Theia 1975

0.11 UTI

0.0

C_N

0.18

C_dens

0.38

C_C3

0.25

C_lit

0.52

C_dup

N₅₀ (P>50% members) 22

Stellar density (N₅₀/rad) 0.9 [N/pc²]

C3 classification CB

C_N 0.0 Sparse
C_dens 0.18 Very loose
C_C3 0.38 Low quality
C_lit 0.25 Poorly studied
C_dup 0.52 Likely unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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Theia 1975 is a sparse, very loose object of low C3 quality. Its parallax locates it at a moderate distance, near the mid-plane, affected by high extinction. It is catalogued as a massive, metal-rich, very young cluster, but with a large variance across recent sources for the distance parameter (see Parameters). It was recently reported in the literature.

Note: This is likely a unique object, which shares a moderate percentage of members with at least one previously reported entry. See table with shared members information.

Relatively close High extinction Massive Metal-rich Very young

Liu et al. (2025)
Classified as primordial binary cluster 135 along with Dolidze_3, and of multiple system 44 along with NGC_6883 and Dolidze_3.

Palma et al. (2025)
Part of multiple system G209, along with UBC_1099 and IC_4996.

Cavallo et al. (2024)
Gold sample.

Data

🔍 Search references for Theia 1975 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–	305.517	37.039	0.495	-2.402	-5.356	53.948
Liu et al.	2025	305.39	36.93	0.5	-2.42	-5.35	21.7
Hunt & Reffert	2024	305.387	36.932	0.497	-2.424	-5.347	21.699
Cavallo et al.	2024	305.61	37.152	0.495	–	–	–
Hunt & Reffert	2023	305.387	36.932	0.497	-2.424	-5.347	21.699

💡 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–	2.23	3.74	2.76	12	0.810	1053	–	–
Liu et al.	2025	7.94	1.34	–	12	–	–	–	–
Hunt & Reffert	2024	–	–	–	–	–	1053⁽¹⁾	–	–
Cavallo et al.	2024	2.23	3.74	–	13	0.810	–	–	–
Hunt & Reffert	2023	1.96	4.08	2.76	7	–	–	–	–

(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 1872	48.0	305.53	37.13	0.5	-2.43	-5.33	53.95	0.05
UBC 1101	44.0	305.72	37.19	0.49	-2.38	-5.32	46.61	0.44
XDOCC 10	20.0	305.52	37.24	0.5	-2.4	-5.26	53.95	0.25
UBC 1098	16.0	305.39	36.93	0.49	-2.63	-5.41	-134.78	0.38

💡 Note: The % column shows the percentage of members that Theia 1975 shares with each listed object.

Visualization

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