Theia 31

0.64 UTI

0.69

C_N

1.0

C_dens

1.0

C_C3

0.25

C_lit

1.0

C_dup

N₅₀ (P>50% members) 88

Stellar density (N₅₀/rad) 16.4 [N/pc²]

C3 classification AA

C_N 0.69 Moderately populated
C_dens 1.0 Very dense
C_C3 1.0 Very high quality
C_lit 0.25 Poorly studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

MOCA 🔍 CDS 🔍 Simbad 🔍 CDS (α, δ) 🔍 Simbad (α, δ)

Overview

ℹ️

Theia 31 is a moderately populated, very 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 poorly studied in the literature.

Note: This object shares a large percentage of members with a later reported entry. See table with shared members information.

Very close Low extinction Near-solar metallicity Very young

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 a moving group.

Data

🔍 Search references for Theia 31 in: SciX Simbad

ℹ️

Reference	Year	RA [deg]	DEC [deg]	Plx [mas]	pmRA [mas/yr]	pmDE [mas/yr]	Rv [km/s]
UCC	99999–	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	–	–	–
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	–

💡 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]	B_frac	BSS
UCC	99999–	0.36	0.23	0.88	7	-0.150	–	–	–
Liu et al.	2025	0.37	0.04	–	7	–	–	–	–
Cavallo et al.	2024	0.36	0.78	–	5	-0.150	–	–	–
Hunt & Reffert	2023	0.35	0.31	0.88	7	–	–	–	–
He et al.	2022	–	0.15	–	7	–	–	–	–

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
OCSN 202	100.0	126.93	-34.74	2.81	-6.96	10.9	13.13	0.09

💡 Note: The % column shows the percentage of members that Theia 31 shares with each listed object.

Visualization

ℹ️

1 2