Theia 291
0.10
UTI
0.0
CN
0.04
Cdens
0.25
CC3
0.1
Clit
1.0
Cdup
Nm (P>50%)
22
Core radius and density
3.1 [pc], 0.2 [pc-2]
- CN 0.0 Sparse
- Cdens 0.04 Very loose
- CC3 0.25 Low quality
- Clit 0.1 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 291 is a sparse, very loose object of low C3 quality. Its parallax locates it at a relatively close distance, below the mid-plane, affected by low extinction. It is catalogued as a low-mass, near-solar metallicity, young 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 | 287.27 | -7.715 | 0.911 | -0.229 | -4.647 | 15.086 |
| Yan et al. | 2026 | 287.172 | -7.653 | 0.92 | -0.24 | -4.691 | â |
| Hunt & Reffert | 2024 | 287.172 | -7.653 | 0.92 | -0.24 | -4.691 | -10.27 |
| Cavallo et al. | 2024 | 287.18 | -8.371 | 0.922 | â | â | â |
| Hunt & Reffert | 2023 | 287.172 | -7.653 | 0.92 | -0.24 | -4.691 | -10.27 |
| Kounkel & Covey | 2019 | 285.177 | -8.443 | 1.174 | â | â | -1.554 |
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 | 1.01 | 0.95 | 0.75 | 57 | 0.060 | 45 | â | â |
| Yan et al. | 2026 | â | â | â | 58 | â | â | â | â |
| Hunt & Reffert | 2024 | 1.01 | 0.95 | 0.75 | 57 | â | 45(1) | â | â |
| Cavallo et al. | 2024 | 1.05 | 1.32 | â | 51 | 0.060 | â | â | â |
| Hunt & Reffert | 2023 | 1.01 | 0.95 | 0.75 | 57 | â | â | â | â |
| Kounkel & Covey | 2019 | 0.86 | 0.95 | â | 86 | â | â | â | â |
(N): Indicates that there are N extra values assigned to this parameter in the corresponding reference.
Yan et al. (2026)
Number of WDs: expected from single-star evolution N=2, with probability of formation through binary evolution >=0.5 N=0.
Cavallo et al. (2024)
Gold sample.
Hunt & Reffert (2024)
Classified as open cluster. CMD class: 1.00 (50th percentile).
Hunt & Reffert (2023)
Classified as open cluster. CMD class: 1.00 (50th percentile).