Theia 181

0.23 UTI

0.38

C_N

0.07

C_dens

0.5

C_C3

0.1

C_lit

1.0

C_dup

N_m (P>50%) 38

Core radius and density 2.3 [pc], 0.4 [pc^-2]

C3 classification BB

C_N 0.38 Poorly populated
C_dens 0.07 Very loose
C_C3 0.5 Intermediate quality
C_lit 0.1 Rarely studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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Theia 181 is a poorly populated, very loose object of intermediate 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, intermediate-age cluster (see Parameters). It is rarely studied in the literature.

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

⚠️ Warning: the low UTI value and no obvious signs of duplication (C_dup=1.0) indicate that this is quite probably an asterism, moving group, or artifact, and not a real open cluster.

Close Low extinction Near-solar metallicity Intermediate age

Yan et al. (2026)
Number of WDs: expected from single-star evolution N=4, with probability of formation through binary evolution >=0.5 N=7.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 0.98 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.98 (50th percentile).

Data

🔍 Search references for Theia 181 in: SciX Simbad

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Reference	Year	RA [deg]	DEC [deg]	Plx [mas]	pmRA [mas/yr]	pmDE [mas/yr]	Rv [km/s]
UCC	99999–	234.453	-64.678	1.806	-4.007	-5.33	10.824
Yan et al.	2026	234.546	-64.857	1.789	-4.007	-5.276	–
Hunt & Reffert	2024	234.546	-64.857	1.789	-4.007	-5.276	8.726
Cavallo et al.	2024	234.232	-64.845	1.794	–	–	–
Hunt & Reffert	2023	234.546	-64.857	1.789	-4.007	-5.276	8.726
Kounkel & Covey	2019	235.612	-65.377	1.773	–	–	1.339

💡 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–	0.54	0.285	0.77	112	0.310	75	–	–
Yan et al.	2026	–	–	–	112	–	–	–	–
Hunt & Reffert	2024	0.53	0.23	0.77	113	–	75⁽¹⁾	–	–
Cavallo et al.	2024	0.55	0.38	–	135	0.310	–	–	–
Hunt & Reffert	2023	0.53	0.23	0.77	112	–	–	–	–
Kounkel & Covey	2019	0.56	0.34	–	73	–	–	–	–

(N): Indicates that there are N extra values assigned to this parameter in the corresponding reference.

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
CWWDL 14599	73.7	235.32	-64.36	1.82	-3.98	-5.4	10.59	0.12

💡 Note: The % column shows the percentage of members that Theia 181 shares with each listed object.

Visualization

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