HSC 803

0.05 UTI

0.0

C_N

0.08

C_dens

0.12

C_C3

0.03

C_lit

1.0

C_dup

N_m (P>50%) 22

Core radius and density 2.1 [pc], 0.4 [pc^-2]

C3 classification DC

C_N 0.0 Sparse
C_dens 0.08 Very loose
C_C3 0.12 Very low 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 803 is a sparse, very loose object of very low C3 quality. Its parallax locates it at a very close distance, near the mid-plane, affected by low 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.

⚠️ 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.

Very close Low extinction Near-solar metallicity Intermediate age

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.08 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.08 (50th percentile).

Data

🔍 Search references for HSC 803 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–	332.246	58.608	2.531	13.723	7.976	-11.176
Yang et al.	2025	332.198	58.59	–	–	–	–
Cavallo et al.	2024	332.343	58.087	2.541	–	–	–
Hunt & Reffert	2023	332.198	58.59	2.546	13.547	7.975	-11.542

💡 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–	0.395	0.765	0.67	135	0.085	–	–	–
Yang et al.	2025	–	–	–	135	-0.130⁽³⁾	–	–	–
Cavallo et al.	2024	0.41	0.90	–	98	0.300	–	–	–
Hunt & Reffert	2023	0.38	0.63	0.67	136	–	–	–	–

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

Visualization

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