UPK 55
0.71
UTI
0.64
CN
0.88
Cdens
0.75
CC3
0.65
Clit
1.0
Cdup
Stellar density (N50/rad)
4.4 [N/pc2]
- CN 0.64 Moderately populated
- Cdens 0.88 Dense
- CC3 0.75 High quality
- Clit 0.65 Moderately studied
- Cdup 1.0 Unique
Overview
UPK 55 is a moderately populated, dense object of high C3 quality. Its parallax locates it at a close distance, below 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 age and metallicity parameters (see Parameters). It is moderately studied in the literature.
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | 99999â | 296.809 | 10.421 | 1.261 | -1.438 | -6.908 | -9.477 |
| Li et al. | 2025 | 296.812 | 10.428 | 1.252 | -1.383 | -6.87 | â |
| Almeida et al. | 2025 | 296.798 | 10.421 | â | â | â | â |
| Alfonso et al. | 2024 | 296.723 | 10.487 | 1.217 | -1.423 | -6.868 | â |
| Hunt & Reffert | 2024 | 296.669 | 10.433 | 1.243 | -1.437 | -6.885 | -15.757 |
| Cavallo et al. | 2024 | 296.799 | 10.451 | 1.248 | â | â | â |
| Hunt & Reffert | 2023 | 296.669 | 10.433 | 1.243 | -1.437 | -6.885 | -15.757 |
| Almeida et al. | 2023 | 296.773 | 10.434 | â | â | â | â |
| Tarricq et al. | 2022 | 296.844 | 10.401 | 1.258 | -1.441 | -6.884 | â |
| Dias et al. | 2021 | 296.798 | 10.421 | 1.253 | -1.386 | -6.86 | â |
| Cantat-Gaudin et al. | 2020 | 296.812 | 10.428 | 1.252 | -1.383 | -6.87 | â |
| Cantat-Gaudin & Anders | 2020 | 296.768 | 10.421 | 1.251 | -1.411 | -6.859 | â |
| Sim et al. | 2019 | 296.7 | 10.463 | â | -1.43 | -6.86 | â |
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 | 0.77 | 0.7 | 1.3 | 235 | 0.042 | 192 | 0.68 | â |
| Li et al. | 2025 | 0.79 | 0.41 | â | 404 | 0.353 | â | â | â |
| Almeida et al. | 2025 | 0.77 | 0.74 | â | 247 | â | 135 | â | â |
| Alfonso et al. | 2024 | 0.77 | 0.54 | â | 223 | 0.042 | â | â | â |
| Hunt & Reffert | 2024 | â | â | â | â | â | 208(1) | â | â |
| Cavallo et al. | 2024 | 0.81 | 0.72 | â | 115 | 0.400 | â | â | â |
| Hunt & Reffert | 2023 | 0.76 | 0.68 | 1.30 | 95 | â | â | â | â |
| Almeida et al. | 2023 | 0.78 | 0.76 | â | 308 | -0.048 | 192(1) | 0.68 | â |
| Tarricq et al. | 2022 | 0.76 | â | â | 251 | â | â | â | â |
| Dias et al. | 2021 | 0.77 | 0.74 | â | 247 | 0.042 | â | â | â |
| Cantat-Gaudin et al. | 2020 | 0.77 | 0.54 | â | 214 | â | â | â | â |
| Cantat-Gaudin & Anders | 2020 | 0.78 | â | â | â | â | â | â | â |
| Sim et al. | 2019 | 0.78 | â | â | 89 | â | â | â | â |
(N): Indicates that there are N extra values assigned to this parameter in the corresponding reference.
MOCA


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