Theia 290

0.29 UTI

0.0

C_N

0.19

C_dens

0.75

C_C3

0.25

C_lit

1.0

C_dup

N₅₀ (P>50% members) 23

Stellar density (N₅₀/rad) 0.9 [N/pc²]

C3 classification AB

C_N 0.0 Sparse
C_dens 0.19 Very loose
C_C3 0.75 High quality
C_lit 0.25 Poorly studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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Theia 290 is a sparse, very loose object of high C3 quality. Its parallax locates it at a close distance, near the mid-plane, affected by low extinction. It is catalogued as a metal-poor, young cluster, but with a large variance across recent sources for the absorption parameter (see Parameters). It was recently reported 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.

Close Low extinction Metal-poor Young

Liu et al. (2025)
Classified as tidal capture (resonant trapping binary) 251 along with HSC_2885.

Cavallo et al. (2024)
Gold sample.

Data

🔍 Search references for Theia 290 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–	262.459	-35.703	1.153	-1.315	-3.776	-3.191
Hunt & Reffert	2024	262.465	-35.75	1.15	-1.327	-3.778	0.782
Cavallo et al.	2024	262.481	-35.71	1.149	–	–	–
Hunt & Reffert	2023	262.465	-35.75	1.15	-1.327	-3.778	0.782

💡 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–	0.81	0.88	0.73	98	-0.760	74	–	–
Liu et al.	2025	1.17	0.31	–	98	–	–	–	–
Hunt & Reffert	2024	–	–	–	–	–	74⁽¹⁾	–	–
Cavallo et al.	2024	0.73	1.39	–	59	-0.760	–	–	–
Hunt & Reffert	2023	0.81	0.88	0.73	103	–	–	–	–

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

Visualization

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