UBC 321
0.64
UTI
0.81
CN
1.0
Cdens
1.0
CC3
0.19
Clit
1.0
Cdup
Nm (P>50%)
266
Core radius and density
1.5 [pc], 12 [pc-2]
- CN 0.81 Rich
- Cdens 1.0 Very dense
- CC3 1.0 Very high quality
- Clit 0.19 Rarely studied
- Cdup 1.0 Unique
đĨ Members
đ Colab
đŦ Bayestar19
MOCA
đ CDS
đ Simbad
đ CDS (Îą, δ)
đ Simbad (Îą, δ)
MOCA
đ CDS
đ Simbad
đ CDS (Îą, δ)
đ Simbad (Îą, δ)
Overview
UBC 321 is a rich, very dense object of very high C3 quality. Its parallax locates it at a moderate distance, near the mid-plane, affected by moderate extinction. It is catalogued as a massive, near-solar metallicity, old cluster, but with a large variance across recent sources for the age parameter (see Parameters). It is rarely studied in the literature.
Note: This object contains blue stragglers according to at least one source.
Note: This object shares a large percentage of members with a later reported entry. See table with shared members information.
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | 99999â | 251.893 | -44.539 | 0.39 | -1.594 | -3.142 | -19.858 |
| Hu & Soubiran | 2025 | 251.894 | -44.53 | â | â | â | â |
| Hunt & Reffert | 2024 | 251.893 | -44.535 | 0.39 | -1.593 | -3.125 | -15.861 |
| Cavallo et al. | 2024 | 251.894 | -44.53 | 0.392 | â | â | â |
| Hunt & Reffert | 2023 | 251.893 | -44.535 | 0.39 | -1.593 | -3.125 | -15.861 |
| Jadhav & Subramaniam | 2021 | 251.906 | -44.536 | â | â | â | â |
| Cantat-Gaudin et al. | 2020 | 251.906 | -44.536 | 0.368 | -1.556 | -3.117 | â |
| Castro-Ginard et al. | 2020 | 251.909 | -44.53 | 0.369 | -1.545 | -3.116 | 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 | 2.395 | 2.975 | 1.97 | 1005 | -0.305 | 2432 | â | 2 |
| Hu & Soubiran | 2025 | â | â | â | â | -0.290(5) | â | â | â |
| Hunt & Reffert | 2024 | 2.38 | 3.19 | 1.97 | 206 | â | 3142(1) | â | â |
| Cavallo et al. | 2024 | 1.56 | 2.83 | â | 1905 | -0.320 | â | â | â |
| Hunt & Reffert | 2023 | 2.38 | 3.19 | 1.97 | 206 | â | â | â | â |
| Jadhav & Subramaniam | 2021 | 2.41 | 2.00 | â | 1318 | â | 1722 | â | 2(1) |
| Cantat-Gaudin et al. | 2020 | 2.41 | 2.00 | â | 1318 | â | â | â | â |
| Kounkel et al. | 2020 | 2.80 | 3.12 | â | 692 | â | â | â | â |
(N): Indicates that there are N extra values assigned to this parameter in the corresponding reference.
Palma et al. (2025)
Part of multiple system G255, along with UBC_1557, UBC_550 and UBC_1558.
Cavallo et al. (2024)
Gold sample.
Hunt & Reffert (2024)
Classified as open cluster. CMD class: 0.81 (50th percentile).
Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.81 (50th percentile).