Theia 5504

0.06 UTI

0.0

C_N

0.04

C_dens

0.12

C_C3

0.06

C_lit

0.96

C_dup

N_m (P>50%) 22

Core radius and density 2.7 [pc], 0.2 [pc^-2]

C3 classification DC

C_N 0.0 Sparse
C_dens 0.04 Very loose
C_C3 0.12 Very low quality
C_lit 0.06 Rarely studied
C_dup 0.96 Unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

ℹ️

Theia 5504 is a sparse, very loose object of very low C3 quality. Its parallax locates it at a close distance, below the mid-plane, affected by low extinction. It is catalogued as a near-solar metallicity, intermediate-age cluster (see Parameters). It was recently reported in the literature.

Note: This is a unique object, which shares a very 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=0.96) indicate that this is quite probably an asterism, moving group, or artifact, and not a real open cluster.

Close Low extinction Near-solar metallicity Intermediate age

Palma et al. (2025)
Classified as optical pair P85, along with COIN-Gaia_5.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 1.00 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 1.00 (50th percentile).

Data

🔍 Search references for Theia 5504 in: SciX Simbad

ℹ️

Reference	Year	RA [deg]	DEC [deg]	Plx [mas]	pmRA [mas/yr]	pmDE [mas/yr]	Rv [km/s]
UCC	99999–	23.589	57.112	1.088	1.651	-2.919	-12.502
Yang et al.	2025	23.583	57.255	–	–	–	–
Zhang et al.	2024	23.583	57.255	–	–	–	–
Cavallo et al.	2024	22.567	57.076	1.094	–	–	–
Hunt & Reffert	2023	23.583	57.255	1.089	1.601	-2.969	-15.482

💡 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–	0.885	0.69	1.02	162	-0.043	–	–	–
Yang et al.	2025	–	–	–	162	-0.090⁽³⁾	–	–	–
Zhang et al.	2024	–	–	–	–	-0.043⁽¹⁾	–	–	–
Cavallo et al.	2024	0.90	0.80	–	269	0.050	–	–	–
Hunt & Reffert	2023	0.87	0.58	1.02	162	–	–	–	–

(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 74	4.0	21.37	57.22	1.07	1.62	-2.98	-9.49	0.06

💡 Note: The % column shows the percentage of members that Theia 5504 shares with each listed object.

Visualization

ℹ️

1 2