HSC 823

0.11 UTI

0.0

C_N

0.16

C_dens

0.38

C_C3

0.0

C_lit

1.0

C_dup

N₅₀ (P>50% members) 21

Stellar density (N₅₀/rad) 0.8 [N/pc²]

C3 classification BC

C_N 0.0 Sparse
C_dens 0.16 Very loose
C_C3 0.38 Low quality
C_lit 0.0 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 823 is a sparse, very loose object of low C3 quality. Its parallax locates it at a relatively close distance, above the mid-plane, affected by moderate extinction. It is catalogued as a near-solar metallicity, old cluster, but with a large variance across recent sources for the age and metallicity parameters (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.

Close Moderate extinction Near-solar metallicity Old

Palma et al. (2025)
Classified as optical pair P529, along with Theia_1474.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as a moving group.

Data

🔍 Search references for HSC 823 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–	333.343	61.419	0.991	-3.568	-3.647	-20.416
Hu & Soubiran	2025	333.359	61.496	–	–	–	–
Cavallo et al.	2024	333.359	61.496	0.992	–	–	–
Hunt & Reffert	2023	333.435	61.41	0.991	-3.539	-3.65	-20.419

💡 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–	0.935	1.685	1.53	1070	-0.195	–	–	–
Hu & Soubiran	2025	–	–	–	–	-0.010⁽⁵⁾	–	–	–
Cavallo et al.	2024	0.90	1.55	–	1738	-0.380	–	–	–
Hunt & Reffert	2023	0.97	1.82	1.53	402	–	–	–	–

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

Visualization

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