UPK 303

(OCSN 302)

0.48 UTI

0.62

C_N

0.08

C_dens

1.0

C_C3

0.35

C_lit

1.0

C_dup

N_m (P>50%) 73

Core radius and density 5.0 [pc], 0.4 [pc^-2]

C3 classification AA

C_N 0.62 Moderately populated
C_dens 0.08 Very loose
C_C3 1.0 Very high quality
C_lit 0.35 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 303 is a moderately populated, very loose object of very high 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 absorption and age parameters (see Parameters). It is poorly studied in the literature.

Very close Low extinction Near-solar metallicity Young

Malhotra et al. (2026)
Lowest/Highest stellar mass in the catalogue with a mass-ratio estimate: 0.2/2.86 Msun

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as moving group. CMD class: 0.98 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.98 (50th percentile).

Hu et al. (2021)
Ellipticities (core, all): e_core=0.3455, e_all=0.429.

Data

🔍 Search references for UPK 303 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–	39.565	40.654	4.702	18.137	-24.384	-8.643
Malhotra et al.	2026	41.202	40.261	–	–	–	–
Li et al.	2025	40.054	40.291	4.606	18.197	-24.154	–
Yang et al.	2025	38.631	40.807	–	–	–	–
Alfonso et al.	2024	40.619	40.232	4.719	18.098	-24.949	–
Zhang et al.	2024	38.631	40.807	–	–	–	–
Cavallo et al.	2024	39.298	40.807	4.683	–	–	–
Hunt & Reffert	2023	38.631	40.807	4.696	18.21	-23.949	-7.779
Qin et al.	2023	39.16	40.61	4.72	18.13	-24.14	-9.0
He et al.	2022	38.482	40.825	4.696	18.147	-24.353	–
Tarricq et al.	2022	39.53	40.232	4.744	18.097	-24.72	–
Cantat-Gaudin et al.	2020	40.054	40.291	4.606	18.197	-24.154	–
Cantat-Gaudin & Anders	2020	40.054	40.291	4.662	18.261	-24.27	–
Sim et al.	2019	40.177	40.208	–	18.25	-24.33	–

💡 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–	0.21	0.115	0.59	88	0.083	–	–	–
Malhotra et al.	2026	0.21	0.02	–	315	0.118	–	–	–
Li et al.	2025	0.23	0.23	–	84	0.075	–	–	–
Yang et al.	2025	–	–	–	112	-0.040⁽³⁾	–	–	–
Alfonso et al.	2024	0.21	0.05	–	88	0.118	–	–	–
Zhang et al.	2024	–	–	–	–	0.061⁽¹⁾	–	–	–
Cavallo et al.	2024	0.22	0.49	–	54	0.090	–	–	–
Hunt & Reffert	2023	0.22	0.08	0.59	111	–	–	–	–
Qin et al.	2023	0.23	0.32	–	158	–	–	–	–
He et al.	2022	–	0.15	–	63	–	–	–	–
Tarricq et al.	2022	0.20	–	–	81	–	–	–	–
Cantat-Gaudin et al.	2020	0.21	0.05	–	79	–	–	–	–
Cantat-Gaudin & Anders	2020	0.21	–	–	–	–	–	–	–
Sim et al.	2019	0.21	–	–	89	–	–	–	–

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

Visualization

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