HSC 2181

0.26 UTI

0.33

C_N

0.1

C_dens

0.75

C_C3

0.06

C_lit

1.0

C_dup

N_m (P>50%) 33

Core radius and density 2.5 [pc], 0.5 [pc^-2]

C3 classification AB

C_N 0.33 Poorly populated
C_dens 0.1 Very loose
C_C3 0.75 High quality
C_lit 0.06 Rarely studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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HSC 2181 is a poorly populated, very loose object of high 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, intermediate-age cluster, but with a large variance across recent sources for the metallicity parameter (see Parameters). It was recently reported in the literature.

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

Distant Moderate extinction Near-solar metallicity Intermediate age

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 0.99 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.99 (50th percentile).

Data

🔍 Search references for HSC 2181 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–	131.607	-50.829	0.194	-4.727	4.852	–
Hu & Soubiran	2025	131.581	-50.823	–	–	–	–
Hunt & Reffert	2024	131.593	-50.815	0.184	-4.706	4.885	–
Cavallo et al.	2024	131.581	-50.823	0.185	–	–	–
Hunt & Reffert	2023	131.593	-50.815	0.184	-4.706	4.885	–

💡 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–	4.75	2.94	0.96	323	0.150	378	–	–
Hu & Soubiran	2025	–	–	–	–	-0.190⁽⁵⁾	–	–	–
Hunt & Reffert	2024	4.75	2.94	0.96	323	–	378⁽¹⁾	–	–
Cavallo et al.	2024	3.78	2.42	–	759	0.490	–	–	–
Hunt & Reffert	2023	4.76	2.94	0.96	323	–	–	–	–

(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 3208	87.9	131.61	-50.83	0.18	-4.72	4.85	–	0.02

💡 Note: The % column shows the percentage of members that HSC 2181 shares with each listed object.

Visualization

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