Theia 89
0.12
UTI
0.0
CN
0.1
Cdens
0.38
CC3
0.06
Clit
1.0
Cdup
Nm (P>50%)
21
Core radius and density
1.9 [pc], 0.5 [pc-2]
- CN 0.0 Sparse
- Cdens 0.1 Very loose
- CC3 0.38 Low quality
- Clit 0.06 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
Theia 89 is a sparse, very loose object of low C3 quality. Its parallax locates it at a close distance, near the mid-plane, affected by low extinction. It is catalogued as a near-solar metallicity, intermediate-age cluster (see Parameters). It is rarely studied 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 | 230.048 | -60.746 | 1.328 | -1.813 | -5.207 | 12.762 |
| Hu & Soubiran | 2025 | 230.961 | -60.217 | â | â | â | â |
| Cavallo et al. | 2024 | 230.961 | -60.217 | 1.339 | â | â | â |
| Hunt & Reffert | 2023 | 230.075 | -60.819 | 1.336 | -1.791 | -5.306 | 9.212 |
| Kounkel & Covey | 2019 | 229.937 | -60.727 | 1.199 | â | â | 1.481 |
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 | 0.7 | 0.47 | 0.64 | 676 | -0.200 | â | â | â |
| Hu & Soubiran | 2025 | â | â | â | â | -0.200(5) | â | â | â |
| Cavallo et al. | 2024 | 0.64 | 0.47 | â | 676 | -0.200 | â | â | â |
| Hunt & Reffert | 2023 | 0.70 | 0.25 | 0.64 | 685 | â | â | â | â |
| Kounkel & Covey | 2019 | 0.83 | 0.70 | â | 26 | â | â | â | â |
(N): Indicates that there are N extra values assigned to this parameter in the corresponding reference.
Palma et al. (2025)
Classified as optical pair P590, along with UPK_604.
Cavallo et al. (2024)
Gold sample.
Hunt & Reffert (2024)
Classified as moving group. CMD class: 1.00 (50th percentile).
Hunt & Reffert (2023)
Classified as open cluster. CMD class: 1.00 (50th percentile).