Theia 698

0.19 UTI

0.27

C_N

0.1

C_dens

0.5

C_C3

0.03

C_lit

1.0

C_dup

N_m (P>50%) 27

Core radius and density 3.3 [pc], 0.5 [pc^-2]

C3 classification DA

C_N 0.27 Poorly populated
C_dens 0.1 Very loose
C_C3 0.5 Intermediate quality
C_lit 0.03 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 698 is a poorly populated, very 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 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.

Very close Low extinction Near-solar metallicity Intermediate age

Palma et al. (2025)
Classified as optical pair P533, along with HSC_940.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.61 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.61 (50th percentile).

Data

🔍 Search references for Theia 698 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–	5.247	68.588	2.996	-6.66	0.104	-8.854
Cavallo et al.	2024	4.231	68.458	2.992	–	–	–
Hunt & Reffert	2023	4.921	68.746	2.978	-6.682	-0.178	-6.529
Kounkel & Covey	2019	1.307	67.514	2.729	–	–	-14.12

💡 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–	0.33	0.46	1.14	251	0.400	–	–	–
Cavallo et al.	2024	0.33	0.56	–	251	0.400	–	–	–
Hunt & Reffert	2023	0.32	0.45	1.14	210	–	–	–	–
Kounkel & Covey	2019	0.37	0.46	–	330	–	–	–	–

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
CWNU 1006	100.0	5.31	68.57	3.0	-6.66	0.12	-8.66	0.05

💡 Note: The % column shows the percentage of members that Theia 698 shares with each listed object.

Visualization

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