Theia 684

0.24 UTI

0.3

C_N

0.42

C_dens

0.5

C_C3

0.0

C_lit

1.0

C_dup

N₅₀ (P>50% members) 30

Stellar density (N₅₀/rad) 2.1 [N/pc²]

C3 classification BB

C_N 0.3 Poorly populated
C_dens 0.42 Loose
C_C3 0.5 Intermediate quality
C_lit 0.0 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 684 is a poorly populated, loose object of intermediate C3 quality. Its parallax locates it at a very close distance, above the mid-plane, affected by low extinction. It is catalogued as an 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.

Low extinction Intermediate age

Data

🔍 Search references for Theia 684 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–	90.311	45.115	4.682	-4.103	-7.927	-0.553
He et al.	2022	90.319	45.0	4.739	-4.068	-7.925	–

💡 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–	–	0.15	–	708	–	–	–	–
He et al.	2022	–	0.15	–	708	–	–	–	–

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
OCSN 49	80.0	90.6	45.07	4.63	-4.06	-7.84	-0.49	0.01

💡 Note: The % column shows the percentage of members that Theia 684 shares with each listed object.

Visualization

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