Melotte 22
(Collinder 42; Pleiades; MWSC 305; Messier 45; M45; OCL 421; Escorial 1; OCSN 219)
1.0
UTI
1.0
CN
1.0
Cdens
1.0
CC3
1.0
Clit
1.0
Cdup
Radius (P>50% members)
95.5 [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
Overview
Melotte 22 is a very rich, very dense object of very high C3 quality. Its parallax locates it at a very close distance, near the mid-plane, affected by low extinction. It is catalogued as a massive, near-solar metallicity, intermediate-age cluster, but with a large variance across recent sources for the absorption parameter (see Parameters). It is very well-studied in the literature.
Very close
Low extinction
Massive
Near-solar metallicity
Intermediate age
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | – | 56.6 | 24.114 | 7.361 | 19.904 | -45.35 | 5.491 |
| Almeida et al. | 2025 | 56.647 | 24.099 | – | – | – | – |
| Alfonso et al. | 2024 | 56.608 | 24.102 | 7.322 | 19.92 | -45.402 | – |
| Zhang et al. | 2024 | 56.68 | 24.108 | – | – | – | – |
| Hunt & Reffert | 2024 | 56.68 | 24.108 | 7.378 | 19.955 | -45.457 | 5.343 |
| Cavallo et al. | 2024 | 56.601 | 24.191 | 7.373 | – | – | – |
| Hunt & Reffert | 2023 | 56.68 | 24.108 | 7.378 | 19.955 | -45.457 | 5.343 |
| Cordoni et al. | 2023 | 56.647 | 24.099 | 7.352 | 19.954 | -45.511 | – |
| Qin et al. | 2023 | 56.7 | 24.08 | 7.36 | 19.95 | -45.35 | 5.66 |
| Just et al. | 2023 | 56.497 | 24.369 | – | – | – | – |
| He et al. | 2022 | 56.606 | 24.145 | 7.365 | 19.995 | -45.434 | – |
| Tarricq et al. | 2022 | 56.742 | 24.093 | 7.354 | 19.959 | -45.398 | – |
| Jaehnig et al. | 2021 | 56.557 | 24.086 | 7.368 | 20.03 | -45.452 | – |
| Rain et al. | 2021 | 56.601 | 24.114 | 7.346 | 20.077 | -45.503 | – |
| Dias et al. | 2021 | 56.647 | 24.099 | 7.352 | 19.954 | -45.511 | 5.792 |
| Cantat-Gaudin et al. | 2020 | 56.601 | 24.114 | 7.346 | 20.077 | -45.503 | – |
| Donor et al. | 2020 | 56.505 | 24.37 | – | 20.35 | -44.59 | 6.1 |
| Bossini et al. | 2019 | 56.601 | 24.114 | – | – | – | – |
| Soubiran et al. | 2018 | 56.601 | 24.114 | – | – | – | 5.92 |
| Bica et al. | 2019 | 56.743 | 24.124 | – | – | – | – |
| Cantat-Gaudin et al. | 2018 | 56.601 | 24.114 | 7.346 | 20.077 | -45.503 | – |
| Yen et al. | 2018 | 56.57 | 24.224 | 7.38 | 19.92 | -45.2 | – |
| Loktin & Popova | 2017 | 56.745 | 24.117 | – | 19.85 | -44.81 | 5.5 |
| Kharchenko et al. | 2016 | 56.497 | 24.369 | – | – | – | – |
| Kharchenko et al. | 2013 | 56.505 | 24.37 | – | 19.4 | -46.0 | 5.5 |
| Kharchenko et al. | 2012 | 56.505 | 24.37 | – | 19.4 | -46.0 | 5.9 |
| Piskunov et al. | 2008 | 56.832 | 24.118 | – | – | – | – |
| Kharchenko et al. | 2007 | 56.74 | 24.12 | – | 6.4 | – | 5.9 |
| Piskunov et al. | 2007 | 56.832 | 24.118 | – | – | – | – |
| Kharchenko et al. | 2005 | 56.83 | 24.12 | – | 19.33 | -45.0 | 5.41 |
| Kharchenko et al. | 2003 | 56.83 | 24.12 | – | 19.44 | -44.41 | – |
| Chen et al. | 2003 | 56.75 | 24.118 | – | 19.15 | -45.72 | 5.6 |
| Dias et al. | 2002 | 56.75 | 24.117 | – | 19.88 | -45.0 | 5.94 |
| Dambis | 1999 | 56.75 | 24.117 | – | – | – | – |
💡 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 |
|---|---|---|---|---|---|---|---|---|---|
| Almeida et al. | 2025 | 0.14 | 0.17 | – | 131 | – | 653 | – | – |
| Alfonso et al. | 2024 | 0.13 | 0.17 | – | 103 | 0.029 | – | – | – |
| Zhang et al. | 2024 | – | – | – | – | -0.000* | – | – | – |
| Hunt & Reffert | 2024 | – | – | – | – | – | 947* | – | – |
| Cavallo et al. | 2024 | 0.14 | 0.67 | – | 87 | 0.100 | – | – | – |
| Hunt & Reffert | 2023 | 0.13 | 0.10 | 0.63 | 122 | – | – | – | – |
| Cordoni et al. | 2023 | 0.14 | 0.17 | – | 131 | 0.032 | 936 | 0.15 | 0.00 |
| Qin et al. | 2023 | 0.15 | 0.25 | – | 100 | – | – | – | – |
| Just et al. | 2023 | – | – | – | 141 | – | 1452 | – | – |
| He et al. | 2022 | – | 0.55 | – | 141 | – | – | – | – |
| Tarricq et al. | 2022 | 0.13 | – | – | 79 | – | – | – | – |
| Jaehnig et al. | 2021 | 0.14* | – | – | – | – | – | – | – |
| Rain et al. | 2021 | 0.14 | 0.09 | – | 135 | – | – | – | 0 |
| Dias et al. | 2021 | 0.14 | 0.17 | – | 131 | 0.032 | – | – | – |
| Cantat-Gaudin et al. | 2020 | 0.13 | 0.18 | – | 78 | – | – | – | – |
| Donor et al. | 2020 | – | – | – | – | 0.000 | – | – | – |
| Bossini et al. | 2019 | 0.14 | 0.14 | – | 86 | 0.000 | – | – | – |
| Soubiran et al. | 2018 | 0.14 | – | – | – | – | – | – | – |
| Cantat-Gaudin et al. | 2018 | 0.14 | – | – | – | – | – | – | – |
| Yen et al. | 2018 | 0.13 | 0.03 | – | 141 | – | – | – | – |
| Loktin & Popova | 2017 | 0.15 | 0.09 | – | 135 | – | – | – | – |
| Kharchenko et al. | 2016 | 0.13 | 0.07 | – | 141 | – | – | – | – |
| Kharchenko et al. | 2013 | 0.13 | 0.07 | – | 141 | -0.036 | – | – | – |
| Kharchenko et al. | 2012 | 0.13 | 0.07 | – | 141 | -0.030 | – | – | – |
| Piskunov et al. | 2008 | 0.13 | 0.06 | – | 120 | – | 3467* | – | – |
| Piskunov et al. | 2007 | 0.13 | 0.06 | – | 120 | – | 3105 | – | – |
| Kharchenko et al. | 2005 | 0.13 | 0.06 | – | 120 | – | – | – | – |
| Kharchenko et al. | 2003 | 0.12 | 0.06 | – | – | – | – | – | – |
| Chen et al. | 2003 | 0.15 | 0.09 | – | 130 | -0.030* | – | – | – |
| Dias et al. | 2002 | 0.13 | 0.09 | – | 135 | -0.030 | – | – | – |
| Dambis | 1999 | 0.12 | 0.12 | – | 112 | – | – | – | – |
💡 Note: The parameters are sometimes
transformed from their original values to match the format of the
columns shown here, see FAQ.
The columns DAv, Bfr, BSS correspond to differential
extinction, binary fraction, and blue stragglers, respectively.
BSS values can be listed as fractions or integers.
(*): indicates that this parameter is
assigned more than one value in the corresponding reference.
Almeida et al. (2025): Mass determination: good fit. Isochrone match: good fit. Silver sample.
Cavallo et al. (2024): Gold sample.