Theia 128
0.25
UTI
0.25
CN
0.31
Cdens
0.62
CC3
0.03
Clit
1.0
Cdup
Nm (P>50%)
25
Core radius and density
1.0 [pc], 1.6 [pc-2]
- CN 0.25 Poorly populated
- Cdens 0.31 Loose
- CC3 0.62 Intermediate 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 128 is a poorly populated, loose object of intermediate 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, young cluster (see Parameters). It is rarely studied in the literature.
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | 99999â | 108.651 | -7.682 | 1.996 | -8.461 | 2.171 | 22.953 |
| Cavallo et al. | 2024 | 108.684 | -7.639 | 1.994 | â | â | â |
| Hunt & Reffert | 2023 | 108.653 | -7.694 | 1.992 | -8.399 | 2.23 | 31.15 |
| Kounkel & Covey | 2019 | 109.804 | -7.695 | 1.489 | â | â | 6.74 |
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 | 0.5 | 0.4 | 0.46 | 45 | 0.270 | â | â | â |
| Cavallo et al. | 2024 | 0.50 | 0.40 | â | 38 | 0.270 | â | â | â |
| Hunt & Reffert | 2023 | 0.48 | 0.15 | 0.46 | 96 | â | â | â | â |
| Kounkel & Covey | 2019 | 0.67 | 0.63 | â | 45 | â | â | â | â |
Palma et al. (2025)
Classified as optical pair P571, along with Theia_546.
Cavallo et al. (2024)
Gold sample.
Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.98 (50th percentile).
Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.98 (50th percentile).