Theia 100

0.39 UTI

0.68

C_N

0.06

C_dens

1.0

C_C3

0.1

C_lit

1.0

C_dup

N_m (P>50%) 87

Core radius and density 5.0 [pc], 0.3 [pc^-2]

C3 classification AA

C_N 0.68 Moderately populated
C_dens 0.06 Very loose
C_C3 1.0 Very high 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 100 is a moderately populated, very loose object of very high 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, very young cluster (see Parameters). It is rarely studied in the literature.

Note: This object shares a significant percentage of members with at least one entry reported in the same catalogue. See table with shared members information.

Very close Low extinction Near-solar metallicity Very young

Palma et al. (2025)
Part of multiple system G195, along with OCSN_36 and HSC_825.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.98 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.98 (50th percentile).

Data

🔍 Search references for Theia 100 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–	346.904	45.932	2.036	-0.806	-3.026	-12.975
Zhang et al.	2024	346.888	46.068	–	–	–	–
Swiggum et al.	2024	346.888	46.068	2.066	-0.826	-3.143	-13.615
Cavallo et al.	2024	346.969	45.567	2.062	–	–	–
Hunt & Reffert	2023	346.888	46.068	2.066	-0.826	-3.143	-13.655
Kounkel & Covey	2019	347.008	45.171	2.084	–	–	-3.826

💡 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–	0.48	0.52	0.68	16	-0.083	195	–	–
Zhang et al.	2024	–	–	–	–	-0.036⁽¹⁾	–	–	–
Swiggum et al.	2024	0.48	–	–	16	–	195	–	–
Cavallo et al.	2024	0.50	0.74	–	7	-0.130	–	–	–
Hunt & Reffert	2023	0.46	0.33	0.68	16	–	–	–	–
Kounkel & Covey	2019	0.48	0.52	–	35	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
Theia 824	74.7	346.9	45.45	2.04	-0.78	-3.31	-13.76	0.37
OCSN 35	16.1	347.01	45.29	2.07	-0.72	-3.54	-16.54	0.02

💡 Note: The % column shows the percentage of members that Theia 100 shares with each listed object.

Visualization

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