HSC 857

0.24 UTI

0.32

C_N

0.08

C_dens

0.75

C_C3

0.03

C_lit

1.0

C_dup

N_m (P>50%) 32

Core radius and density 2.0 [pc], 0.4 [pc^-2]

C3 classification AB

C_N 0.32 Poorly populated
C_dens 0.08 Very loose
C_C3 0.75 High 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 857 is a poorly populated, very loose object of high C3 quality. Its parallax locates it at a large distance, well above the mid-plane, affected by moderate extinction. It is catalogued as a near-solar metallicity, very young cluster (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 Moderate extinction Near-solar metallicity Very young

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 1.00 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 1.00 (50th percentile).

Data

🔍 Search references for HSC 857 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–	340.269	64.151	0.106	-2.587	-1.242	–
Hunt & Reffert	2024	340.234	64.137	0.096	-2.591	-1.261	–
Cavallo et al.	2024	340.255	64.145	0.094	–	–	–
Hunt & Reffert	2023	340.234	64.137	0.096	-2.591	-1.261	–

💡 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–	8.25	2.65	0.5	12	0.200	996	–	–
Hunt & Reffert	2024	8.25	2.65	0.50	12	–	996⁽¹⁾	–	–
Cavallo et al.	2024	4.59	2.41	–	50	0.200	–	–	–
Hunt & Reffert	2023	8.25	2.65	0.50	12	–	–	–	–

(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 3477	100.0	340.28	64.15	0.1	-2.58	-1.25	–	0.18

💡 Note: The % column shows the percentage of members that HSC 857 shares with each listed object.

Visualization

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