Melotte 27
(Collinder 56; NGC 1664; MWSC 430; OCL 411; FoF 1365)
0.95
UTI
1.0
CN
1.0
Cdens
0.75
CC3
1.0
Clit
1.0
Cdup
Stellar density (N50/rad)
48.2 [N/pc2]
- CN 1.0 Very rich
- Cdens 1.0 Very dense
- CC3 0.75 High quality
- Clit 1.0 Very well-studied
- Cdup 1.0 Unique
Overview
Melotte 27 is a very rich, very dense object of high C3 quality. Its parallax locates it at a relatively close distance, near the mid-plane, affected by low 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.
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | 99999â | 72.755 | 43.666 | 0.738 | 1.607 | -5.788 | 2.289 |
| Li et al. | 2025 | 72.763 | 43.676 | 0.734 | 1.703 | -5.738 | â |
| Hu & Soubiran | 2025 | 72.755 | 43.677 | â | â | â | â |
| Wei et al. | 2025 | 72.752 | 43.673 | 0.736 | 1.597 | -5.808 | â |
| Almeida et al. | 2025 | 72.754 | 43.674 | â | â | â | â |
| Zhang et al. | 2024 | 72.766 | 43.675 | â | â | â | â |
| Hunt & Reffert | 2024 | 72.766 | 43.675 | 0.736 | 1.608 | -5.803 | 4.112 |
| Cavallo et al. | 2024 | 72.755 | 43.677 | 0.734 | â | â | â |
| Hunt & Reffert | 2023 | 72.766 | 43.675 | 0.736 | 1.608 | -5.803 | 4.112 |
| Almeida et al. | 2023 | 72.743 | 43.673 | â | â | â | â |
| Cordoni et al. | 2023 | 72.754 | 43.674 | 0.733 | 1.727 | -5.72 | â |
| Just et al. | 2023 | 72.798 | 43.66 | â | â | â | â |
| Tarricq et al. | 2022 | 72.769 | 43.685 | 0.749 | 1.615 | -5.799 | â |
| Jaehnig et al. | 2021 | 72.755 | 43.676 | 0.76 | 1.695 | -5.715 | â |
| Rain et al. | 2021 | 72.763 | 43.676 | 0.734 | 1.703 | -5.738 | â |
| Dias et al. | 2021 | 72.754 | 43.674 | 0.733 | 1.727 | -5.72 | 6.308 |
| Cantat-Gaudin et al. | 2020 | 72.763 | 43.676 | 0.734 | 1.703 | -5.738 | â |
| Donor et al. | 2020 | 72.808 | 43.66 | â | 1.84 | -5.76 | 7.0 |
| Cantat-Gaudin & Anders | 2020 | 72.763 | 43.676 | 0.734 | 1.703 | -5.738 | â |
| Liu & Pang | 2019 | 72.765 | 43.674 | 0.737 | 1.733 | -5.701 | â |
| Bossini et al. | 2019 | 72.763 | 43.676 | â | â | â | â |
| Soubiran et al. | 2018 | 72.763 | 43.676 | â | â | â | 6.38 |
| Bica et al. | 2019 | 72.775 | 43.684 | â | â | â | â |
| Cantat-Gaudin et al. | 2018 | 72.763 | 43.676 | 0.734 | 1.703 | -5.738 | â |
| Loktin & Popova | 2017 | 72.78 | 43.676 | â | -4.594 | -3.24 | 36.1 |
| Kharchenko et al. | 2016 | 72.798 | 43.66 | â | â | â | â |
| Dias et al. | 2014 | 72.775 | 43.675 | â | -1.83 | -4.15 | â |
| Kharchenko et al. | 2013 | 72.808 | 43.66 | â | -4.23 | -4.2 | 36.1 |
| Gozha et al. | 2012 | 72.775 | 43.675 | â | â | â | â |
| Kharchenko et al. | 2012 | 72.808 | 43.66 | â | -4.4 | -4.6 | 36.1 |
| Piskunov et al. | 2008 | 72.782 | 43.662 | â | â | â | â |
| Kharchenko et al. | 2007 | 72.78 | 43.67 | â | 0.33 | â | 36.1 |
| Piskunov et al. | 2007 | 72.782 | 43.662 | â | â | â | â |
| van den Bergh | 2006 | 72.8 | 43.667 | â | â | â | â |
| Kharchenko et al. | 2005 | 72.79 | 43.66 | â | -2.54 | -6.21 | 36.1 |
| Kharchenko et al. | 2003 | 72.78 | 43.7 | â | -2.44 | -5.86 | â |
| Chen et al. | 2003 | 72.738 | 43.623 | â | 1.96 | -5.1 | 7.8 |
| Dias et al. | 2002 | 72.775 | 43.675 | â | 1.96 | -5.1 | 7.5 |
đĄ 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 | 99999â | 1.23 | 0.78 | 0.52 | 525 | -0.009 | 912 | 0.41 | 0.0 |
| Li et al. | 2025 | 1.26 | 0.82 | â | 604 | -0.037 | â | â | â |
| Hu & Soubiran | 2025 | â | â | â | â | -0.110(5) | â | â | â |
| Wei et al. | 2025 | 1.95 | 0.80 | â | 501 | 0.500 | 1133 | 0.33 | â |
| Almeida et al. | 2025 | 1.22 | 0.87 | â | 643 | â | 968 | â | â |
| Zhang et al. | 2024 | â | â | â | â | -0.092(1) | â | â | â |
| Hunt & Reffert | 2024 | â | â | â | â | â | 1822(1) | â | â |
| Cavallo et al. | 2024 | 1.37 | 0.72 | â | 661 | 0.370 | â | â | â |
| Hunt & Reffert | 2023 | 1.27 | 0.72 | 0.52 | 340 | â | â | â | â |
| Almeida et al. | 2023 | 1.28 | 0.92 | â | 555 | -0.005 | 778(1) | 0.43 | â |
| Cordoni et al. | 2023 | 1.22 | 0.87 | â | 643 | -0.009 | 1191 | 0.41 | 0.00 |
| Just et al. | 2023 | â | â | â | 562 | â | 207 | â | â |
| Tarricq et al. | 2022 | 1.30 | â | â | 525 | â | â | â | â |
| Jaehnig et al. | 2021 | 1.31(1) | â | â | â | â | â | â | â |
| Rain et al. | 2021 | 1.31 | 0.78 | â | 288 | â | â | â | 0 |
| Dias et al. | 2021 | 1.22 | 0.87 | â | 643 | -0.009 | â | â | â |
| Cantat-Gaudin et al. | 2020 | 1.34 | 0.69 | â | 513 | â | â | â | â |
| Donor et al. | 2020 | â | â | â | â | -0.030 | â | â | â |
| Cantat-Gaudin & Anders | 2020 | 1.31 | â | â | â | â | â | â | â |
| Liu & Pang | 2019 | â | â | â | 372 | 0.250 | â | â | â |
| Bossini et al. | 2019 | 1.33 | 0.71 | â | 471 | 0.000 | â | â | â |
| Soubiran et al. | 2018 | 1.31 | â | â | â | â | â | â | â |
| Cantat-Gaudin et al. | 2018 | 1.31 | â | â | â | â | â | â | â |
| Loktin & Popova | 2017 | 1.24 | 0.80 | â | 289 | â | â | â | â |
| Kharchenko et al. | 2016 | 1.20 | 0.78 | â | 562 | â | â | â | â |
| Kharchenko et al. | 2013 | 1.20 | 0.78 | â | 562 | â | â | â | â |
| Gozha et al. | 2012 | 1.20 | â | â | 292 | â | 912 | â | â |
| Kharchenko et al. | 2012 | 1.20 | 0.78 | â | 550 | â | â | â | â |
| Piskunov et al. | 2008 | 1.20 | 0.78 | â | 525 | â | 640(1) | â | â |
| Piskunov et al. | 2007 | 1.20 | 0.78 | â | 525 | â | 192 | â | â |
| van den Bergh | 2006 | 1.20 | 0.78 | â | 288 | â | â | â | â |
| Kharchenko et al. | 2005 | 1.20 | 0.78 | â | 525 | â | â | â | â |
| Kharchenko et al. | 2003 | 1.20 | 0.78 | â | â | â | â | â | â |
| Chen et al. | 2003 | 1.20 | â | â | 290 | â | â | â | â |
| Dias et al. | 2002 | 1.20 | 0.79 | â | 292 | â | â | â | â |
(N): Indicates that there are N extra values assigned to this parameter in the corresponding reference.
MOCA


Almeida et al. (2025)
Mass determination: good fit. Isochrone match: good fit. Gold sample.
Cavallo et al. (2024)
Gold sample.