Theia 246

0.13 UTI

0.0

C_N

0.13

C_dens

0.38

C_C3

0.06

C_lit

1.0

C_dup

N_m (P>50%) 22

Core radius and density 1.4 [pc], 0.6 [pc^-2]

C3 classification BC

C_N 0.0 Sparse
C_dens 0.13 Very loose
C_C3 0.38 Low quality
C_lit 0.06 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 246 is a sparse, 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 metal-rich, young cluster, but with a large variance across recent sources for the absorption and age parameters (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 Metal-rich Young

Palma et al. (2025)
Classified as optical pair P561, along with OCSN_89.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 1.00 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 1.00 (50th percentile).

Data

🔍 Search references for Theia 246 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–	188.387	-65.992	2.451	-13.566	-2.62	5.372
Cavallo et al.	2024	199.543	-66.224	2.603	–	–	–
Hunt & Reffert	2023	193.784	-66.429	2.606	-14.88	-6.516	-12.936
He et al.	2022	188.868	-65.977	2.452	-13.657	-2.705	–
Kounkel & Covey	2019	190.47	-66.274	2.289	–	–	5.252

💡 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–	0.4	0.375	0.42	72	0.540	–	–	–
Cavallo et al.	2024	0.40	0.40	–	63	0.540	–	–	–
Hunt & Reffert	2023	0.37	0.17	0.42	193	–	–	–	–
He et al.	2022	–	1.00	–	35	–	–	–	–
Kounkel & Covey	2019	0.42	0.35	–	80	–	–	–	–

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
OCSN 89	100.0	187.91	-66.01	2.45	-13.58	-2.65	2.59	0.26

💡 Note: The % column shows the percentage of members that Theia 246 shares with each listed object.

Visualization

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