Theia 31
0.48
UTI
0.69
CN
0.53
Cdens
1.0
CC3
0.1
Clit
1.0
Cdup
Nm (P>50%)
88
Core radius and density
2.5 [pc], 2.6 [pc-2]
- CN 0.69 Moderately populated
- Cdens 0.53 Moderately dense
- CC3 1.0 Very high 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 31 is a moderately populated, moderately dense object of very high C3 quality. Its parallax locates it at a very close distance, near the mid-plane, affected by low extinction. It is catalogued as a near-solar metallicity, very young cluster, but with a large variance across recent sources for the absorption parameter (see Parameters). It is rarely studied in the literature.
Note: This object shares a large percentage of members with a later reported entry. See table with shared members information.
Data
| Reference | Year | RA [deg] | DEC [deg] | Plx [mas] | pmRA [mas/yr] | pmDE [mas/yr] | Rv [km/s] |
|---|---|---|---|---|---|---|---|
| UCC | 99999â | 126.956 | -34.757 | 2.803 | -6.94 | 10.853 | 21.016 |
| Liu et al. | 2025 | 127.0 | -34.91 | 2.8 | -7.01 | 10.85 | 11.62 |
| Cavallo et al. | 2024 | 126.857 | -34.898 | 2.803 | â | â | â |
| Hunt & Reffert | 2023 | 127.002 | -34.911 | 2.804 | -7.006 | 10.853 | 11.621 |
| He et al. | 2022 | 126.887 | -34.8 | 2.803 | -6.978 | 10.874 | â |
| Kounkel & Covey | 2019 | 126.909 | -34.88 | 2.723 | â | â | 8.852 |
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 | 0.365 | 0.31 | 0.88 | 7 | -0.150 | â | â | â |
| Liu et al. | 2025 | 0.37 | 0.04 | â | 7 | â | â | â | â |
| Cavallo et al. | 2024 | 0.36 | 0.78 | â | 5 | -0.150 | â | â | â |
| Hunt & Reffert | 2023 | 0.35 | 0.31 | 0.88 | 7 | â | â | â | â |
| He et al. | 2022 | â | 0.15 | â | 7 | â | â | â | â |
| Kounkel & Covey | 2019 | 0.37 | 0.50 | â | 13 | â | â | â | â |
Liu et al. (2025)
Classified as primordial binary cluster 93 along with CWNU_1096, and of multiple system 30 along with CWNU_1096 and CWNU_1083.
Palma et al. (2025)
Classified as optical pair P89, along with CWNU_1096.
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).