OC 0181

0.15 UTI

0.0

C_N

0.08

C_dens

0.62

C_C3

0.06

C_lit

0.88

C_dup

N_m (P>50%) 17

Core radius and density 2.5 [pc], 0.4 [pc^-2]

C3 classification AC

C_N 0.0 Sparse
C_dens 0.08 Very loose
C_C3 0.62 Intermediate quality
C_lit 0.06 Rarely studied
C_dup 0.88 Very likely unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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OC 0181 is a sparse, very loose object of intermediate C3 quality. Its parallax locates it at a close distance, above the mid-plane, affected by moderate extinction. It is catalogued as a near-solar metallicity, very young cluster, but with a large variance across recent sources for the absorption, age, and metallicity parameters (see Parameters). It is rarely studied in the literature.

Note: This is very likely a unique object, which shares a 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=0.88) indicate that this is quite probably an asterism, moving group, or artifact, and not a real open cluster.

Close Moderate extinction Near-solar metallicity Very young

Palma et al. (2025)
Classified as tidal capture (resonant trapping pair) P2, along with BDSB_30.

Cavallo et al. (2024)
Wood sample.

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

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

Data

🔍 Search references for OC 0181 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–	334.018	61.118	1.131	-1.005	-3.011	-15.424
Hunt & Reffert	2024	334.027	60.912	1.139	-1.227	-3.018	-8.424
Cavallo et al.	2024	333.989	60.883	1.142	–	–	–
Hunt & Reffert	2023	334.027	60.912	1.139	-1.227	-3.018	-8.424
Hao et al.	2022	334.125	60.856	1.127	-0.654	-2.911	–

💡 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–	0.86	2.525	0.93	3	0.254	120	–	–
Hunt & Reffert	2024	0.86	2.80	0.93	3	–	120⁽¹⁾	–	–
Cavallo et al.	2024	1.22	2.25	–	138	0.410	–	–	–
Hunt & Reffert	2023	0.86	2.80	0.93	3	–	–	–	–
Hao et al.	2022	–	0.71	–	2	0.097	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
BDSB 30	12.0	333.65	61.44	1.11	-1.54	-3.0	-16.15	0.61
FSR 0369	4.0	334.15	60.81	1.09	-0.27	-2.94	-22.72	0.56

💡 Note: The % column shows the percentage of members that OC 0181 shares with each listed object.

Visualization

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