Theia 249

0.21 UTI

0.26

C_N

0.25

C_dens

0.5

C_C3

0.03

C_lit

1.0

C_dup

N_m (P>50%) 26

Core radius and density 1.5 [pc], 1.2 [pc^-2]

C3 classification DA

C_N 0.26 Poorly populated
C_dens 0.25 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 249 is a poorly populated, loose object of intermediate C3 quality. Its parallax locates it at a very close distance, below the mid-plane, affected by low extinction. It is catalogued as a near-solar metallicity, young 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 Young

Palma et al. (2025)
Part of multiple system G231, along with OCSN_82, NGC_2451B and Collinder_140.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.21 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.21 (50th percentile).

Data

🔍 Search references for Theia 249 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–	103.76	-37.56	2.234	-8.868	10.52	28.763
Cavallo et al.	2024	102.182	-37.325	2.335	–	–	–
Hunt & Reffert	2023	103.735	-37.536	2.327	-8.878	11.037	27.693
Kounkel & Covey	2019	101.809	-37.263	2.111	–	–	20.466

💡 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–	0.44	0.22	1.09	89	0.150	–	–	–
Cavallo et al.	2024	0.44	0.55	–	81	0.150	–	–	–
Hunt & Reffert	2023	0.41	0.22	1.09	139	–	–	–	–
Kounkel & Covey	2019	0.47	0.20	–	89	–	–	–	–

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
CWNU 539	92.3	103.79	-37.56	2.23	-8.94	10.49	29.39	0.04

💡 Note: The % column shows the percentage of members that Theia 249 shares with each listed object.

Visualization

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