Theia 71

0.36 UTI

0.28

C_N

0.51

C_dens

0.75

C_C3

0.13

C_lit

1.0

C_dup

N_m (P>50%) 28

Core radius and density 1.1 [pc], 2.5 [pc^-2]

C3 classification AB

C_N 0.28 Poorly populated
C_dens 0.51 Moderately dense
C_C3 0.75 High quality
C_lit 0.13 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 71 is a poorly populated, moderately dense object of 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 and metallicity parameters (see Parameters). It is rarely studied in the literature.

Note: This object shares a very small 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 347 along with CWNU_1129, and of multiple system 35 along with HSC_1438, CWNU_1129, Theia_54, HSC_1426 and Theia_66.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.85 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.85 (50th percentile).

Data

🔍 Search references for Theia 71 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–	68.561	20.384	5.243	4.136	-6.511	15.034
Liu et al.	2025	68.58	20.47	5.29	4.09	-6.78	12.67
Yang et al.	2025	68.582	20.467	–	–	–	–
Zhang et al.	2024	68.582	20.467	–	–	–	–
Cavallo et al.	2024	68.82	20.485	5.286	–	–	–
Hunt & Reffert	2023	68.582	20.467	5.286	4.091	-6.783	12.667
Kounkel & Covey	2019	67.684	20.286	4.561	–	–	0.675

💡 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–	0.205	0.54	0.45	16	0.073	–	–	–
Liu et al.	2025	0.23	0.17	–	14	–	–	–	–
Yang et al.	2025	–	–	–	16	-0.070⁽³⁾	–	–	–
Zhang et al.	2024	–	–	–	–	0.073⁽¹⁾	–	–	–
Cavallo et al.	2024	0.18	1.43	–	44	0.380	–	–	–
Hunt & Reffert	2023	0.19	0.71	0.45	16	–	–	–	–
Kounkel & Covey	2019	0.22	0.37	–	27	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
HSC 1390	3.6	66.8	18.56	4.41	4.0	-8.1	17.55	0.13

💡 Note: The % column shows the percentage of members that Theia 71 shares with each listed object.

Visualization

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