Theia 1927

0.19 UTI

0.0

C_N

0.41

C_dens

0.75

C_C3

0.0

C_lit

0.84

C_dup

N_m (P>50%) 17

Core radius and density 1.1 [pc], 2.0 [pc^-2]

C3 classification AB

C_N 0.0 Sparse
C_dens 0.41 Loose
C_C3 0.75 High quality
C_lit 0.0 Rarely studied
C_dup 0.84 Very likely unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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Theia 1927 is a sparse, loose object of high C3 quality. Its parallax locates it at a relatively close distance, near the mid-plane, affected by low extinction. It is catalogued as an old cluster (see Parameters). It was recently reported in the literature.

Note: This is very likely a unique object, which shares a small percentage of members with at least one previously reported entry. See table with shared members information.

⚠️ Warning: the low UTI value and no obvious signs of duplication (C_dup=0.84) indicate that this is quite probably an asterism, moving group, or artifact, and not a real open cluster.

Relatively close Low extinction Old

Palma et al. (2025)
Classified as optical pair P551, along with NGC_6568.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 0.03 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.03 (50th percentile).

Data

🔍 Search references for Theia 1927 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–	273.025	-22.911	0.809	0.275	0.739	12.176
Hunt & Reffert	2024	273.077	-22.909	0.953	0.223	0.727	–
Hunt & Reffert	2023	273.077	-22.909	0.953	0.223	0.727	–

💡 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–	1.04	0.75	0.71	3228	–	75	–	–
Hunt & Reffert	2024	1.04	0.75	0.71	3228	–	75⁽¹⁾	–	–
Hunt & Reffert	2023	1.04	0.75	0.71	3228	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
OC 0011	16.0	272.99	-22.96	0.61	0.46	0.81	12.11	0.6

💡 Note: The % column shows the percentage of members that Theia 1927 shares with each listed object.

Visualization

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