UPK 99

0.34 UTI

0.0

C_N

0.14

C_dens

0.38

C_C3

0.6

C_lit

1.0

C_dup

N₅₀ (P>50% members) 20

Stellar density (N₅₀/rad) 0.7 [N/pc²]

C3 classification BC

C_N 0.0 Sparse
C_dens 0.14 Very loose
C_C3 0.38 Low quality
C_lit 0.6 Moderately studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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UPK 99 is a sparse, very loose object of low C3 quality. Its parallax locates it at a close distance, below the mid-plane, affected by low extinction. It is catalogued as a low-mass, near-solar metallicity, intermediate-age cluster, but with a large variance across recent sources for the absorption, age, and metallicity parameters (see Parameters). It is moderately studied in the literature.

Close Low extinction Low mass Near-solar metallicity Intermediate age

Cavallo et al. (2024)
Gold sample.

Almeida et al. (2025)
Mass determination: intermediate fit. Isochrone match: good fit.

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

Data

🔍 Search references for UPK 99 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–	312.459	25.556	1.249	0.31	-7.976	-15.464
Li et al.	2025	312.427	25.488	1.291	0.422	-8.02	–
Hu & Soubiran	2025	312.476	25.713	–	–	–	–
Almeida et al.	2025	312.423	25.505	–	–	–	–
Alfonso et al.	2024	312.567	25.552	1.174	0.38	-7.667	–
Cavallo et al.	2024	312.476	25.713	1.256	–	–	–
Hunt & Reffert	2023	312.479	25.561	1.258	0.225	-7.911	-11.93
Dias et al.	2021	312.423	25.505	1.276	0.351	-7.897	–
Cantat-Gaudin et al.	2020	312.427	25.488	1.291	0.422	-8.02	–
Cantat-Gaudin & Anders	2020	312.479	25.556	1.252	0.332	-7.877	–
Sim et al.	2019	312.486	25.604	–	0.27	-7.84	–

💡 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–	0.77	0.28	0.4	212	-0.100	42	–	–
Li et al.	2025	0.90	0.63	–	1801	-0.158	–	–	–
Hu & Soubiran	2025	–	–	–	–	-0.210⁽⁵⁾	–	–	–
Almeida et al.	2025	0.77	0.51	–	212	–	42	–	–
Alfonso et al.	2024	0.76	0.28	–	135	-0.100	–	–	–
Cavallo et al.	2024	0.81	0.06	–	813	0.270	–	–	–
Hunt & Reffert	2023	0.76	0.23	0.40	216	–	–	–	–
Tarricq et al.	2022	0.75	–	–	166	–	–	–	–
Dias et al.	2021	0.77	0.51	–	212	-0.100	–	–	–
Cantat-Gaudin et al.	2020	0.76	0.28	–	158	–	–	–	–
Cantat-Gaudin & Anders	2020	0.78	–	–	–	–	–	–	–
Sim et al.	2019	0.78	–	–	126	–	–	–	–

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

Visualization

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