OC 0257

0.15 UTI

0.0

C_N

0.15

C_dens

0.12

C_C3

0.25

C_lit

1.0

C_dup

N₅₀ (P>50% members) 22

Stellar density (N₅₀/rad) 0.7 [N/pc²]

C3 classification DC

C_N 0.0 Sparse
C_dens 0.15 Very loose
C_C3 0.12 Very low quality
C_lit 0.25 Poorly studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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OC 0257 is a sparse, very loose object of very low C3 quality. Its parallax locates it at a close distance, near the mid-plane, affected by moderate extinction. It is catalogued as a near-solar metallicity, intermediate-age cluster, but with a large variance across recent sources for the age and metallicity parameters (see Parameters). It is poorly studied in the literature.

Note: This object shares a large percentage of members with a later reported entry. See table with shared members information.

⚠️ 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 Moderate extinction Near-solar metallicity Intermediate age

Cavallo et al. (2024)
Gold sample.

Data

🔍 Search references for OC 0257 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–	46.058	59.297	1.192	-0.182	-1.433	-14.009
Hunt & Reffert	2024	46.16	59.27	1.197	-0.113	-1.429	-13.125
Cavallo et al.	2024	46.06	59.257	1.193	–	–	–
Hunt & Reffert	2023	46.16	59.27	1.197	-0.113	-1.429	-13.125
Hao et al.	2022	46.179	59.255	1.186	-0.267	-1.278	–

💡 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–	0.82	1.61	0.79	316	0.420	79	–	–
Hunt & Reffert	2024	–	–	–	–	–	79⁽¹⁾	–	–
Cavallo et al.	2024	0.82	1.34	–	355	0.230	–	–	–
Hunt & Reffert	2023	0.82	1.61	0.79	95	–	–	–	–
Hao et al.	2022	–	3.72	–	316	0.611	–	–	–

(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 1154	84.0	46.04	59.25	1.2	-0.18	-1.45	-14.01	0.01

💡 Note: The % column shows the percentage of members that OC 0257 shares with each listed object.

Visualization

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