Theia 248

0.20 UTI

0.25

C_N

0.08

C_dens

0.5

C_C3

0.1

C_lit

1.0

C_dup

N_m (P>50%) 25

Core radius and density 2.5 [pc], 0.4 [pc^-2]

C3 classification BB

C_N 0.25 Poorly populated
C_dens 0.08 Very loose
C_C3 0.5 Intermediate quality
C_lit 0.1 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 248 is a poorly populated, very loose object of intermediate 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.

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)
Part of multiple system G239, along with Theia_101, OCSN_28 and OCSN_27.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.97 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.97 (50th percentile).

Data

🔍 Search references for Theia 248 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–	324.03	53.3	2.086	8.983	6.471	-14.958
Zhang et al.	2024	324.696	53.669	–	–	–	–
Cavallo et al.	2024	323.937	53.124	2.073	–	–	–
Hunt & Reffert	2023	324.696	53.669	2.077	8.837	6.29	-16.834
He et al.	2022	323.597	53.179	2.079	8.729	6.471	–
Kounkel & Covey	2019	323.355	52.764	2.172	–	–	-5.187

💡 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–	0.46	0.78	1.35	102	0.181	–	–	–
Zhang et al.	2024	–	–	–	–	0.182⁽¹⁾	–	–	–
Cavallo et al.	2024	0.49	0.95	–	120	0.180	–	–	–
Hunt & Reffert	2023	0.46	0.61	1.35	112	–	–	–	–
He et al.	2022	–	1.05	–	63	–	–	–	–
Kounkel & Covey	2019	0.45	0.51	–	93	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
OCSN 30	96.0	323.81	53.28	2.1	8.91	6.5	-16.6	0.15

💡 Note: The % column shows the percentage of members that Theia 248 shares with each listed object.

Visualization

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