Theia 3666
0.17
UTI
0.0
CN
0.22
Cdens
0.62
CC3
0.0
Clit
1.0
Cdup
Stellar density (N50/rad)
1.1 [N/pc2]
- CN 0.0 Sparse
- Cdens 0.22 Very loose
- CC3 0.62 Intermediate quality
- Clit 0.0 Rarely studied
- Cdup 1.0 Unique
Overview
Theia 3666 is a sparse, very loose object of intermediate 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 (see Parameters). It was recently reported in the literature.
â ī¸ Warning: the low UTI value and no obvious signs of duplication (Cdup=1.0) indicate that this is quite probably an asterism, moving group, or artifact, and not a real open cluster.
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | 99999â | 208.13 | -63.697 | 0.501 | -3.948 | -3.271 | -26.097 |
| Hunt & Reffert | 2024 | 207.955 | -63.714 | 0.493 | -3.944 | -3.282 | -24.622 |
| Cavallo et al. | 2024 | 208.566 | -63.67 | 0.497 | â | â | â |
| Hunt & Reffert | 2023 | 207.955 | -63.714 | 0.493 | -3.944 | -3.282 | -24.622 |
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 | 1.715 | 0.975 | 1.47 | 192 | -0.220 | 89 | â | â |
| Hunt & Reffert | 2024 | â | â | â | â | â | 89(1) | â | â |
| Cavallo et al. | 2024 | 1.57 | 0.99 | â | 195 | -0.220 | â | â | â |
| Hunt & Reffert | 2023 | 1.86 | 0.96 | 1.47 | 190 | â | â | â | â |
(N): Indicates that there are N extra values assigned to this parameter in the corresponding reference.
MOCA


Palma et al. (2025)
Classified as optical pair (not dynamically associated) P175, along with Theia_3319.
Cavallo et al. (2024)
Gold sample.