Theia 339

0.51 UTI

0.6

C_N

1.0

C_dens

0.75

C_C3

0.1

C_lit

1.0

C_dup

N_m (P>50%) 71

Core radius and density 0.8 [pc], 5.8 [pc^-2]

C3 classification AB

C_N 0.6 Moderately populated
C_dens 1.0 Very dense
C_C3 0.75 High 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 339 is a moderately populated, very dense object of high C3 quality. Its parallax locates it at a relatively 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.

Relatively close Low extinction Near-solar metallicity Intermediate age

Liu et al. (2025)
Classified as primordial binary cluster 312 along with OC_0606.

Palma et al. (2025)
Classified as optical pair (not dynamically associated) P243, along with OC_0606.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 1.00 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 1.00 (50th percentile).

Data

🔍 Search references for Theia 339 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–	213.876	-63.741	0.518	-4.695	-3.115	–
Hunt & Reffert	2024	213.87	-63.74	0.507	-4.707	-3.133	–
Cavallo et al.	2024	213.903	-63.742	0.512	–	–	–
Hunt & Reffert	2023	213.87	-63.74	0.507	-4.707	-3.133	–
Kounkel & Covey	2019	211.822	-64.287	1.436	–	–	-1.787

💡 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–	1.78	0.98	0.5	113	0.050	213	–	–
Liu et al.	2025	2.82	0.40	–	89	–	–	–	–
Hunt & Reffert	2024	1.78	0.98	0.50	113	–	213⁽¹⁾	–	–
Cavallo et al.	2024	1.63	1.11	–	229	0.050	–	–	–
Hunt & Reffert	2023	1.78	0.98	0.50	113	–	–	–	–
Kounkel & Covey	2019	0.74	0.49	–	114	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
HXHWL 25	71.8	213.87	-63.74	0.52	-4.72	-3.13	–	0.01

💡 Note: The % column shows the percentage of members that Theia 339 shares with each listed object.

Visualization

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