Theia 1813

0.07 UTI

0.68

C_N

0.82

C_dens

1.0

C_C3

0.06

C_lit

0.13

C_dup

N_m (P>50%) 86

Core radius and density 1.5 [pc], 4.1 [pc^-2]

C3 classification AA

C_N 0.68 Moderately populated
C_dens 0.82 Dense
C_C3 1.0 Very high quality
C_lit 0.06 Rarely studied
C_dup 0.13 Likely duplicate

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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Theia 1813 is a moderately populated, dense object of very high C3 quality. Its parallax locates it at a moderate distance, below the mid-plane, affected by high extinction. It is catalogued as a massive, metal-poor, intermediate-age cluster, but with a large variance across recent sources for the metallicity parameter (see Parameters). It was recently reported in the literature.

⚠️ Warning: This is likely a duplicate object, which shares a large percentage of members with at least one previously reported entry. See table with shared members information.

Distant High extinction Massive Metal-poor Intermediate age

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 0.76 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.76 (50th percentile).

Data

🔍 Search references for Theia 1813 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–	264.34	-33.842	0.244	-0.889	-2.067	-4.184
Hu & Soubiran	2025	264.324	-33.839	–	–	–	–
Hunt & Reffert	2024	264.338	-33.838	0.255	-0.883	-2.075	-5.053
Cavallo et al.	2024	264.324	-33.839	0.254	–	–	–
Hunt & Reffert	2023	264.338	-33.838	0.255	-0.883	-2.075	-5.053

💡 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–	3.41	4.71	2.31	330	-0.815	3928	–	–
Hu & Soubiran	2025	–	–	–	–	-0.410⁽⁵⁾	–	–	–
Hunt & Reffert	2024	3.41	4.71	2.31	330	–	3928⁽¹⁾	–	–
Cavallo et al.	2024	6.14	4.44	–	631	-1.220	–	–	–
Hunt & Reffert	2023	3.41	4.71	2.31	330	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
FoF 1200	87.2	264.34	-33.84	0.24	-0.85	-2.06	-3.9	0.48

💡 Note: The % column shows the percentage of members that Theia 1813 shares with each listed object.

Visualization

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