Berkeley 81

(MWSC 3039; OCL 88)

0.96 UTI

0.8

C_N

1.0

C_dens

1.0

C_C3

1.0

C_lit

1.0

C_dup

N₅₀ (P>50% members) 230

Stellar density (N₅₀/rad) 31.7 [N/pc²]

C3 classification AA

C_N 0.8 Rich
C_dens 1.0 Very dense
C_C3 1.0 Very high quality
C_lit 1.0 Very well-studied
C_dup 1.0 Unique

📥 Members 📊 Colab 🔬 Bayestar19

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

Overview

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Berkeley 81 is a rich, very dense object of very high C3 quality. Its parallax locates it at a moderate distance, below the mid-plane, affected by high extinction. It is catalogued as a massive, near-solar metallicity, old cluster, but with a large variance across recent sources for the age parameter (see Parameters). It is very well-studied in the literature.

Note: This object contains blue stragglers according to at least one source.

Distant High extinction Massive Near-solar metallicity Old Contains BSS

Piecka & Paunzen (2021)
Belongs to cluster aggregate 'Agg13' along with NGC 6735.

Cavallo et al. (2024)
Gold sample.

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

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 0.81 (50th percentile).

Data

🔍 Search references for Berkeley 81 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–	285.418	-0.454	0.248	-1.153	-1.929	46.795
Hu & Soubiran	2025	285.426	-0.44	–	–	–	–
Almeida et al.	2025	285.417	-0.454	–	–	–	–
Hunt & Reffert	2024	285.417	-0.457	0.252	-1.145	-1.962	44.696
Cavallo et al.	2024	285.426	-0.44	0.247	–	–	–
Hunt & Reffert	2023	285.417	-0.457	0.252	-1.145	-1.962	44.696
Almeida et al.	2023	285.419	-0.452	–	–	–	–
Just et al.	2023	285.398	-0.462	–	–	–	–
Jaehnig et al.	2021	285.42	-0.454	0.275	-1.213	-1.864	–
Rain et al.	2021	285.419	-0.454	0.254	-1.204	-1.853	–
Dias et al.	2021	285.417	-0.454	0.255	-1.191	-1.85	49.891
Cantat-Gaudin et al.	2020	285.419	-0.454	0.254	-1.204	-1.853	–
Sánchez et al.	2020	285.417	-0.456	–	-1.327	-1.706	–
Cantat-Gaudin & Anders	2020	285.419	-0.454	0.254	-1.204	-1.853	–
Soubiran et al.	2018	285.419	-0.454	–	–	–	50.01
Bica et al.	2019	285.412	-0.456	–	–	–	–
Cantat-Gaudin et al.	2018	285.419	-0.454	0.254	-1.204	-1.853	–
Loktin & Popova	2017	285.42	-0.456	–	2.724	-8.142	13.0
Kharchenko et al.	2016	285.398	-0.462	–	–	–	–
Dias et al.	2014	285.417	-0.456	–	1.46	-0.7	–
Kharchenko et al.	2013	285.405	-0.46	–	-0.99	-8.59	13.0
Gozha et al.	2012	285.417	-0.456	–	–	–	–
Bukowiecki et al.	2011	285.404	0.449	–	–	–	–
van den Bergh	2006	285.4	-0.517	–	–	–	–
Dias et al.	2002	285.417	-0.456	–	1.46	-0.7	48.1

💡 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–	3.45	3.1	2.17	1000	-0.070	2004	0.79	1.0
Hu & Soubiran	2025	–	–	–	–	-0.070⁽⁵⁾	–	–	–
Almeida et al.	2025	3.69	3.04	–	769	–	1262	–	–
Hunt & Reffert	2024	–	–	–	–	–	4001⁽¹⁾	–	–
Cavallo et al.	2024	2.78	3.34	–	1096	-0.070	–	–	–
Hunt & Reffert	2023	3.45	3.88	2.17	225	–	–	–	–
Almeida et al.	2023	3.10	3.15	–	791	0.139	1972⁽¹⁾	0.79	–
Just et al.	2023	–	–	–	1000	–	2037	–	–
Jaehnig et al.	2021	3.68⁽¹⁾	–	–	–	–	–	–	–
Rain et al.	2021	3.53	3.10	–	1000	–	–	–	1
Dias et al.	2021	3.69	3.04	–	769	0.215	–	–	–
Cantat-Gaudin et al.	2020	3.31	2.75	–	1148	–	–	–	–
Kounkel et al.	2020	3.06	3.14	–	933	–	–	–	–
Cantat-Gaudin & Anders	2020	3.53	–	–	–	–	–	–	–
Soubiran et al.	2018	3.53	–	–	–	–	–	–	–
Cantat-Gaudin et al.	2018	3.53	–	–	–	–	–	–	–
Loktin & Popova	2017	4.73	2.78	–	589	–	–	–	–
Kharchenko et al.	2016	3.40	3.29	–	1000	–	–	–	–
Kharchenko et al.	2013	3.40	3.29	–	1000	-0.150	–	–	–
Gozha et al.	2012	3.00	–	–	1000	-0.150	–	–	–
Bukowiecki et al.	2011	5.13⁽¹⁾	2.79	–	891	–	–	–	–
van den Bergh	2006	3.00	3.10	–	1000	–	–	–	–
Dias et al.	2002	3.00	3.10	–	1000	-0.150	–	–	–

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

Visualization

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