UPK 39

(OCSN 291)

0.69 UTI

0.79

C_N

1.0

C_dens

0.75

C_C3

0.45

C_lit

1.0

C_dup

N₅₀ (P>50% members) 196

Stellar density (N₅₀/rad) 38.2 [N/pc²]

C3 classification AB

C_N 0.79 Rich
C_dens 1.0 Very dense
C_C3 0.75 High quality
C_lit 0.45 Poorly studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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UPK 39 is a rich, very dense object of high C3 quality. Its parallax locates it at a very close^* distance, above the mid-plane, affected by moderate extinction. It is catalogued as a near-solar metallicity, very young cluster, but with a large variance across recent sources for the absorption parameter (see Parameters). It is poorly studied in the literature.

(*): The parallax distance estimate (~0.44 kpc) differs significantly from the median photometric distance (~0.70 kpc).

Note: This object shares a significant percentage of members with a later reported entry. See table with shared members information.

Close Moderate extinction Near-solar metallicity Very young

Liu et al. (2025)
Classified as primordial binary cluster 391 along with UPK_41, and of multiple system 75 along with UPK_41 and IC_4756.

Palma et al. (2025)
Part of multiple system G257, along with UPK_41 and IC_4756.

Cavallo et al. (2024)
Wood sample.

Data

🔍 Search references for UPK 39 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–	277.475	0.929	2.285	3.265	-8.731	-11.206
Liu et al.	2025	277.48	1.08	2.25	3.27	-8.67	14.75
Zhang et al.	2024	277.478	1.076	–	–	–	–
Hunt & Reffert	2024	277.478	1.076	2.251	3.271	-8.668	14.747
Cavallo et al.	2024	277.427	0.982	2.253	–	–	–
Hunt & Reffert	2023	277.478	1.076	2.251	3.271	-8.668	14.747
Qin et al.	2023	277.53	1.04	2.26	3.24	-8.68	-8.0
He et al.	2022	277.519	0.975	2.252	3.255	-8.639	–
Sim et al.	2019	277.485	1.002	–	3.29	-8.65	–

💡 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–	0.7	2.08	2.23	6	-0.032	204	–	–
Liu et al.	2025	0.74	0.61	–	11	–	–	–	–
Zhang et al.	2024	–	–	–	–	0.037⁽¹⁾	–	–	–
Hunt & Reffert	2024	–	–	–	–	–	204⁽¹⁾	–	–
Cavallo et al.	2024	0.70	3.27	–	8	-0.100	–	–	–
Hunt & Reffert	2023	0.42	2.31	2.23	4	–	–	–	–
Qin et al.	2023	1.00	2.08	–	7	–	–	–	–
He et al.	2022	–	0.50	–	2	–	–	–	–
Sim et al.	2019	0.43	–	–	3	–	–	–	–

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

Cluster	%	RA	DEC	Plx	pmRA	pmDE	Rv	UTI
CWWDL 14652	57.1	277.5	1.02	2.29	3.03	-8.83	-11.21	0.0

💡 Note: The % column shows the percentage of members that UPK 39 shares with each listed object.

Visualization

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