Theia 177
0.12
UTI
0.0
CN
0.15
Cdens
0.38
CC3
0.03
Clit
1.0
Cdup
Nm (P>50%)
23
Core radius and density
1.3 [pc], 0.8 [pc-2]
- CN 0.0 Sparse
- Cdens 0.15 Very loose
- CC3 0.38 Low quality
- Clit 0.03 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 177 is a sparse, very loose object of low C3 quality. Its parallax locates it at a close distance, below the mid-plane, affected by low extinction. It is catalogued as a 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 | 99.67 | -45.134 | 1.875 | -5.752 | 9.348 | 25.445 |
| Cavallo et al. | 2024 | 100.645 | -46.305 | 1.837 | â | â | â |
| Hunt & Reffert | 2023 | 99.609 | -45.134 | 1.836 | -5.916 | 9.31 | 25.421 |
| Kounkel & Covey | 2019 | 99.165 | -46.679 | 1.937 | â | â | 9.313 |
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 | 0.53 | 0.15 | 0.47 | 34 | 0.000 | â | â | â |
| Cavallo et al. | 2024 | 0.58 | 0.46 | â | 13 | 0.000 | â | â | â |
| Hunt & Reffert | 2023 | 0.53 | 0.07 | 0.47 | 34 | â | â | â | â |
| Kounkel & Covey | 2019 | 0.52 | 0.15 | â | 66 | â | â | â | â |
Palma et al. (2025)
Classified as optical pair P457, along with HSC_2032.
Cavallo et al. (2024)
Gold sample.
Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.23 (50th percentile).
Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.23 (50th percentile).