HSC 381

0.34 UTI

0.27

C_N

0.23

C_dens

0.75

C_C3

0.25

C_lit

0.96

C_dup

N₅₀ (P>50% members) 27

Stellar density (N₅₀/rad) 1.1 [N/pc²]

C3 classification BA

C_N 0.27 Poorly populated
C_dens 0.23 Very loose
C_C3 0.75 High quality
C_lit 0.25 Poorly studied
C_dup 0.96 Unique

📥 Members 📊 Colab 🔬 Bayestar19

MOCA 🔍 CDS 🔍 Simbad 🔍 CDS (α, δ) 🔍 Simbad (α, δ)

Overview

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HSC 381 is a poorly populated, very loose object of high C3 quality. Its parallax locates it at a very close distance, above the mid-plane, affected by low extinction. It is catalogued as a near-solar metallicity, young cluster, but with a large variance across recent sources for the absorption parameter (see Parameters). It was recently reported in the literature.

Note: This is a unique object, which shares a very small percentage of members with at least one previously reported entry. See table with shared members information.

⚠️ Warning: the low UTI value and no obvious signs of duplication (C_dup=0.96) 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 Young

Liu et al. (2025)
Classified as primordial binary cluster 168 along with HSC_415.

Palma et al. (2025)
Classified as genetic pair P614, along with HSC_415.

Cavallo et al. (2024)
Gold sample.

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

Data

🔍 Search references for HSC 381 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–	270.961	19.467	3.227	-1.162	-8.033	-16.73
Zhang et al.	2024	271.386	17.771	–	–	–	–
Cavallo et al.	2024	270.773	19.135	3.178	–	–	–
Hunt & Reffert	2023	271.386	17.771	3.161	-1.036	-8.11	-17.045

💡 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–	0.32	0.21	0.83	31	-0.008	–	–	–
Liu et al.	2025	0.33	0.06	–	41	–	–	–	–
Zhang et al.	2024	–	–	–	–	0.034⁽¹⁾	–	–	–
Cavallo et al.	2024	0.32	0.66	–	17	-0.050	–	–	–
Hunt & Reffert	2023	0.31	0.21	0.83	31	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
OCSN 11	3.7	270.09	21.47	3.39	-1.34	-7.63	-18.06	0.19

💡 Note: The % column shows the percentage of members that HSC 381 shares with each listed object.

Visualization

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