Berkeley 21

(MWSC 682; OCL 469; FSR 0875)

0.91 UTI

0.83

C_N

0.98

C_dens

0.75

C_C3

1.0

C_lit

1.0

C_dup

N_m (P>50%) 304

Core radius and density 1.9 [pc], 4.9 [pc^-2]

C3 classification AB

C_N 0.83 Rich
C_dens 0.98 Very dense
C_C3 0.75 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 21 is a rich, very dense object of high C3 quality. Its parallax locates it at a large distance, below the mid-plane, affected by moderate extinction. It is catalogued as a massive, near-solar metallicity, old cluster (see Parameters). It is very well-studied in the literature.

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

Very distant Moderate extinction Massive Near-solar metallicity Old Contains BSS

Cavallo et al. (2024)
Gold sample.

Hunt & Reffert (2024)
Classified as open cluster. CMD class: 0.13 (50th percentile).

Hunt & Reffert (2023)
Classified as open cluster. CMD class: 0.13 (50th percentile).

Hu et al. (2021)
Ellipticities (core, all): e_core=0.0773, e_all=0.1266.

Rain et al. (2021)
The red limit of the straggler area is BP-RP=1.44. Apparently, star Gaia DR2 3424171202249574656 is a massive straggler.

Ahumada & Lapasset (2007)
The red limit of the blue straggler area is (B-V)=0.97.

Data

🔍 Search references for Berkeley 21 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–	87.938	21.808	0.146	0.528	-1.032	1.249
Otto et al.	2026	87.949	21.811	–	0.56	-1.05	1.3
Guerco et al.	2025	88.0	21.8	0.16	0.5	-0.82	0.84
Hu & Soubiran	2025	87.936	21.808	–	–	–	–
Zhang et al.	2024	87.949	21.811	–	–	–	–
Hunt & Reffert	2024	87.949	21.811	0.144	0.506	-1.031	3.88
Cavallo et al.	2024	87.936	21.808	0.145	–	–	–
Hunt & Reffert	2023	87.949	21.811	0.144	0.506	-1.031	3.88
Just et al.	2023	87.936	21.816	–	–	–	–
Jadhav & Subramaniam	2021	87.93	21.812	–	–	–	–
Jaehnig et al.	2021	87.94	21.809	0.152	0.468	-0.951	–
Netopil et al.	2022	87.925	21.783	–	–	–	4.84
Rain et al.	2021	87.93	21.812	0.159	0.562	-1.051	–
Cantat-Gaudin et al.	2020	87.93	21.812	0.159	0.562	-1.051	–
Zhong et al.	2020	87.93	21.812	–	0.562	-1.051	3.325
Cantat-Gaudin & Anders	2020	87.93	21.812	0.159	0.562	-1.051	–
Soubiran et al.	2018	87.93	21.812	–	–	–	0.49
Bica et al.	2019	87.941	21.815	–	–	–	–
Cantat-Gaudin et al.	2018	87.93	21.812	0.159	0.562	-1.051	–
Dias et al.	2018	–	–	–	0.87	-3.45	–
Loktin & Popova	2017	87.93	21.815	–	0.266	-1.085	12.4
Sampedro et al.	2017	87.925	21.783	–	1.16	-5.6	–
Kharchenko et al.	2016	87.936	21.816	–	–	–	–
Netopil et al.	2016	87.925	21.783	–	–	–	–
Dias et al.	2014	87.925	21.783	–	1.47	-5.8	–
Kharchenko et al.	2013	87.945	21.815	–	0.0	-2.29	12.4
Gozha et al.	2012	87.925	21.783	–	–	–	–
Bukowiecki et al.	2011	87.942	21.817	–	–	–	–
Kharchenko et al.	2007	87.93	21.78	–	0.04	–	–
Ahumada & Lapasset	2007	87.925	21.783	–	–	–	–
van den Bergh	2006	87.925	21.783	–	–	–	–
Chen et al.	2003	87.924	21.782	–	–	–	–
Dias et al.	2002	87.925	21.783	–	1.47	-5.8	-0.6
Lynga	1987	87.928	21.796	–	–	–	–

💡 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–	5.31	2.1	1.84	2089	-0.263	1632	–	20
Otto et al.	2026	–	–	–	2138	-0.230⁽¹⁵⁾	–	–	–
Guerco et al.	2025	–	–	–	2140	-0.220	–	–	–
Hu & Soubiran	2025	–	–	–	–	-0.200⁽⁵⁾	–	–	–
Zhang et al.	2024	–	–	–	–	-0.263⁽¹⁾	–	–	–
Hunt & Reffert	2024	5.93	2.49	1.84	882	–	1632⁽¹⁾	–	–
Cavallo et al.	2024	5.94	2.05	–	2089	-0.380	–	–	–
Hunt & Reffert	2023	5.93	2.50	1.84	881	–	–	–	–
Just et al.	2023	–	–	–	1995	–	1230	–	–
Spina et al.	2022	–	–	–	–	-0.254	–	–	–
Jadhav & Subramaniam	2021	6.43	1.96	–	2138	–	2230	–	2⁽¹⁾
Jaehnig et al.	2021	6.65⁽¹⁾	–	–	–	–	–	–	–
Netopil et al.	2022	6.03⁽¹⁾	–	–	1995	-0.180⁽¹⁾	–	–	–
Rain et al.	2021	5.31	2.40	–	2188	–	–	–	20
Cantat-Gaudin et al.	2020	6.43	1.96	–	2138	–	–	–	–
Kounkel et al.	2020	4.96	1.97	–	977	–	–	–	–
Zhong et al.	2020	5.31⁽¹⁾	2.10	–	9300	-0.356	–	–	–
Cantat-Gaudin & Anders	2020	5.31	–	–	–	–	–	–	–
Soubiran et al.	2018	5.31	–	–	–	–	–	–	–
Cantat-Gaudin et al.	2018	5.31	–	–	–	–	–	–	–
Loktin & Popova	2017	3.45	1.52	–	1122	–	–	–	–
Kharchenko et al.	2016	5.72	2.10	–	1995	–	–	–	–
Netopil et al.	2016	12.88	–	–	1420	-0.180⁽²⁾	–	–	–
Heiter et al.	2014	–	–	–	–	-0.180	–	–	–
Kharchenko et al.	2013	5.72	2.10	–	1995	-0.835	–	–	–
Gozha et al.	2012	5.00	–	–	2188	-0.840	–	–	–
Bukowiecki et al.	2011	6.30⁽¹⁾	1.89	–	1585	–	–	–	–
Paunzen et al.	2010	–	–	–	–	-0.960	–	–	–
Ahumada & Lapasset	2007	–	2.40	–	2188	–	–	–	51
van den Bergh	2006	5.00	2.40	–	2188	–	–	–	–
Chen et al.	2003	5.00	2.40	–	2180	-0.830⁽¹⁾	–	–	–
Dias et al.	2002	5.00	2.40	–	2188	-0.835	–	–	–
Lynga	1987	0.00	–	–	30	–	–	–	–

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

Visualization

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