massive, near-solar metallicity, young cluster, but with a large variance across recent sources for the age parameter (see Parameters). It is very well-studied in the literature.

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

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=0.2906, e_all=0.0523.

Data
🔍 Search references for Melotte 186 in: SciX Simbad
ℹī¸
Reference Year RA [deg] DEC [deg] Plx [mas] pmRA [mas/yr] pmDE [mas/yr] Rv [km/s]
UCC 99999– 270.414 3.165 1.794 0.648 -8.828 -7.422
Li et al. 2025 270.598 3.26 1.786 0.637 -8.668 –
Almeida et al. 2025 270.987 3.354 – – – –
Alfonso et al. 2024 270.404 3.327 1.782 0.612 -8.815 –
Zhang et al. 2024 270.318 3.193 – – – –
Swiggum et al. 2024 270.318 3.193 1.812 0.606 -8.818 -7.637
Hunt & Reffert 2024 270.318 3.193 1.812 0.606 -8.818 -9.435
Cavallo et al. 2024 270.349 3.479 1.81 – – –
Hunt & Reffert 2023 270.318 3.193 1.812 0.606 -8.818 -9.435
Just et al. 2023 270.113 2.874 – – – –
He et al. 2022 270.372 3.011 1.8 0.655 -8.862 –
Dias et al. 2021 270.987 3.354 1.787 0.659 -8.659 8.441
Spina et al. 2021 270.595 3.286 1.795 0.643 -8.658 –
Cantat-Gaudin et al. 2020 270.598 3.26 1.786 0.637 -8.668 –
Zhong et al. 2020 270.598 3.26 – 0.637 -8.668 -0.195
Cantat-Gaudin & Anders 2020 270.598 3.26 1.786 0.637 -8.668 –
Dias et al. 2019 180.6 3.26 1.786 0.637 -8.668 -3.243
Soubiran et al. 2018 270.598 3.26 – – – 5.28
Bica et al. 2019 270.277 2.888 – – – –
Cantat-Gaudin et al. 2018 270.598 3.26 1.786 0.637 -8.668 –
Dib et al. 2018 270.12 2.875 – – – –
Loktin & Popova 2017 270.27 2.9 – 0.47 9.1 -4.6
Joshi et al. 2016 270.12 2.875 – – – –
Kharchenko et al. 2016 270.113 2.874 – – – –
Dias et al. 2014 270.275 2.9 – 0.47 -2.84 –
Kharchenko et al. 2013 270.12 2.875 – 0.22 -8.9 -4.6
Gozha et al. 2012 270.275 2.9 – – – –
Piskunov et al. 2008 270.161 2.926 – – – –
Kharchenko et al. 2007 270.27 2.9 – 1.1 – -4.57
Piskunov et al. 2007 270.161 2.926 – – – –
van den Bergh 2006 270.15 2.933 – – – –
Kharchenko et al. 2005 270.16 2.93 – 0.22 -8.9 -4.45
Kharchenko et al. 2003 270.16 2.93 – -0.44 -7.61 –
Dias et al. 2002 270.275 2.9 – 0.47 -9.1 -5.37
Dambis 1999 270.275 2.9 – – – –
Lynga 1987 270.255 2.911 – – – –

💡 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– 0.55 0.505 0.67 28 0.047 2297 – –
Li et al. 2025 0.53 0.56 – 24 0.047 – – –
Almeida et al. 2025 0.55 0.57 – 55 – 686 – –
Alfonso et al. 2024 0.55 0.51 – 28 0.186 – – –
Zhang et al. 2024 – – – – -0.040(1) – – –
Swiggum et al. 2024 0.54 – – 14 – 648 – –
Hunt & Reffert 2024 0.53 0.41 0.67 14 – 181(1) – –
Cavallo et al. 2024 0.57 0.91 – 8 -0.100 – – –
Hunt & Reffert 2023 0.53 0.41 0.67 14 – – – –
Just et al. 2023 – – – 28 – 179 – –
He et al. 2022 – 0.85 – 18 – – – –
Spina et al. 2022 – – – – -0.031 – – –
Dias et al. 2021 0.55 0.57 – 55 0.186 – – –
Spina et al. 2021 0.56 – – 37 -0.034(20) – – –
Cantat-Gaudin et al. 2020 0.55 0.51 – 37 – – – –
Kounkel et al. 2020 0.57 0.75 – 37 – – – –
Zhong et al. 2020 0.55(1) 0.50 – 7450 0.048 – – –
Cantat-Gaudin & Anders 2020 0.55 – – – – – – –
Dias et al. 2019 0.60 0.50 – 37 0.250 – – –
Soubiran et al. 2018 0.55 – – – – – – –
Cantat-Gaudin et al. 2018 0.55 – – – – – – –
Dib et al. 2018 0.64 – – 28 – – – –
Loktin & Popova 2017 0.25 0.61 – 32 – – – –
Joshi et al. 2016 0.64 0.50 – 28 – 7413 – –
Kharchenko et al. 2016 0.64 0.50 – 28 – – – –
Kharchenko et al. 2013 0.64 0.50 – 28 – – – –
Gozha et al. 2012 0.25 – – 32 – 7413 – –
Piskunov et al. 2008 0.64 0.50 – 28 – 8790(1) – –
Piskunov et al. 2007 0.64 0.50 – 28 – 3908 – –
van den Bergh 2006 0.25 0.60 – 32 – – – –
Kharchenko et al. 2005 0.64 0.50 – 28 – – – –
Kharchenko et al. 2003 0.25 0.47 – – – – – –
Dias et al. 2002 0.25 0.61 – 32 – – – –
Dambis 1999 0.31 0.66 – 16 – – – –
Lynga 1987 0.20 0.00 – – – – – –

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

Cluster % RA DEC Plx pmRA pmDE Rv UTI
CWWDL 14664 72.0 270.36 3.03 1.79 0.64 -8.88 -7.34 0.13
HSC 297 5.3 270.7 2.76 1.94 0.42 -8.66 -4.84 0.11

💡 Note: The % column shows the percentage of members that Melotte 186 shares with each listed object.

Visualization
ℹī¸
Melotte 186 UCC
Melotte 186 HUNT23
Melotte 186 CANTAT20
Galactocentric position diagram