HSC 20

0.24 UTI

0.0

C_N

0.14

C_dens

1.0

C_C3

0.03

C_lit

1.0

C_dup

N_m (P>50%) 22

Core radius and density 2.2 [pc], 0.7 [pc^-2]

C3 classification AA

C_N 0.0 Sparse
C_dens 0.14 Very loose
C_C3 1.0 Very high quality
C_lit 0.03 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 20 is a sparse, very loose object of very high C3 quality. Its parallax locates it at a moderate distance, above the mid-plane, affected by high extinction. It is catalogued as a metal-poor, intermediate-age cluster (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.

⚠️ 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.

Relatively close High extinction Metal-poor Intermediate age

Cavallo et al. (2024)
Gold 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 HSC 20 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–	265.559	-26.102	0.342	0.541	-0.192	15.202
Hunt & Reffert	2024	265.566	-26.111	0.326	0.536	-0.207	-0.682
Cavallo et al.	2024	265.552	-26.102	0.328	–	–	–
Hunt & Reffert	2023	265.566	-26.111	0.326	0.536	-0.207	-0.682

💡 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–	2.81	3.88	0.89	169	-0.580	371	–	–
Hunt & Reffert	2024	2.81	3.88	0.89	169	–	371⁽¹⁾	–	–
Cavallo et al.	2024	3.16	3.88	–	372	-0.580	–	–	–
Hunt & Reffert	2023	2.81	3.88	0.89	169	–	–	–	–

(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 3240	100.0	265.55	-26.11	0.34	0.54	-0.19	5.24	0.05

💡 Note: The % column shows the percentage of members that HSC 20 shares with each listed object.

Visualization

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