UBC 657

0.24 UTI

0.0

C_N

0.2

C_dens

0.5

C_C3

0.25

C_lit

1.0

C_dup

C3 classification BB

Number of members (P>50%) 20

Radius (P>50% members) 2.9 [arcmin]

C_N 0.0 Sparse
C_dens 0.2 Very loose
C_C3 0.5 Intermediate quality
C_lit 0.25 Poorly studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19 🔍 CDS 🔍 Simbad 🔍 CDS (α, δ) 🔍 Simbad (α, δ)

Overview

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UBC 657 is a sparse, very loose object of intermediate C3 quality. Its parallax locates it at a large distance, below the mid-plane, affected by moderate extinction. It is catalogued as a near-solar metallicity, very young cluster (see Parameters). It is poorly 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.

Very distant Moderate extinction Near-solar metallicity Very young

Almeida et al. (2025)
Mass determination: intermediate fit. Isochrone match: intermediate fit.

Data

🔍 Search references for UBC 657 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	–	161.811	-61.147	0.187	-5.495	2.579	–
Almeida et al.	2025	161.807	-61.129	–	–	–	–
Dias et al.	2021	161.807	-61.129	0.171	-5.486	2.581	–
Cantat-Gaudin et al.	2020	161.796	-61.144	0.171	-5.486	2.58	–
Castro-Ginard et al.	2020	161.776	-61.126	0.173	-5.487	2.569	–

💡 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]	Bfr	BSS
Almeida et al.	2025	5.56	1.89	–	5	–	838	–	–
Dias et al.	2021	5.56	1.89	–	5	0.016	–	–	–

Visualization

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