HSC 1822

0.18 UTI

0.0

C_N

0.02

C_dens

0.75

C_C3

0.06

C_lit

1.0

C_dup

N_m (P>50%) 20

Core radius and density 5.7 [pc], 0.1 [pc^-2]

C3 classification AB

C_N 0.0 Sparse
C_dens 0.02 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 1822 is a sparse, very loose object of high C3 quality. Its parallax locates it at a large distance, near the mid-plane, affected by moderate extinction. It is catalogued as a metal-poor, very old cluster (see Parameters). It was recently reported 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.

Distant Moderate extinction Metal-poor Very old

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 0.64 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.64 (50th percentile).

Data

🔍 Search references for HSC 1822 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–	110.727	-16.086	0.195	-0.402	1.273	79.529
Hu & Soubiran	2025	110.731	-16.111	–	–	–	–
Hunt & Reffert	2024	110.703	-16.086	0.184	-0.399	1.292	78.156
Cavallo et al.	2024	110.731	-16.111	0.186	–	–	–
Hunt & Reffert	2023	110.703	-16.086	0.184	-0.399	1.292	78.156

💡 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–	4.63	2.65	1.0	5294	-0.600	697	–	–
Hu & Soubiran	2025	–	–	–	–	-0.450⁽⁵⁾	–	–	–
Hunt & Reffert	2024	4.63	2.65	1.00	5294	–	697⁽¹⁾	–	–
Cavallo et al.	2024	4.74	3.03	–	4571	-0.750	–	–	–
Hunt & Reffert	2023	4.63	2.65	1.00	5297	–	–	–	–

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

Visualization

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