HSC 901

0.19 UTI

0.0

C_N

0.05

C_dens

0.75

C_C3

0.06

C_lit

1.0

C_dup

N_m (P>50%) 17

Core radius and density 2.6 [pc], 0.2 [pc^-2]

C3 classification AB

C_N 0.0 Sparse
C_dens 0.05 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 901 is a sparse, very loose object of high C3 quality. Its parallax locates it at a very large distance, well above the mid-plane, affected by high extinction. It is catalogued as a massive, near-solar metallicity, intermediate-age cluster, but with a large variance across recent sources for the age 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.

⚠️ 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 distant High extinction Massive Near-solar metallicity Intermediate age

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 0.43 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.43 (50th percentile).

Data

🔍 Search references for HSC 901 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–	348.536	65.676	0.087	-1.188	-0.215	-102.021
Hu & Soubiran	2025	348.519	65.681	–	–	–	–
Hunt & Reffert	2024	348.54	65.664	0.084	-1.218	-0.193	-102.01
Cavallo et al.	2024	348.519	65.681	0.083	–	–	–
Hunt & Reffert	2023	348.54	65.664	0.084	-1.218	-0.193	-102.01

💡 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–	8.72	4.51	1.8	509	-0.215	1541	–	–
Hu & Soubiran	2025	–	–	–	–	-0.200⁽⁵⁾	–	–	–
Hunt & Reffert	2024	8.72	4.51	1.80	509	–	1541⁽¹⁾	–	–
Cavallo et al.	2024	7.66	3.24	–	1950	-0.230	–	–	–
Hunt & Reffert	2023	8.72	4.51	1.80	509	–	–	–	–

(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 3008	96.0	348.58	65.69	0.09	-1.18	-0.24	-103.58	0.17

💡 Note: The % column shows the percentage of members that HSC 901 shares with each listed object.

Visualization

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