Theia 213

0.13 UTI

0.33

C_N

0.02

C_dens

0.25

C_C3

0.03

C_lit

1.0

C_dup

N_m (P>50%) 33

Core radius and density 4.8 [pc], 0.1 [pc^-2]

C3 classification CC

C_N 0.33 Poorly populated
C_dens 0.02 Very loose
C_C3 0.25 Low 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 213 is a poorly populated, very loose object of low 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, intermediate-age cluster (see Parameters). It is rarely studied in the literature.

⚠️ 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)
Part of multiple system G180, along with HSC_442, HSC_507 and HSC_517.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.98 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.98 (50th percentile).

Data

🔍 Search references for Theia 213 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–	303.722	28.399	6.368	25.367	23.765	-28.471
Cavallo et al.	2024	304.068	29.383	6.549	–	–	–
Hunt & Reffert	2023	302.079	28.392	6.52	25.039	23.943	-21.373
Kounkel & Covey	2019	302.923	29.685	4.593	–	–	-8.603

💡 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	0.25	0.38	141	0.090	–	–	–
Cavallo et al.	2024	0.15	0.62	–	200	0.090	–	–	–
Hunt & Reffert	2023	0.14	0.11	0.38	141	–	–	–	–
Kounkel & Covey	2019	0.23	0.25	–	97	–	–	–	–

Visualization

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