Theia 253

0.37 UTI

0.64

C_N

0.32

C_dens

0.75

C_C3

0.06

C_lit

1.0

C_dup

N_m (P>50%) 78

Core radius and density 1.7 [pc], 1.6 [pc^-2]

C3 classification AB

C_N 0.64 Moderately populated
C_dens 0.32 Loose
C_C3 0.75 High 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 253 is a moderately populated, loose object of high C3 quality. Its parallax locates it at a very close distance, above the mid-plane, affected by low extinction. It is catalogued as a low-mass, near-solar metallicity, intermediate-age cluster (see Parameters). It is rarely studied in the literature.

Note: This object shares a significant percentage of members with 2 later reported entries. See table with shared members information.

Very close Low extinction Low mass Near-solar metallicity Intermediate age

Palma et al. (2025)
Classified as optical pair P608, along with ASCC_101.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 0.44 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.44 (50th percentile).

Data

🔍 Search references for Theia 253 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–	293.629	32.11	2.348	2.443	-1.329	-19.421
Hunt & Reffert	2024	293.685	32.122	2.363	2.35	-1.32	-19.223
Cavallo et al.	2024	293.546	32.186	2.367	–	–	–
Hunt & Reffert	2023	293.685	32.122	2.363	2.35	-1.32	-19.223
Kounkel & Covey	2019	295.273	32.226	1.86	–	–	-4.153

💡 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–	0.415	0.27	0.45	112	0.120	43	–	–
Hunt & Reffert	2024	0.40	0.16	0.45	137	–	43⁽¹⁾	–	–
Cavallo et al.	2024	0.43	0.51	–	66	0.120	–	–	–
Hunt & Reffert	2023	0.40	0.16	0.45	137	–	–	–	–
Kounkel & Covey	2019	0.60	0.38	–	87	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
CWNU 347	69.2	293.63	32.16	2.38	2.53	-1.31	-20.97	0.0
CWWDL 14662	39.7	293.7	32.1	2.41	2.68	-1.33	-20.77	0.0

💡 Note: The % column shows the percentage of members that Theia 253 shares with each listed object.

Visualization

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