Theia 399

0.15 UTI

0.0

C_N

0.19

C_dens

0.38

C_C3

0.1

C_lit

1.0

C_dup

N_m (P>50%) 20

Core radius and density 1.3 [pc], 0.9 [pc^-2]

C3 classification CB

C_N 0.0 Sparse
C_dens 0.19 Very loose
C_C3 0.38 Low 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

ℹ️

Theia 399 is a sparse, very loose object of low C3 quality. Its parallax locates it at a close distance, near 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.

⚠️ 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.

Close Low extinction Near-solar metallicity Young

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.95 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.95 (50th percentile).

Data

🔍 Search references for Theia 399 in: SciX Simbad

ℹ️

Reference	Year	RA [deg]	DEC [deg]	Plx [mas]	pmRA [mas/yr]	pmDE [mas/yr]	Rv [km/s]
UCC	99999–	93.616	17.411	1.667	-0.488	-4.522	17.828
Zhang et al.	2024	93.671	17.398	–	–	–	–
Swiggum et al.	2024	93.671	17.398	1.669	-0.451	-4.559	17.139
Cavallo et al.	2024	93.296	17.651	1.684	–	–	–
Hunt & Reffert	2023	93.671	17.398	1.669	-0.451	-4.559	18.312
Kounkel & Covey	2019	92.842	17.008	1.478	–	–	0.771

💡 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–	0.62	0.4	0.95	27	-0.015	138	–	–
Zhang et al.	2024	–	–	–	–	-0.110⁽¹⁾	–	–	–
Swiggum et al.	2024	0.59	–	–	27	–	138	–	–
Cavallo et al.	2024	0.65	0.58	–	27	0.080	–	–	–
Hunt & Reffert	2023	0.58	0.24	0.95	27	–	–	–	–
Kounkel & Covey	2019	0.68	0.40	–	136	–	–	–	–

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

Visualization

ℹ️

1 2