Theia 780

0.24 UTI

0.28

C_N

0.28

C_dens

0.38

C_C3

0.13

C_lit

1.0

C_dup

N_m (P>50%) 28

Core radius and density 1.2 [pc], 1.4 [pc^-2]

C3 classification BC

C_N 0.28 Poorly populated
C_dens 0.28 Loose
C_C3 0.38 Low 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 780 is a poorly populated, loose object of low C3 quality. Its parallax locates it at a close distance, near 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 large 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

Palma et al. (2025)
Part of multiple system G116, along with HSC_1404 and HSC_1402.

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 780 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–	81.669	30.344	1.052	-0.687	-4.481	3.743
Yang et al.	2025	81.659	30.32	–	–	–	–
Zhang et al.	2024	81.659	30.32	–	–	–	–
Hunt & Reffert	2024	81.659	30.32	1.034	-0.618	-4.341	7.345
Cavallo et al.	2024	81.47	30.156	1.034	–	–	–
Hunt & Reffert	2023	81.659	30.32	1.034	-0.618	-4.341	7.345
Kounkel & Covey	2019	81.25	31.049	1.126	–	–	-11.986

💡 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–	0.91	0.59	0.97	232	-0.120	89	–	–
Yang et al.	2025	–	–	–	234	-0.120⁽³⁾	–	–	–
Zhang et al.	2024	–	–	–	–	-0.165⁽¹⁾	–	–	–
Hunt & Reffert	2024	0.91	0.59	0.97	232	–	89⁽¹⁾	–	–
Cavallo et al.	2024	0.93	0.85	–	89	-0.120	–	–	–
Hunt & Reffert	2023	0.91	0.59	0.97	232	–	–	–	–
Kounkel & Covey	2019	0.89	0.56	–	357	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
CWNU 1104	100.0	81.65	30.35	1.05	-0.67	-4.48	3.74	0.1

💡 Note: The % column shows the percentage of members that Theia 780 shares with each listed object.

Visualization

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