UBC 640
0.50
UTI
0.39
CN
0.62
Cdens
0.75
CC3
0.38
Clit
1.0
Cdup
Radius (P>50% members)
2.2 [arcmin]
- CN 0.39 Poorly populated
- Cdens 0.62 Moderately dense
- CC3 0.75 High quality
- Clit 0.38 Poorly studied
- Cdup 1.0 Unique
Overview
UBC 640 is a poorly populated, moderately dense object of high C3 quality. Its parallax locates it at a large distance, above the mid-plane, affected by low extinction. It is catalogued as a near-solar metallicity, young cluster, but with a large variance across recent sources for the metallicity parameter (see Parameters). It is poorly studied in the literature.
Distant
Low extinction
Near-solar metallicity
Young
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | â | 120.607 | -27.849 | 0.18 | -2.496 | 3.141 | â |
| Li et al. | 2025 | 120.586 | -27.873 | 0.185 | -2.483 | 3.152 | â |
| Hunt & Reffert | 2024 | 120.624 | -27.83 | 0.186 | -2.496 | 3.148 | â |
| Cavallo et al. | 2024 | 120.601 | -27.853 | 0.185 | â | â | â |
| Hunt & Reffert | 2023 | 120.624 | -27.83 | 0.186 | -2.496 | 3.148 | â |
| Cantat-Gaudin et al. | 2020 | 120.586 | -27.873 | 0.185 | -2.483 | 3.152 | â |
| Castro-Ginard et al. | 2020 | 120.565 | -27.879 | 0.186 | -2.477 | 3.138 | 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] | Bfr | BSS |
|---|---|---|---|---|---|---|---|---|---|
| Li et al. | 2025 | 5.04 | 0.96 | â | 30 | 0.062 | â | â | â |
| Hunt & Reffert | 2024 | â | â | â | â | â | 317* | â | â |
| Cavallo et al. | 2024 | 4.00 | 1.00 | â | 71 | -0.510 | â | â | â |
| Hunt & Reffert | 2023 | 5.56 | 0.75 | 1.00 | 69 | â | â | â | â |
| Cantat-Gaudin et al. | 2020 | 4.70 | 0.71 | â | 87 | â | â | â | â |
(*): Indicates that this parameter is assigned more than one value in the corresponding reference.
Cavallo et al. (2024)
Gold sample.