HSC 878

0.09 UTI

0.0

C_N

0.01

C_dens

0.38

C_C3

0.06

C_lit

0.84

C_dup

N_m (P>50%) 21

Core radius and density 3.6 [pc], 0.07 [pc^-2]

C3 classification CB

C_N 0.0 Sparse
C_dens 0.01 Very loose
C_C3 0.38 Low quality
C_lit 0.06 Rarely studied
C_dup 0.84 Very likely unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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HSC 878 is a sparse, very loose object of 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, young cluster, but with a large variance across recent sources for the metallicity parameter (see Parameters). It was recently reported in the literature.

Note: This is very likely a unique object, which shares a 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=0.84) 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

Palma et al. (2025)
Part of multiple system G202, along with HSC_926 and HSC_981.

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.85 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.85 (50th percentile).

Data

🔍 Search references for HSC 878 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–	344.75	59.42	3.133	13.831	1.77	-14.566
Yang et al.	2025	348.313	60.36	–	–	–	–
Zhang et al.	2024	348.313	60.36	–	–	–	–
Cavallo et al.	2024	345.711	58.413	3.083	–	–	–
Hunt & Reffert	2023	348.313	60.36	3.1	13.648	1.613	-19.284

💡 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	0.52	0.75	87	0.044	–	–	–
Yang et al.	2025	–	–	–	87	-0.020⁽³⁾	–	–	–
Zhang et al.	2024	–	–	–	–	0.044⁽¹⁾	–	–	–
Cavallo et al.	2024	0.33	0.80	–	62	0.310	–	–	–
Hunt & Reffert	2023	0.31	0.24	0.75	87	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
Theia 164	16.0	346.1	57.67	3.02	13.69	0.92	-20.24	0.06

💡 Note: The % column shows the percentage of members that HSC 878 shares with each listed object.

Visualization

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